Adjustment of scanning parameters during contrast-enhanced scanning

Abstract

A computed tomography imaging system (102) includes an X-ray radiation source (110) configured to emit X-ray radiation that passes through an examination region (108) and an X-ray sensitive detector array (112) configured to detect X-rays that pass through the examination region and generate a line-integrated view. The imaging system also includes an object support table (118) that is configured to translate in the examination region for scanning based on at least one scanning parameter. The imaging system also includes an operator console (122) that includes a processor (128) and a computer readable storage medium (130) having a scanning parameter adapter module (132). The processor is configured to execute instructions of the scanning parameter adapter module that cause the processor to determine a contrast agent concentration based on the line-integrated view and adjust at least one scanning parameter based on the determined concentration.

Description

Technical Field

[0001] The following relates generally to imaging, and more specifically to adjusting scan parameters during a contrast-enhanced scan using contrast agent concentration estimates determined from acquired data during the scan, and is described as having particular application to computed tomography (CT) imaging, including non-spectral CT imaging and / or spectral CT imaging, and is applicable to other imaging modalities. Background Art

[0002] A computed tomography (CT) scanner typically includes a rotating frame that supports an X-ray tube and a detector array that are positioned relative to each other across a bore of the frame that defines an examination region. For a volumetric scan, the rotating frame rotates while the X-ray tube emits radiation that passes through the examination region and the detector array detects radiation that passes through the examination region. The detector array outputs a signal indicative of the detected radiation, and the signal is processed to generate volumetric image data representative of the examination region and any object or subject disposed therein.

[0003] Contrast enhanced imaging procedures such as CT angiography include scanning an object to which a radiocontrast agent has been administered to image the distribution of the contrast agent in the cardiovascular system. In one example, this includes administering the agent via a vein and / or other entry point in the arm using a syringe or catheter with a monophasic, biphasic, or multiphasic injection regimen. In the case of a bolus of contrast agent, initially there will be no contrast agent for a given location upstream of the injection site in the cardiovascular system. As the contrast agent distributes and enters the location (uptake), the amount of contrast agent at the location will increase until a peak amount (peak enhancement), and then decrease as the contrast agent leaves the location (washout). In one instance, the scan is configured to track peak enhancement during the scan.

[0004] However, the rate at which contrast media is distributed in the cardiovascular system depends on multiple factors, such as the subject's cardiac performance, cardiovascular disease, subject-specific anatomy, and injection site and flow rate, to name a few. As a result, for a given set of scan parameters, the scan may miss peak contrast enhancement at at least some times during the scan. Unfortunately, the resulting volumetric image data will not include the peak enhancement at that time(s), which can negatively impact the assessment of the extent of obstruction and / or coronary artery disease based on the resulting reconstructed volumetric image data.

[0005] US 2017 / 0086772 A1 describes a method for adaptive scan control, which includes performing a non-contrast scan, determining a monitoring position, injecting a contrast agent, starting the scan with predetermined scan parameters, monitoring the contrast level in the monitoring area based on the non-contrast scan, and adjusting the scan parameters based on the contrast level.

[0006] DE 10 2005 024 323 A1 describes a method for determining scanning parameters of an X-ray imaging device. The method comprises selecting a first and a second scanning position, injecting a contrast agent, determining a first time when a contrast level at the first scanning position reaches a threshold value, determining a second time when a contrast level at the second scanning position reaches the threshold value, and determining the scanning parameters based on the first time and the second time. Summary of the invention

[0007] Aspects described herein address the above-referenced issues and others.

[0008] In one aspect, a computed tomography imaging system includes: an X-ray radiation source configured to emit X-ray radiation that passes through an examination region; and an X-ray radiation sensitive detector array configured to detect the X-ray radiation that passes through the examination region and generate a line-integrated view. The imaging system also includes an object support table configured to translate in the examination region for scanning based on at least one scanning parameter. The imaging system also includes an operator console, the operator console including a processor and a computer-readable storage medium having a scanning parameter adapter module. The processor is configured to execute instructions of the scanning parameter adapter module, the instructions causing the processor to determine a contrast agent concentration based on the line-integrated view and adjust at least one scanning parameter based on the determined concentration.

[0009] In another aspect, a method includes receiving views of projection data during CT angiography; determining, for one or more of the views, an amount of contrast agent in a current scan plane; and adjusting a scan parameter of the CT angiography in response to the amount of contrast agent not satisfying a predetermined condition.

