DYNAMIC PERFUSION IMAGING

• US 20140037046A1
• Filed: 04/17/2012
• Published: 02/06/2014
• Est. Priority Date: 04/18/2011
• Status: Active Grant

• Current Assignee: Koninklijke Philips Electronics N.V. (Koninklijke Philips N.V.)
• Original Assignee: Koninklijke Philips N.V.
• Inventors: Grass, Michael, Schmitt, Holger
• Granted Patent: US 9,848,843 B2
• Time in Patent Office: Days
• US Class Current: 378/8
• CPC Class Codes: A61B 6/00 Apparatus or devices for radiation diagnosis; Apparatus or devices for radiation diagnosis combined with radiation therapy equipment instruments measuring radiation intensity for application in the field of nuclear medicine, e.g. in vivo counting, G01T1/161; apparatus for taking X-ray photographs G03B42/02
• 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 6/503 for diagnosis of the heart
• 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 6/542 involving control of exposure
• CPC Class Codes: A61B 6/545 involving automatic set-up of acquisition parameters
• CPC Class Codes: F04C 2270/0421 Controlled or regulated
• CPC Class Codes: G16H 50/30 for calculating health indices; for individual health risk assessment

Abstract

A method includes scanning a region of interest, during a contrast agent based perfusion scan, at a predetermined temporal sampling rate during contrast agent uptake in the region of interest, and generating time frame data indicative of the scanned region of interest. The method further includes identifying a predetermined change in an amount of the contrast agent in the region of interest from the time frame data. The method further includes scanning the region of interest at a lower temporal sampling rate, which is lower than the temporal sampling rate during the contrast agent uptake, in response to identifying the predetermined change in the amount of the contrast agent in the region of interest.

Claims

1. A method, comprising:

scanning a region of interest, during a contrast agent based perfusion scan, at a predetermined temporal sampling rate during contrast agent uptake in the region of interest, and generating time frame data indicative of the scanned region of interest;

identifying a predetermined change in an amount of contrast agent in the region of interest from the time frame data; and

scanning the region of interest at a lower temporal sampling rate, which is lower than the temporal sampling rate during the contrast agent uptake, in response to identifying the predetermined change in the amount of the contrast agent in the region of interest

wherein the lower temporal sampling rate varies during scanning the region of interest.

2. The method of claim 1, wherein the predetermined change is a decrease in the amount of the contrast agent, wherein the decrease is indicative of contrast agent washout.

3. The method of claim 1, further comprising:

determining an average pixel intensity of structure in the time frame data;

comparing the average pixel intensity with an average pixel intensity of previous time frame data; and

identifying the predetermined change based on a result of the comparison.

4. The method of claim 1, further comprising:

segmenting the time frame data into sub-structure;

determining an average pixel intensity of a sub-set of the sub-structure;

comparing the average pixel intensity with an average pixel intensity of corresponding previous time frame data; and

identifying the predetermined change based on a result of the comparison.

5. The method of claim 1, further comprising:

segmenting the time frame data into sub-structure;

segmenting at least one sub-structure into sub-regions;

determining an average pixel intensity of a sub-set of the sub-regions;

comparing the average pixel intensity with an average pixel intensity of corresponding previous time frame data; and

identifying the predetermined change based on a result of the comparison.

6. The method of claim 3, further comprising:

identifying the predetermined change in the amount of the contrast agent in the region of interest in response to the average pixel intensity of previous time frame data exceeding the average pixel intensity of the time frame data.

7. The method of claim 1, further comprising:

segmenting the time frame data into sub-structure;

segmenting at least one sub-structure into sub-regions;

determining an average pixel intensity of at least one of the sub-regions;

determining an average pixel intensity of at least another of the sub-regions;

comparing the average pixel intensities; and

identifying the predetermined change based on a result of the comparison.

8. The method of claim 1, further comprising:

performing a data acquisition at a predetermined fixed temporal distance from the predetermined change to capture late contrast agent enhancement.

9. The method of claim 1, further comprising:

scanning the region of interest at a second lower temporal sampling rate before the contrast agent uptake in the region of interest, and generating time frame data indicative of the scanned region of interest;

identifying a presence of the contrast agent in the region of interest from the time frame data; and

scanning the region of interest at the predetermined temporal sampling rate, in response to identifying the presence of the contrast agent in the region of interest.

10. The method of claim 1, further comprising:

sensing a motion cycle of the region of interest;

identifying a sub-portion of the motion cycle; and

scanning the region of interest only during the sub-portion of the motion cycle.

11. The method of claim 10, wherein the sub-portion corresponds to a lower motion phase of the motion cycle, and further comprising:

scanning the region of interest during at least two of the sub-portions.

12. The method of claim 1, wherein the predetermined temporal sampling rate varies during contrast agent uptake in the region of interest.

13. The method of claim 1, further comprising:

scanning using a sparse spatial sampling; and

reconstructing the time frame data using a sparse reconstruction algorithm.

14. The method of claim 1, further comprising:

using a lower tube current during at least one of pre-contrast agent uptake scanning or contrast agent washout scanning and using a higher tube current during contrast agent uptake scanning, wherein the higher tube current is greater than the lower tube current.

15. A system, comprising:

a contrast agent detector, including;

a contrast identifier that identifies a presence of contrast agent in time frame perfusion scan acquisition data and generates a contrast signal indicating the presence of the contrast agent in the time frame acquisition data,

wherein the contrast signal is used to vary a temporal sampling rate between a lower varying temporal sampling rate when the contrast agent is not present in the time frame data and a higher temporal sampling rate when the contrast agent is present in the time frame data.

16. The system of claim 15, wherein the contrast agent identifier identifies the presence of contrast agent in the time frame acquisition data using on a model based segmentation approach.

17. The system of claim 16, wherein the model based segmentation approach segments a structure of interest into sub-regions, and the contrast identifier identifies the presence of the contrast agent in a sub-set of the sub-regions.

18. The system of claim 16, wherein the contrast agent identifier identifies the presence of the contrast agent based on pixel intensity.

19. The system of claim 15, the contrast agent detector, further comprising:

a peak contrast identifier that identifies peak contrast agent in time frame acquisition data and generates a peak contrast signal indicating the peak contrast agent in the time frame acquisition data, wherein the peak contrast signal is used to vary a temporal sampling rate between the higher temporal sampling rate and second lower temporal sampling rates in response to the peak contrast signal indicating peak contrast agent in the time frame acquisition data.

20. The system of claim 15, further comprising:

an imaging system that performs a perfusion scan that generates the time frame perfusion scan acquisition data.

21. The system of claim 20, wherein the imaging system is a spectral computed tomography scanner.

22. The system of claim 21, wherein a concentration of contrast agent level is determined through material separation and/or k-edge imaging.

23. Computer readable storage medium encoded with computer readable instructions, which, when executed by a processor, causes the processor to:

vary a temporal sampling rate of data acquisition during a perfusion scan based on a state of a contrast agent in resulting acquisition time frame data, wherein the temporal sampling rate is at least varied between contrast agent uptake and contrast agent washout based on a contrast agent level determined using a model based segmentation of the time frame data, wherein the temporal sampling rate varies during contrast agent uptake.