System and method for processing and visualizing tube current modulation in a medical imaging device

Abstract

When performing an imaging scan on a patient, the x-ray tube current is modulated as the scan is performed. The x-ray tube current values ​​and modulation can be recorded and accessed. The accessed values ​​are processed to generate overlays and displays to identify patient and diagnostic equipment problems.

Description

[Technical Field]

[0001] The present invention relates to the field of medical diagnostic imaging, and more particularly to the processing and visualization of X-ray tube current values. [Background technology]

[0002]

[0002] Computed tomography (CT) scans are commonly performed on patients as part of a medical examination. A typical CT scan involves taking multiple x-ray images from different angles around the patient. These x-ray images are combined and processed to generate cross-sectional data of the scanned patient. In effect, a composite image is created from the multiple x-ray images.

[0003] However, additional information can be obtained from generating a CT scan in addition to the x-ray image data, and such information can be useful in treating a patient. Furthermore, this additional information can be presented in an intuitive and easily understandable manner that avoids introducing friction or inefficiencies into the workflow of a medical practitioner. Summary of the Invention [Problem to be solved by the invention]

[0004] It is an object of the present invention to provide a system and method as claimed. [Means for solving the problem]

[0005]

[0004] In one example, a computer-implemented method for visualizing tube current modulation includes: accessing one or more X-ray tube current values for a portion of a patient scan, wherein the one or more X-ray tube current values correspond to an X-ray tube used to perform the portion of the patient scan; mapping the one or more accessed X-ray tube current values to a region of a scout scan associated with the patient scan; and applying a transformation function based on the accessed X-ray tube current values to the region of the scout scan to generate a transformed scout scan, wherein the region of the scout scan contrasts (highlights) with other adjacent regions of the scout scan when displayed to a user.

[0006] In some examples of the computer-implemented method, the transformation function includes converting pixel colors of the pixels of the scout scan to new colors corresponding to the accessed one or more x-ray tube current values.

[0007] In some examples of the computer-implemented method, the transformation function includes a saturation transformation function for modulating the opacity of the new color.

[0008] In some examples of the computer-implemented method, the accessed x-ray tube current values are normalized.

[0009] In some examples of the computer-implemented method, the one or more x-ray tube current values are placed in a metadata field of a DICOM header file.

[0010]

[0009] In some examples of the computer-implemented method, the method further includes: accessing a plurality of other patient scans related to the patient scan based on one or more of the patient information or the scanned anatomical structure, wherein the plurality of other patient scans include other X-ray tube current values; identifying other X-ray tube current values corresponding to the one or more X-ray tube current values, wherein the correspondence is based on the other X-ray tube current values and the anatomical region from which the one or more X-ray tube current values were generated; and displaying the identified other X-ray tube current values to a user.

[0011]

[0010] In some examples of the computer-implemented method, the method further includes: generating one or more tube current fingerprints based on one or more X-ray tube current values or identified other X-ray tube current values, each fingerprint including sequential colored line segments, each line segment corresponding to an anatomical region, and each color being based on the X-ray tube current value or identified other X-ray tube current value; and displaying the one or more tube current fingerprints to a user in a stacked format, each fingerprint being aligned according to its respective sequential colored line segment.

[0012]

[0011] In some examples of the computer-implemented method, the method further includes: determining an average X-ray tube current value for one of the anatomical regions based on the identified other X-ray tube current values; applying a transformation function to the determined average X-ray tube current value to obtain a transformed value; and displaying the transformed value to a user in association with one of the anatomical regions and the displayed region of the scout scan.

[0013]

[0012] In one example, a system for visualizing tube current modulation in a patient scan includes: a medical diagnostic imaging device; a display communicatively coupled to the medical diagnostic imaging device; and a computing device; wherein the computing device is configured to: access one or more X-ray tube current values relating to a portion of the patient scan, wherein the one or more X-ray tube current values correspond to an X-ray tube of the medical diagnostic imaging device used to perform the portion of the patient scan; map the accessed one or more X-ray tube current values to a region of a scout scan associated with the patient scan; apply a transformation function based on the accessed X-ray tube current values to the region of the scout scan to generate a transformed scout scan; and display the transformed scout scan on the display; wherein the region of the scout scan contrasts with other adjacent regions of the scout scan when displayed to a user.

[0014] In some examples of the system, the conversion function includes a pixel color conversion of the pixels of the scout scan to a new color corresponding to one or more accessed x-ray tube current values.

[0015] In some examples of the system, the transformation function includes a saturation transformation function for modulating the opacity of the new color.

[0016] In some examples of the system, the computing device is further configured to normalize the accessed x-ray tube current values.

[0017] In some examples of the system, the one or more x-ray tube current values are placed in a metadata field of a DICOM header file.

[0018]

[0017] In some examples of the system, the computing device is further configured to: access a plurality of other patient scans related to the patient scan based on one or more of the patient information or the scanned anatomical structure, where the plurality of other patient scans include other X-ray tube current values; identify other X-ray tube current values that correspond to the one or more X-ray tube current values, where the correspondence is based on the other X-ray tube current values and the anatomical region in which the one or more X-ray tube current values were generated; and display the identified other X-ray tube current values to the user.