[0010] In another aspect, a computer-readable medium is encoded with computer-executable instructions that, when executed by a processor of a computer, cause the processor to: receive views of projection data during CT angiography, determine an amount of contrast agent in a current scan plane for one or more of the views, and adjust a scan parameter of the CT angiography in response to the amount of contrast agent not satisfying a predetermined condition. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] The invention may take the form of various components and arrangements of components, and may take the form of various steps and arrangements of steps.The drawings are only for the purpose of illustrating the preferred embodiments and are not to be construed as limiting the invention.

[0012] Figure 1 An example CT imaging system with a scan parameter adapter module is schematically illustrated.

[0013] Figure 2 An example of a scan parameter adapter module for non-spectral projection data is schematically illustrated.

[0014] Figure 3 An example scan plan associated with an object is illustrated.

[0015] Figure 4 An example of a desirable situation in which contrast concentrations of interest are captured during the entire volume is illustrated.

[0016] Figure 5 An example of regulating the velocity of a subject support by a control loop feedback mechanism for setting a set point for peak contrast concentration is schematically illustrated.

[0017] Figure 6 An example of a scan parameter adapter module for spectral projection data is schematically illustrated.

[0018] Figure 7 An example method for adjusting scan parameters of non-spectral projection data is illustrated.

[0019] Figure 8 An example method for adjusting scan parameters of spectral projection data is illustrated. DETAILED DESCRIPTION

[0020] Figure 1 An imaging system 100 , such as a computed tomography (CT) scanner, is schematically illustrated.

[0021] The imaging system 102 includes a generally fixed gantry 104 and a rotating gantry 106. The rotating gantry 106 is rotatably supported by the fixed gantry 104 (e.g., via bearings, etc.), and rotates about an examination region 108 about a longitudinal or rotational axis (z-axis). An X-ray source 110, such as an X-ray tube, is rotatably supported by the rotating gantry 104, rotates in coordination with the rotating gantry 104, and emits X-ray radiation. The X-ray source 110 includes a collimator that shapes the emitted X-ray radiation to form a beam (e.g., a beam in the shape of a fan, a wedge, a cone, etc.) that passes through the examination region 108.

[0022] A radiation sensitive detector 112 (which includes a one-dimensional or two-dimensional array of rows of detector elements) is rotatably supported by the rotating gantry 104 along an arc opposite the x-ray source 110 and across the examination region 108. As the detector 112 rotates, the detector elements 114 detect radiation over successive arc segments (integration periods) along the rotational path. For each arc segment, each detector element generates an electrical signal indicative of the total x-ray attenuation (line integral) along the path from the x-ray source 110 to the detector element. The collection of line integrals for an arc is referred to herein as a view, and the collection of views is referred to herein as projection data.

[0023] In a variation, the imaging system 102 is configured for spectral (multi-energy) imaging. For example, the radiation sensitive detector 112 may include an energy-resolving detector, such as a multilayer scintillator / photosensor detector (e.g., US 7968853 B2, which is incorporated herein by reference in its entirety) and / or a photon counting (direct conversion) detector (e.g., WO2009072056A2, which is incorporated herein by reference in its entirety). In this example, the X-ray source 110 may include a broadband source, a kVp switch (e.g., US 8442184 B2, which is incorporated herein by reference in its entirety) and / or a plurality of X-ray tubes (e.g., US 8442184 B2).

[0024] In another variation, the imaging system 102 is configured for phase contrast imaging. An example of a CT scanner configured for phase contrast imaging is described in U.S. Patent No. 8,565,371 B2, filed on December 8, 2010, entitled “Rotational X-ray device for phase contrast imaging”, which is incorporated herein by reference in its entirety. An example of a CT scanner configured for phase contrast imaging is described in US 2010 / 0322380 A1, filed on August 9, 2010, entitled “X-ray detector for phase contrast imaging”, which is incorporated herein by reference in its entirety.

[0025] The reconstructor 116 reconstructs the projection data and generates volumetric image data. For non-spectral projection data, the reconstructor 116 generates conventional broadband (non-spectral) volumetric image data. Using the spectral projection data, the reconstructor 116 generates conventional broadband (non-spectral) volumetric image data and / or spectral volumetric image data. The spectral volumetric image data may include at least a contrast (e.g., iodine) concentration map. Examples of other data include, but are not limited to, monoenergetic image data, effective Z (atomic number) image data, photoelectric effect and Compton scattering image data, and / or other image data.

