DYNAMIC ACQUISITION SAMPLING RATE FOR COMPUTED TOMOGRAPHY PERFUSION (CTP) IMAGING

• US 20130211245A1
• Filed: 10/17/2011
• Published: 08/15/2013
• Est. Priority Date: 10/19/2010
• Status: Active Grant

• Current Assignee: Koninklijke Philips N.V.
• Original Assignee: Koninklijke Philips Electronics N.V. (Koninklijke Philips N.V.)
• Inventors: Vembar, Mani, Ivanc, Thomas Bernard, Virmani, Sunny
• Granted Patent: US 9,955,934 B2
• Time in Patent Office: Days
• US Class Current: 600/428
• CPC Class Codes: A61B 6/03 Computed tomography [CT] echo-tomography A61B8/14
• CPC Class Codes: A61B 6/032 Transmission computed tomography [CT]
• CPC Class Codes: A61B 6/467 characterised by special input means
• 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 6/507 for determination of haemodynamic parameters, e.g. perfusion CT
• CPC Class Codes: A61B 6/541 involving acquisition triggered by a physiological signal
• CPC Class Codes: A61B 6/542 involving control of exposure

Abstract

A method includes dynamically varying a data acquisition sample rate between at least two data acquisition sample rates during a contrast enhanced perfusion scan based on a level of contrast in image data generated during the scan. A system includes a computed tomography scanner and a console that controls the scanner based on a scan protocol, wherein the console dynamically varies a data acquisition sample rate of scanner during a contrast enhanced perfusion scan based on a level of contrast in the image data generated during the scan. A method for optimizing dose of a scan includes reducing a data acquisition sampling rate during at least a sub-portion of the scan in which a state of interest is not being scanned.

Claims

1. A method, comprising:

dynamically varying a data acquisition sample rate between at least two different data acquisition sample rates during a contrast enhanced perfusion scan based on a level of contrast in image data generated during the scan.

2. The method of claim 1, further comprising:

acquiring data at a lower data acquisition sampling rate in an absence of a predetermined level of contrast in the image data; and

acquiring data at a higher predetermined data acquisition sampling rate during contrast uptake.

3. The method of claim 2, further comprising:

acquiring data at a third predetermined data acquisition sampling rate during contrast washout.

4. The method of claim 2, further comprising:

comparing voxels values from the image data with a threshold value corresponding to the predetermined level of contrast; and

generating a signal indicative of the comparison.

5. The method of claim 4, further comprising:

determining the absence of the predetermined level of contrast in response to the signal not satisfying the threshold value.

6. The method of claim 4, further comprising:

determining contrast uptake in response to the signal satisfying the threshold value.

7. The method of claim 3, wherein a radiation dose of the scan is decreased relative to acquiring the data only at the higher sampling rate.

8. The method of claim 3, wherein, for a given sampling rate, selectively reducing or raising an x-ray source output during the scan based on a user preference.

9. The method of claim 2, wherein at least one of the first or second data acquisition sampling rates is based on a scan protocol.

10. The method of claim 2, wherein at least one of the first or second data acquisition sampling rates is determined based on a signal indicative of a user input.

11. The method of claim 1, wherein the data acquisition sample rate is dynamically varied based on time.

12. The method of claim 1, wherein a desired acquisition phase is a function of a cardiac phase of interest, and further comprising acquiring data at the higher predetermined data acquisition sampling rate in response to detecting the cardiac phase of interest.

13. The method of claim 1, wherein a desired acquisition phase is a function of a respiratory phase of interest, and further comprising acquiring data at the higher predetermined data acquisition sampling rate in response to detecting the respiratory phase of interest.

14. A system, comprising:

a computed tomography scanner; and

a console that controls the scanner based on a scan protocol, wherein the console dynamically varies a data acquisition sample rate of scanner during a contrast enhanced perfusion scan based on a level of contrast in the image data generated during the scan.

15. The system of claim 14, further comprising:

a data evaluator that determines whether the level of contrast in the image data indicates substantially no contrast, contrast uptake or contrast wash out.

16. The system of claim 15, wherein the console controls the scanner to acquire data at a first data acquisition sampling rate in response to the data evaluator determining that the level of contrast in the image data indicates no contrast.

17. The system of claim 16, wherein the console controls the scanner to acquire data at a second data acquisition sampling rate in response to the data evaluator determining that the level of contrast in the image data indicates contrast uptake, and the second data acquisition sampling rate is greater than the first data acquisition sampling rate.

18. The system of claim 17, wherein the console controls the scanner to acquire data at a third data acquisition sampling rate in response to the data evaluator determining that the level of contrast in the image data indicates contrast wash out, wherein third data acquisition sampling rate is one of equal to or less than the second data acquisition sampling rate.

19. The system of claim 15, wherein an acquisition phase of the scanner corresponds to one of a cardiac phase of interest or a respiratory phase of interest.

20. (canceled)

21. A perfusion imaging method comprising:

acquiring data at a first sampling rate until contrast uptake has been determined; and

acquiring data at a second sampling rate, which is greater than the first sampling rate, during contrast uptake.

22. The method of claim 21, further comprising:

acquiring data at a third sampling rate during contrast wash-out, wherein the third sampling rate is less than the second sampling rate.

23. The method of claim 21, further comprising:

varying scan dose in conjunction with the sampling rate.

24. The method of claim 21, wherein the first sampling rate is variable and is increased over time until the contrast uptake has been determined.

25. The method of claim 21, further comprising:

increasing a sampling duration along with increasing the sampling rate.