Image-guided intervention method and system

Abstract

A method and system for guiding kidney stone removal is provided. The method includes steps for facilitating or guiding three phases of intervention: renal access, stone removal, and stone-free confirmation. This is facilitated by a method that includes three phases: an intraoperative image-guided phase in which CT-based images of the renal region are obtained, a renal access guidance phase in which the CT-based images are used to generate intervention guidance images for guiding renal access, and a stone-free check phase in which additional intraoperative CT images are acquired to confirm the patient's stone-free status.

Description

[Technical Field]

[0001] The present invention relates to the field of image-guided interventions. [Background technology]

[0002] The invention particularly relates to the field of urology, for example in the field of renal interventions for the removal of kidney stones. Summary of the Invention [Problem to be solved by the invention]

[0003] In the field of image-guided interventions, the challenge remains of balancing the efficiency of the interventional workflow with patient safety and surgical success rates.

[0004] One particular area of ​​interest that motivated the present invention is image-guided interventions in the field of urology, and more specifically image guidance during percutaneous nephrolithotripsy (PCNL).

[0005] In urolithiasis or nephrolithiasis, stones form in the urinary system, which can lead to blockage of the ureters and severe pain in the lower back or abdomen. The lifetime prevalence of urinary stones is about 12% in men and 7% in women in the United States, and is increasing, possibly due to dietary factors.

[0006] Urolithiasis can be treated by fragmentation and / or removal of stones using either extracorporeal shock wave lithotripsy (ESWL), ureteroscopy (URS), or PCNL. Treatment is selected based on the location, size, and hardness of the stone, with PCNL being the option of choice for larger stones (greater than 2 cm in diameter).

[0007] A PCNL procedure is usually performed by a team of medical professionals including a urologist, sterile nurses, non-sterile nurses, often an interventional radiologist, radiographers, anesthesiologists, anesthesiology assistants, and sometimes others.

[0008] While many workflow variations exist in performing a PCNL procedure, a typical procedure involves collaboration between an interventional radiologist and a urologist. The interventional radiologist begins by gaining access to the kidney using fluoroscopy and / or ultrasound image guidance while the patient is under local anesthesia. If necessary, this includes administering contrast through an inserted needle to improve fluoroscopic imaging.

[0009] Once renal access is confirmed by urine flow through the needle, a guidewire is inserted and the patient is transferred from the interventional radiology suite to the operating room, where they receive general anesthesia and are positioned in either the prone or supine position. The urologist then uses the guidewire to dilate this access to a diameter of 1 cm and inserts an endoscope into the renal urinary collecting system, after which lithotripsy is performed. Large stone fragments are retrieved through the access sheath, while smaller stone fragments are automatically flushed away.

[0010] Fluoroscopy and nephroscopic imaging are used to confirm that all stone fragments are removed. Ultimately, renal drainage needs to be secured by placing a JJ catheter or nephrostomy tube under fluoroscopic guidance, the access sheath can be removed, and the incision closed with sutures.

[0011] After the procedure, the patient must be confirmed stone-free with a diagnostic CT scan, usually performed one week after the procedure.

[0012] The clinical outcome of the PCNL procedure is highly dependent on the renal access strategy. For successful stone removal, it is important that the urologist gain access through the correct renal calyx so that the stone can be easily reached and residual fragments, if present, can be visualized.

[0013] Renal stone removal using PCNL is a clinically challenging procedure, and its success depends heavily on renal access. The optimal access strategy for reaching the stone must be determined, and the renal calyx must be approached at the correct angle to avoid complications. To gain access to the kidney, the urologist often needs to be supported by an interventional radiologist. In current clinical practice, gaining renal access requires complex 3D navigation techniques based on either 2D projection, real-time fluoroscopy, or a combination of fluoroscopy and ultrasound imaging. Errors in this process can result in unusable access or inability to gain access at all. Renal access gained through the wrong calyx is associated with a lower stone removal rate. Inadequate renal access is associated with complications such as renal artery branch injury resulting in (serious) bleeding, colonic perforation, or lung injury resulting in pneumothorax. In this regard, see, for example, the article by JJ Tomaszweski et al., "Renal access by urologist or radiologist during percutaneous nephrolithotomy." Journal of Endourology 24:1733-1737, 2010.

[0014] After gaining access to the kidney, the urologist begins to break up the kidney stone, which may result in residual stone fragments remaining lodged in the bladder or proximal ureter of the kidney. To identify these during the procedure, the urologist uses preoperative (intraoperative) fluoroscopy and endoscopic imaging. As mentioned above, this process is also confirmed sometime after the procedure, for example, one week later, with a postoperative CT scan to confirm the patient's stone-free status. In fact, postoperative examination reveals residual stone fragments in up to 25% of cases. Up to 73% of these patients require additional treatment, such as ESWL, URS, or PCNL. In this regard, D. Olvera-Posada et al., "Natural History of Residual Fragments After Percutaneous Nephrolithotomy: Evaluation of Factors Related to Clinical Events and Intervention," Urology 97:46-50, 2016; and See JD Raman et al., "Natural history of residual fragments after percutaneous nephrostolithotomy," Journal of Urology, 181(3):1163-1168, 2009.

[0015] The complexity of gaining renal access and ensuring stone-free status not only negatively impacts patient outcomes, but also makes urologists dependent on other specialists such as interventional and diagnostic radiologists, which is associated with various clinical workflow difficulties and a significant impact on the cost of these procedures.

[0016] Improvements in this area would be generally beneficial. [Means for solving the problem]

[0017] The invention is defined by the claims. The dependent claims define advantageous embodiments.

[0018] According to an example of one aspect of the present invention, there is provided a processing unit having one or more processors configured to execute a computer-implemented method for interventional assistance during a renal intervention procedure for kidney stone removal.

[0019] The method includes at least one intraoperative image acquisition phase, which includes receiving computed tomography (CT) image data of an anatomical region that includes at least a portion of a subject's kidney.

[0020] The method further includes an intervention image guidance phase, which includes the steps of receiving real-time tool tracking data indicating the positioning of an intervention tool used in the intervention procedure, generating a real-time guidance image based on the CT image data, and further generating a guidance image based on the tracking data that visualizes the position of the intervention tool relative to the anatomical region imaged in the received CT image data, and communicating with a user interface device and displaying the generated guidance image in real time on a display unit of the user interface device.

[0021] The method further includes a quality assurance check phase following the interventional image-guided phase, which includes acquiring further CT image data of the anatomical region using a CT imaging device in communication with the CT imaging device for use in visualizing any remaining stone or stone fragments, e.g., to determine whether complete stone removal has been achieved. The further CT image data is preferably cone-beam CT image data. The CT imaging device used to acquire the further CT image data may be a C-arm CT device or a flat-panel CT device. It may be a cone-beam CT device. The further CT image data may also be cone-beam CT image data.

[0022] The method further comprises communicating with the user interface device to display the additional CT image data on a display unit of the user interface.

[0023] The proposed method advantageously facilitates a single lead surgeon to perform all steps of the stone removal procedure in one operation: kidney access, stone removal, and stone-free confirmation. This is facilitated by combining CT image-based intervention guidance to guide the surgeon in gaining kidney access and the use of intraoperative CT images to confirm stone-free status before kidney access is removed.

