Systems and methods for determining timing bolus delay

Abstract

To provide a CT imaging method for determining a timing bolus delay based on test bolus images.SOLUTION: The method includes administering a test bolus to a subject; acquiring, via a computed tomography (CT) imaging system, a plurality of images of the subject; determining a contrast value for each of the images; generating a contrast curve based on the determined contrast values; determining a peak contrast value on the contrast curve; determining a preparation delay based on the peak contrast value; and administering a contrast-enhanced CT scan of the subject based on the determined preparation delay.SELECTED DRAWING: Figure 3

Description

[Background technology]

[0001] Computed tomography (CT) imaging is a common diagnostic test used to diagnose disease or injury by creating images of various parts of the human body (e.g., bones, blood vessels, and soft tissues). In some cases, patients may require a contrast CT scan, in which the patient is injected with a contrast agent before the scan. The contrast agent attenuates X-rays, allowing specific areas of the body to be identified and highlighted on the CT image, thereby enabling relevant medical professionals to make a more accurate and detailed diagnosis. For example, the contrast agent may increase the visibility of tumors, inflammation, blood vessels, and blood flow in certain organs. Summary of the Invention

[0002] According to one aspect of the present disclosure, a method for determining a timing bolus delay may include administering a test bolus to a subject, acquiring a plurality of images of the subject with a computed tomography (CT) imaging system, determining a contrast value for each image of the plurality of images, generating a contrast curve based on the determined contrast values, determining a peak contrast value of the contrast curve, determining a preparation delay based on the peak contrast value, and performing a contrast-enhanced CT scan of the subject based on the determined preparation delay.

[0003] In some embodiments, administering the test bolus to the subject includes injecting a contrast agent into the subject. In some embodiments, determining a preparation delay based on the peak contrast value includes automatically determining a total elapsed time from administration of the test bolus to the peak contrast value. In some embodiments, automatically determining the total elapsed time includes analyzing at least one of a relative Hounsfield Unit (HU) change, an absolute HU change, and reaching a predetermined percentage of the peak contrast value.

[0004] In some embodiments, the method may include receiving a selection from a user via a user interface, and analyzing at least one of a relative Hounsfield Unit (HU) change, an absolute HU change, and reaching a predetermined percentage of a peak contrast value based on the received selection. In some embodiments, the method may include receiving a definition of a region of interest from a user via a user interface, and manipulating the contrast curve based on the definition of the region of interest. In some embodiments, the method may include adjusting the total elapsed time by a predetermined correction factor. In some embodiments, the predetermined correction factor may be set by a user via a user interface. In some embodiments, acquiring multiple images of the subject may include acquiring one image every second for 10 seconds.

[0005] According to another aspect of the present disclosure, a method for determining a timing bolus delay may include administering a test bolus to a subject, acquiring a plurality of images of the subject with a computed tomography (CT) imaging system, determining a contrast value for each image of the plurality of images, generating a contrast curve based on the determined contrast values, identifying a plateau in the contrast curve, determining a preparation delay based on the identified plateau, and performing a contrast-enhanced CT scan of the subject based on the identified plateau.

[0006] In some embodiments, administering the test bolus to the subject can include injecting a contrast agent into the subject. In some embodiments, determining a preparation delay based on an identified plateau can include automatically determining a total elapsed time from administration of the test bolus to the identified plateau. In some embodiments, automatically determining the total elapsed time can include analyzing at least one of a relative Hounsfield Unit (HU) change, an absolute HU change, and reaching a predetermined percentage of a peak contrast value.

[0007] In some embodiments, the method may include receiving a selection from a user via a user interface, and analyzing at least one of a relative Hounsfield Unit (HU) change, an absolute HU change, and reaching a predetermined percentage of a peak contrast value based on the received selection. In some embodiments, the method may include receiving a definition of a region of interest from a user via a user interface, and manipulating the contrast curve based on the definition of the region of interest.

[0008] In some embodiments, the method may include adjusting the total elapsed time by a predetermined correction factor. In some embodiments, the predetermined correction factor may be set by a user through a user interface. In some embodiments, the plateau may occur at a specified location after a peak contrast value. In some embodiments, acquiring multiple images of the subject may include acquiring one image every second for 10 seconds.