[0019]

[0018] In some examples of the system, the computing device is further configured to: generate one or more tube current fingerprints based on one or more of the X-ray tube current values or identified other X-ray tube current values, where each fingerprint includes sequential colored line segments, each line segment corresponding to an anatomical region, and each color is based on the X-ray tube current value or identified other X-ray tube current value; and display the one or more tube current fingerprints to the user in a stacked format, where each fingerprint is aligned according to each sequential colored line segment.

[0020]

[0019] In some examples of the system, the computing device is further configured to: determine an average X-ray tube current value for one of the anatomical regions based on the identified other X-ray tube current values; apply a transformation function to the determined average X-ray tube current value to generate a transformed value; and display the transformed value to the user in association with one of the anatomical regions and the displayed region of the scout scan.

[0021]

[0020] In one example, a non-transitory computer-readable medium stores instructions that, when executed by one or more processors, cause the one or more processors to: access one or more X-ray tube current values for a portion of a patient scan, where the one or more X-ray tube current values correspond to an X-ray tube used to perform the portion of the patient scan and are located in a metadata field of a DICOM header file; map the one or more accessed X-ray tube current values to a region of a scout scan associated with the patient scan; and apply a transformation function based on the accessed X-ray tube current values to the region of the scout scan to generate a transformed scout scan; the transformation function includes: a pixel color transformation of pixels of the scout scan to a new color corresponding to the one or more accessed X-ray tube current values; and a saturation transformation function for modulating the opacity of the new color, so that the region of the scout scan contrasts with other adjacent regions of the scout scan when displayed to a user.

[0022]

[0021] In some examples of the non-transitory computer-readable medium, the instructions further cause the one or more processors to: access a plurality of other patient scans associated with the patient scan based on one or more of the patient information or the scanned anatomical structure, where the plurality of other patient scans include other X-ray tube current values; identify other X-ray tube current values that correspond to the one or more X-ray tube current values, where the correspondence is based on the other X-ray tube current values and the anatomical region in which the one or more X-ray tube current values were generated; and display the identified other X-ray tube current values to a user.

[0023]

[0022] In some examples of the non-transitory computer-readable medium, the instructions further cause the one or more processors to: generate one or more tube current fingerprints based on one or more of the X-ray tube current values or identified other X-ray tube current values, where each fingerprint includes sequential colored line segments, each line segment corresponding to an anatomical region, and each color is based on the X-ray tube current value or identified other X-ray tube current value; and display the one or more tube current fingerprints to a user in a stacked format, where each fingerprint is aligned according to each sequential colored line segment.

[0024]

[0023] In some examples of the non-transitory computer-readable medium, the instructions further cause one or more processors to: determine an average X-ray tube current value for one of the anatomical regions based on the identified other X-ray tube current values; apply a transformation function to the determined average X-ray tube current value to generate a transformed value; and display the transformed value to a user in association with one of the anatomical regions and the displayed region of the scout scan. [Brief explanation of the drawings]

[0025] [Figure 1] FIG. 1 is a system diagram illustrating an example computer system in accordance with some embodiments of the present technology. [Figure 2A] FIG. 2A is a system diagram illustrating an example of a tube current modulation overlay system, in accordance with some embodiments of the present technology. [Figure 2B]

[0026] FIG. 2B is a flowchart illustrating an example method for generating a tube current modulation view, in accordance with some embodiments of the present technology. [Figure 2C]

[0027] FIG. 2C is a system diagram illustrating an example of a tube current value statistics engine, in accordance with some embodiments of the present technology. [Figure 2D]

[0028] FIG. 2D is a flowchart illustrating an example method for generating a context tube current modulation view, in accordance with some embodiments of the present technology. [Figure 3A]

[0029] FIG. 3A is an exemplary view of a tube current modulation overlay in accordance with some embodiments of the present technology. [Figure 3B]

[0030] FIG. 3B is an exemplary view of a tube current modulation overlay in accordance with some embodiments of the present technology. [Figure 4]

[0031] FIG. 4 is an exemplary view of a tube current modulation overlay with identification of anatomical structures, in accordance with some embodiments of the present technology. [Figure 5A]

[0032] FIG. 5A is an exemplary view of a stacked tube current modulation display in accordance with some embodiments of the present technique. [Figure 5B]

[0033] FIG. 5B is an exemplary view of a comparative tube current modulation display, in accordance with some embodiments of the present technology. DETAILED DESCRIPTION OF THE INVENTION

[0026]

[0034] A CT scan is produced by taking multiple x-ray images simultaneously or nearly simultaneously with one another. These x-ray images are then used via computer algorithms to generate tomographic data, producing a composite image of the cross-section of the scanned patient. In many instances, the x-rays that produce the x-ray images are set at multiple varying angles relative to the patient. Nevertheless, an x-ray tube is typically used to produce the x-rays and x-ray images.

[0027]

[0035] A standard X-ray tube converts electrical energy into X-rays (e.g., via an anode). The electrical energy is supplied to the tube in the form of an electric current, and the X-rays produced are proportional to the current supplied to the X-ray tube. Conversely, the tube current is proportional to the number of X-ray photons produced (also called photon flux). However, although the signal-to-noise ratio (SNR) increases as the photon flux increases, the correlation is not strictly proportional.