[0024] The inventors' motivating goal for making this invention is to reduce the complexity of gaining renal access, particularly in PCNL procedures, and improve the stone-free success rate of the procedure. By performing a stone-free check concurrently with the procedure before the renal access is closed, this improves the probability of a stone-free state, since any remaining stone fragments can be immediately addressed in further interventional steps.

[0025] In some embodiments, the method includes obtaining an indication of a result of the quality assurance check phase, and based on the result of the quality assurance check indicating insufficient stone removal, controlling the execution of a further iteration of the interventional image-guided phase and subsequently controlling the execution of a further quality assurance check phase, where a further iteration of the interventional image-guided phase means, for example, controlling the generation of a further guidance image.

[0026] The results of the quality assurance check phase can be obtained manually from a user or automatically based on image analysis. For example, in some embodiments, an indication of the results of the quality assurance check is obtained based on user input received at a user interface device. In some embodiments, an indication of the results of the quality assurance check is obtained based on application of a stone clearance check algorithm to the acquired further CT image data to automatically determine complete or incomplete stone clearance.

[0027] In some embodiments, the quality assurance check phase comprises obtaining location information associated with any remaining stones present in the kidney based on user input or based on application of an automated segmentation algorithm, and in some embodiments, during said further iterations of the image-guided phase, the guidance image may include visualization of location information associated with the remaining stones.

[0028] In some embodiments, the quality assurance check phase is triggered based on receipt of a predetermined user input command from a user interface.

[0029] In some embodiments, at least one intraoperative image acquisition phase includes communicating with a CT imaging device to acquire CT image data of the anatomical region using the CT imaging device. Preferably, cone-beam CT image data is acquired. The CT imaging device may be a cone-beam CT imaging device. It may be a C-arm CT imaging device or a flat-panel CT imaging device.

[0030] In some embodiments, the guidance image has a visual overlay indicating the position of the interventional tool that is fused with an anatomical image representing the anatomical region, the anatomical image being based on CT image data acquired during the intraoperative image acquisition phase, which may be a CT image alone or a synthetic fused image formed, for example, from a CT image and a preoperative image.

[0031] In some embodiments, the guidance image includes one or more visual overlays that provide navigation guidance for navigating the insertion of an interventional tool along a predetermined tool entry path from an incision point on the skin to a predetermined entry point in the kidney.

[0032] In some embodiments, the one or more visual overlays providing navigational guidance provide a visual indication of the target location of the incision point (e.g., relative to the patient's anatomy) and an indication of the target angle for inserting the tool.

[0033] In some advantageous embodiments, the method can include an intervention planning phase. The intervention planning phase can include obtaining an indication of a planned renal entry point. The intervention planning phase can further include obtaining an indication of a planned entry path through the body to the renal entry point. In some embodiments, one or more visual overlays for providing navigation guidance can be generated based on the obtained indications.

[0034] In some embodiments, the indication of the intended renal entry point may comprise an indication of the intended calyx of the kidney where renal entry will be achieved.

[0035] In some embodiments, the method includes obtaining an indication of a planned calyx entering the kidney, manually or automatically segmenting the planned calyx within the received CT image data, and based thereon, locating the planned kidney entry point relative to the CT image data.

[0036] In some embodiments, the indication of the intended calyx of the kidney through which renal entry will be achieved may be obtained based on user input received at the user interface, hi some embodiments, the intended entry path through the body and the intended incision point are automatically determined, for example, based on the indication of the intended calyx of the kidney through which renal entry will be achieved.

[0037] With respect to the guidance image, in some embodiments, it may be generated by fusing CT image data received during at least one intraoperative image acquisition phase with preoperative image data of the same anatomical region of the same patient acquired from a data store to generate composite image data. The advantage of this is that the preoperative image data may be obtained at a higher resolution than is possible or practical to obtain intraoperatively (i.e., simultaneously with the interventional procedure), and thus details may be enhanced. Also, the preoperative images may be acquired with the same modality or a different modality, potentially allowing additional details to be added by fusion. Furthermore, even if the same modality is used, the preoperative images may optionally be further enhanced, for example, by contrast enhancement.

[0038] For example, in some embodiments, the CT image data acquired in at least one intraoperative image acquisition phase is non-contrast-enhanced cone beam CT image data, and the method includes generating a composite image by fusing the acquired non-contrast-enhanced CT image data with preoperative contrast-enhanced cone beam CT image data of the same anatomical region of the same patient acquired from a data store.

[0039] However, in other embodiments, the CT image data acquired in at least one intraoperative image acquisition phase may be contrast-enhanced cone-beam CT image data.

[0040] In some embodiments, imaging of other modalities is used to support the intervention in addition to intraoperative CT images. For example, the image-guided phase further includes receiving auxiliary image data, which may include one or more of real-time endoscopic imaging data from an endoscopic imaging system, real-time ultrasound imaging data from an ultrasound imaging system, or real-time fluoroscopic imaging data from a cone-beam CT imager. While these modalities enable real-time imaging and thus complement and enhance the CT image data, real-time CT imaging (with sufficient temporal resolution to be used for interventional guidance) is simply not a practical possibility (with the current state of the art). The resulting radiation dose would be prohibitive.

[0041] In some embodiments, the image guidance phase comprises communicating with a user interface to simultaneously display the guidance image and the auxiliary image data, thus producing a multi-modality display that is output to a display unit.

[0042] In some embodiments, the processing unit further comprises a communication interface for wired or wireless connection with one or more of a cone beam CT imaging device, a user interface device, a tool tracking system, and an ultrasound imaging system and / or an endoscopic imaging system.

[0043] The present invention may be embodied in the form of a mobile base station that can be moved within an operating room, comprising a processing unit according to any of the embodiments described herein or any of the claims. This can thus serve as a hub connecting all hardware, providing a mobile cart housing the processing unit that facilitates the computer-implemented method. For example, the mobile unit may have a base station mounted on rollers or wheels. This has the advantage that the system can be moved between different operating rooms, avoiding the need to completely reconfigure an operating room with permanent equipment to perform the procedure. Existing operating rooms can be readily utilized to implement the method. The mobile base station may in fact further include a user interface with the display unit described above, avoiding the need to manually connect and configure the video output from the processing unit to the operating room's existing display equipment.

[0044] Another aspect of the present invention is a system that includes a processing unit according to any of the embodiments or examples described herein or a mobile base station including such a processing unit, an intraoperative cone-beam CT imaging device, and a tracking system that tracks the position of an interventional tool within a patient. The intraoperative cone-beam CT imaging device may be movable in and out of an imaging position relative to a patient without moving the patient. For example, it may have a C-arm configuration.

[0045] Another aspect of the invention is a computer-implemented method for assisting intervention during a renal intervention procedure for kidney stone removal, the method having at least one intraoperative image acquisition phase, which includes receiving computed tomography (CT) image data of an anatomical region including at least a portion of a subject's kidney.

[0046] The method further includes an intervention image guidance phase, which includes receiving real-time tool tracking data indicating the positioning of an intervention tool used in the intervention procedure, generating a real-time guidance image based on the CT image data, and further generating a guidance image based on the tracking data that visualizes the position of the intervention tool relative to the anatomical region imaged in the received CT image data, and communicating with a user interface device and displaying the generated guidance image in real time on a display unit of the user interface device.

[0047] In some embodiments, receiving real-time tool tracking can be based on image guidance and can include real-time methods as well as post- or pre-operative images, i.e., not only CT or cone-beam CT, but also different types of imaging modalities (e.g., MR, US, PET, SPECT).