[0026] An object support, such as a couch, includes a table 118 movably coupled to a frame / base 120. In the illustrated example, the table 118 is slidably coupled to the frame / base 120 via bearings or the like. A drive system (not visible) including a controller, motor, lead screw, and nut (or other drive system) moves the table 118 into and out of the examination region 108 along the frame / base 120. The table 118 is configured to support an object or subject in the examination region 108, thereby guiding the object or subject relative to the examination region 108 for loading, scanning, and / or unloading the object or subject.

[0027] A computing system or computer serves as an operator console 122 and includes a human-readable output device 124 such as a display, an input device 126 such as a keyboard, a mouse, etc., a processor 128 (e.g., a microprocessor, a central processing unit (CPU), etc.), and a computer-readable storage medium 130, which includes non-transitory media (hardware memory) and does not include transient media (signals, carrier waves, etc.). Software resident on the operator console 122 (e.g., in the computer-readable storage medium 130) allows the operator to control the operation of the system 102, including selecting imaging protocols, setting scanning parameters, etc.

[0028] The illustrated computer readable storage medium 130 includes at least a scan parameter adapter module 132 that includes instructions for adjusting scan parameter(s) (e.g., table 118 speed, pitch for spiral scans, acquisition timing / duration for axial scans, frame rate for sparse sampling, rotation speed, etc.) during a scan. As described in more detail below, in one example, the scan parameters are adjusted for a CT angiography scan so that contrast concentrations around a peak concentration (or other desired level) are imaged in one or more (e.g., all) slice planes of the scan. In one example, this can be achieved while maintaining the anatomically specific requirements of the scan protocol, e.g., ECG-gated acquisitions at the heart, and non-ECG-gated acquisitions in the remaining scan areas.

[0029] Figure 2 An example of a scan parameter adapter module 132 is schematically illustrated for adjusting scan parameters during CT angiography using non-spectral projection data. The non-spectral projection data is generated by a non-spectral scanner or by combining spectral projection data generated by a spectral scanner. In this example, the scan parameter adapter module 132 includes a forward projector 202, a difference determiner 204, a metric determiner 206, a decision logic 208, and a parameter adjuster 210. The scan parameter adapter module 132 receives a non-contrast enhanced volume image generated during a pre-scan.

[0030] To this end, in one example, a 3D scan is performed using sparse angular sampling. For example, where full angular sampling includes emitting and detecting X-ray radiation for each of N views per rotation, with sparse angular sampling, X-rays are emitted and detected only for a subset (less than N) of these views, e.g., every 10th, 16th, 20th, etc. view. In another example, a 3D scan is performed with full angular sampling. Scan parameters such as mAs (X-ray intensity, as the product of X-ray tube current in milliamperes (mA) and exposure time in seconds (S)) can be set so that the patient radiation dose is no greater than the dose of a 2D scan map (also called surveillance, reconnaissance, pilot, etc.).

[0031] The projection data produced by the detector array 112 is reconstructed by a reconstructor 116 to generate volumetric image data. An operator console 122 receives the pre-scan volumetric image data. A user of the operator console 122 plans the angiography using the pre-scan volumetric image data. To this end, the volumetric image data is displayed via an output device 124, and the user plans the angiography using an input device 126. Planning may include identifying a start scan position and at least one of a scan range or an end scan position, selecting parameters (e.g., pitch, mAs, kV (average kilovolt voltage of the x-ray tube), employing automatic and / or semi-automatic tissue segmentation, etc.

[0032] During angiography, the operator console 122 receives views of projection data as they are acquired. For the received views, the forward projector 202 forward projects the pre-scan volumetric image data (all or a subset thereof) to estimate line integrals corresponding to the same angular positions as the received views. This can include estimating the line integrals and / or sub-portions of the entire view, or a view corresponding to a particular predetermined region of interest (ROI). The ROI can be determined, for example, based on an image-based ROI as determined from the pre-scan by the operator and / or by an automatic segmentation algorithm and converted to a projection / view ROI by forward projection using the forward projector. A difference determiner 204 calculates the difference between the acquired view and the estimated view. Typically, the difference indicates the amount of contrast agent present because the pre-scan is a non-contrast enhanced scan and the angiogram is a contrast enhanced scan.