[0028]

[0036] Many x-ray scanners allow for modulation of the electrical current (i.e., tube current) to adjust the x-rays produced. Often, the tube current is modified to maintain a consistent signal to signal-to-noise ratio (SNR) throughout the scanning process. In particular, different tube currents can result in different SNRs when different volumes of dense tissue (e.g., muscle, fat, bone, etc.) are x-rayed. As a result, the tube current can be modulated accordingly for x-raying different organs, body parts, etc.

[0029]

[0037] In some examples, tube current modulation is performed automatically (e.g., in response to monitoring the SNR in real time throughout the CT scan process). For example, the tube current can be modulated based on the amount and density of tissue to be penetrated by the resulting x-rays. A scan of a patient's lungs and abdomen may include decreasing the z-portion of the scan that runs over the lungs and increasing the same portion of the scan that runs over the abdominal region. Additionally, the tube current applied to each cross-sectional slice (e.g., x-ray image) of a CT scan can be saved in a corresponding DICOM file that is typically generated and associated with each cross-sectional slice.

[0030]

[0038] Some CT scanner suppliers provide tube current data for verifying scanner settings and functionality. In some instances, the provided tube current data can be displayed to the end user as a graph overlaid on a scout scan image. However, such a representation can obscure portions of the scout scan image, making it difficult to visually assess local tube current values at the level of individual pixels or groups of pixels. Furthermore, detailed estimation of organ location and extent is often difficult to determine due to various factors, such as the superposition of organs with different absorption characteristics. In practice, displayed information regarding determinable tube current modulation requires the reader to collate and decompose the displayed information to understand the relationship between the anatomical region and the characteristics of the applied modulation, which is time-consuming and distracts from medically interpreting the reading. What is disclosed is a solution to the technical problem of determining the relationship between tube current modulation and corresponding anatomical region and displaying the determination in an intuitive and efficient manner that allows the user to maintain their attention on more relevant tasks, such as medically interpreting the scan.

[0031]

[0039] In particular, the tube current can be determined and converted into a color code. The color code can then be used to convert the grayscale scout scan image into a colorized version (e.g., RGB) corresponding to the tube current value. As a result, a clinician can quickly determine the approximate tube current value and tube current value modulation throughout the scanning process by evaluating the colorized scout scan image. Visual clutter is reduced, and the risk of obstructing the graphic user interface, which would interfere with the features of the scout scan image, is avoided.

[0032]

[0040] Additionally, the tube current modulation information can be associated with a particular anatomical region of interest, such as, but not limited to, the lungs, abdomen, pelvis, etc. In some instances, associated information can be collected and derived values, such as, but not limited to, the mean tube current, minimum tube current, and / or maximum tube current, can be calculated for each region of interest. The location and extent of the anatomical region can be estimated using image segmentation algorithms and / or region of interest regression techniques well known in the art for scout scans and / or CT images.

[0033]

[0041] In some cases, the axial extent of the scout image may differ from the axial extent of the reconstructed 3D CT image (for which DICOM slices are exported from the scanner). As a result, the extent of the color overlay may not perfectly match the underlying image. This difference can be either positive if the axial extent of the CT volume is smaller than the axial extent of the scout image, or negative if the axial extent of the scout image is smaller than the axial extent of the CT volume; therefore, the overlap may be different at each end (e.g., top and / or bottom) of the axial image extent.

[0034]

[0042] To account for mismatches in axial extent, the tube current modulation information may be overlaid over only a portion of the vertical extent of the image. Additionally, in some examples, but not by way of limitation, a horizontal bar (relative to the axial extent) may be aligned with the axial position of the 3D CT scout image to display a color bar representing the tube current modulation.

[0035]

[0043] In addition to or instead of color-coded bands, various visualization and evaluation techniques can be applied using the collected and derived tube current modulation values to generate useful overlays, for example, graphic elements in the form of tables, plots, and overlays can be added to the images of the scan.

[0036]

[0044] A quantitative representation of statistical characteristics of tube current modulation (e.g., minimum, maximum, mean, median, etc.) for an anatomical region of interest can be displayed to the user as a table (e.g., alongside a scan output image, etc.). The table can include, for example, but not limited to, information related to patient history (longitudinal) or a larger patient population (global) for comparison with the current scan to identify drift warnings when a significant difference in the current patient's value from the long-term or global value is detected. Statistical plots can be provided, for example, in the form of box plots to visualize tube current modulation per region of interest. Additional overlays, such as the color overlays described above, can be combined with the tabular and / or box plot displays to quickly evaluate scans in a single display. In some examples, an ensemble of studies can include one or more of the visualizations described above and can be anatomically aligned to provide an easily comparable view of multiple studies.

[0037]

[0045] A description of specific exemplary embodiments of the present technology follows. While architectures, systems, methods, and / or apparatuses are disclosed, those skilled in the art will understand that these are examples for general understanding and clarity. Thus, variations on the disclosed embodiments, such as more or fewer steps, alternative architectures, and other modifications, may still fall within the spirit and scope of the present disclosure.