[0048] The method further includes a quality assurance check phase following the interventional image-guided phase, which includes communicating with a CT imaging device to acquire further CT image data of the anatomical region using the CT imaging device, e.g., for use in visualizing any remaining stone or stone fragments and thereby determining whether complete stone removal has been achieved, the further CT image data preferably being cone-beam CT image data.

[0049] The method further comprises communicating with the user interface device to display the additional CT image data on a display unit of the user interface.

[0050] Another aspect of the invention is a computer program having computer program code configured, when executed on a processor, to cause the processor to perform a method according to any embodiment or according to any claim described herein.

[0051] These and other aspects of the invention will be apparent from and elucidated with reference to the embodiments described hereinafter. [Brief explanation of the drawings]

[0052] [Figure 1] FIG. 1 outlines steps of an exemplary method in accordance with one or more embodiments of the present invention. [Figure 2] FIG. 2 is a diagram outlining elements of an exemplary processing unit in accordance with one or more embodiments of the present invention. [Figure 3] FIG. 1 is a diagram illustrating a schematic of at least some of the elements of an exemplary system in operation, according to one or more embodiments. DETAILED DESCRIPTION OF THE INVENTION

[0053] For a better understanding of the present invention, and in order to show more clearly how it may be carried into effect, reference will now be made to the accompanying drawings, which are given by way of example only, in which:

[0054] The present invention will now be described with reference to the figures.

[0055] It should be understood that the detailed description and specific examples, while indicating exemplary embodiments of the devices, systems, and methods, are for purposes of illustration only and are not intended to limit the scope of the invention. These and other features, aspects, and advantages of the devices, systems, and methods of the present invention will be better understood from the following description, appended claims, and accompanying drawings. It should be understood that the figures are schematic only and are not drawn to scale. It should also be understood that the same reference numerals are used throughout the figures to indicate the same or similar parts.

[0056] The present invention provides a method and system for guiding kidney stone removal in a single procedure, e.g., all steps can be performed by a single lead surgeon, and further provides a method for improving the stone-free rate of the resulting procedure. Specifically, the method includes facilitating or guiding three phases of the intervention: renal access, stone removal, and stone-free check. This is facilitated by a method including three phases: an intraoperative image-guided phase in which CT-based images of the renal region are obtained; a renal access guidance phase in which the CT-based images are used to generate intervention guidance images for guiding renal access along the access pathway; and a stone-free check phase in which additional intraoperative CT images are acquired to confirm the patient's stone-free status. Cone-beam CT (CBCT) images are preferably used in the final phase because they are associated with a lower radiation dose to the patient for images of the same spatial resolution. They are also preferred because they are more readily available in the operating room than conventional cone-beam CT imaging, e.g., helical or axial fan-beam imaging. They are also preferred because they allow acquisition using a smaller and simpler device configuration. For example, a C-arm or flat panel CT device can be used for cone beam imaging, providing easier access to the patient compared to systems with a circular rotating gantry.

[0057] The inventors' motivating goal for making this invention is to reduce the complexity of gaining renal access, particularly in PCNL procedures, and improve the stone-free success rate of the procedure. By performing a stone-free check concurrently with the procedure before the renal access is closed, this improves the probability of a stone-free state, since any remaining stone fragments can be immediately addressed in further interventional steps.

[0058] The above objects are achieved by a system and method for tool tracking and needle guidance using CBCT imaging.

[0059] To further explain, a PCNL procedure typically involves two separate steps: renal access and stone removal, which are typically performed by different clinicians. In the United States, in 90% of cases, renal access for a PCNL procedure is obtained by an interventional radiologist. The interventional radiologist begins by gaining access to the kidney using fluoroscopy or ultrasound image guidance while the patient is under local anesthesia. Once access is obtained, a guidewire is inserted. At this point, the patient is transferred from the interventional radiology suite to the operating room, where they receive general anesthesia. The stone removal procedure then begins.

[0060] This division in the interventional workflow creates additional overhead and procedural inefficiencies. An objective of embodiments of the present invention is to simplify the workflow, which results in simplified procedures, reduced miscommunication regarding access strategies, reduced hospital costs, and improved patient satisfaction. A system and method for treatment guidance are proposed. In particular, a system is proposed that can perform at least both of the following operations: a renal access guidance operation to guide needle navigation based on preoperative (intraoperative) CT images (preferably cone-beam CT images); and a stone-free check operation to enable confirmation of stone-free status based on preoperative (intraoperative) CT images (preferably cone-beam CT images).

[0061] As further described, it is envisioned that the treatment guidance and evaluation method according to at least one set of embodiments is embodied or realized by a hardware system having a cone beam computed tomography (CBCT) image acquisition device, an intervention tool tracking unit, a computing unit (hosting dedicated application software configured to perform the steps of the computer-implemented method), and a display.

[0062] 1 outlines in block diagram form the steps of an exemplary computer-implemented method 10 according to one or more embodiments. Before being further described in the form of an exemplary embodiment, the steps will be summarized. The method 10 is for providing interventional assistance during a renal intervention procedure, for example, for kidney stone removal.

[0063] The method comprises at least one intraoperative image acquisition phase 12, at least one interventional image-guided phase 14, and at least one quality assurance check phase 16 following the interventional image-guided phase.

[0064] The image acquisition phase includes receiving 18 computed tomography (CT) image data of an anatomical region including at least a portion of the subject's kidney, which may be cone-beam CT image data or other types of CT image data.

[0065] The interventional image guidance phase 14 comprises a step 20 of receiving real-time tool tracking data indicative of the positioning of an interventional tool for use in the interventional procedure. The interventional image guidance phase 14 further comprises a step 22 of generating a real-time guidance image based on the CT image data and further generating a guidance image based on the tracking data that visualizes the position of the interventional tool relative to the anatomical region imaged in the CT image data. The interventional image guidance phase 14 further comprises a step 24 of communicating with a user interface device for displaying the generated guidance image in real time on a display unit of the user interface device.

[0066] The quality assurance check phase 16, which follows the interventional image-guided phase, includes communicating 26 with a CT imaging device to acquire additional CT image data of the anatomical region using the CT imaging device. This additional CT image data is used to visualize any remaining stones or stone fragments, allowing for a determination of whether complete stone removal has been achieved. In some instances, this includes, from a computer-implemented perspective, simply displaying the additional CT image data to allow a clinician to determine whether complete stone removal has been achieved. Optionally, in some embodiments, the method includes receiving user input indicating the clinician's assessment of the check result as stone-free or not. In some embodiments, stone-free status can be automatically assessed by an image analysis algorithm. The quality assurance check phase preferably further includes communicating 28 with a user interface device to display the additional CT image data on a display unit of a user interface.

[0067] In some embodiments, the additional CT image data acquired in the quality assurance check phase is cone beam CT image data.

[0068] As mentioned above, the method may also be embodied in the form of hardware, for example in the form of a processing unit configured to perform the method according to any example or embodiment described herein or according to any claim of the present application.

[0069] To further aid in understanding, Figure 2 depicts a schematic diagram of an exemplary processing unit 32 configured to perform methods according to one or more embodiments of the present invention. The processing unit is shown in the context of a system 30 having the processing unit. The processing unit alone represents one aspect of the present invention. The system 30 is another aspect of the present invention. A provided system need not include all of the illustrated hardware elements, but may include only a subset thereof.