[0033] The metric determiner 206 calculates the metric based on the differences in the line integrals of the view. In one example, the metric is calculated by summing all the differences or only summing the differences for a predetermined sub-region of the view. In one instance, the metric is calculated using data from a single slice / detector row. In another instance, the metric is calculated using data from multiple slices / detector rows, for example, where the detector array 112 is configured with multiple rows of detectors. The decision logic 208 determines whether the metric satisfies a predetermined condition. The condition can be a value plus or minus a given tolerance, range, etc. In one embodiment, a motion correction algorithm (e.g., elastic 2D-3D registration) is employed. In one example, the algorithm limits the difference between the forward projection pre-scan and the actual scan to the difference generated by the contrast agent. In one instance, this mitigates differences caused by non-contrast agents due to motion between the forward projection pre-scan and the actual scan.

[0034] In response to the metric not satisfying the predetermined condition, the parameter adjuster 210 adjusts at least one scan parameter (e.g., table 118 speed, etc.). In one example, the predetermined condition identifies the amount of contrast agent or the contrast agent concentration. In this example, the parameter(s) are adjusted so that a predetermined amount of contrast agent (e.g., peak contrast concentration) is represented in subsequently acquired projections. Typically, the parameter adjuster 210 does not adjust the scan parameter when the metric satisfies the predetermined condition. However, if desired, the scan parameter may be adjusted in this case.

[0035] For example, historical values ​​of a metric over time may indicate that the metric is more likely than not to fail a predetermined condition at a subsequent scan plane. In this instance, scan parameters may be actively adjusted. In another example, contrast agent administration information (such as flow rate, concentration, needle size, saline tracker, etc.), patient information (such as weight, height, heart rate, etc.), scan information (such as tube potential (kVp), virtual monoenergetic (keV), scan distance, etc., and / or other information is used to adjust scan parameters. In another variation, module 132 uses an anatomical model that includes information about an average contrast dose per body slice relative to a standardized value at a certain body height.

[0036] The above process is repeated for one or more views during the scan: forward projecting the pre-scan volumetric image data, determining the difference between the measured and estimated line integrals, determining a metric based on the difference, and adjusting the scan parameters based on a predetermined condition. Typically, this allows imaging of a peak contrast agent concentration or a range around the peak contrast agent concentration (or other predetermined level or range of the bolus) as the contrast agent bolus is distributed through the cardiovascular system.

[0037] Figure 3 and Figure 4 An example of a desired situation for capturing peak contrast concentration during a scan is shown, and Figure 3 and Figure 5 An example is shown in which the speed (scanning speed) of the table 118 is adjusted by a control loop feedback mechanism to set the set point to the peak contrast concentration. Figure 4 and 5 , a first axis 402 represents the integral of the contrast agent concentration, a second axis 404 represents the position of the scanning plane, and a third axis 406 represents time.

[0038] Figure 3A scan plan 302 is shown for a patient 304. The scan plan 302 includes a start scan position 306 and an end scan position 308. The scan starts at the start scan position 306 and ends at the end scan position 308. To scan the volume 302, the table 118 moves the patient 304 into the examination region 108. In this example, the scan starts at the start scan position 306 at or shortly after the contrast bolus is administered (stationary table 118 position), and the scan of the volume begins when the amount of contrast agent at that position reaches a predetermined threshold level (which triggers the table 118 to move the patient 304 at a predetermined rate defined in the scan protocol). Figure 3 The current scan plane 310 is shown about one-third of the way into the scan plan 302. In one example, the predetermined rate is planned based on a "normal" scan protocol. In a variation, it is based on a "normal" contrast agent rate for an average patient. In a variation, the scan begins after a predetermined duration from the administration of the contrast bolus and / or otherwise.

[0039] exist Figure 4 In FIG. 4 , a first curve 408 represents contrast agent concentration as a function of time, and a second curve 410 represents the scanning plane position as a function of time. Figure 4 Also shown is a predetermined threshold level of contrast agent concentration 412 that triggers scanning of the volume of patient 304. During time interval 414, contrast agent concentration increases over time at start position 306 as the bolus progresses, but is below predetermined threshold level 412, and table 118 remains at start position 306.