[0038]

[0046] 1 illustrates an exemplary computing system (computer system) 100 in which various systems and methods described herein can be implemented. The computer system 100 includes one or more computing elements communicating via a bus 102. In one implementation, the computing system 100 includes one or more processors 114. The processor 114 may include one or more internal-level caches 116 and a bus controller or bus interface. The processor 114 is capable of, among other things, performing the various methods described herein. The main memory 108 may include one or more memory cards and control circuitry (not shown), or other forms of removable memory, and may store various software applications that, when executed on the processor 114, include computer-executable instructions that implement the methods and systems described herein. Other forms of memory, such as a storage device 110 and a mass storage device 112, are also included and accessible by the processor(s) 114 via the bus 102. The storage device 110 and the mass storage device 112 may each include any or all of the methods and systems described herein.

[0039]

[0047] The computer system 100 may further include a communications interface 118, which may enable the computer system 100 to connect to a network, receive data useful in implementing the methods and systems described herein, and transmit information to other devices. The computer system 100 may also include an input device 106, through which information may be input. The input device 106 may be a scanner, keyboard, and / or other input device, as will be apparent to those skilled in the art. The computer system 100 may also include an output device 104, through which information may be output. The output device 104 may be a monitor, printer, USB, and / or other output device or port, as will be apparent to those skilled in the art.

[0040]

[0048] 1 is merely one possible example of a computer system that may be employed or configured in accordance with aspects of the present disclosure. It will be appreciated that other non-transitory, tangible, computer-readable storage media that store computer-executable instructions for implementing the disclosed techniques on a computing system may also be utilized.

[0041]

[0049] In this disclosure, the disclosed methods may be implemented as a set of apparatus-readable instructions or software. It is further understood that the specific order or hierarchy of steps in the disclosed methods is an example of exemplary approaches. Based on design preferences, it is understood that the specific order or hierarchy of steps in the methods may be rearranged while remaining within the scope of the disclosed subject matter. The accompanying method claims present elements of the various steps in a sample order, and are not necessarily meant to be limited to the specific order or hierarchy presented.

[0042]

[0050] The described disclosure may be provided as a computer program product or software, which may include a computer-readable storage medium having stored thereon instructions that can be used to program a computer system (or other electronic device) to perform processes in accordance with the present disclosure. A computer-readable storage medium includes any mechanism for storing information (e.g., software, processing applications) in a form readable by a computer. The computer-readable storage medium may include, but is not limited to, optical storage media (e.g., CD-ROMs), magneto-optical storage media, read-only memory (ROM), random access memory (RAM), erasable programmable memory (e.g., EPROMs and EEPROMs), flash memory, or other types of media suitable for storing electronic instructions.

[0043]

[0051] 2A illustrates an example of a tube current modulation overlay system 200. While the tube current modulation overlay system 200 is shown as a standalone system, it is understood that this is for illustrative purposes only and that the tube current modulation overlay system 200 can be deployed as a monolithic architecture, a separated architecture, a cloud service, and various other deployment configurations, as will be apparent to those skilled in the art.

[0044]

[0052] Nevertheless, the tube current modulation overlay system 200 includes various interfaces for interacting with external systems, including a scanner data receiver 208, an image retrieval unit 206, and an interface 214. The scanner data receiver 208 receives scanner information in the form of image data from a medical diagnostic device, either as individual image files or as an image file stack of slices. In one example, the medical diagnostic device is a CT scanner, and the scanner data receiver 208 is configured to receive the image data from the CT scanner in the form of a DICOM file. In some examples, the scanner data receiver 208 is directly connected to each medical diagnostic device. In some examples, the scanner data receiver 208 can intercept or otherwise receive DICOM files transmitted over a hospital network.

[0045]

[0053] The scanner data receiver 208 provides tube current values to the tube current monitor 202. DICOM files include tube current values in the metadata of each file header, which can be extracted, for example, by a packet parser. The tube current monitor 202 receives and tracks the extracted tube current values from the scanner data receiver 208. The tube current monitor 202 also receives tracking values included in the DICOM header, such as "slice position," "image position," "image orientation," and / or "pixel spacing." For example, slice position may be defined as a relative position on the image plane and may include a value stored as "(0020,1401)"; image position may include a patient identifier and z-, y-, and z-axis coordinate values (e.g., using the center of the first voxel transmitted as the upper-left reference point); image orientation may include direction cosines of the first row and first column relative to the patient; and pixel spacing may provide the physical distance between adjacent pixels. In general, special values may be defined in millimeters.

[0046]

[0054] The scanner data receiver 208 can process DICOM files using parsers known in the art to identify the various fields and corresponding values. The pydicom Python package is one example, although several alternative DICOM parsers can be used to process DICOM files.

[0047]

[0055] In some examples, the tube current monitor 202 can normalize tube current values to a specified range. The normalized values can then be used by the current-to-image mapper 210 to convert corresponding scout scan color values to represent tube current. The current-to-image mapper 210 applies a color scale to the corresponding scout scan based on the normalized tube current values. In some examples, the color scale can be set by a user via the interface 214 and customized to suit user preferences, clinical situation, patient history, etc. While any color scale can be used, a scale ranging from blue to red is provided in this disclosure for illustrative purposes only. Other color scales can include ranges from green to red, green to yellow, yellow to red, etc.