[0009] According to another aspect of the present disclosure, a system for determining a timing bolus delay can include a computed tomography (CT) imaging system configured to acquire a plurality of images of a subject after a test bolus is administered to the subject, and a computing device having a processor and a non-transitory computer-readable storage device storing computer-executable instructions that cause the processor to: receive a plurality of images of the subject from the CT imaging system, determine a contrast value for each image of the plurality of images, generate a contrast curve based on the determined contrast values, determine a peak contrast value of the contrast curve, and determine a preparation delay based on the peak contrast value. The method may be executable to perform operations including: [Brief explanation of the drawings]

[0010] Various objects, features, and advantages of the disclosed subject matter can be better understood by reference to the detailed description of the disclosed subject matter in conjunction with the accompanying drawings, in which like reference numerals refer to like elements. [Figure 1] FIG. 1 is a block diagram of an exemplary system for automatically determining a timing bolus delay, according to some embodiments of the present disclosure. [Figure 2] 10 is a flowchart of an exemplary process for automatically determining a timing bolus delay, according to an exemplary embodiment of the present disclosure. [Figure 3] 10 is another flowchart of an exemplary process for automatically determining a timing bolus delay, according to an exemplary embodiment of the present disclosure. [Figure 4] 4A-4B are exemplary user interfaces that may be displayed within the system of FIG. 1 according to one embodiment of the present disclosure. [Figure 5] 2 is another exemplary user interface that may be displayed within the system of FIG. 1 according to one embodiment of the present disclosure. [Figure 6] 2 illustrates an exemplary computing device that can be used in the system of FIG. 1 according to one embodiment of the present disclosure.

[0011] The drawings are not necessarily to scale, nor do they include all elements of the system, emphasis generally being placed upon illustrating the concepts, structures and techniques sought to protect herein. DETAILED DESCRIPTION OF THE INVENTION

[0012] The following detailed description is merely illustrative and is not intended to limit the scope of the claimed invention or its uses.

[0013] Timing is a critical aspect of contrast-enhanced CT imaging technology. In particular, it is highly desirable for data acquisition (i.e., the CT imaging system) to be synchronized with the administration of the contrast agent. In other words, it is highly desirable for the CT imaging system to perform imaging while the contrast agent passes through the region of interest within the patient's body. This maximizes image quality and highlights specific structures in the images acquired by the imaging system. To synchronize this timing and achieve maximum accuracy in such imaging, a common technique involves the use of a test bolus to determine the "delay" of the contrast agent traveling from the injection site to the region of interest. A test bolus is a small amount of "test" contrast agent that is administered (i.e., via injection) to the patient. The CT imaging system can then monitor the uptake of the contrast agent in the imaging region, acquiring a fixed number of images at a preset frequency (e.g., one image per second for 10 seconds). The contrast of each image is then plotted as a function of time, e.g., as a scatter plot. The user must then manually evaluate the graph, typically by counting points and manually adding some initial values ​​to estimate the fixed delay. The estimated delay is then used when the contrast agent is actually administered to ensure optimal timing, but such manual calculations are unreliable, tedious, time-consuming, and generally undesirable.

[0014] Accordingly, embodiments of the present disclosure relate to systems and methods for automatically determining a timing bolus delay. The disclosed techniques involve administering a test bolus to a subject and acquiring multiple CT images (which typically include a series of X-ray images) of the subject's region of interest over a period of time after the test bolus is administered. The images are sent to a computing device for analysis, and a contrast value is determined for each image. The contrast values ​​are then plotted, and the computing device automatically identifies the image with the peak contrast value. The computing device then calculates the elapsed time from the injection of the test bolus to the peak contrast value. This elapsed time (i.e., the "preparation delay") can then be used to perform a full contrast-enhanced CT scan. Additionally, various plots (e.g., contrast curves) can be displayed in a user interface to a technician or other person administering the CT scan. Furthermore, the disclosed system allows for significant customization to the technician's advantage. For example, rather than automatically using a determined preparation delay, the technician can manually edit the delay through the user interface. In other embodiments, the user can customize what values ​​are calculated and displayed through the user interface. For example, rather than the peak contrast value, the system may calculate and display the time to peak plus buffer, the time to reach a predetermined percentage of the peak, the time to reach contrast threshold (relative or absolute) in Hounsfield units (HU), etc.

