Medical systems, devices, and kits useful for treatment in magnetic resonance imaging

Abstract

Example medical systems, and related devices, kits, and methods, are described that can be used for treatment under magnetic resonance imaging. An example medical system includes a first medical device and a second medical device. The first medical device has a first passive marker. The first passive marker is formed of a first material having a first magnetic sensitivity. The second medical device has a second passive marker. The second passive marker is formed of a second material having a second magnetic sensitivity. The second passive marker creates an image artifact under MRI. When the first passive marker overlaps the second passive marker, an image artifact created by the second passive marker is changed under MRI.

Description

Technical Field

[0001] The present disclosure generally relates to the field of medical devices. More specifically, the present disclosure relates to a medical system that can be used for treatment under magnetic resonance imaging (MRI), a medical device that can be used for treatment under MRI, a kit that can be used for treatment under MRI, and a method for treatment under MRI. Background Art

[0002] The field of interventional MRI is gaining wider acceptance, and the number of procedures that can be performed is also increasing. Interventional procedures performed under MRI have several advantages over X-ray guided interventions. For example, the patient is not exposed to ionizing radiation. Moreover, MRI enables characterization of tissue and functional flow during interventional procedures.

[0003] The development of these procedures is limited due to the inability to use the tools required to perform interventional procedures performed under MRI. Therefore, patients need to visit treatment institutions many times for visualization, diagnosis and treatment of various diseases. In addition, multiple imaging modalities are often required, which affects the accuracy of using magnetic resonance (MR) images to guide intervention. For example, interventional medical devices with high magnetic sensitivity placed in the magnetic field generated by the MR scanner tend to interact with the externally applied field and / or distort the externally applied field. Therefore, these devices may cause large image artifacts, which may eliminate key features in the target anatomical structure and may potentially injure the patient being scanned due to the forces and torques caused by this interaction. Alternatively, interventional medical devices with low magnetic sensitivity placed in the magnetic field generated by the MR scanner may make the device almost invisible under MRI, making it almost impossible to identify, track and navigate the device during the interventional procedure.

[0004] To overcome these challenges, current MRI-compatible devices have adopted a variety of visualization techniques, including sensitivity-based passive markers, semi-active resonant circuits, and active antenna coils. Among them, sensitivity-based passive markers have the lowest design and manufacturing complexity because they do not require any circuit design and integration, nor do they require high-frequency operation. However, current sensitivity-based passive markers are typically customized for specific devices, remain fixed to the device or component in a specific configuration, and produce image artifacts under MRI that cannot be changed during the procedure.

[0005] Therefore, there is a need for new and improved medical systems that can be used for treatment under MRI, medical devices that can be used for treatment under MRI, kits that can be used for treatment under MRI, and methods of treatment under MRI. Summary of the invention

[0006] This document describes various example medical systems that can be used to perform treatment under MRI, various example medical devices that can be used to perform treatment under MRI, various example kits that can be used to perform treatment under MRI, and various example methods of performing treatment under MRI.

[0007] An example medical system that can be used for treatment under MRI includes a first medical device and a second medical device. The first medical device has a first passive marker. The first passive marker is formed of a first material having a first magnetic susceptibility. The second medical device has a second passive marker. The second passive marker is formed of a second material having a second magnetic susceptibility. The second passive marker creates an image artifact under MRI. When the first passive marker overlaps with the second passive marker, the image artifact created by the second passive marker is changed under MRI.

[0008] An example kit that can be used for treatment under MRI includes a medical system that includes a first medical device and a second medical device. The first medical device has a first passive marker. The first passive marker is formed of a first material having a first magnetic susceptibility. The second medical device has a second passive marker. The second passive marker is formed of a second material having a second magnetic susceptibility. The second passive marker creates an image artifact under MRI. When the first passive marker overlaps with the second passive marker, the image artifact created by the second passive marker is changed under MRI.

[0009] An example method for performing treatment under MRI includes: positioning a patient in a magnetic resonance scanner; scanning a first portion of the patient using the magnetic resonance scanner, the magnetic resonance scanner having a first set of MR image parameters; obtaining a magnetic resonance image of the first portion of the patient; identifying tissue having predefined characteristics using the magnetic resonance image; selecting a procedure for treating the tissue based on the predefined characteristics; selecting a medical system having a first medical device and a second medical device to perform the procedure; while the patient remains positioned in the magnetic resonance scanner for scanning the first portion of the patient, advancing the medical system into a body passage and into the tissue while scanning the patient's tissue using the magnetic resonance scanner, the medical system and the markers disposed on the second medical device. a second portion of the image artifact created by the marker; obtaining a magnetic resonance image of the patient including the medical system and the second portion of the image artifact created by the marker; identifying the image artifact within the MR image; confirming the position of the medical system within the body passage; manipulating the position of the first medical device relative to the second medical device to change the image artifact created by the marker by overlapping the marker with a second marker disposed on the first medical device; scanning a third portion of the patient including the medical system and the changed image artifact using a magnetic resonance scanner; obtaining a magnetic resonance image of the third portion of the patient including the medical system and the changed image artifact; changing the first set of MR image parameters to a second set of MR image parameters based on the changed image artifact; and performing treatment.

[0010] These example medical systems, devices, kits, and methods can be further understood by reading the following detailed description and accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 is a partial elevation view of a first example medical system including a first example medical device and a second example medical device.

[0012] Figure 2 is included in Figure 1 An elevational view of a first example medical device in a medical system is shown.

[0013] Figure 3 is included in Figure 1 An elevation view of a second example medical device within a medical system is shown.

[0014] Figure 4 yes Figure 2 Magnified view of area A in the middle.

[0015] Figure 5 yes Figure 3 Magnified view of area B in the middle.

[0016] Figure 6 is an exploded elevation view of a second example medical system including a first example medical device and a second example medical device.

[0017] Figure 7 is an exploded elevation view of a third example medical system including the first example medical device and the second example medical device.

[0018] Figure 8 An example kit including an example medical system that may be used to perform treatment under MRI is illustrated.

[0019] Fig. 9 is a partial perspective view of a fourth example medical system including a first example medical device, a second example medical device, a third example medical device, and a fourth example medical device.

[0020] Fig.10 yes Fig. 9 A fourth example medical system is shown in cross-sectional view taken along line 10 - 10 .

[0021] Fig.11 is a schematic diagram of an example method of performing treatment under MRI.

[0022] Fig.12 The first medical device of the medical system is disposed in a body passage. The first medical device includes a first plurality of markers. Each marker generates an image artifact under MRI.

[0023] Fig.13 The invention is an MR image showing a medical system disposed in a body passage. The medical system includes a first medical device and a second medical device. The first medical device includes a first plurality of markers, and the second medical device includes a second plurality of markers. The overlapping arrangement of the first plurality of markers and the second plurality of markers changes (e.g., amplifies, weakens, eliminates) image artifacts generated by the first plurality of markers under MRI.

[0024] Fig.14 The invention is an MR image showing a medical system disposed in a body passage. The medical system includes a first medical device and a second medical device. The first medical device includes a first plurality of markers, and the second medical device includes a second plurality of markers. The overlapping arrangement of the first plurality of markers and the second plurality of markers changes (e.g., amplifies) image artifacts generated by the first plurality of markers under MRI.

[0025] Fig.15 The invention is an MR image showing a medical system disposed in a body passage. The medical system includes a first medical device and a second medical device. The first medical device includes a first plurality of markers, and the second medical device includes a second plurality of markers. The overlapping arrangement of markers in the first plurality of markers and markers in the second plurality of markers changes (e.g., amplifies, weakens, eliminates) image artifacts generated by markers in the first plurality of markers under MRI. DETAILED DESCRIPTION

[0026] The following detailed description and accompanying drawings describe and illustrate different example medical systems that can be used for treating under MRI, different example medical devices that can be used for treating under MRI, different example kits that can be used for treating under MRI, and different example methods for treating under MRI. The description and illustration of these examples are provided to enable those skilled in the art to manufacture and use medical systems, devices, kits and practice the method for treating under MRI. They are not intended to limit the scope of the present invention or the protection scope sought in any way. The present invention can be practiced or implemented in different ways, and the examples described and illustrated herein are only selected examples of practicing or implementing different ways of the present invention, and are not considered to be exhaustive.

[0027] As used herein, the term "attached" refers to one component being fixed to another component so that the components do not completely separate from each other during use according to the intended use of the article including the components in the attached form.

[0028] As used herein, the term "circumference" refers to the outer or inner closed boundary of a body, element, or feature, and does not impart any structural configuration to the body, element, or feature.

[0029] As used herein, the term "marker" refers to a discrete deposition of a first material on a second material such that the first material is visible under MRI and can be distinguished from the second material under MRI; refers to a portion of an interventional device in which the first material has been incorporated into the second material such that the combination of the first material and the second material is visible under MRI and can be distinguished from the second material under MRI; and / or refers to a portion of an interventional device in which a material forming a portion of the interventional device has been manipulated such that the portion is visible under MRI and can be distinguished from the remainder of the interventional device under MRI.

[0030] As used herein, the term "passive" with respect to markers refers to markers that are not powered or are powered only by the electromagnetic field of the MR scanner.

[0031] As used herein, the term "treatment" refers to a medical procedure performed on or in a part of a patient's body. Examples of treatment include delivering a pharmaceutical agent to a site within a body vessel, modifying the local environment within a body vessel (such as by heating or cooling), and removing tissue or a portion of tissue from a site within a patient's body (i.e., a biopsy).

[0032] As used herein, the term "magnetic susceptibility" refers to an intrinsic property of a material that is related to the degree to which the material becomes magnetized in an applied magnetic field.

[0033] As used herein, the term "susceptibility" without "magnetic" refers to the ability of an element to affect an external magnetic field. The sensitivity depends on various characteristics of the element, including size, density, volume, geometry, and other physical characteristics, as well as the magnetic susceptibility of the material from which the element is formed.

[0034] Figure 1 , Figure 2 , Figure 3 , Figure 4 and Figure 5 A first example medical system 8 that can be used for treatment under MRI is illustrated. In this example, the first example medical system 8 includes a first medical device 10 and a second medical device 50.

[0035] In the illustrated embodiment, the first medical device 10 is a cannula 12 and the second medical device 50 is a stylet 52 that may be used coaxially with the first medical device 10 .

[0036] The cannula 12 has a longitudinal axis 13, a hub member 14, and an elongated member 16. The hub member 14 has a proximal end 18, a distal end 20, and a body 22 that defines a lumen 24 and a protrusion 26. The hub member 14 provides a mechanism for attaching other devices (e.g., a second medical device 50) to the cannula 12. The lumen 24 extends from the proximal end 18 to the distal end 20 so that one or more devices can enter and pass through the hub member 14. The elongated member 16 has a proximal end 30, a distal end 32, a length 31, an inner diameter 33, an outer surface 34, an inner surface 36, and a body 38 that defines a lumen 40 and a distal tapered tip 42 with a cutting edge 44. The lumen 40 extends from the proximal end 30 to the distal end 32 so that one or more devices can enter and pass through the elongated member 16 of the cannula 12. In the illustrated embodiment, the elongated member 16 of the cannula 12 is formed of a first material having a first magnetic susceptibility.