[0048]

[0056] The image data preprocessor 204 can receive image data files from a scanner data receiver 208 and / or an image retriever 206. The image retriever 206 may include integration with a picture archiving and communication system (PACS). Patient images, such as scout scans, can be retrieved from the image retriever 206 and prepared by the image data preprocessor 204. In some examples, the image data preprocessor 204 adds metadata or modifies the retrieved scout scan image files to allow the current-to-image mapper 210 to apply color transformations.

[0049]

[0057] In some examples, additional or alternative values can be generated by the image data preprocessor 204 via either or both extracted information from the DICOM header metadata or calculated derivatives of the image or metadata. For example, “exposure,” “dose savings,” and / or “CTDI_vol” can be extracted from the DICOM header metadata and provided to the current-to-image mapper 210 for correlation of the values to a scout scan. Exposure is the product of the tube current in milliamperes (mA) and the corresponding exposure time in seconds. Dose savings is the percentage of dose saved due to the corresponding applied tube current modulation compared to a scan acquired at maximum tube current. CTDI_vol is a volumetric dose index and is a standardized measure of the radiation dose output of a CT scanner. Similarly, the image data preprocessor 204 can calculate values such as “water equivalent diameter” from the image content of the DICOM file using, for example, but not limited to, image processing algorithms and / or trained classifiers. The calculated values can also be provided to the current-to-image mapper 210 for correlation with a scout scan.

[0050]

[0058] The visualizer 212 compiles the mapped tube current information from the current-to-image mapper 210 and generates graphical content that is displayed to the user via the interface 214. The user can configure specific visualization settings for the visualizer 212, such as thresholds, color scales, and what data is visualized, by interacting with the interface 214. Additionally, in some examples, the visualizer 212 can receive various statistical or other global information from a statistical engine or database, which is further described below with reference to FIG. 2C . This additional information can be integrated into the visual elements prepared by the visualizer 212 and provided to the user via the interface 214.

[0051]

[0059] 2B illustrates, by way of example and not limitation, a method 250 for generating and visualizing mapped tube current values from a CT scan. Method 250 can be performed by one or more processors executing stored instructions and / or on a system such as that shown in FIG. 2A and described above. Nevertheless, method 250 is provided for purposes of explanation and understanding, and it will be understood that steps illustrated in method 250 may be modified, substituted, or added without departing from the spirit and scope of the present disclosure.

[0052]

[0060] In step 252, tube current values are extracted from the image data. In some examples, the image data is received by the scanner data receiver 208 described above with reference to FIG. 2A. The tube current values include x-ray current values for one slice or image of a CT scan. If the image is provided as part of a DICOM file, the tube current values can be extracted from metadata in the header portion of the DICOM file.

[0053]

[0061] In step 254, the extracted tube current values are mapped to corresponding coordinates in a scout scan. The mapping of the extracted tube current values can be performed using coordinate information in a DICOM header file that indicates slice location, image location, image orientation, and pixel spacing. The scout scan can be retrieved, for example, from a network PACS via the image retrieval unit 206.

[0054]

[0062] The scout scan may then be copied to each channel of the multi-channel image. For example, if an RGB image is used, the scout scan may be copied to each of the three channels of the RGB image. This allows the RGB image of the scout scan to be color-modified along each primary color channel (e.g., red, green, blue, etc.). Additionally, the tube current values may be normalized; in one example, the tube current values are normalized to a range of -1 to 1.

[0055]

[0063] In step 256, a color transformation function is applied to each vertical pixel column in the scout scan. In some examples, the color scale can be selected from various options by the user via interface 214, or can be input by the user. For example, the minimum tube current value can be mapped to "blue" and the maximum tube current value can be mapped to "red." Using the normalized tube current values, the following mapping function (1) can be applied to each vertical pixel column to achieve a scout scan image color-mapped to tube current: Color Mapping Function (1): If TC_n(z)<0: R(z)=(1+TC_n(z))*R(z);G(z)=(1+TC_n(z))*G(z) If TC_n(z)>0: R(z)=(1-TC_n(z))*R(z);B(z)=(1-TC_n(z))*B(z)

[0056]

[0064] In mapping function (1), TC_n(z) represents the tube current value mapped to the z-coordinate of the scout scan, normalized to a span ranging from -1 to 1. R(z), G(z), and B(z) represent the pixel values of the red, green, and blue channels, respectively, at the corresponding z-coordinate in the RGB image of the scout scan. In effect, mapping function (1) proportionally modifies (corrects) the red and green channel pixels at that coordinate in the RGB scout scan image if the corresponding normalized tube current value is greater than 0. If the corresponding normalized tube current value is less than 0, mapping function (1) instead proportionally modifies the red and blue channels of the pixel at each coordinate. In this way, the resulting RGB scout scan image will be colored according to a scale closely tied to and representative of the tube current values for imaging the corresponding location in the corresponding CT scan.

[0057]

[0065] In step 258, a saturation conversion factor is applied to each vertical pixel column in the scout scan. The saturation conversion factor, an example of which is shown integrated in mapping function (2) below, ensures that color saturation does not overwhelm the underlying scout scan image, effectively making feature structures and image textures unreadable. In effect, the saturation conversion factor softens the colorization of the image. Mapping Function (2): If TC_n(z)<0: R(z)=(1+s*TC_n(z))*R(z);G(z)=(1+s*TC_n(z))*G(z) If TC_n(z)>0: R(z)=(1-s*TC_n(z))*R(z);B(z)=(1-s*TC_n(z))*B(z)

[0058]

[0066] Mapping function (2) integrates the saturation conversion coefficients and can be used in place of mapping function (1). In mapping function (2), an additional saturation coefficient, denoted by s, is applied directly to the normalized tube current values to generate modified RGB values. Typically, the saturation coefficient s has values 0 and 1. Once the saturation function is applied, a transformed scout scan image can be displayed with three color channels mapped to tube current values, an example of which is shown in FIG. 3A below.

