Medical scanner

Abstract

The medical scanner has a detection system that can identify the Valsalva maneuver. In response to the detection of the Valsalva maneuver, the scanner is controlled to stop the delivery of scanning radiation or to stop the injection of contrast agent, or user advice is provided to stop the delivery of scanning radiation or to stop the injection of contrast agent.

Description

Technical Field

[0001] The present invention relates to medical scanners, and in particular to detection of the Valsalva maneuver during scanning.

Background Art

[0002] The main cause of motion artifacts in radiological examinations such as CT scans using contrast media is the Valsalva maneuver. The Valsalva maneuver is one of the key factors that causes transient interruption of contrast (TIC) in veins and arteries, resulting in the need for repeated scanning or re-injection of contrast media. Even re-scheduling is required if sufficient contrast media is already present in the body.

[0003] The Valsalva maneuver is a forced attempt to expel air against a closed airway, which results in increased intra-abdominal, intrathoracic, and pharyngeal pressures. This phenomenon of sudden cessation of breathing and tensing of the chest muscles slows down the contrast medium in the first few seconds, and when the sympathetic nerve response is triggered to relax the myocardium and increase blood flow, the contrast medium moves very rapidly. The contrast medium may not reach the target location at the desired time, and the radiographer and scanner may miss the scanning window.

[0004] This transient interruption of contrast media is a common phenomenon in computed tomographic pulmonary angiography (CTPA) studies. Opacification of the pulmonary artery by contrast medium is often suboptimal during deep inspiration due to increased flow of non-opacified blood from the inferior vena cava (IVC) to the right side of the heart.

[0005] There are several types of CT examinations that should be performed during breath-holding without the Valsalva maneuver, such as CT scans of the chest and abdomen, and scans for cardiac and pulmonary embolism cases.

[0006] Additionally, there are certain tests that, when performed during the Valsalva maneuver, can provide improved detection and better characterization of anatomical structures, such as CT scans of the hernia or ultrasound scans of the vena cava function. [Overview of the Initiative] [Problems that the invention aims to solve]

[0007] Therefore, it is desirable to be able to detect the presence of the Valsalva maneuver, confirm its presence if desired, and take corrective action if undesirable. [Means for solving the problem]

[0008] The present invention is defined by the claims.

[0009] According to one aspect of the present invention, a medical scanner is provided, and the medical scanner is Scanning system and, A detection system that generates detection output, Interpret the detection output and, if present, detect the Valsalva maneuver. In response to detection of the Valsalva maneuver, provide output instructions advising to stop the delivery of scanning radiation or the injection of contrast agent, or control the medical scanner to stop the delivery of scanning radiation or the injection of contrast agent. A processor configured as follows, It holds.

[0010] This system enables the detection of the Valsalva maneuver and takes appropriate action when detected. In at least some situations, this includes stopping contrast agent injection or stopping imaging (or providing instructions to the operator). In some other situations, providing advice or training to the user may be appropriate.

[0011] For these CT scans, which are supposed to be performed without the Valsalva maneuver but while the patient is holding their breath, if the Valsalva maneuver is detected, the scan should be stopped and no further contrast agent should be added (thus another scan can be performed without delivering more contrast agent than desired).

[0012] In other situations, the Valsalva maneuver may be desirable to aid in the detection and better characterization of anatomical structures, such as CT scans of hernias or ultrasound scans of vena cava function. In these situations, detection using the Valsalva maneuver may be necessary to confirm its presence.

[0013] Therefore, one of the main applications of this system is to stop radiation and contrast agent injection when the Valsalva maneuver is detected, although this detection may be used for other purposes in other uses of the medical scanner.

[0014] The detection system, for example, has an in-bore camera. This provides a low-cost solution.

[0015] The processor configuration interprets the signals generated by the in-bore camera, breathing rate, heart rate, blood pressure, Facial expressions, and Changes in skin tone, It may be configured to detect one or more of these.

[0016] Therefore, cameras can be used to detect various vital signs, one or more of which can be used to detect the Valsalva maneuver.

[0017] For example, in the first configuration, the processor configuration may be configured to detect the Valsalva maneuver based on the change in skin tone from a baseline skin tone.

[0018] In the second configuration, the processor arrangement may be configured to detect the Valsalva maneuver based on a decrease in PPG amplitude from the remote PPG signal.