[0037] The elongated member 16 of the cannula 12 includes a first marker 46 disposed between the proximal end 30 and the distal end 32 of the elongated member 16 and disposed around the entire circumference of the body 38 of the elongated member 16 of the cannula 12. The first marker 46 is a passive marker and is formed of a second material (e.g., pure titanium) that is different from the first material. The second material has a second magnetic susceptibility that is different from the first magnetic susceptibility and creates an image artifact having a first set of characteristics (e.g., size, shape, location, orientation, magnetic susceptibility, intensity) under MRI.

[0038] The stylet 52 has a seat member 54 and an elongated member 56. The seat member 54 has a proximal end 58, a distal end 60, and a body 62 defining a recess 64. The seat member 54 provides a mechanism for attaching other devices (e.g., a first medical device 10) to the stylet 52. The recess 64 extends into the body 62 from a position between the proximal end 58 and the distal end 60 toward the proximal end 58. The size of the recess 64 is configured to receive the protrusion 26 defined by the seat member 14 of the cannula 12, so that a releasable attachment between the cannula 12 and the stylet 42 can be achieved. The elongated member 56 has a proximal end 66, a distal end 68, a length 67, an outer diameter 69, an outer surface 70, and a body 72, which defines a solid member having a distal tapered end 74 with a cutting edge 76. The length 67 of the elongated member 56 of the stylet 52 is greater than the length 31 of the elongated member 16 of the cannula 12. The outer diameter 69 of the elongated member 56 of the stylet 52 is smaller than the inner diameter 33 of the elongated member 16 of the cannula 12. Figure 1As shown, this structural arrangement allows the elongated member 56 of the stylet 52 to enter and pass through the lumen 24 of the seat member 14 and the lumen 40 of the elongated member 16 of the cannula 12. The elongated member 56 of the stylet 52 is formed of a third material having a third magnetic sensitivity. In the illustrated embodiment, the first material forming the elongated member 16 of the cannula 12 and the third material forming the elongated member 56 of the stylet 52 are the same.

[0039] In the illustrated embodiment, the elongated member 56 of the stylet 52 includes a second marker 78 disposed between the proximal end 66 and the distal end 68 and disposed around the entire circumference of the body 62 of the elongated member 56 of the stylet 52. The second marker 78 is a passive marker and is formed of a fourth material (e.g., polycrystalline graphite) that is different from the first material and the third material and has a fourth magnetic sensitivity that is different from (e.g., greater than, less than, opposite to) the first magnetic sensitivity and the third magnetic sensitivity. The second marker 78 creates an image artifact under MRI that has a second set of characteristics (e.g., size, shape, position, orientation, magnetic sensitivity, intensity) that is different from the first set of characteristics. The second marker 78 is positioned on the elongated member 56 so that when the first medical device 10 and the second medical device 50 are used in combination, the first marker 46 can overlap with the second marker 78. For example, as Figure 1 As shown, when the second medical device 50 is disposed within the first medical device 10 and the first marker 46 and the second marker 78 are disposed at the same position along the longitudinal axis 13 of the elongated member 16 of the cannula 12 (eg, in the axial direction), the first marker 46 and the second marker 78 overlap.

[0040] In the illustrated embodiment, the markers 46, 78 are each a strip of material attached to their respective elongated members 16, 56. The first material and the third material are each a non-magnetically sensitive material, or a material having a low magnetic sensitivity relative to the magnetic sensitivity of the material forming the marker included on the medical device (e.g., a non-paramagnetic material, a non-ferromagnetic material, a non-diamagnetic material), the material used to form the marker included on the medical device is a magnetically sensitive material, or a material having a high magnetic sensitivity relative to the magnetic sensitivity of the material forming another portion of the medical device (e.g., an elongated member) (e.g., a paramagnetic material, a ferromagnetic material, a diamagnetic material), or a material having a low magnetic sensitivity relative to the magnetic sensitivity of the material forming another portion of the medical device (e.g., an elongated member) (e.g., a non-paramagnetic material, a non-ferromagnetic material, a non-diamagnetic material).

[0041] The first material forming the elongated member 16 of the first medical device 10, the second material forming the elongated member 56 of the second medical device 50, and the material forming the marker included on the medical device may include any suitable material having the magnetic susceptibility described herein. For example, the first material, the second material, the third material, and the fourth material may include any suitable MRI-compatible material having the magnetic susceptibility described herein. In the illustrated embodiment, the first material and the third material each include titanium, and the first marker 46 is formed of a second material having a second magnetic susceptibility that changes the image artifact created by the second marker 78 under MRI when the first marker 46 overlaps with the second marker 78 (e.g., in the axial direction). Alternatively, the second marker may be formed of a fourth material having a fourth magnetic susceptibility that changes the image artifact created by the first marker under MRI when the first marker overlaps with the second marker (e.g., in the axial direction) during use. These alternatives may be achieved by forming the first marker and the second marker from the same material or different materials or from materials having different magnetic susceptibilities. When formed of the same material, the second magnetic susceptibility or second sensitivity can be the same as or different from the fourth magnetic susceptibility or fourth sensitivity, depending on various considerations, such as how the material is applied to the medical device. When formed of different materials, the second magnetic susceptibility or second sensitivity can be the same as or different from the fourth magnetic susceptibility or fourth sensitivity, depending on various considerations, such as how the material is applied to the medical device.

[0042] For example, using the superposition principle of passive markers based on sensitivity (i.e., the additive or subtractive characteristics of magnetic field distortion caused by marker overlap), when the medical devices 10, 50 are used in combination, the first medical device 10 and the second medical device 50, each having its own corresponding marker 46, 78, can be used to change one or more image artifacts generated under MRI. For example, when the first medical device 10 and the second device 50 are used so that the first marker 46 overlaps with the second marker 78 (e.g., in the axial direction), the image artifacts generated by the second marker 78 under MRI can be weakened by the first marker 46, or completely or partially eliminated, or vice versa. In this embodiment, the first marker 46 has equal but opposite magnetic susceptibility (e.g., opposite sign, opposite magnetic susceptibility) relative to the second marker 78. However, alternative embodiments may include a first marker having unequal opposite magnetic susceptibility relative to the second marker. Alternatively, when the first medical device 10 and the second medical device 50 are used so that the first marker 46 overlaps with the second marker 78, the image artifacts generated by the second marker 78 under MRI can be magnified by the first marker 46, or vice versa. In this embodiment, the first marker 46 has the same magnetic sensitivity (e.g., the same sign, equal magnetic sensitivity, unequal magnetic sensitivity), or the same sensitivity, or a greater magnetic sensitivity than the second marker 78. When the first marker overlaps with the second marker, a changed image artifact with a third set of characteristics (e.g., size, shape, position, orientation, magnetic sensitivity, intensity) different from the first set of characteristics and the second set of characteristics is created under MRI.

[0043] Using the medical system 8 and the first medical device 10 and the second medical device 50 in this manner is considered advantageous, at least because the image artifacts created under MRI can be dynamically changed in real time as described herein during the execution of an MRI-guided procedure or in multiple MRI-guided procedures. For example, by changing the relative positions of the first medical device 10 and the second medical device 50 in real time, a dynamic range of image artifacts can be created under MRI. For example, a first marker on the first medical device and a second marker on the second medical device can act on an external magnetic field independently (e.g., when not overlapping) or jointly (e.g., when overlapping) based on their positions relative to each other, so that a variety of different image artifacts can be created under MRI. Alternatively, the first medical device and the second medical device can be attached to each other or arranged relative to each other so that the image artifacts created under MRI by the marker on one of the first medical device and the second medical device (e.g., by another marker, by another medical device) during the execution of an MRI-guided procedure or in multiple MRI-guided procedures are statically changed.

[0044] By taking advantage of the paramagnetic, ferromagnetic, and diamagnetic properties of materials, clinicians are able to amplify, attenuate, or effectively eliminate all or most image artifacts near an area of ​​interest. For example, when performing a prostate biopsy, it may be desirable to have few or no image artifacts at or near the tip of a cannula (e.g., a needle cannula), such as a cannula formed from titanium. Thus, a first medical device may be formed from titanium, and a second medical device or a portion of the second medical device (e.g., a distal portion, a marker) may be formed from a material (e.g., polycrystalline graphite) that eliminates or attenuates image artifacts produced by the first medical device during use. Pure titanium has a magnetic susceptibility of approximately 160 ppm, and polycrystalline graphite has a magnetic susceptibility of approximately -200 ppm. Using these materials concentrically will nearly cancel out any sensitivity effects, resulting in few or no image artifacts under MRI.

[0045] Although the first medical device 10 has been illustrated as including one marker 46 positioned at a specific location on the first medical device 10, and the second medical device 50 has been illustrated as including one marker 78 positioned at a specific location on the second medical device 50, any suitable number of markers may be positioned at any suitable location on the medical device according to the embodiment. Examples of suitable numbers of markers included in the medical device according to the embodiment include one marker, two markers, more than two markers, three markers, multiple markers, four markers, five markers, six markers, seven markers, eight markers, nine markers, ten markers, and more than ten markers. In addition, in a medical device including two or more markers, the markers may be spaced apart from each other by any desired distance (e.g., equidistant spacing, varying distances between adjacent markers). However, it should be noted that because the markers produce visual artifacts and their utility in the medical device is based on such production of visual artifacts in the MRI procedure, it is desirable to space the markers provided on a single medical device apart from each other at a distance that does not cause the medical device to produce overlapping or nearly overlapping visual artifacts. However, alternative embodiments may include a first medical device wherein the material forming a portion of or the entire elongated member of the first medical device may be used as a marker as described herein to alter image artifacts of a second medical device disposed through the first medical device. Alternatively, alternative embodiments may include a second medical device wherein the material forming a portion of or the entire elongated member of the second medical device may be used as a marker as described herein to alter image artifacts of the first medical device through which the second medical device may be disposed.

[0046] Although the elongated member 16 of the cannula 12 has been illustrated as including a distal tapered tip 42 with a cutting edge 44, and the elongated member 56 of the stylet 52 has been illustrated as including a distal tapered tip 74 with a cutting edge 76, the elongated members included on the medical device may include any suitable structural configuration, such as those having a blunt or non-tapered distal tip. In addition, in alternative embodiments, the seat member may include any suitable structure to enable attachment to another device, the seat member may be omitted from the medical device, and / or the stylet may be hollow so as to define a lumen extending along the entire length of the stylet or a portion of the length of the stylet.

[0047] Figure 6 A second example medical system 108 that can be used to perform treatment under MRI (e.g., change image artifacts under MRI, change characteristics of image artifacts under MRI) is illustrated. In this example, the second example medical system 108 includes a first medical device 110 and a second medical device 150. In the illustrated embodiment, the first medical device 110 is a cannula 112, and the second medical device 150 is a stylet 152 that can be used coaxially with the first medical device 110. The cannula 112 is similar to Figure 1 , Figure 2 and Figure 4 The cannula 12 shown in and described above is the same as that shown in and described above, except as described in detail below. The stylet 152 is similar to Figure 1 , Figure 3 and Figure 5 The stylet 52 shown in and described above differs from that described in detail below.

[0048] In the illustrated embodiment, the cannula 112 has a longitudinal axis 113, a seat member 114, and an elongated member 116. The elongated member 116 has a proximal end 130, a distal end 132, an outer surface 134, an inner surface 136, and a body 138 defining a lumen 140. The lumen 140 extends from the proximal end 130 to the distal end 132 so that one or more devices can enter and pass through the elongated member 116 of the cannula 112. The elongated member 116 of the cannula 112 is formed of a first material having a first magnetic susceptibility.