[0040] After the contrast agent concentration reaches the predetermined threshold level 412 at 416, the table 118 begins to move at the rate in the scan protocol, advancing the scan plane position as shown by curve 410. In this embodiment, the predetermined rate is such that at the desired scan plane 420 i And after 418 the peak contrast concentration is captured at a subsequent scan plane during the volume scan, as indicated by curve 408 , with a linear increase in scan plane position indicated by curve 410 .

[0041] Typically, a contrast agent bolus does not travel at a constant rate through the cardiovascular system, e.g. Figure 4 , where peak contrast concentrations are captured at all scan planes for the same constant table 118 velocity. Additionally, diseases such as atherosclerosis and / or another cardiovascular disease(ies) may alter the flow characteristics of the contrast bolus stream.

[0042] exist Figure 5 In FIG. 5 , a first curve 502 represents contrast agent concentration as a function of time, and a second curve 504 represents the scanning plane position as a function of time. Figure 5 Also shown is a predetermined threshold level of contrast agent concentration 506 that triggers a scan of the volume of the patient 304. During time interval 508, the contrast agent concentration increases over time at the start position 306 as the bolus progresses, but is below the predetermined threshold level 506. After the contrast agent concentration reaches the predetermined threshold level 506 at 510, the table 118 begins moving at the rate in the scan protocol, thereby advancing the scan plane position.

[0043] In this example, the contrast agent concentration is in the scanning plane 514 i At 514, the contrast agent concentration is below the peak concentration. As described herein, the scan parameter adapter module 132 detects this, for example, by evaluating changes in contrast agent concentration from one or more previous scan planes and / or in other ways. i , the scan parameter adapter module 132 detects that the contrast agent concentration is decreasing from scan plane to scan plane, indicating that the table 118 needs to slow down, and the scan plane 514 i In front of the peak contrast concentration 512. In response, the scan parameter adapter module 132 reduces the speed of the table 118, which is caused by the peak contrast concentration 512 in the scan plane 514. i The decreasing slope of curve 504 thereafter indicates.

[0044] For scanning plane 514 j , module 132 detects that the contrast agent concentration is increasing from scan plane to scan plane, indicating that the object support 118 needs to be accelerated and the scan plane is after the peak contrast concentration. In response, module 132 increases the speed of table 118, which is indicated by the contrast agent concentration increasing from scan plane to scan plane. j The increasing slope of the curve 504 indicates that for the scan plane 514 k , module 132 detects that the contrast agent concentration does not vary or varies only within a given tolerance from scan plane to scan plane, indicating that the scan plane is capturing the peak contrast agent concentration at the current table 118 speed, which is indicated by the scan plane 514 k This is indicated by the continuation of the same slope of curve 504 thereafter.

[0045] It should be understood that Figure 5 The sinusoidal nature of the contrast agent concentration curve 502 in FIG. 5 is for purposes of illustration, and not limitation, showing the situation where the speed of the table 118 increases and decreases. For example, the curve may alternatively be irregular, or may oscillate through another pattern. In general, the contrast agent flow characteristics will change as it progresses, and the feedback mechanism will adjust the table 118 speed in response thereto. The frequency of the adjustment depends on the frequency at which the scan plane is evaluated to determine whether to image the peak contrast agent concentration.

[0046] In the above example, the decision to decrease / increase the speed of the subject support 118 and / or the amount of decrease / increase in the speed of the subject support 118 depends on the gradient of the contrast agent concentration per slice. In a variation, the decision is made based on the amount of contrast agent concentration, the predetermined condition is a threshold, and the concentration is compared to the predetermined threshold by the decision logic 208.

[0047] In another variation, Figure 4 and Figure 5 The integrated curves 410 and / or 504 are convolved with a kernel (eg, a Gaussian or other kernel) to reduce the effect of local contrast agent concentration variations.

[0048] Where the predetermined table 118 velocity is based on a "normal" contrast velocity for an average patient, the methods described herein correct for deviations of the actual patient from the average patient.

[0049] Figure 6 An example of a scan parameter adapter module 132 is illustrated for adjusting scan parameters during CT angiography using spectral projection data. In this example, the scan parameter adapter module 132 includes a spectral decomposer 602, decision logic 208, and a parameter adjuster 210. During angiography, the operator console 122 receives a view of the spectral projection data, as described herein.