[0070] The processing unit comprises one or more processors 36 configured to perform the method according to the above summary or according to any embodiment described herein or claimed in the present application. In the illustrated example, the processing unit further comprises a communication interface 34, or input / output.

[0071] In the illustrated example of Figure 2, the system 30 further comprises a user interface 52 including a display unit. The system further comprises an intraoperative CT imaging device 56 (e.g., a cone beam CT imaging device). The system further comprises a tracking system or device 56 for tracking the position of the interventional tool within the patient's body. Of course, it is not essential that the system comprises all of these hardware elements. A system according to the present invention can be provided without one, or with only one or more of these elements.

[0072] The communications interface 34 is configured to receive the CT image data, communicate the guidance image outwardly to the user interface, receive the further CT image data, and communicate the further CT image data outwardly to the user interface. The CT image data in the intraoperative imaging phase can be received from a CT imaging device. Alternatively, it can be received from a data store or from an intermediary communications device, such as a hub server or network node.

[0073] For example, the communications interface 34 may be adapted for wired or wireless connection to one or more external units, including any one or more of a CT imager 56 (e.g., a cone-beam CT imager), a user interface device 52, and a tool tracking system or device 54.

[0074] The system 30 may further include a memory 38 for storing computer program code (i.e., computer-executable code) configured to cause one or more processors 36 of the processing unit 32 to perform the methods outlined above, or according to any embodiment or claim described in this disclosure.

[0075] As will be described in more detail below, the system may further include one or more auxiliary image data acquisition units, including, for example, one or more of an ultrasound imaging system and an endoscopic imaging system, and the communications module may be configured to communicate with one or more of these auxiliary image data acquisition units as well.

[0076] As mentioned above, the present invention may also be embodied in software. Therefore, another aspect of the present invention is a computer program product having code means configured to, when executed on a processor, cause the processor to perform a method according to the examples or embodiments of the invention described herein or according to any claim of the present application.

[0077] With regard to the processing unit 32, there are various options for realizing this. In some embodiments, the processing unit may be the processing unit of the CT imager. In some embodiments, this may be the same processing unit that controls the image acquisition functions of the CT imager. In some embodiments, it may be a dedicated processing unit included in the CT imager. In some embodiments, the processing unit may be a dedicated processing unit provided separately from the CT imager, for example, provided in a dedicated housing. For example, in some embodiments, the processing unit may be included as part of a mobile unit, i.e., a mobile cart structure. As a further example, in some embodiments, the processing unit may be a cloud-based processing unit.

[0078] Reference has been made above to intraoperative imaging. Intraoperative in the context of this disclosure refers to image acquisition that occurs simultaneously with an interventional procedure. This is sometimes also known as preoperative imaging. In other words, this is imaging that occurs while the patient is in the operating room or while surgery is otherwise in progress. For example, it occurs on the same day as the interventional procedure.

[0079] The scope of the present method does not necessarily include the process of actually acquiring intraoperative image data. For example, image data can be acquired prior to the start of the claimed method or in parallel with the claimed method, with the claimed method simply comprising the step of receiving already acquired image data. Of course, alternatively, the claimed method can include the step of acquiring image data.

[0080] It is envisioned that the intraoperative image data may be image data acquired in the operating room itself or in a nearby imaging suite in the same facility.

[0081] It is contemplated that mobile or portable CT imaging devices will be used to acquire the image data, particularly devices operable to be moved in and out of position to image the patient while the patient remains stationary on the operating table. Mobile systems allow the CT device to be moved between different operating rooms. However, alternative methods could provide a fixed CT imaging system, for example, mounted to the floor or ceiling of the operating room.

[0082] It has been noted above that it is preferable for the CT image data (especially intraoperatively) to be cone beam image data. At least one reason for this preference is that cone beam CT image data can be acquired at a given resolution over a given volume with a lower radiation dose to the patient than comparable non-cone beam systems. Another advantage is that, due to the wider spatial extent of the x-ray beam, cone beam images can be acquired faster than conventional CT imaging techniques. These advances in cone beam CT imaging thus make intraoperative CT imaging more practical and safer than ever before, opening up the possibility of using it, for example, to perform the stone-free check of the present invention while the renal access is still open.

[0083] Above, reference is made to an interventional tool. An interventional tool includes, for example, a percutaneous nephrolithotomy (PCN) needle. An interventional tool includes a dilator that passes over an inserted guidewire (inserted after needle insertion). An interventional tool includes a sheath. An interventional tool includes a nephroscope. In some cases, an interventional tool includes an ultrasound probe (e.g., for breaking up large stones). An interventional tool can have an obturator that is used to place a cannula. In some instances, the cannula itself can be tracked.

[0084] In some examples, a patient tracker can be placed on the patient, for example, for use in registering tracking with CBCT imaging.

[0085] There are various options for tool tracking data and tool tracking systems. Surgical tracking systems are known in the art. One example includes electromagnetic tracking. Another example includes optical tracking.

[0086] For example, a tracking system that analyzes the vibrations of an electromagnetic (EM) coil can be utilized. In particular, one option is to incorporate at least one EM sensing element on or within an interventional tool having a coil, and a reference electromagnetic field is generated by a transmit coil arrangement placed near the patient. The reference electromagnetic field induces a current in the interventional tool's coil, the electrical characteristics of which (particularly the voltage amplitude) depend on the tool's distance from the transmit coil arrangement. This may require a data connection from the tracking device to a sensor element within the tool. In another example, to avoid this, the tool can include a transmit coil, and a receive coil or an array of receive coils is placed near the patient and configured to detect the electromagnetic signal emitted from the tool. Based on the signal strength, the distance of the tool transmitter to the associated receive coil can be determined. One or more receivers or transmit coils can be included in the tool, allowing triangulation of the tool's position and / or orientation to be determined. Using these general concepts, it is possible to track the tool's position in real time.

[0087] In a further example, the tracking system can be configured to track the position of the object based on optical visual information, for example, a camera can be used to track the position of a tool based on visual tracking markers applied to the tool at one or more locations.

[0088] In all cases, the output of the tool tracking system 54 may be a data signal indicative of the coordinate position of the tool relative to the coordinate system of the tool tracking system.

[0089] To generate the guidance image, for example, it may typically include a visual overlay indicating the position of the interventional tool that is applied to or fused with an anatomical image representing the anatomical region, the anatomical image being based on CT image data acquired during the intraoperative image acquisition phase. In other words, it is typically a composite image that represents the real-time position of the tool relative to the previously acquired image. To this end, the method may include spatially registering the relevant anatomical image to the coordinate system of the tool tracking system. This may, in some instances, be done in part with input from a user. For example, as part of a calibration operation, the user may touch the tool at multiple fiducial points on the patient's body, thereby calibrating the coordinate locations output by the tracking system for those points with corresponding coordinate locations on the patient's anatomy, as depicted in the image. For example, the points may be standard anatomical locations that are easily identifiable in the relevant anatomical image, which may be locations that the user can point to using a user input device, or locations that can be automatically detected using, for example, image segmentation.

[0090] Optionally, in some embodiments, the interventional image-guided phase may further include receiving image data from one or more auxiliary image data sources. For example, these may be real-time imaging sources, and live images may be used in addition to the composite image described above. By way of example, these may include one or more of: real-time endoscopic imaging data from an endoscopic imaging system; real-time ultrasound imaging data from an ultrasound imaging system; and real-time fluoroscopic imaging data. Fluoroscopic imaging data may be provided by a dedicated fluoroscopic imaging device, or the aforementioned cone-beam CT imaging device may be adapted for both CT imaging and fluoroscopic imaging; such dual-mode CT systems are known in the art. Typically, these have, for example, a gantry C-arm configuration, allowing them to be moved in and out of position around a stationary patient. In the case of a dedicated fluoroscopic imaging device, this may be a digital x-ray device.