[0059]

[0067] In step 260, the transformed scout scan is displayed to the user for review. In some examples, the displayed transformed scout scan provides the user with a colorized view of the scanned patient. The colorized view may include bands of color that correspond to the tube current values recorded in each anatomical region of the scan and are overlaid on the scout scan so as not to obscure the underlying features of the scan while still providing detailed tube current information. In some examples, the user can switch between the colorized view and a conventional view 350, as shown in FIG. 3 .

[0060]

[0068] 3A and 3B respectively illustrate a colorized view 300, such as that produced by method 250 described above, and a conventional view 350 that the colored view 300 improves by, among other things, providing a non-obtrusive view of tube current values mapped to corresponding anatomical regions. In particular, conventional view 350 includes a 2D image 354 (e.g., a scout scan) overlaid with a series of graph lines 356A-D corresponding to various relevant values from the scan. Additionally, legend 352 consumes available display space. Here, graph line 356A indicates the tube current value along the longitudinal axis of the scan corresponding to the region of the scan overlaid with the graph. Similarly, graph lines 356B-D, representing exposure dose, dose savings, and CT dose index (CTDI_vol), respectively, are overlaid directly on the scan.

[0061]

[0069] In contrast, the colorized view 300 illustrated by FIG. 3A illustrates some of the improvements of the present disclosure over conventional view 350. In particular, colorized view 300 includes a scout scan image 302 providing a longitudinal scan 304 of a patient being examined by a CT scanner. Colored bands 306A-D are non-obstructively overlaid on the longitudinal scan 304 of the patient. Each color band 306A-D is generated according to a mapping of tube current values to RGB channel values, such as by method 250 described above.

[0062]

[0070] As shown in Figure 3A, the color bands 306A-D are mapped such that blue corresponds to the minimum tube current value and red corresponds to the maximum tube current value. The mapped colors are linearly scaled. It will be understood that the above mapping is an example and that other mappings and scalings can be used without departing from the spirit and scope of the present disclosure.

[0063]

[0071] Here, each color band 306A-D clearly corresponds to an anatomical region, and a modulation of the tube current can be seen over these regions as a whole: red color band 306A indicates maximum tube current values in the upper lung region, and blue color band 306B indicates a sharp shift to minimum tube current values over most of the lung region.

[0064]

[0072] In comparison, red color bands 306C and 306D each show a rise in tube current values back to a maximum value as the scan progresses from the lung region to the abdominal region and then to the pelvic region, respectively. This visualization can be used, for example, by a medical professional responsible for monitoring dose and in assessing the performance and functionality of tube current modulation in a scan. As another example, if the dose is higher than expected for a given exam type (e.g., a dose warning), a medical professional can perform an immediate visual check to identify where the high dose values occurred relative to the patient's anatomy.

[0065]

[0073] In some examples, the tube current modulation overlay system 200 can supplement the overlay information with a statistical engine 270 to generate additional information related to a particular patient's tube current modulation across multiple exams or for population-level values. The statistical engine 270 shown in FIG. 2C is one such example. The statistical engine 270 can be directly integrated into the tube current modulation overlay system 200, or in some examples, can be made accessible to the tube current modulation overlay system 200 as a microservice or the like. Depending on the evaluation considered, different visualization and evaluation techniques can also be implemented. For example, a tabular format can be displayed to provide a quantitative representation of statistical characteristics (e.g., minimum, maximum, mean, median, etc.) of the tube current modulation for an anatomical region of interest. The visualization of the tube current modulation for each region of interest can also or alternatively be displayed as a statistical plot (e.g., a boxplot to visualize distribution parameters for individual organs such as the lungs). Additionally, overlays that combine scout visualization with curves or color coding can facilitate advanced visualization that takes anatomical structures into account (e.g., by providing interactive visualization that allows visualization of only curves in the scout that indicate anatomical landmarks and region boundaries or curves specific to anatomical structures).

[0066]

[0074] Statistical engine 270 includes aggregator 272 and analytics engine 274. Aggregator 272 can access patient history (e.g., via an electronic medical record (EMR)) and hospital PACS (e.g., as a networked repository 276) to capture either or both of the patient's previous scans and / or scans of other patients. The aggregated information can then be used to generate time series and population comparison data, which can be provided to the user as additional overlays such as those shown in Figures 5A and 5B, described further below.

[0067]

[0075] The statistical engine 270 can determine statistical characteristics (e.g., minimum, maximum, mean, median, etc.) of tube current modulation for an anatomical region of interest for a larger population or for all or a portion of the patient's recorded scans. In some examples, the statistical engine 270 can also automatically detect if a scan significantly deviates from the determined statistical characteristics and alert the user to check for possible flaws in the scan and / or scanning procedure.