[0050] The spectral decomposer 602 decomposes the energy-based spectral projection data into at least two difference spectral components, including at least a contrast agent (e.g., iodine) map indicating the concentration of the contrast agent of the view. Examples of spectral decomposition are described in WO2016135044A1, entitled "A method for the reconstruction of quantitative iodine maps using energyresolved tomography", filed on September 1, 2016, and in WO2016097981A1, entitled "Penalized Maximum Likelihood Material Decomposition", filed on December 14, 2015, which are incorporated herein by reference in their entirety. Other methods are also contemplated herein.

[0051] Decision logic 208 determines whether the concentration of contrast agent as indicated in the contrast agent map satisfies a predetermined condition, e.g., as described above and / or otherwise. Parameter adjuster 210 adjusts at least one scan parameter in response to the concentration not satisfying the predetermined condition, e.g., as described above and / or otherwise. Parameter adjuster 210 may also adjust a scan parameter in response to the concentration satisfying the predetermined condition, e.g., as described above and / or otherwise.

[0052] Figure 7 An example method for adjusting scan parameters during CT angiography based on non-spectral data is illustrated.

[0053] At 702, a pre-scan is performed, as described herein and / or otherwise.

[0054] At 704, angiography is planned using the pre-scan data, as described herein and / or otherwise.

[0055] At 706 , during angiography, for an acquired view, the pre-scan data is forward projected to estimate line integrals for the same view, as described herein and / or otherwise.

[0056] At 708 , a difference is calculated between the acquired view and the estimated view, as described herein and / or otherwise.

[0057] At 710 , a metric is calculated based on the difference, as described herein and / or otherwise.

[0058] At 712, it is determined whether the metric satisfies a predetermined condition.

[0059] If the metric satisfies the predetermined condition, then acts 706 - 712 are repeated for another view.

[0060] If the metric does not satisfy the predetermined condition, then at 714 the scan parameter(s) are adjusted so that a predetermined level of contrast agent is represented in subsequently acquired views, as described herein and / or otherwise, and acts 706 - 712 are repeated.

[0061] Figure 8 An example method for adjusting scan parameters for spectral data during CT angiography is illustrated.

[0062] At 802, a pre-scan is performed, as described herein and / or otherwise.

[0063] At 804, angiography is planned using the pre-scan data, as described herein and / or otherwise.

[0064] At 806 , a contrast agent (eg, iodine) map is generated for the acquired views during angiography, as described herein and / or otherwise.

[0065] At 808, it is determined whether the amount of contrast agent indicated in the angiogram satisfies a predetermined threshold.

[0066] If the metric meets the predetermined threshold, then acts 806 - 808 are repeated.

[0067] If the metric does not meet the predetermined threshold, then at 810 the scan parameter(s) are adjusted so that a predetermined level of contrast agent is represented in subsequently acquired views, as described herein and / or otherwise, and acts 806 - 808 are repeated.

[0068] In one example, the methods described herein can be implemented by an explicit algorithm as has been described above, or in other cases a machine learning or deep learning method can be used to train a neural network to adjust the scan speed during a scan. Here, a large data set of patient scans and patient parameters along with CT acquisition and contrast application parameters can be used as input to train in conjunction with a human reader or automated image quality measurement data. The trained neural network is then applied during a scan to adjust the scan speed.

[0069] The above may be implemented by means of computer-readable instructions encoded or embedded on a computer-readable storage medium (which does not include transient media), which, when executed by (one or more) computer processors (e.g., CPU, microprocessor, etc.), cause (one or more) processors to perform the actions described herein. Additionally or alternatively, at least one of the computer-readable instructions is carried by a signal, carrier wave, or other transient medium that is not a computer-readable storage medium.

[0070] Although the present invention has been illustrated and described in detail in the drawings and the foregoing description, these illustrations and descriptions should be considered illustrative or exemplary rather than restrictive; the present invention is not limited to the disclosed embodiments. Other variations to the disclosed embodiments can be understood and effected by those skilled in the art in practicing the claimed invention by studying the drawings, the disclosure, and the claims.

[0071] In the claims, the word "comprising" does not exclude other elements or steps, and the word "a" or "an" does not exclude a plurality. A single element or other unit may fulfill the functions of several items recited in the claims. Although certain measures are recited in mutually different dependent claims, this does not indicate that a combination of these measures cannot be used to advantage.