[0015] 1 is a block diagram of an example system 100 for automatically determining a timing bolus delay in accordance with some embodiments of the present disclosure. The system 100 can be used to perform a contrast-enhanced CT scan of a subject 108. The system 100 can include a contrast injector 101 configured to inject or administer a contrast agent to the subject 108. The contrast injector 101 can inject both a test bolus and a full amount of contrast agent into the subject 108. Additionally, the system 100 can include a CT imaging system 102 configured to perform a CT imaging technique to acquire various images (e.g., X-ray images) of a patient. For example, the CT imaging system 102 can include a subject table and cradle for supporting and inserting the subject into a gantry (the gantry includes an X-ray source and an X-ray detector array that rotates around the subject during the CT imaging technique to acquire images of the subject), and a controller for implementing various methods described herein. In some embodiments, the images acquired are non-diagnostic images, meaning that the images are not used to diagnose any condition. Instead, the images are used only for bolus timing.

[0016] The system 100 further includes a computing device 103 that is communicatively coupled to the CT imaging system 102 and capable of receiving images acquired by the CT imaging system 102. The computing device 103 may include an imaging module 104, a contrast analysis module 105, a time analysis module 106, and a user interface (UI) 107. In some embodiments, the imaging module 104 is configured to receive images acquired by the CT imaging system 102 and, for example, cause the received images to be displayed by the UI 107 of the computing device 103. In some embodiments, the contrast analysis module 105 is configured to analyze the images received from the CT imaging system 102. For example, the contrast analysis module 105 may measure / detect / calculate / determine the level of contrast (i.e., "contrast value") for each acquired image. Furthermore, the contrast analysis module 105 may generate a contrast curve, which is a plot of the contrast values ​​of the images over time, and identify peak contrast values ​​from a series of images. In some embodiments, the temporal analysis module 106 is configured to determine the elapsed time from the injection of the test bolus to the peak contrast value (i.e., the "preparation delay"). The temporal analysis module 106 can then, in some embodiments, automatically program the CT imaging system 102 to perform a subsequent CT imaging protocol using the determined preparation delay. Additionally, the UI 107 allows a technician or other user (e.g., a radiologist) to interact with the system and customize various details of the contrast analysis and preparation delay calculation.

[0017] In some embodiments, computing device 103 may include one or more computing devices capable of receiving user input through UI 107, transmitting and / or receiving data over a network, and / or communicating with CT imaging system 102. In some embodiments, computing device 103 may be a conventional computer system (such as a desktop or laptop computer or a standalone computer, server, or other computer system). Alternatively, computing device 103 may include a device with computer capabilities (such as a personal digital assistant (PDA), mobile phone, smartphone, tablet, or other suitable device). In some embodiments, computing device 103 may be the same as or similar to computing device 600, described below with respect to FIG. 6.

[0018] 2 is a flowchart of an example process 200 for automatically determining a timing bolus delay according to an example embodiment of the present disclosure. In some embodiments, the process 200 may be performed by a computing device 103 in combination with a test bolus administered to a subject 108 and a full contrast CT imaging scan. In block 201, the contrast injector 101 administers a test bolus to the subject 108. In some embodiments, the administration may be performed by injecting contrast into the arm of the subject 108.

[0019] In block 202, the CT imaging system 102 acquires multiple images of the subject 108. For example, the images may be acquired using standard commonly used CT scanning techniques. In some embodiments, the CT imaging system 102 may acquire a predetermined number of images at a predetermined frequency (e.g., one image per second for 10 seconds). The acquired images may then be sent to the imaging module 104 of the computing device 103 and analyzed. In block 203, the contrast analysis module 105 determines a contrast value for each image. In some embodiments, the contrast value may be expressed in HU, a standard relative quantitative measure of radiodensity.