[0049] In the illustrated embodiment, the elongated member 116 of the cannula 112 includes a first plurality of markers 146 disposed between the proximal end 130 and the distal end 132 of the elongated member 116. Each marker in the first plurality of markers 146 is disposed only around a portion of the circumference of the body 138 of the elongated member 116 of the cannula 112. Each marker in the first plurality of markers 146 is equally spaced apart from adjacent markers in the first plurality of markers 146 along the elongated member 116. Each marker in the first plurality of markers 146 is a passive marker and is formed of a second material different from the first material. The second material has a second magnetic susceptibility different from (e.g., greater than) the first magnetic susceptibility. Each marker in the first plurality of markers 146 creates an image artifact having a first set of characteristics (e.g., size, shape, position, orientation, magnetic susceptibility, intensity) under MRI.

[0050] In the illustrated embodiment, the stylet 152 has a seat member 154 and an elongated member 156. The elongated member 156 has a proximal end 166, a distal end 168, an outer surface 170, and a body 172 defining a solid member. The elongated member 156 of the stylet 152 can enter and pass through the lumen 140 of the elongated member 116 of the cannula 112. The elongated member 156 of the stylet 152 is formed of a third material having a third magnetic sensitivity. In the illustrated embodiment, the first material forming the elongated member 116 of the cannula 112 and the third material forming the elongated member 156 of the stylet 152 are different (e.g., have different magnetic susceptibilities).

[0051] In the illustrated embodiment, the elongated member 156 of the stylet 152 includes a second plurality of markers 178 disposed between the proximal end 166 and the distal end 168. Each marker in the second plurality of markers 178 is disposed only around a portion of the circumference of the body 172 of the elongated member 156 of the stylet 152. Each marker in the second plurality of markers 178 is equally spaced apart from adjacent markers in the second plurality of markers 178 along the elongated member 156. Each marker in the second plurality of markers 178 is a passive marker and is formed of a fourth material that is different from the first material and the third material and has a fourth magnetic sensitivity that is different from (e.g., greater than) the first magnetic sensitivity and the third magnetic sensitivity. Each marker in the second plurality of markers 178 creates an image artifact under MRI that has a second set of characteristics (e.g., size, shape, position, orientation, magnetic sensitivity, intensity) that is different from the first set of characteristics. Each marker in the second plurality of markers 178 is positioned on the elongated member 156 such that each marker in the first plurality of markers 146 can overlap with a marker in the second plurality of markers 178 (e.g., axially) when the second medical device 150 is disposed within the first medical device 110 (e.g., each marker in the first plurality of markers 146 is disposed at the same position as a marker in the second plurality of markers 146 along the longitudinal axis 113 of the elongated member 116 of the cannula 112).

[0052] In the illustrated embodiment, each marker in the first plurality of markers 146 and each marker in the second plurality of markers 178 is a material deposit attached to its respective elongated member 116, 156 and is formed as a dot. The first material forming the elongated member 116 of the first medical device 110, the second material forming the elongated member 156 of the second medical device 150, and the material forming the markers included on the medical devices may include any suitable material having the magnetic susceptibility described herein. For example, the first material, the second material, the third material, and the fourth material may include any suitable MRI-compatible material having the magnetic susceptibility described herein. In the illustrated embodiment, the first material includes titanium, the second material includes a polymer, and each marker in the first plurality of markers 146 is formed of a second material having a second magnetic susceptibility that changes the image artifact created by each marker in the second plurality of markers 178 under MRI when the marker in the first plurality of markers 146 overlaps with the marker in the second plurality of markers 178. When the first plurality of markers 146 overlap with the second plurality of markers, a plurality of altered image artifacts having a third set of characteristics (e.g., size, shape, location, orientation, magnetic susceptibility, intensity) different from the first set of characteristics and the second set of characteristics are created under MRI. Alternatively, each of the second plurality of markers may be formed of a fourth material having a fourth magnetic susceptibility that alters the image artifacts created by each of the first plurality of markers under MRI when the markers in the first plurality of markers overlap with the markers in the second plurality of markers during use. In the illustrated embodiment, this is achieved by forming each of the first plurality of markers 146 from a material different from the material forming each of the second plurality of markers 178, such that the second material has a second magnetic susceptibility different from the fourth magnetic susceptibility (e.g., the magnetic susceptibility has a different sign). In this embodiment, when the first plurality of markers 146 overlap with the second plurality of markers 178 using the first medical device 110 and the second device 150, the image artifacts created by the markers in the second plurality of markers 178 under MRI are attenuated by the markers in the first plurality of markers 146, or vice versa. Alternative embodiments may include a first plurality of markers formed from a second material having a second magnetic sensitivity or a second magnetic sensitivity that is the same as or different from a fourth magnetic sensitivity or a fourth sensitivity of a fourth material forming the second plurality of markers, such that the magnetic sensitivity or sensitivity of the second material and / or the fourth material is amplified (e.g., the magnetic susceptibilities have the same sign), attenuated, or eliminated, and resulting image artifacts under MRI are amplified, attenuated, or eliminated.

[0053] The use of the medical system 108 and the first medical device 110 and the second medical device 150 is believed to be advantageous at least because the image artifacts created by the first plurality of markers 146 and / or the second plurality of markers 178 can be dynamically changed in real time as described herein during the performance of an MRI-guided procedure or in multiple MRI-guided procedures. For example, by changing the relative positions of the first medical device 110 and the second medical device 150 in real time, a dynamic range of image artifacts created under MRI can be created.

[0054] Figure 7 A third example medical system 208 is illustrated that can be used to perform treatment under MRI (e.g., to change image artifacts under MRI). In this example, the second example medical system 208 includes a first medical device 210 and a second medical device 250. In the illustrated embodiment, the first medical device 210 is a cannula 212, and the second medical device 250 is a stylet 252 that can be used coaxially with the first medical device 210. The cannula 212 is similar to Figure 6 The cannula 112 shown in FIG. 1 and described above differs from the cannula 112 described in detail below. The stylet 252 is similar to Figure 6 The stylet 152 shown in and described above differs from that described in detail below.

[0055] In the illustrated embodiment, the cannula 212 has a longitudinal axis 213, a seat member 214, and an elongated member 216. The elongated member 216 of the cannula 212 is formed of a first material having a first magnetic susceptibility. In the illustrated embodiment, the elongated member 216 of the cannula 212 includes a first plurality of markers 246 disposed between the proximal end 230 and the distal end 232 of the elongated member 216. Each marker in the first plurality of markers 246 is a passive marker. The first plurality of markers 246 are spaced apart from each other at different distances along the elongated member 216. The first plurality of markers 246 includes a first marker subset 280, a second marker subset 282, and a third marker subset 284. Each marker in the first marker subset 280 is disposed between the proximal end 230 and the distal end 232 of the elongated member 216 of the first medical device 210 around the entire circumference of the body 238 of the elongated member 216, and is formed of a second material different from the first material. The second material has a second magnetic susceptibility different from (e.g., greater than) the first magnetic susceptibility. Each marker in the first marker subset 280 creates an image artifact under MRI that has a first set of characteristics (e.g., size, shape, location, orientation, magnetic susceptibility, intensity). Each marker in the second marker subset 282 is disposed between the first marker subset 280 and the third marker subset 284, disposed only around a portion of the circumference of the body 238, and formed of a third material that is different from the first material and the second material. The third material has a third magnetic susceptibility that is different from (e.g., greater than) the first magnetic susceptibility and different from (e.g., greater than, less than) the second magnetic susceptibility. Each marker in the second marker subset 282 creates an image artifact under MRI that has a second set of characteristics (e.g., size, shape, location, orientation, magnetic susceptibility, intensity) that is different from the first set of characteristics. Each marker in the third marker subset 284 is disposed between the second marker subset 282 and the distal end 232 of the elongated member 216, disposed only around a portion of the circumference of the body 238, and formed of a fourth material that is different from the first material, the second material, and the third material. The fourth material has a fourth magnetic susceptibility that is different from (e.g., greater than) the first magnetic susceptibility, different from (e.g., greater than, less than) the second magnetic susceptibility, and different from (e.g., greater than, less than) the third magnetic susceptibility. Each marker in the third marker subset 284 creates an image artifact under MRI that has a third set of characteristics (e.g., size, shape, position, orientation, magnetic susceptibility, intensity) that is different from the first set of characteristics and the second set of characteristics. The first marker subset 280 includes three markers, the second marker subset 282 includes one marker, and the third marker subset 284 includes one marker. However, alternative embodiments may include any suitable number and type of markers in a subset of multiple markers, and each marker subset may be formed of any suitable material having the magnetic susceptibility described herein.

[0056] In the illustrated embodiment, each marker in the first marker subset 280 is a strip of material attached to the elongated member 216, each marker in the second marker subset 282 is a deposit of material attached to the elongated member 216 and formed as a dot, and each marker in the third marker subset 284 is a deposit of material attached to the elongated member 216 and formed as a rectangle. Although the markers in the first plurality of markers 246 have been illustrated as being disposed at specific locations and having a specific structural arrangement on the elongated member 216, the markers included on the medical device may be positioned at any suitable location and have any suitable structural arrangement.

[0057] In the illustrated embodiment, the stylet 252 has a seat member 254 and an elongated member 256. The elongated member 256 of the stylet 252 is formed of a fifth material having a fifth magnetic sensitivity. In the illustrated embodiment, the first material forming the elongated member 216 of the cannula 212 and the fifth material forming the elongated member 256 of the stylet 252 are different.

[0058] In the illustrated embodiment, the elongated member 256 of the stylet 252 includes a second plurality of markers 278 disposed between the proximal end 266 and the distal end 268 of the elongated member 256. Each marker in the second plurality of markers 278 is a passive marker. The second plurality of markers 278 are spaced at different distances from each other along the elongated member 256. The second plurality of markers 278 includes a first marker subset 286, a second marker subset 288, and a third marker subset 290. Each marker in the first marker subset 286 is disposed between the proximal end 266 and the distal end 268 of the elongated member 256 of the second medical device 250 around the entire circumference of the body 272 of the elongated member 256, and is formed of a sixth material different from the fifth material. The sixth material has a sixth magnetic susceptibility that is different from (e.g., greater than) the fifth magnetic susceptibility. Each marker in the first marker subset 286 creates an image artifact having a first set of characteristics (e.g., size, shape, position, orientation, magnetic susceptibility, intensity) under MRI. Each marker in the second marker subset 288 is disposed between the first marker subset 286 and the third marker subset 290, disposed only around a portion of the circumference of the body 272, and formed of a seventh material different from the fifth material and the sixth material. The seventh material has a seventh magnetic susceptibility different from (e.g., greater than) the fifth magnetic susceptibility and different from (e.g., greater than, less than) the sixth magnetic susceptibility. Each marker in the second marker subset 288 creates an image artifact under MRI having a second set of characteristics (e.g., size, shape, location, orientation, magnetic susceptibility, intensity) different from the first set of characteristics. Each marker in the third marker subset 290 is disposed between the second marker subset 288 and the distal end 268 of the elongated member 256 of the second medical device 250, disposed only around a portion of the circumference of the body 272, and formed of an eighth material different from the fifth material, the sixth material, and the seventh material. The eighth material has an eighth magnetic susceptibility different from (e.g., greater than) the fifth magnetic susceptibility, different from (e.g., greater than, less than) the sixth magnetic susceptibility, and different from (e.g., greater than, less than) the seventh magnetic susceptibility. Each marker in the third marker subset 290 creates an image artifact under MRI having a third set of characteristics (e.g., size, shape, location, orientation, magnetic susceptibility, intensity) that is different from the first set of characteristics and the second set of characteristics. The first marker subset 286 includes three markers, the second marker subset 288 includes one marker, and the third marker subset 290 includes one marker. However, alternative embodiments may include any suitable number and type of markers in a subset of multiple markers, and each marker subset may be formed of any suitable material having a magnetic susceptibility as described herein.