[0091] Regarding the optional endoscopic imaging system, this may typically include one or more endoscopes, an imaging module carried by the one or more endoscopes, a light source carried by the one or more endoscopes, and a video processor that receives video images output from the imaging module. In the context of renal interventional procedures, a variety of endoscopes are used, including, for example, any one or more of a cystoscope, a nephroscope, a ureteroscope, and a ureteroscope.

[0092] Part or all of an endoscopic imaging system may be provided as part of at least one embodiment of the present invention. For example, if the processing unit is provided housed in a mobile base station, the endoscopic imaging system may be docked or housed in the same base station for ease of transport. Alternatively, the processing unit 32 described above may be configured to simply couple with an external endoscopic imaging system.

[0093] If auxiliary image data is available, the image guidance phase comprises communicating with the user interface to simultaneously display the guidance image and the auxiliary image data, e.g., both can be displayed side by side on a display unit of the user interface.

[0094] With regard to the quality assurance check phase, as previously mentioned, confirmation of stone-free status (i.e., the result of the quality assurance check) can comprise either or both of image review by the treating clinician and / or an automated check based on application of a stone-clearance check algorithm to the acquired further CT image data to automatically determine complete or incomplete stone removal. With regard to the stone-clearance check algorithm, it utilizes computer-aided detection methods. This is applied in addition to the clinician's check for stone-free status in some instances to further prevent oversight of residual stone fragments. In practice, this can be achieved by generating an output from the processing unit for displaying the further CT image data on a display unit of the user interface (so that the clinician can review the images), and further applying the stone-clearance check algorithm and displaying the results to the clinician on the display unit of the user interface.

[0095] In some embodiments, the method may further include receiving a user input indicating a clinician's assessment of stone-free status, with a negative result triggering a further iteration of the image-guided phase.

[0096] With respect to the user interface, it may include a display unit for displaying the guidance image and any other information to be presented to the clinician. The user interface may further include at least one user input device, including, for example, one or more foot pedal controls. The user interface may include a touchscreen display that allows user input by touch. As a more general concept, the user interface may include one or more sterile control elements for use by a clinician within the sterile environment of an operating room to provide user input to the user interface device. The system may further include a remote control device for remotely controlling certain elements of the system, such as the table height or the imaging device.

[0097] According to a preferred set of one or more embodiments, the system 30 has a mobile base station that houses or carries a processing unit 32 according to any embodiment described herein and that is movable, for example, within or between operating rooms. A preferred solution, for example, has a single mobile cart that can interoperate with all other hardware elements of the system, including any optional hardware elements described above or below in this disclosure.

[0098] Using the systems and methods outlined above, a clinical procedure can be performed entirely by a single clinician, e.g., a urologist (after anesthetizing the patient). For example, the patient can be placed in a lithotomy position using a cystoscope under fluoroscopic guidance for insertion of a ureteral catheter.

[0099] The patient can then be placed in the prone position. The urologist can then gain access to the kidney using graphically enhanced cone-beam CT (CBCT) imaging data to facilitate needle navigation. Fluoroscopic ultrasound or other real-time imaging modalities can be used for further assistance. For CBCT and fluoroscopic imaging, contrast may be administered through the ureteral catheter. Once renal access is confirmed by urine flow through the needle, the urologist places and uses a guidewire to dilate the access to a diameter of 2 cm, followed by lithotripsy. Large stone fragments are retrieved through the access sheath, while smaller stone fragments are automatically flushed away.

[0100] After stone removal, additional CBCT images are obtained to confirm that all stone fragments have been removed.

[0101] Finally, renal drainage is performed with placement of a JJ catheter or nephrostomy tube under fluoroscopic guidance, the access sheath is removed, and the incision is closed with sutures.

[0102] Next, exemplary implementations of the method according to a particular set of embodiments will be described to explain the concepts summarized above. It should be understood that not all features of this particular set of embodiments are essential to the inventive concepts and are described to aid understanding and to provide examples to explain the inventive concepts.

[0103] FIG. 3 schematically illustrates an exemplary patient 64 in accordance with the present invention. A cone-beam CT imager 56 with a C-arm configuration is also shown. Also shown is an exemplary receive coil unit 54 of an interventional tool tracking system. Also shown is an exemplary mobile base station 62, which may alternatively be referred to as a mobile cart, housing a processing unit 32 configured to perform a method according to any of the examples or embodiments described in this disclosure. The base station 62 is mounted on casters in this example, allowing it to be moved around. A user interface 52, including a display unit, is also mounted in the base station. Alternatively, the user interface and / or display unit can be mounted elsewhere. The base station may also carry other optional hardware, such as processors or control units for any other auxiliary imaging systems used in the intervention, as previously mentioned.

[0104] The method includes an intraoperative image acquisition phase, which includes acquiring CT image data of the internal anatomical structure of the kidney (urinary collecting system) and preferably a portion of the target anatomical structure extending from the patient's kidney to the body surface where an incision is made for bodily access. The CT image data is preferably cone-beam CT image data. The acquired CT image data is preferably, but not necessarily, contrast-enhanced CT image data.

[0105] In some embodiments, the CT image data acquired in at least one intraoperative image acquisition phase is itself contrast-enhanced cone-beam CT image data.

[0106] Additionally or alternatively, the composite image data can be generated by fusing CT image data received during at least one intraoperative image acquisition phase with preoperative image data of the same anatomical region of the same patient obtained from a data store. This requires registration of the preoperative and intraoperative images. Registration of the intraoperative non-contrast CBCT images with the preoperative images can be performed using an image registration algorithm. Such algorithms are known in the art. In general, registration can be based on image appearance, one or more fiducial markers (which may be trackable), segmentation of the kidney outline in both images, and / or segmentation of the renal parenchyma in both images. Segmentation can be performed using a segmentation algorithm, examples of which are known in the art.

[0107] After the intraoperative images have been acquired, the method may include an intervention planning phase before the intervention begins.

[0108] As an example, the intervention planning phase includes obtaining an indication of a planned entry point into the kidney and obtaining an indication of a planned entry path through the body to the entry point in the kidney. Thereafter, when an image guidance image for guiding the intervention is generated, it can include images showing the real-time position of the tool as well as images for guiding the clinician along the entry path to the entry point. For example, the guidance image includes one or more visual overlays that provide navigation guidance for navigating the insertion of an intervention tool along a predetermined tool entry path from an incision point on the skin to the predetermined entry point in the kidney. For example, the one or more visual overlays can provide navigation guidance that provides a visual indication of a target location of the incision point and an indication of a target insertion angle for the tool.

[0109] The indication of the intended entry point of the kidney can include an indication of the intended calyx of the kidney where entry of the kidney will be achieved. Once the selected calyx is known, the desired needle trajectory can be defined manually or automatically. The selected calyx can be identified based on manual or automatic segmentation, or based on a user-directed location.

[0110] For example, in some instances, an indication of a planned calyx of the kidney through which renal entry will be achieved is obtained based on user input received at user interface 52. In some instances, a planned entry path through the body and an optional planned incision point are automatically determined based thereon. For example, the method may include obtaining an indication of a planned calyx for entry into the kidney, manually or automatically segmenting the planned calyx within the received CT image data, and locating the planned renal entry point relative to the CT image data based thereon.