[0019] In one possible use case, the processor arrangement may be configured to interpret the detection output, thereby detecting the Valsalva maneuver during a surview, and generating advice information for a subsequent clinical scan when the Valsalva maneuver is detected.

[0020] In another possible use case, the processor arrangement may be configured to stop delivery of scanning radiation, or may provide an instruction to an operator to terminate delivery of scanning radiation when the Valsalva maneuver is detected during a contrast-enhanced scan. The contrast-enhanced scan may be a timed or untimed, or bolus tracking contrast-enhanced scan.

[0021] In another possible use case, the processor arrangement may be configured to terminate contrast agent injection when the Valsalva maneuver is detected during breath holding for a contrast-enhanced scan.

[0022] A display for presenting information to a subject while a scan is being performed may be provided, and the processor arrangement is further configured to control the display to present breath-holding instructions to the subject. The same display may be used to provide advice or educational messages to the subject, as described above.

[0023] In some examples, the scanning system is a CT scanning system. In other examples, the scanning system is an MRI scanning system.

[0024] These and other aspects of the present invention will become apparent from and will be described with reference to the embodiments described hereinafter.

[0025] For a better understanding of the present invention and to show more clearly how the present invention is practiced, reference is made to the accompanying drawings by way of example only. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] [Figure 1] Shows a medical scanner. DESCRIPTION OF EMBODIMENTS

[0027] The present invention is described with reference to the drawings.

[0028] It should be understood that the detailed description and specific examples, while indicating exemplary embodiments of the apparatus, systems and methods, are intended for purposes of illustration only and are not intended to limit the scope of the present invention. These and other features, aspects and advantages of the apparatus, systems and methods of the present invention will be better understood from the following description, the appended claims and the accompanying drawings. It should be understood that the drawings are merely schematic and are not drawn to scale. It should also be understood that the same reference numerals are used throughout the drawings to indicate the same or similar parts.

[0029] The present invention provides a medical scanner having a detection system that allows the Valsalva maneuver to be identified. The scanner is controlled to stop delivery of scanning radiation or stop contrast agent injection, or user advice is provided to stop delivery of scanning radiation or stop contrast agent injection in response to detection of the Valsalva maneuver.

[0030] Figure 1 shows a medical scanner 10 comprising a scanning system 12, such as a CT bore, and a detection system 14 that generates a detection output which can be interpreted to detect the Valsalva maneuver when present. In a preferred example, the detection system comprises an in-bore camera.

[0031] The scanner also includes a contrast agent injection system 16 for injecting a contrast agent for contrast-enhanced scanning.

[0032] A processor configuration 20 for interpreting the detection output to detect the Valsalva maneuver and optionally controlling the scanning and injection systems is schematically shown in Figure 1.

[0033] A system for presenting instructions or advice to the patient during the scan is provided, such as a color display panel 22 and associated speaker mounted inside the bore.

[0034] The scanner has a bed 32 that moves through a bore, and a patient 30 is shown on the bed. A display console 40 is also shown to the scan system operator (i.e., the user).

[0035] For detection using the Valsalva method,

[0036] Heart rate (using remote PPG performed via camera)

[0037] Blood pressure (using remote PPG performed with a camera)

[0038] Muscle tension (using galvanic skin response electrodes)

[0039] Measurement of changes in skin tone (using remote PPG or camera image analysis)

[0040] Facial expressions (using camera image analysis) Various vital signs and other patient information, including one or more of the following, may be measured and analyzed.

[0041] One specific example of camera-based detection of Valsalva can be based on changes in skin tone. The Valsalva method involves changes in the blood content of the skin, which can be observed by an RGB camera as a change in the DC level of the skin tone value. A baseline skin tone is monitored, and the onset of Valsalva can be detected as a deviation from this baseline color by a pre-set threshold. This threshold is selected based on a large cohort of volunteers and may be set according to skin type, age, and sex.

[0042] Another specificity of camera-based detection can be based on remote PPG signals. A sudden decrease in PPG amplitude, typically 40% or more, at the onset of Valsalva can be used to detect it.

[0043] A typical CT scan includes a survey, which is a low-dose test irradiation to identify an area of ​​interest for a clinical scan, and one or more clinical scans, with or without contrast.

[0044] In a breath-hold scan, the patient is instructed to inhale and hold their breath when instructed to do so (via a display panel or voice prompt). While breath-holding is important for the clinical scan, the survey is used to educate the patient to practice breath-holding for subsequent clinical scans used for interpretation purposes.