[0059] In the illustrated embodiment, each marker in the first marker subset 286 is a strip of material attached to the elongated member 256, each marker in the second marker subset 288 is a deposit of material attached to the elongated member 256 and formed as a dot, and each marker in the third marker subset 290 is a deposit of material attached to the elongated member 256 and formed as a rectangle. Although the markers in the second plurality of markers 278 have been illustrated as being disposed at specific locations and having a specific structural arrangement on the elongated member 256, the markers included on the medical device may be positioned at any suitable location and have any suitable structural arrangement.

[0060] Each of the second plurality of markings 278 is positioned on the elongated member 256 such that the first plurality of markings 246 overlaps (e.g., axially) with the second plurality of markings 279 when the second medical device 250 is disposed within the first medical device 210 and the plurality of markings 246, 278 are aligned relative to the longitudinal axis 213 of the elongated member 216 of the cannula 212. For example, each of the second plurality of markings 278 is positioned on the elongated member 256 such that when the second medical device 250 is disposed within the first medical device 210 and a marking in the first plurality of markings 246 and a marking in the second plurality of markings 278 are disposed at the same position along the longitudinal axis 213 of the elongated member 216 of the cannula 212, a marking in the first plurality of markings 246 may overlap with a marking in the second plurality of markings 278.

[0061] The first material forming the elongated member 216 of the first medical device 210, the second material forming the elongated member 256 of the second medical device 250, and the material forming the markers included on the medical devices may include any suitable material. For example, the first material, the second material, the third material, the fourth material, the fifth material, the sixth material, the seventh material, and the eighth material may include any suitable MRI-compatible material having the magnetic susceptibility described herein. In the illustrated embodiment, the first material includes titanium, the second material includes a polymer, and each of the first plurality of markers 246 is formed of a material having the following magnetic susceptibility: when a marker in the first plurality of markers 246 overlaps with a marker in the second plurality of markers 278 during use (e.g., in the axial direction), the magnetic susceptibility changes the image artifact of each marker in the second plurality of markers 278 under MRI. Alternatively, each marker in the second plurality of markers may be formed of a material having the following magnetic susceptibility: when a marker in the first plurality of markers overlaps with a marker in the second plurality of markers during use (e.g., in the axial direction), the magnetic susceptibility changes the image artifact created by each marker in the first plurality of markers under MRI.

[0062] Each mark in the first mark subset 280 is formed of a material different from the material forming each mark in the first mark subset 286, so that the second material has a second magnetic sensitivity different from (e.g., greater than, less than) the sixth magnetic sensitivity (e.g., the magnetic sensitivity has a different sign). Each mark in the second mark subset 282 is formed of a material different from the material forming each mark in the second mark subset 288, so that the third material has a third magnetic sensitivity different from (e.g., greater than, less than) the seventh magnetic sensitivity (e.g., the magnetic sensitivity has a different sign). Each mark in the third mark subset 284 is formed of a material different from the material forming each mark in the third mark subset 290, so that the fourth material has a fourth magnetic sensitivity different from (e.g., greater than, less than) the eighth magnetic sensitivity (e.g., the magnetic sensitivity has a different sign).

[0063] In the illustrated embodiment, when the first plurality of markers 246 overlaps with the second plurality of markers 278 (e.g., in the axial direction) using the first medical device 210 and the second device 250, image artifacts generated under MRI by markers in the first marker subset 286 are magnified by markers in the first marker subset 280 or vice versa, image artifacts generated under MRI by markers in the second marker subset 288 are magnified by markers in the second marker subset 282 or vice versa, and image artifacts generated under MRI by markers in the third marker subset 290 are magnified by markers in the third marker subset 284 or vice versa. When markers in the first marker subset 280 overlap with markers in the first marker subset 286, image artifacts with changes in a fourth set of characteristics (e.g., size, shape, position, orientation, magnetic susceptibility, intensity) that are different from the characteristics of the markers included in the first marker subset 280 and the first marker subset 286 are created under MRI. When the markers in the second marker subset 282 overlap with the markers in the first marker subset 288, an altered image artifact is created under MRI that has a fifth set of characteristics (e.g., size, shape, location, orientation, magnetic susceptibility, intensity) that is different from the characteristics of the markers included in the second marker subset 282 and the second marker subset 288. When the markers in the third marker subset 284 overlap with the markers in the third marker subset 288, an altered image artifact is created under MRI that has a sixth set of characteristics (e.g., size, shape, location, orientation, magnetic susceptibility, intensity) that is different from the characteristics of the markers included in the third marker subset 284 and the third marker subset 290. Alternative embodiments may include a marker subset on the first medical device being formed of the same material as a corresponding marker subset on the second medical device having the same magnetic susceptibility or the same sensitivity, such that the image artifacts created by the markers in each subset under MRI are attenuated, eliminated, or amplified (e.g., the magnetic susceptibilities have the same sign).

[0064] In addition, depending on the relative positions of the first medical device 210 and the second medical device 250, the markers of the third marker subset 284 can change the image artifacts generated by the markers in the second marker subset 288 under MRI or the image artifacts generated by the markers in the first marker subset 286 under MRI, or vice versa. In addition, depending on the relative positions of the first medical device 210 and the second medical device 250, the markers of the second marker subset 282 can change the image artifacts generated by the markers in the first marker subset 286 under MRI, or vice versa.

[0065] The use of the medical system 208 and the first medical device 210 and the second medical device 250 is considered advantageous at least because image artifacts created under MRI by markers included in one of the first plurality of markers 246 and the second plurality of markers 278 can be dynamically changed in real time as described herein during the performance of an MRI-guided procedure or in a plurality of MRI-guided procedures. For example, by changing the relative positions of the first medical device 210 and the second medical device 250 in real time, a dynamic range of image artifacts can be created under MRI.

[0066] Although the markers shown in the medical devices described herein have been shown as strips of material, materials deposited on the medical device and forming dots, and / or materials deposited on the medical device and forming rectangles, the markers may include any suitable structure attached to the medical device (e.g., a stylet, a cannula) or any suitable treatment applied to the medical device. For example, the markers may include: strips of material; magnetic ink; sputtered magnetite; embossing, forging, or shot peening of a material (e.g., annealed 304 stainless steel) that forms part of the medical device; a single layer of material (e.g., metal, metal alloy) or multiple layers of material (e.g., metal, metal alloy) deposited along the outer and / or inner surface of the medical device (e.g., an elongated member of the medical device); and / or any other material that is considered suitable for forming distinct markers (e.g., image artifacts) visible under MRI and having the magnetic susceptibility described herein. Any suitable marker having the magnetic susceptibility described herein may be included in the medical device. Examples of markers considered suitable for inclusion in medical devices are described in U.S. patent application Ser. No. 16 / 454,905, filed on June 27, 2019, which is incorporated herein by reference in its entirety for the purpose of describing markers considered suitable for inclusion in medical devices.

[0067] Each marker included on the medical device can have any suitable structural arrangement and characteristics under MRI. For example, the marker can include a structure defining any suitable shape, such as a curve along a portion of the length of the elongated member, a geometric shape (e.g., a circle, a polygon) on a portion of the elongated member, a spiral along a portion of the length of the elongated member, any combination of the shapes described herein, or any other shape deemed suitable for a particular embodiment. The configurations described herein provide a mechanism for creating a marker having a resulting image artifact created by the marker under MRI that can be distinguished from the surrounding fluid and / or tissue imaged under MRI.

[0068] Although the medical devices described herein have included cannulas and stylets, the markers described herein may be included on any suitable medical device that can be used in combination with each other (e.g., coaxially), and the selection of suitable medical devices to include markers may be based on various considerations, including the intended use of the medical device provided with the marker. Examples of medical devices considered suitable for including markers include: cannulas, needles, stylets, sheaths, catheters, balloon catheters, dilators, guidewires, introducers, implantable devices, two medical devices that can be used in combination with each other (e.g., coaxially) (such as needles and guidewires, guidewires and introducers, guidewires and catheters, guidewires and sheaths, sheaths and catheters, implantable medical devices and associated delivery systems), any medical device that can be passed over or within a guidewire, and any other medical device that is considered suitable for a particular embodiment. In addition, the features described herein may be used on more than two medical devices, which may be used independently or in combination with each other.

[0069] The first medical device can include any suitable type of medical device.For example, the first medical device can include the cannula of any suitable type with any suitable length and specification.For example, the first medical device can include Inconel Chiba needle, Inconel micropuncture needle or any other needle that is considered to be suitable for a specific embodiment, with a length equal to, greater than or less than 7 centimeters, 15 centimeters or any other length that is considered to be suitable for a specific embodiment, and / or with a specification equal to, greater than or less than 20, 21, 22 or any other specification that is considered to be suitable for a specific embodiment.The second medical device can include any suitable type of medical device.For example, the second medical device can include the stylet of any suitable type with any suitable length and specification.

[0070] In addition, the medical devices described herein can be used with any suitable number of sheaths to complete treatment. For example, the selection of a suitable number of sheaths to be used in completing sequential expansion can be based on the body passage in which the sequential expansion is being completed. Examples of the number of sheaths that are considered suitable for use in completing sequential expansion include one, two, multiple, three, four, more than four, and any other number that is considered suitable for a particular embodiment.

[0071] Although a marker on a first medical device has been described as overlapping a marker on a second medical device so as to create an altered image artifact in the MR image, such overlap may include a partial overlap between two markers (e.g., two coaxial markers) or a complete overlap between two markers (e.g., two coaxial markers) and will depend on the structural arrangement (e.g., size, shape, position, magnetic susceptibility, strength) of the markers that are intended to overlap each other.

[0072] Any type of change in an image artifact can be achieved by overlapping two marks, and will depend on the size, shape, location, magnetic susceptibility, and / or material from which the marks are formed. Examples of the types of changes that can be achieved using overlapping marks include changing the size, shape, intensity, and / or appearance (e.g., eliminating, amplifying, attenuating) of an image artifact, as well as any other changes deemed appropriate for a particular embodiment.