[0020] In block 204, the contrast analysis module 105 generates a contrast curve. In some embodiments, this may include plotting the determined contrast values ​​for each image as a function of time. In some embodiments, the contrast curve is displayed to the technician on the computing device 103 via the UI 107. From there, the technician can perform various customizations. For example, the technician can manipulate the contrast curve by positioning a region of interest in the subject's anatomy. In block 205, the temporal analysis module 106 determines the peak contrast value of the contrast curve. For example, the temporal analysis module 106 may identify a point on the contrast curve (corresponding to one of the acquired images) with a maximum Hounsfield Unit (HU) value. Then, in block 206, the temporal analysis module 106 may determine the elapsed time from the injection of the test bolus to the time when the peak contrast value was obtained. This is set as the warm-up delay. Furthermore, the peak contrast value and the total elapsed time in HU may be displayed to the technician via the UI 107. In some embodiments, the total elapsed time may be determined by the relative HU change, the absolute HU change, or by reaching a predetermined percentage of the peak contrast value. In some embodiments, the total elapsed time may be adjusted by a predetermined time correction factor (e.g., ±x hours defined by the technician). In block 207, a full contrast-enhanced CT scan of the subject is performed based on the determined preparation delay.

[0021] 3 is another flowchart of an exemplary process 300 for automatically determining a timing bolus delay in accordance with an exemplary embodiment of the present disclosure. In some embodiments, the process 300 may be performed by a computing device 103 in coordination with performing a test bolus and a full contrast-enhanced CT scan on a subject 108. Additionally, the process 300 may be performed to automatically calculate intergroup delays in contrast studies where contrast washout has occurred. In block 301, the contrast injector 101 administers a test bolus to the subject 108. In some embodiments, the administration may be performed by injecting contrast into the arm of the subject 108.

[0022] In block 302, the CT imaging system 102 acquires multiple images of the subject 108. For example, the images may be acquired using standard commonly used CT scanning techniques. In some embodiments, the CT imaging system 102 may acquire a predefined number of images at a predefined frequency (e.g., one image per second for a total of 10 seconds). The acquired images may then be sent to the imaging module 104 of the computing device 103 for analysis. In block 303, the contrast analysis module 105 determines a contrast value for each image. In some embodiments, the contrast value may be expressed in HU, which is a standard relative quantitative measure of radiodensity.

[0023] In block 304, the contrast analysis module 105 generates a contrast curve. In some embodiments, this may include plotting the determined contrast values ​​for each image as a function of time. In some embodiments, the contrast curve is displayed to the technician on the computing device 103 via the UI 107. From here, the technician can perform various customizations. For example, the technician can manipulate the contrast curve by placing a region of interest on the subject's anatomy. In block 305, the temporal analysis module 106 identifies a plateau (i.e., washout) in the contrast curve. In some embodiments, the plateau may be identified at a specified location after the peak contrast value. Next, in block 306, the temporal analysis module 106 may determine the elapsed time from the injection of the test bolus to the time the peak contrast value is obtained. This is set as the warm-up delay. Additionally, the peak contrast value (HU) and total elapsed time may be displayed to the technician via the UI 107. In some embodiments, the total elapsed time may be determined by the relative HU change, the absolute HU change, or reaching a predetermined percentage of the peak contrast value. In some embodiments, the total elapsed time may be adjusted by a predetermined time correction factor (e.g., ±x hours defined by the technician). In block 307, a full contrast-enhanced CT scan of the subject is performed based on the determined preparation delay. For example, the determined time may be set as a group delay for washout of subsequent contrast acquisition groups.

[0024] 4A and 4B are exemplary user interfaces that can be displayed within the system of FIG. 1 in accordance with an embodiment of the present disclosure. FIG. 4A illustrates an exemplary contrast curve 400 that can be displayed on the computing device 103 by the UI 107, with the X-axis representing time and the Y-axis representing HU. Each point is plotted as a HU value point from each image acquired by the CT imaging system 102, and a line is automatically drawn based on the plotted points. The contrast curve 400 also includes an automatic pop-up displaying the automatically calculated elapsed time (18.0 seconds) and peak contrast value (110.0 HU). In some embodiments, the pop-up includes a button selectable by the technician that allows the elapsed time to be used as a setup delay for the subsequent contrast-enhanced CT imaging process. FIG. 4B also illustrates an interface 401 that can be displayed on the computing device 103 by the UI 107. In the interface 401, the setup delay is automatically set to the elapsed time from the contrast curve (18.0 seconds), but this value can be adjusted by the technician.

