METHODS AND SYSTEMS FOR ADAPTIVE SCAN CONTROL

• US 20170086772A1
• Filed: 09/28/2015
• Published: 03/30/2017
• Est. Priority Date: 09/28/2015
• Status: Active Grant

• Current Assignee: General Electric Company
• Original Assignee: General Electric Company
• Inventors: Vaz, Michael Sarju, Nett, Elizabeth Janus, Chevalier, David Erik, Hammond, Christine Carol, Lewis, Chelsey, Pitterle, David Joseph
• Granted Patent: US 10,383,590 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: A61B 6/032 Transmission computed tomography [CT]
• CPC Class Codes: A61B 6/481 involving the use of contrast agents
• CPC Class Codes: A61B 6/486 involving generating temporal series of image data
• CPC Class Codes: A61B 6/501 for diagnosis of the head, e.g. neuroimaging or craniography
• CPC Class Codes: A61B 6/504 for diagnosis of blood vessels, e.g. by angiography
• CPC Class Codes: A61B 6/507 for determination of haemodynamic parameters, e.g. perfusion CT
• CPC Class Codes: A61B 6/5217 extracting a diagnostic or physiological parameter from medical diagnostic data
• CPC Class Codes: A61B 6/54 Control of apparatus or devices for radiation diagnosis
• CPC Class Codes: A61B 6/542 involving control of exposure
• CPC Class Codes: G16H 50/30 for calculating health indices; for individual health risk assessment

Abstract

Methods and systems are provided for adaptive scan control. In one embodiment, a method comprises: while performing a scan of a scan subject, processing acquired projection data to measure a contrast level; responsive to the contrast level increasing above a first threshold, automatically switching the scan from a first scan protocol to a second scan protocol; responsive to the contrast level decreasing below a second threshold, automatically switching the scan from the second scan protocol to the first scan protocol; and responsive to the contrast level decreasing below a third threshold, automatically ending the scan. In this way, multiple scan protocols, such as angiography and perfusion scan protocols, can be interleaved within a single scan without the use of a separate timing bolus scan.

Claims

1. A method, comprising:

while performing a scan of a scan subject, processing acquired projection data to measure a contrast level;

responsive to the contrast level increasing above a first threshold, automatically switching the scan from a first scan protocol to a second scan protocol;

responsive to the contrast level decreasing below a second threshold, automatically switching the scan from the second scan protocol to the first scan protocol; and

responsive to the contrast level decreasing below a third threshold, automatically ending the scan.

2. The method of claim 1, wherein the first scan protocol includes a first scan region of the scan subject, and wherein the second scan protocol includes a second scan region of the scan subject, the second scan region larger than the first scan region.

3. The method of claim 2, wherein the first scan region includes a head of the scan subject and the second scan region includes the head and a neck of the scan subject.

4. The method of claim 1, further comprising adjusting a temporal sampling rate of the first scan protocol responsive to the contrast level.

5. The method of claim 1, wherein processing the acquired projection data comprises reconstructing at least one image slice based on the acquired projection data.

6. The method of claim 1, wherein the first, second, and third thresholds comprise a threshold contrast level and a threshold rate of change of the contrast level.

7. The method of claim 1, wherein the first, second, and third thresholds are calculated based on a non-contrast scan performed prior to the scan.

8. The method of claim 1, wherein a contrast bolus timing scan is not performed prior to the scan.

9. The method of claim 1, further comprising adjusting transition time points of the scan responsive to the contrast level.

10. The method of claim 1, wherein the contrast level is separately measured in an artery and a vein positioned within the first scan region.

11. The method of claim 1, further comprising switching between the first and second scan protocols responsive to user input regardless of the contrast level.

12. A non-transitory computer-readable storage medium including executable instructions stored thereon that when executed by a computer cause the computer to:

identify a monitoring location of a patient;

administer a contrast agent to the patient;

perform a single dynamic scan session to acquire image data, wherein during the single dynamic scan session, the instructions further cause the computer to;

perform a first perfusion scan;

monitor contrast level of the monitoring location based on projection data acquired during the first perfusion scan;

responsive to the contrast level above a first threshold, perform an angiography scan;

monitor contrast level of the monitoring location based on projection data acquired during the angiography scan;

responsive to the contrast level below a second threshold, perform a second perfusion scan;

monitor contrast level of the monitoring location based on projection data acquired during the second perfusion scan;

responsive to the contrast level below a third threshold, end the single dynamic scan session; and

reconstruct at least one diagnostic image based on one or more of the perfusion scan and the angiography scan data.

13. The non-transitory computer-readable storage medium of claim 12, wherein the instructions further cause the computer to:

calculate at least one perfusion parameter based on the projection data acquired during the perfusion scan.

14. The non-transitory computer-readable storage medium of claim 12, wherein the instructions further cause the computer to perform a non-contrast scan of the head prior to identifying the monitoring location.

15. The non-transitory computer-readable storage medium of claim 12, wherein the monitoring location comprises multiple locations at different depths, and wherein the contrast level is separately monitored at the multiple locations.

16. A system, comprising:

an x-ray source that emits a beam of x-rays toward an object to be imaged;

a detector that receives the x-rays attenuated by the object;

a data acquisition system (DAS) operably connected to the detector; and

a computer operably connected to the DAS and configured with instructions in non-transitory memory that when executed cause the computer to;

during a single scan, process projection data received from the DAS to measure a contrast level; and

automatically interleave at least two scan protocols during the single scan responsive to the contrast level.

17. The system of claim 16, wherein the at least two scan protocols include an angiography protocol and a perfusion protocol, wherein the angiography protocol comprises one of a standard angiography protocol or a multi-phase angiography protocol, and wherein automatically interleaving the at least two scan protocols comprises switching from an acquisition of the projection data according to one scan protocol of the at least two scan protocols to another scan protocol of the at least two scan protocols at least once during the single scan.

18. The system of claim 17, wherein the computer is further configured with instructions in the non-transitory memory that when executed cause the computer to reconstruct at least one diagnostic image based on projection data acquired with the angiography protocol.

19. The system of claim 18, further comprising a display device, wherein the computer is further configured with instructions in the non-transitory memory that when executed cause the computer to output the at least one diagnostic image to the display device for display.

20. The system of claim 16, wherein the computer is further configured with instructions in the non-transitory memory that when executed cause the computer to calculate perfusion parameters based on projection data acquired with the perfusion protocol.