[0045] Display 22 is used to guide the patient throughout the examination and to indicate the start and end (and duration) of breath-holding, in order to enable prediction of breath-holding.

[0046] When patient 30 lies on the bed 32, the in-bore camera 14 begins monitoring respiratory rate, heart rate, blood pressure, facial expression, and skin tone changes. A separate galvanic skin response sensor may be used to monitor muscle tension. If the Valsalva maneuver is detected, the operator is notified via console software with suggestions to optimize the scan. In some cases, automatic control of the scanning process may also be present depending on the detection.

[0047] Different automated actions or suggestions are appropriate for different types of scans and for surveys compared to clinical scans. Examples are further explained below.

[0048] Generally, if Valsalva is detected during a survey, the operator will be notified of the Valsalva incident after the survey, and any necessary suggestions will be provided for the next scan. Suggestions for optimization may include guiding the patient on breathing techniques, changing the language of software-generated instructions if the patient cannot understand language, and changing the patient's orientation if it is helpful to the patient.

[0049] If Valsalva is detected during a non-timed or timed contrast-enhanced clinical scan, radiation should be stopped either automatically or by notifying the operator to stop the scan to avoid unnecessary exposure.

[0050] If Valsalva is detected during a bolus-following contrast-enhanced clinical scan, radiation may be stopped again immediately, or the operator may be instructed to stop the scan. If the contrast agent has been partially delivered, the contrast agent infusion may be stopped, and saline may be given to flush the contrast agent away from the anatomical structures. If the contrast agent has already been completely delivered, more saline may be injected to flush the contrast agent away from the anatomical structures.

[0051] As mentioned earlier, there are other scanning scenarios where the Valsalva maneuver is preferable because it can improve image quality. In such cases, the goal is to instruct the patient so that they can perform the Valsalva maneuver at the desired time.

[0052] Several possible use cases are described below in more detail, along with explanations of what actions will be taken if the Valsalva maneuver is detected but undesirable, or if the Valsalva maneuver is not detected but desirable.

[0053] The first category is examinations that are expected to be Valsalva maneuvers-free. In fact, the majority of CT breath-hold examinations are expected to be Valsalva maneuvers-free, allowing the contrast agent to flow uniformly and gradually. This applies, for example, to lung scans, cardiac scans, or abdominal scans. In such cases, the following actions may be taken:

[0054] A. Non-contrast scan (i) Service If Valsalva is detected during the survey, the operator will be notified during or after the survey, and the patient will be coached on proper breath-holding technique so that Valsalva is avoided for subsequent clinical scans. The survey will not be affected by Valsalva, and therefore, re-acquisition of the survey will not be required. (ii) Clinical scan If Valsalva is detected during a clinical scan and image quality is affected, the system will suggest rescanning.

[0055] B. Timed contrast-enhanced scan (i) Service If Valsalva is detected during the survey, the operator will be notified during or after the survey so that the patient can be instructed to avoid Valsalva and hold their breath again for a clinical scan. If necessary, a demonstration acquisition (without radiation) may be performed to ensure that the patient understands how to hold their breath. (ii) Clinical scan If Valsalva is detected during acquisition, the patient may be guided during acquisition, or the acquisition may be immediately stopped to conserve radiation dose, and a re-imaging may be performed on time while the contrast agent is still present in the body. Alternatively, the acquisition may be immediately stopped to conserve radiation dose, and a re-imaging may be performed after the contrast agent has been re-administered and the patient has been guided again. If Valsalva is detected after scanning and image quality is affected, parameters suggesting rescanning can be indicated immediately after the clinical scan (before final reconstruction is performed to save time).

[0056] C. Bolas Tracking (i) Service If Valsalva is detected during the survey, the operator will be notified during or after the survey so that the patient can be instructed to avoid Valsalva and hold their breath again for a clinical scan. If necessary, a demonstration acquisition (without radiation) may be performed to ensure that the patient understands how to hold their breath. (ii) Clinical scan If Valsalva is detected during acquisition, the patient may be guided during acquisition, or contrast agent administration may be immediately stopped to conserve radiation dose, and re-imaging may be performed on time by re-administering contrast agent and guiding the patient again. If Valsalva is detected after a scan and image quality is affected, parameters suggesting rescanning can be indicated immediately after the clinical scan (before final reconstruction is performed to save time). If rescanning is not possible, for example for brain perfusion scans where contrast timing is critical, the information "Valsalva detected during clinical scan" may be tagged with the image to ensure that the radiologist interprets the image accordingly and provides appropriate conclusions.