[0025] 5 is another exemplary user interface 500 that may be displayed within the system of FIG. 1 in accordance with an embodiment of the present disclosure. The interface 500 may be displayed by the UI 107 of the computing device 103. The interface 500 displays CT imaging of the subject 108 as well as a contrast curve generated after administering a test bolus. Additionally, the interface 500 may include a control panel 501 that allows a technician to exercise various controls of the CT imaging system 102, such as the type of HU (absolute vs. relative), defining a region of interest, or setting an HU threshold.

[0026] 6 is an exemplary computing device that can be used in the system of FIG. 1 according to embodiments of the present disclosure. In some embodiments, device 600 can be computing device 103. Exemplary user device 600 can include a memory interface 602, one or more data processors, an image processor, a central processing unit 604, and / or a secure processing unit 605, and a peripheral subsystem 606. Memory interface 602, one or more central processing units 604, and / or a secure processing unit 605, and / or a peripheral subsystem 606 can be separate components or can be integrated into one or more integrated circuits. The various components of user device 600 can be coupled by one or more communication buses or signal lines.

[0027] Sensors, devices, and subsystems can be coupled to the peripheral subsystem 606 to perform multiple functions. For example, a motion sensor 610, a light sensor 612, and a proximity sensor 614 can be coupled to the peripheral subsystem 606 to provide orientation, lighting, and proximity functions. Other sensors 616 can also be connected to the peripheral subsystem 606, such as a Global Navigation Satellite System (GNSS) (e.g., a GPS receiver), a temperature sensor, a biosensor, a magnetometer, or other sensing devices, to provide related functions.

[0028] A camera subsystem 620 and an optical sensor 622 (e.g., a charge-coupled device (CCD) or a complementary metal-oxide semiconductor (CMOS) optical sensor) may be utilized to provide camera functionality, such as recording photographs and video clips. The camera subsystem 620 and the optical sensor 622 may be used to collect images of a user that may be used during authentication of the user, for example, by performing facial recognition analysis.

[0029] Communication functions may be performed by one or more wired and / or wireless communication subsystems 624, which may include radio frequency receivers and transmitters and / or optical (e.g., infrared) receivers and transmitters. For example, the Bluetooth (e.g., Bluetooth Low Energy (BTLE)) and / or WiFi communications described herein may be handled by the wireless communication subsystem 624. The specific design and implementation of the communication subsystem 624 may depend on the communication networks over which the user device 600 is intended to operate. For example, the user device 600 may include a communication subsystem 624 designed to operate on a GSM network, a GPRS network, an EDGE network, a WiFi or WiMax network, and a Bluetooth network. For example, the wireless communication subsystem 624 may include a hosting protocol to configure the device 600 as a base station for other wireless devices or to provide WiFi services.

[0030] The audio subsystem 626 may be coupled to a speaker 628 and a microphone 630 to provide voice-enabled functions such as speaker recognition, voice duplication, digital recording, and telephony functions. The audio subsystem 626 may be configured to perform, for example, voice command processing, voice printing, and voice authentication.

[0031] The I / O subsystem 640 can include a touch surface controller 642 and / or other input controllers 644. The touch surface controller 642 can be coupled to a touch surface 646. The touch surface 646 and touch surface controller 642 can detect contact and movement, or the end of contact and movement, using any of a number of touch sensitivity technologies (including, but not limited to, capacitive, resistive, infrared, and surface acoustic wave technologies), as well as other proximity sensor arrays or other elements to determine one or more points of contact with the touch surface 646.

[0032] Other input controller 644 may be coupled to other input / control devices 648 (e.g., one or more buttons, rocker switches, thumbwheels, infrared ports, USB ports, and / or pointer devices such as styluses). One or more buttons (not shown) may include up / down buttons for volume control of speaker 628 and / or microphone 630.