[0068]

[0076] Furthermore, the visualizer 212 can use the determined statistical features to display the tube current modulation values for the region of interest in terms of a statistical plot. For example, as shown in Figure 4, which is further described below, a box plot can be used to visualize distribution parameters for individual organs or regions such as the lungs, pelvis, abdomen, etc.

[0069]

[0077] The visualizer 212 can integrate data generated by the statistical engine 270 into the overlay. For example, the visualizer can take anatomical structures into account by providing interactive visualization that allows visualization of curves indicating anatomical landmarks and region boundaries in scout scan images, or curves specific to the anatomical structures only. Indeed, the tube current modulation information can be anatomically aligned across multiple exams based on landmarks, thus compensating for variations in anatomical and / or imaging parameters (e.g., field of view (FOV), etc.).

[0070]

[0078] 2D illustrates an example of a method 280 for generating enhanced tube current modulation visualization. Method 280 can be performed by one or more processors executing stored instructions and / or on a system such as that shown in FIG. 2C and described above. Nevertheless, method 280 is provided for purposes of explanation and understanding, and it will be understood that steps illustrated in method 280 may be modified, substituted, or added without departing from the spirit and scope of the present disclosure.

[0071]

[0079] In step 282, multiple DICOM files associated with the current patient scan are accessed. The DICOM files may be related to the patient, such as when obtaining previous scans of the same patient, or may be related to scans of the patient, such as when obtaining DICOM files for scans of the same anatomical region from other patients. The DICOM files may include one or more images or slices stored in a stack, and the slices may include tags in the form of metadata fields.

[0072]

[0080] In step 284, corresponding tube current values are identified across the multiple DICOM files. In one example, the DICOM tags of the DICOM files are checked to ensure that the corresponding scans were performed over the same anatomical region as the current patient's scan. If the scanned anatomical regions match, each tube current value can be obtained from the DICOM tag.

[0073]

[0081] Based on the use of the data, method 280 may proceed from step 284 to step 288 or to step 286. For example, if a user wishes to visually review corresponding tube current values and compare many values at once, method 280 may proceed to step 286 to modify and / or normalize the data to facilitate comparison. In other examples, a user may wish to perform a numerical review, in which case the data may be provided in unmodified form and method 280 may proceed directly to step 280.

[0074]

[0082] Nevertheless, in step 286, the mapping information of the multiple DICOM files with corresponding tube current values is rescaled based on the current patient scan. For example, the axial extent of the scout image of the current patient scan may differ from the axial extent of the reconstructed 3D CT image of each of the accessed DICOM slices. As a result, the extent of the color overlay of the accessed DICOM slice may not perfectly match the color overlay of the scout scan (as described above). The difference may be positive if the axial extent of the CT volume is smaller than that of the scout image, or negative if the axial extent of the scout image is smaller than that of the CT volume, and / or the overlap may be different at each end (e.g., top or bottom) of the axial extent of the scout image. Thus, the tube current modulation information may be rescaled to fit, for example, a horizontal bar aligned with the axial placement of the scout image, displaying a color bar with a representation of the tube current modulation, as shown in FIG. 5A, described further below.

[0075]

[0083] In step 288, a display mode is determined, which may be selected by a user via a GUI such as interface 214 described above, determined by a user setting, automatically determined based on the scan the patient is undergoing, predicted based on user and / or patient characteristics, or determined by a variety of other mechanisms.

[0076]

[0084] In step 290, visualization information is generated according to the display mode and corresponding tube current values. The visualization information may be generated by the visualizer 212 and may provide the user with additional interactable options, such as options to change the display mode, filter the displayed results, perform additional searches and / or comparisons, etc. For example, the user may switch between views 400, 500, and 550 shown in Figures 4 and 5A-B, respectively, as described below.

[0077]

[0085] 4 shows a box plot view 400 of a colorized scout scan supplemented with information from the statistical engine 270. In the box plot view 400, anatomical structure detection information is visualized and overlaid on a colorized scout scan based on tube current values as described above. The colorized tube current values are provided adjacent to the scout scan to provide a user with intuitive and comparable information to, for example, assist the user in identifying abnormal or concerning tube current values on the scout scan.

[0078]

[0086] Box plot view 400 includes a colorized scout scan 402. Overlaid on the colorized scout scan 402 are anatomical structure boxes 406A, 408A, and 410A. Anatomical structure box 406A indicates the region of scout scan 402 that corresponds to the pelvis. Anatomical structure box 408A indicates the region of scout scan 402 that corresponds to the abdomen. Anatomical structure box 410A indicates the region of scout scan 402 that corresponds to the lungs.

[0079]

[0087] Additionally, colorized average tube current bars 406B, 408B, and 410B are positioned below the scout scan 402 and aligned vertically with the anatomical structure boxes 406A, 408A, and 410A. The colorized average tube current bars 406B, 408B, and 410B are color-mapped according to the same mapping function as the scout scan 402 to represent the average tube currents of the corresponding anatomical regions across multiple DICOM files. Here, the lung colorized average tube current bar 410B is blue, while the abdomen colorized average tube current bar 408B and the pelvis colorized average tube current bar 406B are light red and dark red, respectively. In fact, a user can quickly compare the color bands of the scout scan 402 with the corresponding regional colorized average tube current bars to determine whether the tube current values of the patient scan are within an acceptable average range.