[0111] This is followed by an image-guided intervention phase.

[0112] Now, given a desired needle trajectory, the clinician-user can be assisted in inserting a tracked tool (e.g., needle). First, as described above, tracking can assist the user to find a planned skin entry point and / or, given a planned insertion point, to adopt a planned insertion angle for the tool to follow a planned entry path through the tissue. During insertion of a tracked tool under image guidance, feedback provided by the system's visualization assists in gaining access to the kidney.

[0113] More specifically, it is proposed that a guidance image be generated and rendered on a display unit of the user interface, which advantageously has a visual overlay indicating the position of the interventional tool fused with an anatomical image representing the anatomical region. More particularly, the guidance image includes one or more visual overlays that provide navigational guidance for navigating the insertion of the interventional tool along a predetermined tool entry path, e.g., from an incision point on the skin to a predetermined entry point in the kidney. For example, the one or more visual overlays that provide navigational guidance can provide a visual indication of a target location of the incision point and an indication of a target insertion angle of the tool.

[0114] It has already been mentioned that the tool entry path can be pre-planned with input from a user or fully automatically, and the resulting planned tool entry path is stored, for example, as a trajectory defined by a series of coordinates along the path extension relative to the coordinate system of the tool tracking system or image data.

[0115] The anatomical image on which the visual overlay is rendered can be based on CT image data acquired during the intraoperative image acquisition phase. The anatomical image can be simply a CT image, or it can be a synthetic fusion image formed from a CT image and a preoperative image.

[0116] Of course, the CT image dataset is 3D (volumetric) image data. Therefore, generating a guidance image involves extracting one or more relevant 2D image planes from the 3D image data. If the CT image data consists of a stack of axial 2D image slices, one of these axial slices can be selected. Alternatively, a multiplanar reformat (MPR) visualization of the CBCT volume can be generated using MPR techniques common in the art. In this way, 2D slices traversing the 3D image field in any direction can be generated. The user can be presented with user control options via a user interface to select the desired imaging plane orientation, or the most appropriate image plane view can be automatically determined, for example, based on tool tracking data or a planned approach path through the body to the kidney entry point. For example, an image plane orientation that best visualizes the planned approach path can be selected. For example, an image plane orientation parallel to, or including, the planned insertion path can be selected. In some examples, the optimal visualization plane is iteratively updated as the tool moves, so that the planar view presented at each given update point is a plane parallel to at least a local portion of the tool insertion path in which the tool is currently positioned (as determined by the tool tracking data). In other examples, the planar view in which the graphical overlay of the tool position is rendered is selected from a list of standard planar views, e.g., selected from one or more of the common orthogonal views, such as axial, sagittal, and coronal.

[0117] Of course, a further option is to generate guidance images that suggest tool positions for several different planar views of the relevant anatomy and display all of these simultaneously.

[0118] Yet another option is to generate a volume rendering from the 3D CT image data for use in the guidance image. A volume rendering is a 2D image plane that presents a synthetic perspective view of a particular 3D object represented in the 3D image dataset. It is most typically generated based on ray-casting techniques, where, as part of the rendering algorithm, synthetic "rays" are cast through the image plane from the viewpoint of a potential observer into the imaged volume. Those skilled in the art will be familiar with the general techniques of volume rendering.

[0119] In addition to the tracked tool position, the presented guidance image can optionally include one or more graphical indicators indicating segmentation boundaries of one or more anatomical features. This can further assist the clinician in navigating the anatomy. For example, to obtain segmentation data prior to generating the guidance image, one or more segmentation algorithms can be applied to the CT image data acquired during the intraoperative image acquisition phase.

[0120] As mentioned above, in addition to visualizing the position of the tracked tool relative to the CT image data, the method may include displaying real-time images of the anatomical structure during the interventional image-guided phase, e.g., obtained from an ultrasound imaging system, a fluoroscopic imaging system, and / or an endoscopic imaging system. For example, the image-guided phase may further include receiving auxiliary image data, which may include one or more of: real-time endoscopic imaging data from an endoscopic imaging system; real-time ultrasound imaging data from an ultrasound imaging system; or real-time fluoroscopic image data from a cone-beam CT imager.

[0121] This may be simultaneously presented on the same display unit used to present the guidance image generated from the CT image data. Because the CT-based guidance image is partially synthetic (based on non-live CT images fused with live tracking data), it may be useful for the clinician to simultaneously view a live image of the anatomy to compare or corroborate what the guidance image formed from the CT data shows.

[0122] As an example, ultrasound imaging, when the patient is in the prone position, typically provides a perspective view with the tool (e.g., needle) in-plane. For example, fluoroscopy, when the patient is in the prone position and the x-ray generator is above the patient, typically produces a view plane perpendicular to the needle (i.e., the so-called "bull's eye view").

[0123] The guidance image uses live tool tracking data to assist the user in (a) navigating to the intended kidney entry point (i.e., the renal entry point) and (b) performing the stone removal procedure once kidney entry is achieved.

[0124] It has been mentioned above that an intraoperative image acquisition phase can be performed before the start of the intervention to obtain (preferably cone beam) CT image data of the patient for use in generating guidance images.

[0125] Additionally or alternatively, in some embodiments, one or more intraoperative image acquisition phases can be performed during an interventional procedure after the interventional procedure has begun, for example, to update CT image data. This can be done, for example, using a cone-beam CT imaging device. This can utilize an imaging device, such as a C-arm structure, that can be moved in and out of a location to image the patient without moving the patient. Such imaging during an intervention can be performed during induced apnea of ​​the patient, which means temporary breathing cessation. This can avoid the adverse effects of respiratory motion. During an interventional procedure, the patient is usually anesthetized. For this reason, the patient is intubated and connected to a ventilator that is continuously operated and monitored by an anesthesiologist. In this situation, the patient's breathing is under control, making it easy to hold their breath for, for example, the 45 seconds it takes for the scan to be performed.

[0126] Once stone removal has been performed, the proposed computer-implemented method includes a quality assurance check phase.

[0127] The bright appearance of kidney stones makes pre-operative (intra-operative) CBCT imaging particularly suitable for confirming the stone-free status of the patient at the end of the PCNL procedure.

[0128] The quality assurance check phase can actually be triggered based on receiving a predetermined user input command from the user interface, in other words, the clinician indicating that stone removal is complete and that the quality check should begin.

[0129] To confirm stone-free status, further CT image data representing the kidney is acquired. This is preferably a non-contrast-enhanced cone-beam CT scan. Such a scan is performed intraoperatively while the renal access remains open. The resulting CT image data is rendered on a user interface display and presented to the clinician. Confirmation of stone-free status can be achieved with a simple image review by the clinician. Via the user interface, the clinician can input an indication of the results of the image review, and therefore the results of the quality assurance check, which can be recorded and / or trigger one or more subsequent actions.

[0130] Additionally or alternatively, computer-aided detection methods can be applied to the acquired further CT image data to detect the presence of any remaining stone fragments, and thus, in this case, an indication of the results of the quality assurance check can be obtained based on the application of a stone clearance check algorithm to the acquired further CT image data to automatically determine complete or incomplete stone clearance.

[0131] In CT and CBCT imaging, stones appear as bright areas in the images due to their composition, in other words, kidney stones have a different Hounsfield density value than the surrounding tissue.