[0073] Although specific materials have been described as forming a first medical device (e.g., an elongated member), a second medical device (e.g., an elongated member), and a marker, the medical device or a portion thereof (e.g., an elongated member) and the marker can be formed of any suitable material having the magnetic susceptibility described herein to achieve the features described herein. For example, the first medical device, the second medical device, or a portion thereof (e.g., an elongated member), and one or more markers included on the medical device can be formed of any suitable MRI-compatible material having the magnetic susceptibility described herein, and the selection of suitable materials can be based on various considerations, including the intended use of the first medical device, the second medical device, and / or the marker. In addition or in alternative embodiments, the first medical device, the second medical device, or a portion thereof (e.g., an elongated member), one or more markers included on the medical device, and / or any other material described herein can include any suitable MRI-compatible material having a sensitivity or relative sensitivity similar to the magnetic susceptibility or relative magnetic susceptibility described herein with respect to the portion of the system or device formed by the material. Examples of materials considered suitable for forming the first medical device, the second medical device, and / or one or more markers or portions thereof include: biocompatible materials, materials that can be made biocompatible, MRI compatible materials, metals, electrically insulating materials, non-conductive materials, non-ferromagnetic materials (such as non-magnetically sensitive materials), non-diamagnetic materials, passive materials, magnetically sensitive materials (including diamagnetic materials (e.g., pyrolytic carbon), paramagnetic materials, or ferromagnetic materials), ferromagnetic passive materials, ferritic stainless steel, ferritic stainless steel 430L powder, shape memory alloys (including nickel-titanium alloys (such as Nitinol), austenitic nickel-chromium-based alloys (such as Inconel, a brand of austenitic nickel-chromium-based superalloy series from Special Metals Corporation)), stainless steel, 304V SS (including austenitic stainless steel, ferrous stainless steel, stainless steel including Inconel), iron, cobalt, cobalt chromium, cobalt chromium alloys, titanium, materials with a hardness of about 192 KSI (e.g., stainless steel), nickel, nickel plating, bright nickel plating, alloys containing less than 1% iron by weight, metals including murinite (such as MuMetal, which is a brand of nickel-iron ferromagnetic alloy with very high magnetic permeability from Magnetic Shield Corporation), gadolinium, pyrolytic carbon, silver, graphite, polycrystalline graphite, plastics, polymers, PEEK, carbon-filled PEEK, polyethylene (such as high density polyethylene (HDPE)), polypropylene, polycarbonate, silicone, Delrin, ceramics, transparent materials, opaque materials, ceramics, materials described herein, combinations described herein, and any other material deemed suitable for a particular embodiment and having the magnetic susceptibility described herein.Overlay marks or marks that can be overlapped during performance of a procedure can be formed from any suitable material, such as those described herein, paramagnetic materials (e.g., materials for magnifying image artifacts, including iron, nickel, cobalt (e.g., 300 series stainless steel), nickel cobalt, cobalt chromium), ferromagnetic materials (e.g., materials for magnifying image artifacts, including iron, nickel, cobalt (e.g., 300 series stainless steel), nickel cobalt, cobalt chromium), diamagnetic materials (e.g., pyrolytic carbon, silver, carbon (e.g., graphite) for reducing or eliminating image artifacts), and any other material deemed suitable for a particular embodiment.

[0074] The selection of one or more markers to be included on a medical device can also be based on one or more field strengths that the medical device is expected to use. For example, a medical device including a marker can be used to complete one or more MRI-guided interventional procedures using one or more field strengths (0.55 Tesla (T), 1.5T, or 3.0T). Accumulated artifacts based on sensitivity resulting from the overlap of two or more markers can be selected to respond differently to a single imaging sequence or multiple imaging sequences (gradient echo and spin echo) or different magnetic field strengths. As described herein, medical devices are not limited to changing the size, shape, and intensity of a single image artifact, but can (statically or dynamically) combine a series of sensitivity markers in multiple devices to change the geometry of larger (or smaller) accumulated artifacts, thereby creating different image artifacts that can be easily identified under MRI.

[0075] As described herein, the visualization of the device during the execution of the procedure is a basic challenge in interventional MRI. Conventional interventional devices and materials are either highly sensitive, thereby obtaining artifacts that eliminate the key features of the tissue / field of the imaging, or are minimally sensitive, thereby making the device invisible in the image and unable to identify or track. Therefore, it is necessary to directly utilize diagnostic imaging modalities, particularly MR to guide treatment. The identification and precise targeting of damaged or abnormal anatomical structures are important clinical challenges. The medical device described herein is considered to be advantageous, at least because they can significantly improve the ability of clinicians to accurately visualize, identify, track and navigate medical devices to various locations in the body, and improve overall patient care (e.g., diagnosis, treatment delivery). The medical device described herein provides a marker that can be used to produce recognizable, manipulable image artifacts (e.g., patterns) on interventional MR images, thereby allowing a high degree of control of the position, size and intensity of the marker and the associated medical device under MRI.

[0076] Figure 8 An example kit 300 that can be used to perform treatment under MRI is shown. The kit 300 includes a first medical system 302 according to an embodiment, such as Figure 1 , Figure 2 , Figure 3 , Figure 4 and Figure 5 The first medical system 8 shown; the second medical system 304 according to the embodiment, such as Figure 6 The second medical system 108 shown; the third medical system 306 according to the embodiment, such as Figure 7 A third medical system 208 is shown; and instructions for use 308 .

[0077] Although the kit 300 has been illustrated as including three medical systems 302, 304, and 306, any suitable number and type of medical systems and / or medical devices may be included in the kit. The selection of a suitable number of medical systems and / or medical devices to be included in a kit according to a particular embodiment may be based on various considerations, such as the treatment to be performed. Examples of numbers of medical systems and / or medical devices considered suitable for inclusion in a kit include at least one, one, two, a plurality, three, four, five, six, seven, eight, nine, ten, more than ten, and any other number considered suitable for a particular embodiment.

[0078] In addition, although medical system 8, medical system 108 and medical system 208 have been illustrated as being included in kit 300, any suitable medical system and / or medical device may be included in the kit. The selection of suitable medical systems and / or medical devices to be included in a kit according to a particular embodiment may be based on various considerations, such as the treatment to be performed. Examples of medical systems and medical devices considered suitable for inclusion in a kit include those described herein, variations of those described herein, one or more inner sheaths, one or more outer sheaths, one or more access needles, one or more implantable medical devices, one or more delivery systems, and / or any other medical device according to an embodiment that is considered suitable for a particular embodiment.

[0079] For example, in an embodiment where the kit includes multiple medical devices (e.g., a needle and multiple stylets), the first medical device (e.g., the stylet can include a marking formed of a material that forms an image artifact at a first MR field strength (e.g., 0.55T), the second medical device (e.g., the stylet can include a marking formed of a material that forms an image artifact at a second MR field strength (e.g., 1.5T), and the third medical device (e.g., the stylet can include a marking formed of a material that forms an image artifact at a third MR field strength (e.g., 3T). The first MR field strength can be different from or the same as the second MR field strength and / or the third MR field strength. The second MR field strength can be different from or the same as the first MR field strength and / or the third MR field strength. The third MR field strength can be different from or the same as the first MR field strength and / or the second MR field strength. The first medical device, the second medical device, and the third medical device (e.g., the stylet) can each be used with a fourth medical device (e.g., the needle) to perform a procedure.

[0080] In an example, a kit that can be used for treatment under magnetic resonance includes a first medical device of an embodiment, a second medical device of an embodiment, and a third medical device of an embodiment. The first medical device includes a first marker that produces a first image artifact at a first MR field strength. The second medical device includes a second marker that produces a second image artifact at a second MR field strength. The third medical device includes a third marker that produces a third image artifact at a third MR field strength. The first MR field strength is different from the second MR field strength and the third MR field strength. The second MR field strength is different from the third MR field strength. The first image artifact has a first set of characteristics (e.g., size, shape, pattern, and / or intensity) at the first MR field strength, a second set of characteristics at the second MR field strength, and a third set of characteristics at the third MR field strength. The first set of characteristics of the first image artifact is different from the second set of characteristics of the first image artifact and the third set of characteristics of the first image artifact. The second set of characteristics of the first image artifact is different from the third set of characteristics of the first image artifact. The second image artifact has a first set of characteristics at the first MR field strength, a second set of characteristics at the second MR field strength, and a third set of characteristics at the third MR field strength. The first set of characteristics of the second image artifact is different from the second set of characteristics of the second image artifact and the third set of characteristics of the second image artifact. The second set of characteristics of the second image artifact is different from the third set of characteristics of the second image artifact. The third image artifact has a first set of characteristics at a first MR field strength, a second set of characteristics at a second MR field strength, and a third set of characteristics at a third MR field strength. The first set of characteristics of the third image artifact is different from the second set of characteristics of the third image artifact and the third set of characteristics of the third image artifact. The second set of characteristics of the third image artifact is different from the third set of characteristics of the third image artifact.

[0081] In such Fig. 9 and Fig.10 In the particular embodiment shown, the medical system 310 may include a first medical device 312, a second medical device 314, a third medical device 316, and a fourth medical device 318 that can be used concentrically. The first medical device 312 includes a needle (e.g., formed of titanium) according to an embodiment. The second medical device 314, the third medical device 316, and the fourth medical device 318 each include a stylet according to an embodiment. The first medical device 312 can be packaged with a plurality of stylets 314, 316, 318, each of which can be used in combination with a needle independently or collectively, depending on the MRI static field strength to be used or the specific interventional procedure to be performed. For example, each of the plurality of stylets 314, 316, 318 includes a marker 320 having the following magnetic sensitivity, which amplifies, eliminates, or attenuates the magnetic sensitivity created by the marker 322 set on the needle 312 under MRI or vice versa, thereby changing the image artifact of the marker 322 set on the needle 312. This can be accomplished in discrete increments (e.g., 0.25x, 0.5x, 2.0x, 4.0x, etc.), depending on the number of overlapping markers. These stylets can then be used independently or collectively to tune image artifact size in real time throughout or in multiple procedures. In embodiments where a stylet is used collectively, the stylet can be manufactured using a series of concentric tubes, as shown, and any suitable number of concentric tubes can be utilized.

[0082] The kits described herein advantageously provide clinicians with a single product (e.g., a kit) that can be used in a variety of settings. For example, a titanium needle with low magnetic susceptibility allows for precision positioning near the tip of an ongoing treatment (e.g., a biopsy being performed), while markings on one or more of the removable stylets allow for real-time tracking at all field strengths or during multiple interventional procedures. Although this embodiment describes the use of a needle and multiple stylets, such embodiments may include any suitable combination of medical devices such as those described herein (e.g., sheaths, removable dilators). For example, a sheath formed of a material that creates invisible or slightly visible image artifacts under MRI can be packaged with multiple removable dilators, each removable dilator including one or more markings that create highly visible image artifacts under MRI to facilitate use at various MRI static field strengths.

[0083] Different methods of performing interventional medical treatments under MRI are described herein. Although the methods described herein are shown and described as a series of actions, it should be understood and appreciated that these methods are not limited by the order of actions, because according to these methods, some actions can be omitted, occur in the order shown and / or described, occur in a different order, and / or occur before, after, or simultaneously with other actions described herein.

[0084] Fig.11 A schematic diagram of an example method 400 for performing treatment (eg, altering image artifacts) under MRI is illustrated.