[0080]

[0088] 5A shows a stacked view 500 of multiple exams, which uses stacked "fingerprints" to display the variation in tube current values across multiple exams for the same anatomical region. Registration of each exam can be performed according to step 286 described above. The stack 500 allows the user to quickly find outliers.

[0081]

[0089] The stacked view 500 includes a stack 502 of exam fingerprints 504. Each exam fingerprint 504 is a horizontally distributed line segment characterized by an anatomical region, colored and rescaled according to the respective tube current value during the exam. Here, each exam fingerprint 504 includes a lung region 506A, an abdominal region 506B, and a pelvic region 506C. The exam ID axis 504 provides an associated identifier for each exam fingerprint 504. In some examples, by interacting with an identifier in the exam ID axis 504, a user can navigate to the corresponding original exam file and / or access the DICOM file to review each information unmodified for the stacked view 500.

[0082]

[0090] 5B shows a patient context view 550 for comparing tube current modulation values of a current scan of a current patient with other patients (e.g., inter-patient comparison) or with previous scans of the current patient (e.g., intra-patient comparison). The patient context view 550 includes a background scan image 552 aligned with a tube current axis 554. A tube current value line 556 is overlaid on the background scan image 552 and, in combination with the tube current axis 554, indicates relative tube current values associated with different scans. Organ bars 558A-B are set below the background image scan 552 and indicate particular regions related to the values of the tube current value line 556, such as a lung bar 558B and an abdomen bar 558A.

[0083]

[0091] The background scan image 552 can be a previous image, a default normative image, or an artificial image, depending on the comparison being considered in the patient context view 550. For example, when comparing between different patients, a schematic anatomy diagram or a phantom scan can be used for the background scan image 552. In contrast, when the patient context view 550 is being used to compare tube current modulation values across multiple scans of the same patient, a preferred actual scan can be used, such as an earlier scan or the patient scan that best meets a particular image quality threshold.

[0084]

[0092] While the present technology has been described in detail for purposes of illustration based on what are presently considered to be the most practical and preferred embodiments, it should be understood that such details are for illustrative purposes only and that the technology is not limited to the disclosed embodiments, but on the contrary, is intended to cover modifications and equivalent arrangements within the spirit and scope of the appended claims. For example, it should be understood that the present technology contemplates that, to the extent possible, one or more features of any configuration can be combined with one or more features of any other configuration.

Claims

1. 1. A computer-implemented method for visualizing tube current modulation in a patient scan, the computer-implemented method comprising: accessing one or more x-ray tube current values for a portion of the patient scan, the one or more x-ray tube current values corresponding to an x-ray tube used to perform the portion of the patient scan; mapping the accessed one or more x-ray tube current values to a plurality of adjacent regions in a scan direction of a scout scan associated with the patient scan; applying a transformation function based on the accessed x-ray tube current values to the plurality of regions of the scout scan to generate a transformed scout scan; and The transformed scout scan, when displayed to a user, contrasts the plurality of regions.

2. The computer-implemented method of claim 1 , wherein the transformation function comprises converting pixel colors of pixels of the scout scan to new colors corresponding to the accessed one or more x-ray tube current values.

3. The computer-implemented method of claim 2 , wherein the transformation function further comprises a saturation transformation function for modulating the opacity of the new color.

4. The computer-implemented method of claim 1 , further comprising the step of normalizing the accessed x-ray tube current values.

5. The computer-implemented method of claim 1 , wherein the one or more x-ray tube current values are located in a metadata field of a DICOM header file.

6. accessing a plurality of other patient scans related to the patient scan based on one or more of patient information or scanned anatomy, the plurality of other patient scans having other x-ray tube current values; identifying other x-ray tube current values that correspond to the one or more x-ray tube current values, the correspondence being based on the other x-ray tube current values and the anatomical region in which the one or more x-ray tube current values were generated; displaying the identified other x-ray tube current values to a user; The computer-implemented method of claim 1 further comprising:

7. generating one or more tube current fingerprints based on one or more of the x-ray tube current values or the identified other x-ray tube current values, each fingerprint being a sequential colored line segment distributed horizontally, each line segment corresponding to an anatomical region, and each color being based on the x-ray tube current value or the identified other x-ray tube current value; displaying the one or more tube current fingerprints to a user in a stacked format; The computer-implemented method of claim 6 further comprising:

8. determining a mean x-ray tube current value for one of the anatomical regions based on the identified other x-ray tube current values; applying the transformation function to the determined average x-ray tube current value to obtain a transformed value; displaying the transformed values to a user relative to one of the anatomical region and a displayed region of the scout scan; The computer-implemented method of claim 6 further comprising:

9. 1. A system for visualizing tube current modulation in a patient scan, comprising: a medical diagnostic imaging device having one or more x-ray tubes; a display communicatively coupled to the medical diagnostic imaging device; a computing device that executes the computer-implemented method of any one of claims 1 to 8 and displays the transformed scout scan on the display; A system having:

10. A non-transitory computer-readable medium having stored thereon instructions that, when executed by one or more processors, cause the one or more processors to perform the computer-implemented method of claim 3 or any one of claims 6-8.

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