[0132] An exemplary stone clearance check algorithm can be configured to identify such bright objects within the kidney.

[0133] The steps of an exemplary algorithm may include: (1) Segment the kidney in the CT image (e.g., using an AI segmentation model or traditional methods such as Active Contours, Active Appearance Models, or Active Shape Models). (2) Locating bright objects (i.e., above a certain Hounsfield density value) within the kidney. (3) Optionally, filter the detected objects based on size range to prevent false positives and to avoid detecting small fragments that may not require any attention from the physician.

[0134] The further CT image data used for quality assurance checks can be visualized, for example, using multiplanar reformatting, to obtain one or more planar views representing the internal anatomy of the kidney. For example, a set of two or more orthogonal planar views of the anatomical structure can be presented. Another option is to apply volume rendering to generate one or more volume-rendered views of the anatomical structure. Preferably, these are generated to visualize a 3D perspective of any remaining stone fragments. Various techniques exist for volume rendering, such as direct volume rendering or maximum intensity projection, and those skilled in the art will recognize various options for applying this rendering approach.

[0135] Optionally, additional CT image data can be processed with additional visual overlays to provide supplemental information. For example, the overlays may include one or more segmentation overlays representing renal anatomical structures, including the renal parenchyma, the urinary collecting system, etc. In some examples, the overlays may include visual overlays representing live tool tracking positions.

[0136] Preferably, the additional CT image data acquired in the quality assurance check phase may be manipulated with respect to the presented rendered view via user controls of a user interface. For example, the user controls may allow panning, rotation, or scrolling. The user controls may be sterilizable user controls, such as foot pedals, sterilizable touchscreen displays, or sterilizable keypads or joysticks.

[0137] If the quality assurance check results in a negative result, i.e., residual stone fragments are still present, the surgeon user can immediately intervene to remove the residual stone fragments, aided by the known locations of the residual stone fragments shown in the CT image. Indeed, in some advantageous embodiments, the quality assurance check phase comprises obtaining, based on user input or an automated segmentation algorithm, location information associated with any residual stone present in the kidney and a guidance image including a visualization of the location information associated with the residual stone.

[0138] For example, the method may further include obtaining an indication of the quality assurance check result and, based on the quality assurance check result indicating incomplete stone removal, controlling execution of a further iteration of the interventional image-guided phase, and optionally subsequently controlling further execution of the quality assurance check phase. This result may be obtained automatically or from user input, as previously described. Optionally, the further iteration of the interventional image-guided phase may include generating a further guidance image including a visual overlay indicating the position of the interventional tool fused with an anatomical image representing the anatomical region. Preferably, the anatomical image in this iteration may be based on further CT image data acquired in the quality assurance check phase. In this case, it may not be necessary to actually obtain residual stone location information and overlay it on the CT image data, since the further CT image data already includes a visual representation of the stone fragments. Of course, a graphical overlay indicating the location of the stone fragments may be added to aid visualization. For example, the outline of the stone fragment may be shown, and a highlight may be displayed indicating the area / volume extent of the stone fragment.

[0139] Once the further iteration of the image-guided phase is complete, optionally another iteration of the quality assurance check may be performed to recheck for stone-free status. Of course, this too may be omitted. In this case, the clinician may be given the option via the user interface to repeat the check. Here, a balance must be determined between exposing the patient to more radiation and ensuring a complete stone removal.

[0140] In some embodiments, archiving of all acquired intraoperative image data may be facilitated by operatively coupling processing unit 32 to a DICOM interface that allows export of medical image data to one or more databases. These may be third-party databases or local hospital databases. Export may be to a PACS or other DICOM node, for example.

[0141] To briefly summarize the above, an exemplary workflow for an intervention is as follows:

[0142] First, preoperative (intraoperative) CBCT imaging is performed. The user then defines the calyx to be selected for kidney entry and indicates the desired needle entry path via a user interface. This may be facilitated by dedicated clinical application software executed by the processing unit 32. The user then inserts the tracked needle to gain access to the kidney, supported by a visual overlay of real-time tool tracking data on the CT image data. Improved visualization of the internal anatomical structures of the kidney (urinary collecting system) can optionally be achieved by using a contrast agent when acquiring the CT image data or by fusing the preoperative contrast-enhanced CT image data with the intraoperative CT image data before generating the visual overlay rendering. Registration between the intraoperative CBCT image and the preoperative image can be performed based on, for example, one or more of the following: image appearance, fiducial markers (trackable or non-traceable), segmentation of the kidney outline in both images, and segmentation of the renal parenchyma in both images. Registration techniques are well known in the art. As previously mentioned, the selected calyx can be identified by a segmented region (manual / automated) or a user-indicated location. Then, while inserting the needle, which is tracked under image guidance, feedback provided by the system's visualization (guidance image) assists in gaining renal access and stone removal. Following this, further CT image data can be acquired as part of a stone-free check for quality assurance.

[0143] As described above, embodiments use a user interface display unit to display guidance images and further CT image data used to check stone-free status.

[0144] In an advantageous set of embodiments, it is proposed to provide the processing unit with the ability to receive video input from multiple different imaging modalities. This has already been mentioned above, where it was explained that real-time imaging feeds from ultrasound, fluoroscopy, endoscopy, or any other imaging modality can be received and displayed on a display unit of a user interface. These one or more additional video feeds can, in some embodiments, be presented continuously, independently of the different stages of the main method described above in connection with FIG. 1. In other words, in some embodiments, it is proposed that the processing unit hosts two parallel processes: a first one is either video rendering and the presentation of one or more live video feeds to a display on a user interface display unit, and a second one, e.g., comprising the steps of the method outlined in FIG. 1, in which a guidance image is generated from CT image data and is also presented on the display unit.

[0145] The video display capability therefore provides a means for connecting multiple different video inputs, allowing, for example, side-by-side viewing of endoscopic, real-time fluoroscopic, or ultrasound imaging, which may be useful, for example, during placement of a ureteral catheter at the beginning of a procedure, and during placement of a JJ catheter or nephrostomy at the end of a procedure.

[0146] Additionally, processing unit 32 may include functionality to capture image snapshots or record video clips for storage and archiving, and may include functionality to enable export of these, for example, via a DICOM interface operatively coupled to the processing unit.

[0147] Advantageously, an optional video display helps support all stages of the renal intervention procedure.

[0148] The above-described embodiments of the present invention employ a processing unit. A processing unit can generally have a single processor or multiple processors. It may be located in a single containing device, structure, or unit, or distributed among several different devices, structures, or units. Thus, a reference to a processing unit being adapted or configured to perform a particular step or task may correspond to that step or task being performed by any one or more of several processing elements, alone or in combination. Those skilled in the art will understand how such a distributed processing configuration can be implemented. A processing unit may include, for example, a communication module or input / output for receiving data and outputting data to further elements.

[0149] In some embodiments, the system acquires non-contrast-enhanced intraoperative CBCT images, enhances the images with the aid of segmentation techniques and / or computer-aided detection to detect residual stones, acquires an end-of-procedure stone-free check CBCT image including segmentation of residual stones, and displays the two images side-by-side or fuses or otherwise combines the images to indicate the abundance and absence of residual stones.

[0150] In some embodiments, the CBCT image may further include an overlay of the renal anatomy and the current device position.