[0085] An initial step 402 includes positioning a patient within an MR scanner. Another step 404 includes scanning a first portion of the patient using the MR scanner. The MR scanner has a first set of MR image parameters and / or sequence parameters. Another step 406 includes obtaining an MR image of the first portion of the patient. Another step 408 includes identifying tissue having predefined characteristics using the MR image. Another step 410 includes selecting a procedure for treating the tissue based on the predefined characteristics. Another step 412 includes selecting a medical system to perform the procedure. The medical system includes a first medical device and a second medical device. The first medical device has a first marker and the second medical device has a second marker. While the patient remains positioned within the MR scanner for scanning the first portion of the patient, another step 414 includes advancing the first medical device and the second medical device (e.g., concentrically) into the body passage and into the tissue while scanning a second portion of the patient including the first medical device and the second medical device and a first image artifact using the MR scanner. The first image artifact has a first set of characteristics. Another step 416 includes obtaining an MR image of the second portion of the patient including the first medical device and the second medical device and the first image artifact. Another step 418 includes identifying a first image artifact within the MR image. Another step 420 includes confirming the position of the first medical device and the second medical device within the body passage. Another step 422 includes manipulating the position of the first medical device relative to the second medical device or vice versa to change the first image artifact to create a changed image artifact. Another step 424 includes scanning a third portion of the patient including the first medical device and the second medical device and the changed image artifact using an MR scanner. Another step 426 includes obtaining an MR image of the third portion of the patient including the first medical device and the second medical device and the changed image artifact. Another step 428 includes changing (e.g., optimizing) the first set of MR image parameters and / or sequence parameters to a second set of MR image parameters and / or sequence parameters based on the changed image artifact. Another step 430 includes performing treatment.

[0086] Step 402 can be accomplished by positioning the patient in any suitable MR scanner having any suitable field strength, such as: a conventional MR scanner; an MR scanner that can perform gradient refocusing echo imaging; an MR scanner that can perform spin echo imaging; an MR scanner that can perform true steady-state precession fast imaging; an MR scanner that can perform fast low flip angle photography spoiled gradient echo imaging; an MR scanner utilizing a 0.55T field, a 1.5T field, a 3T field, a field between approximately .055T and 1.5T, a field less than 1T; and any other MR scanner deemed suitable for a particular embodiment.

[0087] Step 404 may be accomplished by scanning any suitable portion of the patient, and the selection of a suitable portion of the patient to be scanned may be based on various considerations, including the treatment to be performed. Examples of portions of the patient considered suitable for scanning include extremities (e.g., arms, legs), chest, breast, spine, neck, head, abdomen, pelvis, prostate, peri-prostatic structures, tissue surrounding portions of the patient described herein, and / or any other portion of the patient considered suitable for a particular embodiment. The MR scanner may have any suitable number and type of MR image parameters, such as gradient refocusing echo imaging, spin echo imaging, true steady-state precession fast imaging, fast low flip angle shot spoiled gradient echo imaging, field strength (e.g., 0.55T, 1.5T, 3T, between about .055T and 1.5T, and fields less than 1T), slice thickness, flip angle, field of view, resolution, gradient field, and any other image parameters considered suitable for a particular embodiment.

[0088] Step 406 may be accomplished by obtaining an MR image from the MR scanner used in step 404 .

[0089] Step 408 can be accomplished by reviewing the MR images obtained in step 406 and determining whether the tissue has predefined characteristics (e.g., the tissue has characteristics indicative of cancer, is a lesion, an abnormal mass) using conventional techniques and / or methods. In addition, the margins of any tissue (e.g., an abnormal mass) can be identified and used in additional steps as described herein to remove and / or treat the tissue.

[0090] Step 410 may be accomplished by reviewing the predefined characteristics identified in step 408 and selecting a procedure for treating the tissue based on the predefined characteristics.

[0091] Step 412 can be performed based on the procedure selected in step 410, the available MR scanners, and / or the MR field strength desired to perform the procedure. Any suitable medical system (e.g., a first medical device and a second medical device) can be selected to perform the procedure, such as those described herein, variations of those described herein, and any other medical system and / or medical device deemed suitable for a particular embodiment. Alternatively, the medical system and / or medical device can be selected from a kit, such as kit 300, or a variation of the kit described herein. The medical devices described herein each include a marker or multiple markers that produce one or more image artifacts having a set of characteristics under MRI.

[0092] Step 414 can be performed using the medical system (e.g., the first medical device and the second medical device) selected in step 412. Alternatively, step 414 can be performed using any suitable medical device (such as the medical devices described herein or incorporated by reference herein). Examples of medical devices considered suitable for performing the treatment method and examples of other steps considered suitable for inclusion in the treatment method are described in U.S. Patent Application No. 17 / 573,087 filed on January 11, 2022, which is incorporated herein by reference in its entirety for the purpose of describing medical devices considered suitable for performing the treatment method and for the purpose of describing steps considered suitable for inclusion in the treatment method.

[0093] Step 414 may be accomplished by applying a distally directed force to the first medical device such that the distal end of the first medical device is advanced into the body passage and to, within, or near a tissue that has been identified as having a predefined characteristic. Additionally, step 414 may be accomplished by applying a distally directed force to the second medical device such that the distal end of the second medical device is advanced into a lumen defined by the first medical device and to the distal side of the first medical device. The advancement of the second medical device may be accomplished simultaneously with, before, or after the advancement of the first medical device. Alternatively, the second medical device may be advanced into the lumen defined by the first medical device until the distal end of the second medical device is disposed within the lumen defined by the first medical device between the proximal end and the distal end of the first medical device.

[0094] The body passage can include any suitable part of the body, including an existing body passage, a body lumen, and / or a body passage created through tissue layers and / or fascia using the device described herein. Step 414 can be completed by scanning any suitable part of the patient, and the selection of the suitable part of the patient to be scanned can be based on various considerations, including the location of tissue with predefined characteristics. Examples of parts of the patient considered suitable for scanning include: a part including tissue with predefined characteristics, a part including the first medical device and / or the second medical device, a part including image artifacts and / or altered image artifacts, a part including tissue with predefined characteristics and the first medical device and / or the second medical device, and / or any other part of the patient considered suitable for a particular embodiment. For example, the second part of the patient can be the same or different from the first part of the patient.

[0095] Although step 414 has been described as being performed using both the first medical device and the second medical device, step 414 can be performed in two alternative ways. In the first alternative, the first step includes advancing the first medical device into the body passage and into the tissue while scanning a second portion of the patient including the first medical device using an MR scanner. The second step includes advancing the second medical device into the body passage and into the tissue while scanning a second portion of the patient including the second medical device using an MR scanner. In the second alternative, the first step includes advancing the second medical device into the body passage and into the tissue while scanning a second portion of the patient including the second medical device using an MR scanner. The second step includes advancing the first medical device into the body passage and into the tissue while scanning a second portion of the patient including the first medical device using an MR scanner.

[0096] Image artifacts produced under MRI may include any image artifacts created by a combination of markers included on any medical device or included on a combination of medical devices. For example, a first image artifact may be created by a marker set on a first medical device, a marker set on a second medical device, a combination of markers included on the first medical device and the second medical device, overlapping markers (e.g., altered image artifacts), and / or any other markers deemed appropriate for a particular embodiment.

[0097] Step 416 and its alternatives may be accomplished by obtaining MR images from the MR scanner used in steps 402 and 414 . Fig.12An MR image 500 is illustrated showing a first medical device 502 and a second medical device 503 disposed within a body passage 504. The first medical device 502 includes a first plurality of markers 506. Each marker in the first plurality of markers 506 has a first magnetic susceptibility that produces an image artifact 508. The second medical device 503 includes a second plurality of markers 507. Each marker in the second plurality of markers 507 has a second magnetic susceptibility that is different from the first magnetic susceptibility and produces an image artifact 509. The image artifacts 508, 509 each have a set of characteristics.

[0098] Step 418 may be accomplished by reviewing the MR image obtained in step 416 and identifying characteristics of image artifacts in the image. This may be accomplished using software (e.g., software with artifact recognition, localization, tracking, image processing, and / or machine learning) included in the MR scanner used in step 402 and / or visually by a clinician. For example, the MR scanner used in step 402 and used in the remaining steps included in method 400 includes a database that associates characteristics of image artifacts with each medical device used to perform a treatment, associates characteristics of image artifacts for a combination of medical devices used to perform a treatment with the combination of medical devices, and / or associates characteristics of image artifacts created by overlapping markings with the combination of medical devices used to perform a treatment, such that when the MR scanner identifies an image artifact using the characteristics of the image artifact, the MR scanner may identify and / or track the medical device or combination of medical devices, change a first set of MR image parameters and / or sequence parameters to a second set of MR image parameters and / or sequence parameters as described herein, and / or change an image created by the MR scanner to create an altered MR image. The characteristics of the image artifacts included in the database may include those described herein, such as the size, shape, location, orientation, pattern, and / or intensity of the image artifacts. For example, each of the medical devices 10, 50, 110, 150, 210, 250, 312, 314, 316, and 318 has a different marking pattern relative to the other medical devices. Therefore, each of the medical devices 10, 50, 110, 150, 210, 250, 312, 314, 316, and 318 or a combination of medical devices will have different image artifact characteristics (e.g., patterns or codes) under MRI that can be identified using a database included in the MR scanner. Image processing software or machine learning can optionally be used to determine the status of these markings or image artifacts in near real time, thereby helping to estimate device positioning through automatic sequence selection and allowing path planning to the target location during treatment to avoid critical or sensitive anatomical structures.

[0099] Step 420 can be accomplished by reviewing the MR image obtained in step 416 and confirming that the first medical device and the second medical device are positioned at a desired location within the body passage (e.g., at, within, or near a tissue that has been identified as having predefined characteristics). This can be accomplished by visualizing one or more image artifacts created by a marker included on the first medical device and / or the second medical device, as described herein. If the first medical device and / or the second medical device are not positioned at the desired location, an optional step includes manipulating the position of the first medical device and / or the second medical device. If the first medical device and / or the second medical device are not positioned at the desired location, an optional step 432 includes repeating steps 414, 416, 418, and 420 to manipulate the position of the first medical device (e.g., in real time) and / or the second medical device (e.g., in real time). Although steps 414, 416, 418, and 420 have been illustrated as separate steps, these steps can optionally be accomplished simultaneously in real time. Optional step 432 may be performed any suitable number of times to properly position the first medical device and / or the second medical device.

[0100] An optional step that may be performed after steps 418 and / or 420 or at any other time in the process of completing method 400 includes changing a first set of MR image parameters and / or sequence parameters (e.g., SE / GRE, TR, TE, flip angle, field of view, resolution, slice thickness, gradient fields) to a second set of MR image parameters and / or sequence parameters based on the identified image artifact. This optional step may be performed using software included in the MR scanner used in step 402 and / or a clinician. This step may be performed at any time (when an MR image is taken, an image artifact is detected, a changed image artifact is detected, a changed image artifact is detected, multiple image artifacts are detected, or a combination of image artifacts are detected) such that the MR image parameters and / or sequence parameters are periodically changed or updated based on image artifacts generated by a marker or markers disposed on the first medical device, the second medical device, and / or a combination of the first medical device and the second medical device. The altered MR image may include an overlay graphic of a medical device (e.g., a portion of a medical device, an entire medical device) or a combination of medical devices identified using characteristics of an image artifact or a combination of image artifacts, may include an enlarged, attenuated, or omitted portion of the identified medical device (e.g., distal end), combination of medical devices, image artifacts, or other objects within the image, and / or include any other image manipulation deemed appropriate for a particular embodiment. For example, the altered MR image may include manipulation of planes, slices, slice thicknesses, and / or sequence parameters based on the identified image artifacts. For example, when an image artifact or altered image artifact is identified by software or a clinician, image parameters (e.g., related to plane selection, slices, slice thicknesses, planes, sequence parameters) may be automatically altered based on the identified image artifact or altered image artifact (e.g., by MR scanner software).