[0057] The second category is examinations requiring Valsalva maneuvers. Certain CT breath-hold examinations are expected to be performed with Valsalva maneuvers to allow for better visualization of the internal characteristics of organ walls. This applies, for example, to scans for hernias, cheek / oral cavity, and heart failure. In such cases, the following actions may be taken:

[0058] D. Non-contrast scan (i) Service If Valsalva is not detected by survey, the patient will be referred again for a clinical scan. (ii) Post-scan If Valsalva is not present and the final structure is unsatisfactory (i.e., does not produce a sufficiently distinctive difference in the tissue), rescanning is suggested using a system that proposes changes to relevant parameters of the clinical scan, such as longer scan time and reduced rotation speed. The patient may also be instructed again for the clinical scan.

[0059] E. Timed contrast-enhanced scan (i) Service If Valsalva is not detected by survey, the patient will be referred again for a clinical scan. (ii) Post-scan If Valsalva is not present and the final structure is unsatisfactory (i.e., does not produce a sufficiently distinctive difference in the tissue), rescanning is suggested using a system that proposes changes to relevant parameters of the clinical scan, such as longer scan time and reduced rotation speed. The patient may also be instructed again for the clinical scan.

[0060] C. Bolas Tracking (i) Service If Valsalva is not detected by survey, the patient will be referred again for a clinical scan. (ii) Post-scan If Valsalva is not achieved within the first few seconds, acquisition and contrast agent administration can be immediately stopped to conserve radiation dose, and re-imaging can be performed on time by re-administering contrast agent and guiding the patient again. If re-imaging is not possible, the system may suggest a post-processing method that can improve tissue characteristics.

[0061] These examples relate to different types of CT scans. However, the present invention may also be applicable to other imaging types.

[0062] For example, the Valsalva maneuver is used with MRI as well as CT to better depict certain conditions, not only in the pelvic floor and anal canal, but also in the head and neck region. In most cases, patients perform the Valsalva maneuver unsupervised by command, but this depends on the patient's compliance. Therefore, the approach of the present invention can again be used to instruct the patient to perform the Valsalva maneuver or to suggest a rescan when the absence of the Valsalva maneuver is detected.

[0063] In other breath-hold MRI scans, spontaneous Valsalva maneuvers during a scan generally require breath-holding and impair image quality in all ways that are highly sensitive to motion, such as in imaging the heart and brain. Many MR scans consist of multiple breath-holds. In the case of spontaneous Valsalva maneuvers during one breath-hold, this condition can be detected so that the breath-hold can be interrupted. The patient can then breathe, and the scan can continue with the next breath-hold. If spontaneous Valsalva maneuvers affect only a portion of the breath-hold, the other portion of the data can be used, and the corrupted data can be reacquired with the next breath-hold. In the case of detection of spontaneous Valsalva maneuvers in a particular patient, the MR system may change or suggest a different type of scan, or adapt the parameters of the planned scan, with the aim of reducing sensitivity to motion artifacts. Details of these adaptations are known and depend on the type of scan.

[0064] The above examples demonstrate that detecting the presence or absence of Valsalva has potential applications in various types of scans.

[0065] As is clear from the above, the core concept of the present invention is to instruct or control the cessation of scanning radiation or contrast agent injection in response to the detection of the Valsalva maneuver. The system of the present invention may provide other options in response to the detection of Valsalva, so that it can provide appropriate action for a variety of different scenarios, as described above.

[0066] Modifications of the disclosed embodiments can be understood and implemented by those skilled in the art in carrying out the claimed invention, based on a review of the drawings, disclosures, and appended claims. In the claims, the words “comprising” do not exclude other components or steps, and the indefinite articles “a” or “an” do not exclude plurality.

[0067] The mere fact that certain means are described in mutually different dependent claims does not mean that combinations of these means cannot be used advantageously.

[0068] When the term “adapted” is used in a claim or description, it is intended to be equivalent to the term “configured.” When the term “apparatus” is used in a claim or description, it is intended to be equivalent to the term “system,” and vice versa.