[0033] In some implementations, pressing and holding the button for a first period of time can unlock the touch surface 646, and pressing and holding the button for a second period of time longer than the first period can power the user device 600 on or off. Pressing and holding the button for a third period of time can activate a voice control (or voice command) module, allowing the user to speak commands into the microphone 630 and have the device execute the spoken commands. The user can customize the functionality of one or more buttons. The touch surface 646 can also be used to implement, for example, virtual or soft buttons and / or a keyboard.

[0034] In some implementations, user device 600 can present recorded audio and / or video files (e.g., MP3, AAC, and MPEG files). In some implementations, user device 600 can include MP3 player functionality (e.g., iPod®). Thus, user device 600 can include a 36-pin connector and / or an 8-pin connector compatible with an iPod®. Other input / output devices and control devices can also be used.

[0035] The memory interface 602 can be coupled to memory 650. The memory 650 can include high-speed random-access memory and / or non-volatile memory (such as one or more magnetic disk storage devices, one or more optical storage devices, and / or flash memory (e.g., NAND, NOR)). The memory 650 can store an operating system 652 (e.g., Darwin, RTXC, LINUX, UNIX, OSX, Windows, or an embedded operating system (such as VxWorks)).

[0036] Operating system 652 may include instructions for handling basic system services and performing hardware-dependent tasks. In some implementations, operating system 652 may be a kernel (e.g., a UNIX kernel). In some implementations, operating system 652 may include instructions for performing voice authentication.

[0037] Memory 650 may also store communications instructions 654 for performing communications with one or more additional devices, one or more computers, or one or more servers. Memory 650 may include graphical user interface instructions 656 for performing graphical user interface processes, sensor processing instructions 658 for performing sensor-related processes and functions, telephony instructions 660 for performing telephony-related processes and functions, electronic messaging instructions 662 for performing electronic messaging-related processes and functions, web browsing instructions 664 for performing web browsing-related processes and functions, media processing instructions 666 for performing media processing-related functions and processes, GNSS / navigation instructions 668 for performing GNSS and navigation-related processes and instructions, and / or camera instructions 670 for performing camera-related processes and functions.

[0038] Memory 650 can store application (or "app") instructions and data 672 (such as the app instructions described above in the description of FIGS. 1-6). Memory 650 can also store software instructions 674 for various other software applications of device 600. The described functionality can be implemented in one or more computer programs, which are executable on a programmable system including at least one programmable processor coupled to receive data and instructions from, and transmit data and instructions to, a data storage system, at least one input device, and at least one output device. A computer program is a set of instructions that can be used, directly or indirectly, by a computer to perform a particular activity or bring about a particular result. The computer program may be written in any type of programming language, including compiled or interpreted languages ​​(e.g., Objective-C, Java), and the computer program may be deployed in any form (e.g., as a stand-alone program or as a module, component, subroutine, or other unit suitable for use in a computing environment).

[0039] The described functions may be implemented in one or more computer programs, which may be executable on a programmable system including at least one programmable processor coupled to receive data and instructions from, and transmit data and instructions to, a data storage system, at least one input device, and at least one output device. A computer program is a set of instructions that can be used, directly or indirectly, by a computer to perform a particular activity or bring about a particular result. Computer programs may be written in any type of programming language, including compiled or interpreted languages ​​(e.g., Objective-C, Java), and may be deployed in any form (e.g., as a stand-alone program or as a module, component, subroutine, or other unit suitable for use in a computing environment).

[0040] Processors suitable for the execution of program instructions include, by way of example, both general and special purpose microprocessors, and either a single processor or multiple processors or cores in any type of computer. Generally, a processor can receive instructions and data from a read-only memory, a random-access memory, or both. Essential elements of a computer include a processor for executing instructions and one or more memories for storing instructions and data. Generally, a computer may include, or be operatively coupled to communicate with, one or more mass storage devices for storing data files. Such devices include magnetic disks (such as internal hard disks and removable disks), magneto-optical disks, optical disks, and the like. Storage devices suitable for tangibly embodying computer program instructions and data include all forms of non-volatile memory (e.g., by way of example, semiconductor memory devices (such as EPROMs, EEPROMs, flash memory devices), magnetic disks (such as internal hard disks and removable disks), magneto-optical disks, CD-ROM disks, and DVD-ROM disks). The processor and memory may be supplemented by, or incorporated in, application-specific integrated circuits (ASICs).