[0072] The computer program may be stored / distributed on a suitable medium, such as an optical storage medium or solid-state medium provided together with or as part of other hardware, but the computer program may also be distributed in other forms, such as via the Internet or other wired or wireless telecommunication systems. Any reference signs in the claims should not be construed as limiting the scope.

Claims

1. A computer tomography imaging system (102), comprising: an X-ray radiation source (110) configured to emit X-ray radiation that traverses an examination region (108); an X-ray radiation sensitive detector array (112) configured to detect X-ray radiation traversing the examination region and generate line-integrated views; an object support table (118) configured to translate within the examination region for scanning based on at least one scanning parameter; as well as an operator console (122) comprising a processor (128) and a computer readable storage medium (130) having a scan parameter adapter module (132), wherein the processor is configured to execute instructions of the scan parameter adapter module, the instructions causing the processor to determine a contrast agent concentration from the line-integrated views and adjust the at least one scan parameter based on the determined concentration; and The computer tomography imaging system is characterized in that: The instructions further cause the processor to forward project the pre-scan volumetric image data to estimate a line-integrated view corresponding to the generated line-integrated view, and adjust the at least one scan parameter based on the estimated line-integrated view and the generated line-integrated view.

2. The system according to claim 1, wherein: The at least one scanning parameter is a velocity of the object supporting table.

3. The system according to claim 1 or 2, wherein: The instructions further cause the processor to determine a difference between the estimated view of line integrals and the generated view of line integrals, and to adjust the at least one scan parameter based on the difference between the line integrals.

4. The system according to claim 1 or 2, wherein: The X-ray radiation sensitive detector array is a multi-slice energy resolving detector array, and the instructions further cause the processor to spectrally decompose the line-integrated views to generate a contrast agent map, and adjust the at least one scan parameter based on the contrast agent map.

5. The system according to claim 1 or 2, wherein: The at least one scan parameter is adjusted such that a subsequent current view images a peak contrast concentration.

6. The system according to claim 1 or 2, wherein: The processor is configured to adjust the at least one scan parameter based on contrast media administration information.

7. The system according to claim 1 or 2, wherein: The processor is configured to adjust the at least one scanning parameter based on patient physiological information.

8. The system according to claim 1 or 2, wherein: The instructions include a neural network configured to adjust the at least one scan parameter based on the contrast agent concentration, and the processor is configured to employ the neural network to adjust the at least one scan parameter based on the contrast agent concentration.

9. The system according to claim 8, wherein: The neural network is trained using a machine learning algorithm or a deep learning algorithm to adjust the velocity of the object support table during scanning.

10. The system according to claim 9, wherein: The neural network is trained using as input image data from a patient scan, patient information of a patient for the patient scan, acquisition for the patient scan, and contrast agent parameters for the patient scan and using an image quality criterion.

11. A computer tomography imaging method comprising: A view for receiving projection data during CT angiography; determining, for one or more of the views, an amount of contrast agent in a current scan plane; and adjusting a scanning parameter of the CT angiography in response to the amount of the contrast agent not satisfying a predetermined condition; and The method is characterized in that it also includes: The amount of contrast agent in the current scan plane is determined based on an estimated view of the same scan plane from pre-scan volumetric image data.

12. The method according to claim 11, further comprising: decomposing the one or more of the views to generate an iodine map; and The amount of the contrast agent is determined based on the iodine map.

13. The method according to any one of claims 11 to 12, wherein: Adjusting the scan parameters includes employing a trained neural network to adjust the scan parameters based on the contrast agent concentration.

14. A computer-readable medium encoded with computer-executable instructions, wherein: The computer executable instructions, when executed by a processor, cause the processor to: A view for receiving projection data during CT angiography; determining, for one or more of the views, an amount of contrast agent in a current scan plane; and adjusting a scanning parameter of the CT angiography in response to the amount of the contrast agent not satisfying a predetermined condition; and The instruction further causes the processor to: The amount of contrast agent in the current scan plane is determined based on an estimated view of the same scan plane from pre-scan volumetric image data.

15. The computer-readable medium of claim 14, wherein: The computer executable instructions, when executed by the processor, further cause the processor to: decomposing one or more of the views to generate an iodine map; and The amount of the contrast agent is determined based on the iodine map.

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