[0151] In some embodiments, the patient's anatomy is generated, and the system generates guide support (e.g., via a guide wire), where the guide wire can be automatically drawn from the inner tip of the access point to the residual stone.

[0152] In some embodiments, the system may provide feedback to the user regarding the absence / abundance of remaining stones.

[0153] The one or more processors of a processing unit can be implemented in several ways using software and / or hardware to perform the various functions required. A processor typically uses one or more microprocessors, which can be programmed using software (e.g., microcode) to perform the required functions. A processor can also be implemented as a combination of dedicated hardware to perform some functions and one or more programmed microprocessors and associated circuitry to perform other functions.

[0154] Examples of circuitry that may be employed in various embodiments of the present application include, but are not limited to, conventional microprocessors, application specific integrated circuits (ASICs), and field programmable gate arrays (FPGAs).

[0155] In various implementations, a processor may be associated with one or more storage media, such as volatile and non-volatile computer memory, including RAM, PROM, EPROM, and EEPROM. The storage media may be encoded with one or more programs that, when executed by the one or more processors and / or controllers, perform the required functions. The various storage media may be fixed within the processor or controller, or may be transportable such that one or more programs stored thereon can be loaded into the processor.

[0156] Variations to the disclosed embodiments can be understood and effected by those skilled in the art in practicing the claimed invention, from a study of the figures, the disclosure and the appended claims. In the claims, the word "comprising" does not exclude other elements or steps, and the indefinite article "a" or "an" does not exclude a plurality.

[0157] A single processor or other unit may fulfill the functions of several items recited in the claims.

[0158] The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage.

[0159] The computer program may be stored / distributed on a suitable medium, such as an optical storage medium or a solid-state medium supplied together with or as part of other hardware, but may also be distributed in other forms, such as via the Internet or other wired or wireless communication systems.

[0160] It should be noted that when the term "adapted to" is used in the claims or specification, the term "adapted to" is intended to be equivalent to the term "configured to."

[0161] Any reference signs in the claims should not be construed as limiting the scope of the invention.

Claims

1. 1. A processing unit including one or more processors for executing a computer-implemented method for interventional assistance during a renal intervention procedure for kidney stone removal, the method comprising: at least one intraoperative image acquisition phase, receiving computed tomography image data, or CT image data, of an anatomical region including at least a portion of a kidney of a subject; An image-guided phase of an intervention, comprising: receiving real-time tool tracking data indicative of positioning of an interventional tool used in the interventional procedure; generating a real-time guidance image based on the CT image data, and further generating a guidance image based on the tracking data that visualizes the position of the interventional tool relative to the anatomical region imaged in the CT image data; communicating with the user interface device and displaying the generated guidance image on a display unit of the user interface device in real time; a quality assurance check phase following the interventional image-guided phase, comprising: acquiring additional CT image data of the anatomical region using a CT imaging device in communication with the CT imaging device for use in visualizing any remaining stone or stone fragments, thereby determining whether complete stone removal has been achieved, wherein the additional CT image data is cone beam CT image data; and a processing unit communicating with the user interface device and displaying the further CT image data on a display unit of the user interface.

2. The method comprises: obtaining an indication of the results of the quality assurance check; 2. The processing unit of claim 1, further comprising: controlling execution of a further iteration of the interventional image-guided phase and thereafter a further execution of the quality assurance check phase based on a result of the quality assurance check indicating incomplete stone removal.

3. an indication of the results of the quality assurance check is obtained based on user input received at the user interface device; or 3. The processing unit of claim 2, wherein the indication of the result of the quality assurance check is obtained based on application of a stone clearance check algorithm to the obtained further CT image data to automatically determine complete or incomplete stone clearance.

4. the quality assurance check phase comprising obtaining location information associated with any remaining stones present in the kidney based on user input or based on an automated segmentation algorithm; The processing unit of claim 1 , wherein during further iterations of the image-guided phase, the guidance image comprises a visualization of the position information relative to a remaining stone.

5. 5. The processing unit of claim 1, wherein the at least one intraoperative image acquisition phase comprises communicating with a CT imaging device and acquiring cone beam CT image data of the anatomical region using the CT imaging device.

6. The guidance image has a visual overlay indicating the position of the interventional tool fused with an anatomical image representing the anatomical region, the anatomical image being based on CT image data acquired during the intraoperative image acquisition phase. A processing unit according to any one of claims 1 to 5.

7. the guidance image further includes one or more visual overlays that provide navigation guidance for navigating insertion of the interventional tool along a predetermined tool entry path from an incision point on the skin to a predetermined entry point in the kidney; 7. The processing unit of claim 6, wherein optionally the one or more visual overlays providing navigation guidance provide a visual indication of a target location of the incision point and an indication of a target insertion angle of the tool.

8. The method includes an intervention planning phase, the planning phase comprising: obtaining an indication of a proposed kidney entry point; obtaining an indication of a planned entry path through the body to the renal entry point; The processing unit of claim 7 , wherein one or more visual overlays for providing the navigation guidance are generated based on the obtained indication.

9. 9. The processing unit of claim 8, wherein the indication of the intended renal entry point comprises an indication of an intended calyx of the kidney where renal entry will be achieved.

10. generating the guidance image, 94. The processing unit of any one of claims 1 to 93, further comprising the step of generating composite image data by fusing CT image data received during the at least one intraoperative image acquisition phase with preoperative image data of the same anatomical region of the same patient obtained from a data store.

11. the image-guided phase real-time endoscopic imaging data from an endoscopic imaging system; real-time ultrasound imaging data from an ultrasound imaging system; real-time fluoroscopic imaging data from a cone-beam CT imager; 11. A processing unit according to any preceding claim, optionally wherein the image guidance phase comprises communicating with the user interface to simultaneously display the guidance image and the auxiliary image data.

12. The processing unit Cone beam CT imaging device, a user interface device; Tool tracking system, as well as 12. A processing unit according to any of the preceding claims, optionally further comprising a communication interface for wired or wireless connection to one or more of an ultrasound imaging system and / or an endoscopic imaging system.

13. A mobile base station movable within an operating room, the mobile base station comprising a processing unit according to any one of claims 1 to 13.

14. 1. A system comprising: a processing unit according to any one of claims 1 to 12 or a mobile base station according to claim 13; a cone beam CT imaging device; a tracking system that tracks the position of the interventional tool within the patient's body.

15. 1. A computer-implemented method for interventional assistance during a renal intervention procedure for kidney stone removal, comprising: at least one intraoperative image acquisition phase, receiving computed tomography image data, or CT image data, of an anatomical region including at least a portion of a kidney of a subject; An image-guided phase of an intervention, comprising: receiving real-time tool tracking data indicative of positioning of an interventional tool used in the interventional procedure; generating a real-time guidance image based on the CT image data, and further generating a guidance image based on the tracking data that visualizes the position of the interventional tool relative to the anatomical region imaged in the CT image data; communicating with the user interface device and displaying the generated guidance image on a display unit of the user interface device in real time; a quality assurance check phase following the interventional image-guided phase, comprising: acquiring additional CT image data of the anatomical region using a CT imaging device in communication with the CT imaging device for use in visualizing any remaining stone or stone fragments, thereby determining whether complete stone removal has been achieved, wherein the additional CT image data is cone beam CT image data; communicating with the user interface device and displaying the further CT image data on a display unit of the user interface.

16. A computer program comprising computer program code means for causing a processor to carry out the method of claim 15 when the computer program is executed on the processor.

Images