[0041] To interact with a user, the functionality may be implemented in a computer that has a display device, such as an LED or LCD monitor, that displays information to the user, and a keyboard and pointing device, such as a mouse or trackball, that allows the user to provide input to the computer.

[0042] The functionality may be implemented in a computer system that includes back-end components (such as data servers), middleware components (such as application servers or Internet servers), front-end components (such as client computers with graphical user interfaces or Internet browsers), or any combination thereof. The components of the system may be connected by any form or medium of digital data communication, such as a communications network. Examples of communications networks include, for example, the telephone network, a LAN, a WAN, and the computers and networks forming the Internet.

[0043] A computer system may include clients and servers. Clients and servers may generally be remote from each other and typically interact through a network. The relationship of client and server arises by virtue of computer programs running on the respective computers and having a client-server relationship to each other.

[0044] One or more functions or steps of the disclosed embodiments may be implemented using an API, which may define one or more parameters passed between a calling application and other software code (e.g., an operating system, library routine, function) that provides a service, provides data, or performs an operation or calculation.

[0045] An API may be implemented as one or more calls in program code that receive and send one or more parameters via a parameter list or other structure based on a calling convention defined in an API specification. A parameter may be a constant, key, data structure, object, object class, variable, data type, pointer, array, list, or another call. API calls and parameters may be implemented in any programming language. A programming language may define the vocabulary and calling conventions that programmers employ to access functions that support the API.

[0046] In some implementations, the API calls may report to the application the capabilities (input capabilities, output capabilities, processing capabilities, power capabilities, communication capabilities, etc.) of the device on which the application is running.

[0047] While various embodiments have been described above, it should be understood that these embodiments are presented by way of example and are not intended to be limiting. It will be apparent to those skilled in the art that various changes in form and detail may be made without departing from the spirit and scope of the present invention. Indeed, upon reading the above description, it will be apparent to those skilled in the art how to implement alternative embodiments. For example, other steps may be added to the described flows, steps may be deleted from the described flows, other components may be added to the described systems, or components may be deleted from the described systems. Accordingly, other implementations are within the scope of the following claims.

[0048] Additionally, it should be understood that the diagrams highlighting functionality and advantages are presented for illustrative purposes only, and the disclosed methods and systems are sufficiently flexible and configurable so that they can be used in ways other than those shown.

[0049] In this specification, claims, and drawings, the term "at least one" may be used, but terms such as "a," "an," "the," and "said" also mean "at least one" or "said at least one" in this specification, claims, and drawings.

[0050] Finally, Applicant intends that only claims that expressly include the phrase "means for" or "step for" be construed under 35 U.S.C. 112(f). Claims that do not expressly include the phrase "means for" or "step for" are not to be construed under 35 U.S.C. 112(f). [Explanation of symbols]

[0051] 100 systems 101 Contrast agent injector 102 CT Imaging System 103 Computing Devices 104 Imaging Module 105 Contrast Analysis Module 106 Time Analysis Module 108 specimens 110 Peak Contrast Value 200 processes Block 201 Block 202 Block 203 Block 204 205 Block Block 206 Block 207 300 processes 301 Block 302 Block Block 303 304 Block 305 Block Block 306 Block 307 400 Contrast Curve 401 Interface 501 Control Panel 600 computing devices 602 Memory Interface 604 Central Processing Unit 605 Secure Processing Unit 606 Peripheral Subsystem 610 Motion Sensor 612 Optical Sensor 614 Proximity Sensor 616 Sensors 620 Camera Subsystem 622 Optical Sensor 624 Wireless Communication Subsystem 626 Audio Subsystem 628 Speaker 630 Microphone 640 I / O Subsystem 642 Touch Surface Controller 644 Input Controller 646 Touch Surface 648 Control Device 650 memory 652 Operating Systems 654 Communication Order 656 Graphical User Interface Instructions 658 Sensor Processing Instructions 660 Telephone Instruction 662 Electronic Messaging Order 664 Web Browsing Instructions 666 Media Processing Instructions 668 Navigation Instructions 670 Camera Command 672 data 674 Software Instructions