[0101] Step 422 can be accomplished by applying a force (e.g., distally directed, proximally directed torque) to the first medical device and / or the second medical device to change the first image artifact (e.g., amplify, attenuate, eliminate). This can be accomplished as described herein (e.g., positioning the first medical device and the second medical device so that a marker on the first medical device overlaps with a marker on the second medical device (e.g., axially), or positioning the first medical device and the second medical device so that a marker on the first medical device does not overlap with a marker on the second medical device). This step advantageously provides a mechanism for dynamically tuning the markers and resulting image artifacts as the procedure is completed (e.g., in real time, under continuous MR imaging), so that the manner in which the MR scanner operates can be changed as described herein (e.g., changing image parameters and / or changing sequence parameters). For example, a clinician can change one or more image artifacts (e.g., turn them on (e.g., amplify), turn them off (attenuate)) by manipulating the relative positions of the first medical device and the second medical device and the markers included on the first medical device and the second medical device.

[0102] As described herein, it is necessary to utilize diagnostic imaging modalities, particularly MR, to directly guide medical treatment. Thus, identification and precise targeting of specific features of tissues (e.g., lesions, abnormal anatomical structures) represent a significant clinical challenge. The medical systems, devices, kits, and methods described herein are intended to substantially improve current interventional MRI technology by providing clinicians with the ability to dynamically change the visibility of image artifacts created by markers included on medical devices throughout multiple procedures or in multiple procedures using passive markers. The medical systems, devices, kits, and methods described herein allow for precise identification, tracking, and navigation of interventional devices to various locations within the body, and use the characteristics of image artifacts created by a medical device or a combination of medical devices to improve overall patient care (e.g., diagnosis, targeted therapy delivery, etc.).

[0103] For example, during at least one portion of an interventional procedure, the first medical device and the second medical device can be positioned so that a marker on the first medical device overlaps a marker on the second medical device to change (e.g., eliminate, attenuate, amplify) image artifacts of the marker on the first medical device and / or the marker on the second medical device, and characteristics associated with the image artifacts. In both the subtractive configuration and the additive configuration, the marker with magnetic susceptibility along the second medical device can be customized to interact differently with the marker on the first medical device based on its position or orientation relative to the first medical device and / or the marker disposed on the first medical device. For example, the first medical device and the second medical device can be designed to have two artifact position modes: in one, the first medical device and the second medical device are positioned so that a set of alternative image artifacts created by the marker on the first medical device are offset (or amplified) by the image artifacts created by the marker on the second medical device, and in another position, a set of different image artifacts of the first medical device are offset (or amplified) by the image artifacts created by the marker on the second medical device. In this way, the size, shape, and intensity of the image artifacts of the first medical device can be dynamically shifted or changed along the first medical device (e.g., an elongated member) at any time during the procedure. Applications of these concepts extend to device tracking, following changes in a set of image artifacts as devices move relative to each other, or as a way to dynamically tune a set of image artifacts and their associated characteristics to better suit a specific portion of a procedure.

[0104] Use of the medical systems, devices, kits, and methods described herein can allow for the creation of different image artifacts within MR images that can be identified by software (e.g., software with artifact recognition, localization, tracking, image processing, and / or machine learning). In addition, as described herein, the sensitivity-based cumulative artifacts produced by a combination of multiple devices can be customized to respond differently to single or multiple imaging sequences (gradient echo vs. spin echo) or different magnetic field strengths. In these procedures, image processing software or machine learning can optionally be used to determine the state of these markers in near real time, thereby helping to estimate device positioning through automatic sequence selection, and allowing path planning to the target location during treatment delivery to avoid critical or sensitive anatomical structures.

[0105] Step 424 can be accomplished by scanning any suitable portion of the patient as described herein, and the selection of a suitable portion of the patient to be scanned can be based on various considerations, including the location of tissue having predefined characteristics. Examples of portions of the patient considered suitable for scanning include: a portion including tissue having predefined characteristics, a portion including the first medical device and / or the second medical device, a portion including image artifacts and / or altered image artifacts, a portion including tissue having predefined characteristics and the first medical device and / or the second medical device, and any other portion of the patient considered suitable for a particular embodiment. For example, a third portion of the patient can be the same as or different from the first portion of the patient and / or the second portion of the patient.

[0106] Step 426 may be accomplished by obtaining an MR image from the MR scanner used in step 402 . Fig.13 An MR image 510 is illustrated showing a first medical device 512 and a second medical device 514 disposed within a body passage 516. The first medical device 512 includes a first plurality of markers 518 and the second medical device 514 includes a second plurality of markers 520. The overlapping arrangement of the first plurality of markers 518 and the second plurality of markers 520 alters (e.g., amplifies, attenuates, eliminates) image artifacts generated by the first plurality of markers 518. Fig.13 In the illustrated embodiment, when the plurality of markers 518 , 520 overlap, image artifacts produced by the first plurality of markers 518 and the second plurality of markers 520 are eliminated. Fig.14 An MR image 528 is illustrated showing a first medical device 530 and a second medical device 532 disposed within a body passage 534. The first medical device 530 includes a first plurality of markers 536 and the second medical device 532 includes a second plurality of markers 538. The overlapping arrangement of the first plurality of markers 534 and the second plurality of markers 538 alters (e.g., amplifies) image artifacts 540 generated by the first plurality of markers 534. Fig.15 An MR image 550 is illustrated showing a first medical device 552 and a second medical device 554 disposed within a body passage 556. The first medical device 552 includes a first plurality of markers 558 and the second medical device 554 includes a second plurality of markers 560. The overlapping arrangement of markers 562 in the first plurality of markers 558 and markers 564 in the second plurality of markers 560 alters (e.g., amplifies, attenuates, eliminates) image artifacts generated by markers 562 in the first plurality of markers 558.

[0107] Step 428 may be performed using software (e.g., software with artifact recognition, localization, tracking, image processing, and / or machine learning) included in the MR scanner used in step 402 and / or a clinician. Depending on whether the image parameters and / or sequence parameters have been updated before step 428, step 428 may alternatively include changing the second set of MR image parameters and / or sequence parameters to a third set of MR image parameters and / or sequence parameters based on the image artifact or the changed image artifact. Optionally, step 428 may be performed at any time (taking an MR image (e.g., step 404, step 414, step 424), detecting an image artifact, detecting a changed image artifact, detecting multiple image artifacts, detecting a combination of image artifacts, and / or changing image artifacts (e.g., step 414, step 424)) so that the MR image parameters and / or sequence are periodically changed or updated based on the image artifacts generated and / or changed by one or more markers disposed on the first medical device, the second medical device, and / or the combination of the first medical device and the second medical device. This step may be performed using software and / or a clinician included in the MR scanner used in step 602. The altered MR image may include an overlay graphic of a medical device (e.g., a portion of a medical device, an entire medical device) or a combination of medical devices identified using characteristics of an image artifact or a combination of image artifacts, may include an enlarged, attenuated, or omitted portion of the identified medical device (e.g., distal end), combination of medical devices, image artifacts, or other objects within the image, and / or include any other image manipulation deemed appropriate for a particular embodiment. For example, the altered MR image may include manipulation of planes, slices, slice thicknesses, and / or sequence parameters based on the identified image artifacts. For example, when an image artifact or altered image artifact is identified by software or a clinician, image parameters (e.g., related to plane selection, slices, slice thicknesses, planes, sequence parameters) may be automatically altered based on the detected image artifact or altered image artifact (e.g., by MR scanner software).

[0108] Interventional MR procedures often require frequent adjustment or change of MR imaging sequence parameters throughout the various stages of a given procedure. For example, a vascular procedure may be best performed by using one sequence type (e.g., fast frame rate, low resolution, enhancement of certain tissue features) during device tracking and another sequence type (e.g., high resolution, enhancement of different tissue features to detect damage (such as inflammation, ADC)) once the interventional device has been advanced to the target site. Alternatively, one or more interventional devices may be employed in multiple MRI-based procedures, such that specific device and procedure configurations require specific imaging sequences. For example, an MRI-compatible needle may be used in multiple soft tissue biopsy procedures, each of which requires different gross or fine tracking features and highlights different anatomical structures or tissue types. Currently, many of these imaging protocols involve manual optimization by the clinician using an MR scanner, which may introduce operator-related variability and be inefficient.

[0109] Thus, the medical systems, devices, kits, and methods described herein provide mechanisms for at least increasing efficiency in completing procedures. For example, software included on an MR scanner (such as software for completing the methods described herein) can be used to provide automation of parameter adjustments throughout a procedure (e.g., plane selection, slice selection) or in multiple procedures based on changes in image artifacts created by one or more markers set on a first medical device, one or more markers created on a second medical device, or provided by overlapping markers as described herein. Thus, an MR scanner or clinician can use the presence of one or more image artifacts and / or dynamic changes in image artifacts produced by different device or component configurations to automatically select MRI sequence parameters.

[0110] For some procedures, the transition from one procedural phase to another is consistent with the specific configuration of two or more devices and may require a change in the image protocol. The dynamic changes of the marker artifacts on these devices can be customized to create easily identifiable image artifacts (e.g., signal; changes in size, shape, intensity, or pattern) or changes in image artifacts within the resulting MR images. The imaging software included on the MR scanner (such as the imaging software used to perform the methods described herein) can detect image artifacts or changes in image artifacts and automatically optimize the MR imaging parameters and / or sequences to those that best meet the clinician's needs for the new phase of the procedure.

[0111] The medical systems, devices, kits, and methods described herein can be used to automatically change other imaging parameters and / or sequences in one or more procedures using the same one or more devices. For example, changes in MRI sequence parameters (SE / GRE, TR, TE, flip angle, field of view, resolution, slice thickness, gradient field) can be triggered by characteristics of effective image artifacts created by the medical device or two or more medical devices in a specific combination that cause cumulative changes in at least one image artifact. These artifact-driven triggers can be used to issue switching signals when tracking devices, guide how to adjust MR sequences to follow devices or components in multiple device fields, or customize MR sequences to highlight characteristics of specific tissues during specific parts of the procedure (e.g., T1 v. T2 weighted images).

[0112] For example, a series of sequential MRI sequence parameters may be triggered sequentially based on identified image artifacts or altered image artifacts produced by the current and / or previous configuration of one or more devices. This process may then be used to automate imaging protocols throughout a procedure. Alternatively, utilizing a single base device and multiple different but compatible medical devices (e.g., different guide catheters or balloon catheters) all having one or more unique interacting sensitivity markers, a specific imaging procedure associated with the use of at least one compatible device with the base device may be automatically detected based on the identification of unique image artifacts (e.g., a combination of image artifacts created by a first medical device and a second medical device) produced by an initial multi-device configuration. Using detection of such pairings, a set of pre-programmed MRI sequences may be automatically loaded and triggered by software included on the MR scanner based on image artifacts produced by the previously described sequential device configurations. In other words, the image artifact (or series of artifacts) produced by the interaction of sensitivity markers on two or more medical devices will be used as a unique fingerprint to identify a specific medical device pairing or device configuration that the MRI machine automatically reconfigures for a procedure or the next step in the procedure.