[0069] No reference numeral in a claim should be construed as limiting in scope. The embodiments of the present invention are described below. (Note 1) Scanning system and, A detection system that generates detection output, Processor and In a medical scanner having, the processor is Interpret the aforementioned detection output, and thereby detect the Valsalva maneuver if present. In response to detection of the Valsalva maneuver, provide output instructions advising to stop the delivery of scanning radiation or the injection of contrast agent, or control the medical scanner to stop the delivery of scanning radiation or the injection of contrast agent. It is configured in such a way. Medical scanner. (Note 2) The detection system is a medical scanner as described in Appendix 1, having an in-bore camera. (Note 3) The aforementioned processor configuration is, Respiratory rate and Heart rate and, Blood pressure and, Facial expressions and, Changes in skin tone, A medical scanner as described in Appendix 2, configured to interpret the signals generated by the in-bore camera to detect one or more of the following. (Note 4) The medical scanner described in Appendix 3, wherein the processor configuration is configured to detect the Valsalva maneuver based on a change in skin tone from a baseline skin tone. (Note 5) The medical scanner according to Appendix 3 or 4, wherein the processor configuration is configured to detect the Valsalva maneuver based on a decrease in PPG amplitude from a remote PPG signal. (Note 6) The medical scanner according to any one of Annexes 1 to 5, wherein the processor configuration is configured to interpret the detection output to thereby detect the Valsalva maneuver during a survey, and, if detected, to generate advice information for a subsequent clinical scan. (Note 7) The medical scanner according to any one of Appendix 1 to 5, wherein the processor configuration is configured to instruct the scan operator to stop or terminate the delivery of scan radiation when the Valsalva maneuver is detected during a contrast-enhanced scan. (Note 8) The medical scanner according to any one of Appendix 1 to 5, wherein the processor configuration is configured to terminate contrast agent injection when the Valsalva maneuver is detected during breath-holding of a contrast agent scan. (Note 9) The medical scanner according to any one of the appendices 1 to 8, further comprising a display for presenting information to a subject while scanning is being performed, and the processor configuration further configured to control the display to present breath-holding instructions to the subject. (Note 10) The aforementioned scanning system is a CT scanning system, a medical scanner as described in any one of the appendices 1 to 9. (Note 11) The aforementioned scanning system is an MRI scanning system, a medical scanner as described in any one of the items 1 to 9.

Claims

1. Scanning system and, A detection system that generates detection output, Processor and In a medical scanner having, the processor is Interpret the aforementioned detection output, and thereby detect the Valsalva maneuver if present. In response to detection of the Valsalva maneuver, provide output instructions advising to stop the delivery of scanning radiation or the injection of contrast agent, or control the medical scanner to stop the delivery of scanning radiation or the injection of contrast agent. It is configured in such a way. Medical scanner.

2. The detection system is a medical scanner according to claim 1, comprising an in-bore camera.

3. The aforementioned processor, Respiratory rate and Heart rate and, Blood pressure and, Facial expressions and, Changes in skin tone, The medical scanner according to claim 2, configured to interpret the signals generated by the in-bore camera to detect one or more of the following:

4. The medical scanner according to claim 3, wherein the processor is configured to detect the Valsalva maneuver based on a change in skin tone from a baseline skin tone.

5. The medical scanner according to claim 3 or 4, wherein the processor is configured to detect the Valsalva maneuver based on a decrease in PPG amplitude from a remote PPG signal.

6. The medical scanner according to any one of claims 1 to 4, wherein the processor is configured to interpret the detection output to thereby detect the Valsalva maneuver during a survey, and, if detected, to generate advice information for a subsequent clinical scan.

7. The medical scanner according to any one of claims 1 to 4, wherein the processor is configured to provide instructions to the scan operator to stop or terminate the delivery of scan radiation when the Valsalva maneuver is detected during a contrast-enhanced scan.

8. The medical scanner according to any one of claims 1 to 4, wherein the processor is configured to terminate contrast agent injection if the Valsalva maneuver is detected during breath-holding of a contrast agent scan.

9. The medical scanner according to any one of claims 1 to 4, further comprising a display for presenting information to a subject while scanning is being performed, and the processor further configured to control the display to present breath-holding instructions to the subject.

10. The medical scanner according to any one of claims 1 to 4, wherein the scanning system is a CT scanning system.

11. The medical scanner according to any one of claims 1 to 4, wherein the scanning system is an MRI scanning system.

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