Claims

1. 1. A method for determining a timing bolus delay, comprising: administering a test bolus to the subject; acquiring a plurality of images of the subject with a computed tomography (CT) imaging system; determining a contrast value for each image of the plurality of images; generating a contrast curve based on the determined contrast values; determining a peak contrast value of said contrast curve; determining a preparation delay based on the peak contrast value; and performing a contrast-enhanced CT scan of the subject based on the determined preparation delay; A method comprising:

2. The method of claim 1 , wherein administering the test bolus to the subject comprises injecting a contrast agent into the subject.

3. The method of claim 1 , wherein determining a preparation delay based on the peak contrast value comprises automatically determining a total elapsed time from administration of the test bolus to the peak contrast value.

4. 4. The method of claim 3, wherein automatically determining the total elapsed time includes analyzing at least one of a relative Hounsfield Unit (HU) change, an absolute HU change, and reaching a predetermined percentage of a peak contrast value.

5. receiving a selection from a user via a user interface; and analyzing at least one of a relative Hounsfield Unit (HU) change, an absolute HU change, and reaching a predetermined percentage of the peak contrast value based on the received selection; The method of claim 4, comprising:

6. receiving a definition of a region of interest from a user via a user interface; and Manipulating the contrast curve based on a definition of a region of interest. The method of claim 1 , comprising:

7. 4. The method of claim 3, further comprising adjusting the total elapsed time by a predetermined correction factor.

8. The method of claim 7 , wherein the predetermined correction factor is set by a user through a user interface.

9. The method of claim 1 , wherein acquiring multiple images of the subject comprises acquiring one image every second for a period of 10 seconds.

10. 1. A method for determining a timing bolus delay, comprising: administering a test bolus to the subject; acquiring a plurality of images of the subject with a computed tomography (CT) imaging system; determining a contrast value for each image of the plurality of images; generating a contrast curve based on the determined contrast values; identifying a plateau in the contrast curve; determining a preparation delay based on the identified plateau; and performing a contrast-enhanced CT scan of the subject based on the identified plateau. A method comprising:

11. The method of claim 10 , wherein administering the test bolus to the subject comprises injecting a contrast agent into the subject.

12. 11. The method of claim 10, wherein determining a warm-up delay based on an identified plateau comprises automatically determining a total elapsed time from administration of the test bolus to the identified plateau.

13. 13. The method of claim 12, wherein automatically determining the total elapsed time includes analyzing at least one of a relative Hounsfield Unit (HU) change, an absolute HU change, and reaching a predetermined percentage of a peak contrast value.

14. receiving a selection from a user via a user interface; and analyzing at least one of a relative Hounsfield Unit (HU) change, an absolute HU change, and reaching a predetermined percentage of the peak contrast value based on the received selection; 14. The method of claim 13, comprising:

15. receiving a definition of a region of interest from a user via a user interface; and Manipulating the contrast curve based on a definition of a region of interest. The method of claim 10, comprising:

16. The method of claim 12, comprising adjusting the total elapsed time by a predetermined correction factor.

17. The method of claim 16 , wherein the predetermined correction factor is set by a user through a user interface.

18. The method of claim 10 , wherein the plateau occurs at a specified location after a peak contrast value.

19. The method of claim 10 , wherein acquiring multiple images of the subject comprises acquiring one image every second for a period of 10 seconds.

20. 1. A system for determining a timing bolus delay, comprising: a computed tomography (CT) imaging system configured to acquire a plurality of images of the subject after the subject has been administered a test bolus; and A computing device having a processor and a non-transitory computer-readable storage device that stores computer-executable instructions. and The instructions cause the processor to: receiving a plurality of images of a subject from the CT imaging system; determining a contrast value for each image of the plurality of images; generating a contrast curve based on the determined contrast values; determining a peak contrast value of the contrast curve; and determining a warm-up delay based on said peak contrast value; The system is executable to cause the system to perform operations including:

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