[0113] Step 430 may be accomplished by using any suitable medical system and / or medical device (such as the first medical device and / or the second medical device) to perform the treatment and / or execute the procedure selected in step 410. For example, treatment may be performed and based on the tissue identified in step 408. Examples of treatments deemed suitable for performance include: a biopsy, treatment using the medical systems and / or medical devices described herein, treatment using a first medical device already positioned within a body passageway and switching the second medical device to a third medical device, and any other treatment deemed suitable for a particular embodiment.

[0114] Each of steps 404 , 406 , 408 , 410 , 412 , 414 , 416 , 418 , 420 , 422 , 424 , 426 , 428 , and / or 430 may be accomplished without removing the patient from the MR scanner in which the patient was positioned in step 402 .

[0115] Method 400 is considered advantageous at least because each step of method 400 can be performed using the same MR scanner during a single visit to the patient, thereby improving efficiency and reducing the number of patient visits and procedures performed. This results in a set of procedures in which a physician can visualize, diagnose, and treat a patient in a single visit to the patient. Although some steps have been described as being performed when a portion of a patient is scanned using an MR scanner and other steps have not been described as being performed when a portion of a patient is scanned using an MR scanner, any step described herein can be performed when a portion of a patient is scanned using an MR scanner and / or an ultrasound device, or when a portion of a patient is scanned without using an MR scanner. In an embodiment in which an ultrasound image is obtained, the MR image obtained can be electronically fused with a real-time ultrasound image (e.g., a transrectal ultrasound image of the prostate). Although some steps have been described as being performed when a portion of a patient is scanned using an MR scanner, the step can be divided into two separate steps so that the subsequent step of scanning a portion of a patient using an MR scanner can be completed. In addition, any steps performed when scanning a portion of a patient using an MR scanner may include obtaining a single still image and repeating it any desired number of times to obtain multiple MR images that can be combined as a movie to show motion, and / or any steps performed when scanning a portion of a patient using an MR scanner may include obtaining a live image, such as that performed under live real-time MRI visualization.

[0116] The medical systems, devices, kits, and methods described herein advantageously provide sensitivity-based marker artifacts that can be dynamically changed throughout a procedure or in multiple procedures using a system or a set of devices, components, or features in different configurations. In this way, the medical systems, devices, kits, and methods described herein expand the current use of fixed sensitivity marker artifacts and increase the versatility of medical devices used in MR-guided interventional procedures. In addition, by utilizing the position-based addition and subtraction characteristics of sensitivity marker magnetic field distortions (e.g., superposition), the medical systems, devices, kits, and methods described herein can be used on a variety of medical devices that can be used in combination with each other. Finally, the medical systems, devices, kits, and methods described herein can replicate or at least mimic aspects of dynamically tunable image artifacts produced by semi-active resonant circuits or active antenna coils, but do not require circuit integration or external power supplies.

[0117] Interventional systems with dynamically tunable passive markers that can adjust the size, shape or intensity of image artifacts throughout a procedure or in real time in multiple procedures improve the efficiency associated with patient care and improve current medical systems that are considered suitable for use with MRI-guided treatments. For example, the medical systems, devices, kits and methods described herein simplify the clinician experience during MRI-guided procedures. This includes automatically identifying marker image artifacts or changes, interpreting new marker image artifacts as representing new stages or new procedures within a procedure, and changing or optimizing MRI sequence parameters to MRI sequence parameters that best meet the needs of clinicians at a given period or stage of the procedure based on the identified image artifacts. This removes the need for manual sequence adjustment, standardizes procedures and imaging parameters, and improves the safety and efficiency of interventional MR procedures.

[0118] Although many methods have been described herein, it should be understood that the methods can be non-invasive methods that do not require traumatic intervention by a medical professional. For example, the methods can be performed within a body cavity or passage (such as an ear canal or nasal passage), for example, so that the device is placed within such a passage. Similarly, the methods can be implemented on a corpse or an artificial body part, for example, for training purposes. In addition, it will be understood by those skilled in the art that the methods described herein may not be used on the human or animal body at all, but can be used to observe other types of devices using MRI imaging techniques (for example, in an industrial environment).

[0119] Those skilled in the art will appreciate that various modifications and alternatives to the described and illustrated examples may be developed based on the overall teachings of this disclosure, and that various elements and features of one example described and illustrated herein may be combined with various elements and features of other examples without departing from the scope of the present invention. Accordingly, the inventors have selected the specific arrangements of elements and steps disclosed herein for the purpose of describing and illustrating examples of the present invention only, and are not intended to limit the scope of the present invention or its scope of protection, which shall be limited by the full scope of the appended claims and any and all equivalents thereof.

Claims

1. A medical system for treatment under magnetic resonance imaging, the medical system comprising: a first medical device having a first passive marker formed of a first material having a first magnetic susceptibility; as well as a second medical device having a second passive marker formed of a second material having a second magnetic susceptibility, the second passive marker creating an image artifact under MRI; When the first passive marker overlaps with the second passive marker, the image artifact created by the second passive marker is changed under MRI.

2. The medical system of claim 1, wherein: The first magnetic susceptibility is the same as the second magnetic susceptibility.

3. The medical system of claim 2, wherein: When the first passive marker overlaps the second passive marker, image artifacts created by the second passive marker are amplified.

4. The medical system of claim 1, wherein: The first magnetic susceptibility is different from the second magnetic susceptibility.

5. The medical system of claim 4, wherein: When the first passive marker overlaps the second passive marker, image artifacts created by the second passive marker are reduced.

6. The medical system of claim 1, wherein: The first material is the same as the second material.

7. The medical system of claim 1, wherein: The first material is different from the second material.

8. The medical system of claim 1, wherein: The first medical device comprises an elongated member, the first passive marker being disposed on the elongated member of the first medical device; and The second medical device comprises an elongated member, and the second passive marker is disposed on the elongated member of the second medical device.

9. The medical system of claim 8, wherein: The elongated member of the first medical device is formed from a third material different from the first material.

10. The medical system of claim 9, wherein: The elongated member of the second medical device is formed from a fourth material different from the second material.

11. The medical system of claim 10, wherein: The third material and the fourth material are titanium.

12. The medical system of claim 8, wherein: The first medical device and the second medical device can be used coaxially.

13. The medical system of claim 1, wherein: The first passive marker includes a first plurality of passive markers, each marker in the first plurality of passive markers is formed of the first material, each marker in the first plurality of passive markers creates an image artifact under MRI; wherein the second passive marker comprises a second plurality of passive markers, each marker in the second plurality of passive markers is formed of the second material, and each marker in the second plurality of passive markers creates an image artifact under MRI; and Wherein, when the first plurality of passive markers overlap the second plurality of passive markers, an image artifact created by each marker in the second plurality of passive markers is altered.

14. The medical system of claim 1, wherein: The first passive marker includes a first plurality of passive markers, the first plurality of passive markers including a first marker subset, a second marker subset and a third marker subset, each marker in the first marker subset is formed of the first material, each marker in the second marker subset is formed of a third material having a third magnetic sensitivity, each marker in the third marker subset is formed of a fourth material having a fourth magnetic sensitivity, the first magnetic sensitivity is different from the third magnetic sensitivity and the fourth magnetic sensitivity, and the third magnetic sensitivity is different from the fourth magnetic sensitivity.

15. The medical system of claim 14, wherein: The second passive marker comprises a second plurality of passive markers, the second plurality of passive markers comprising a first marker subset, a second marker subset and a third marker subset, each marker in the first marker subset of the second plurality of passive markers is formed of the second material, each marker in the second marker subset of the second plurality of passive markers is formed of a fifth material having a fifth magnetic sensitivity, each marker in the third marker subset of the second plurality of passive markers is formed of a sixth material having a sixth magnetic sensitivity, the second magnetic sensitivity is different from the fifth magnetic sensitivity and the sixth magnetic sensitivity, and the fifth magnetic sensitivity is different from the sixth magnetic sensitivity; and Wherein, each marker in the first marker subset of the second plurality of markers creates an image artifact under MRI, each marker in the second marker subset of the second plurality of markers creates an image artifact under MRI, and each marker in the third marker subset of the second plurality of markers creates an image artifact under MRI.

16. The medical system of claim 15, wherein: When a first subset of the first plurality of passive markers overlaps a first subset of the second plurality of passive markers, an image artifact created by each marker in the first subset of the second plurality of passive markers is altered; wherein when a second subset of the first plurality of passive markers overlaps a second subset of the second plurality of passive markers, an image artifact created by each marker in the second subset of the second plurality of passive markers is altered; and Wherein, when the third subset of markers of the first plurality of passive markers overlaps with the third subset of markers of the second plurality of passive markers, image artifacts created by each marker of the third subset of markers of the second plurality of passive markers are altered.

17. A method for treatment under magnetic resonance imaging, the method comprising: Positioning the patient within the MRI scanner; scanning a first portion of the patient using the magnetic resonance scanner, the magnetic resonance scanner having a first set of MR image parameters; obtaining a magnetic resonance image of a first portion of the patient; using the magnetic resonance image to identify tissue having predefined characteristics; The procedure used to treat the tissue is selected based on these predefined characteristics; selecting a medical system including a first medical device and a second medical device to perform the procedure; while the patient is positioned within the magnetic resonance scanner for scanning a first portion of the patient, advancing the medical system into the body passage and into the tissue while simultaneously scanning a second portion of the patient including the medical system and a first image artifact using the magnetic resonance scanner; obtaining a magnetic resonance image of a second portion of the patient including the medical system and the first image artifact; identifying the first image artifact within the MR image; confirming the location of the medical system within the body passage; manipulating a position of the first medical device relative to the second medical device to alter the first image artifact to create an altered image artifact; scanning a third portion of the patient including the medical system and the altered image artifact using the magnetic resonance scanner; obtaining a magnetic resonance image of a third portion of the patient including image artifacts of the medical system and the change; changing the first set of MR image parameters to a second set of MR image parameters based on the changed image artifacts; and Get treatment.

18. The method of claim 17, wherein: The first medical device has a first marker, the first marker being a passive marker formed of a first material, the first material having a first magnetic susceptibility; and The second medical device has a second marker, which is a passive marker formed of a second material, and the second material has a second magnetic sensitivity.

19. The method of claim 18, wherein: The first magnetic susceptibility is the same as the second magnetic susceptibility.

20. A method for treatment under magnetic resonance imaging, the method comprising: Positioning the patient within the MRI scanner; scanning a first portion of the patient using the magnetic resonance scanner, the magnetic resonance scanner having a first set of MR image parameters; obtaining a magnetic resonance image of a first portion of the patient; using the magnetic resonance image to identify tissue having predefined characteristics; The procedure used to treat the tissue is selected based on these predefined characteristics; selecting a first medical device to perform the procedure, the first medical device having a first indicia; while the patient is positioned within the magnetic resonance scanner for scanning a first portion of the patient, advancing the first medical device into the body passage and into the tissue while scanning a second portion of the patient including a first image artifact created by the first marker, the first image artifact having a first set of characteristics; obtaining a magnetic resonance image of a second portion of the patient including the first image artifact; identifying the first image artifact within the MR image using the first set of features; changing the first set of MR image parameters to a second set of MR image parameters based on the identified first image artifact; and Get treatment.

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