METHOD FOR TRANSCATHETER INTRA-ARTERIAL PERFUSION MAGNETIC RESONANCE IMAGING

• US 20090116711A1
• Filed: 10/31/2008
• Published: 05/07/2009
• Est. Priority Date: 10/31/2007
• Status: Active Grant

• Current Assignee: Northwestern University
• Original Assignee: Northwestern University
• Inventors: Larson, Andrew Christian, Omary, Reed Ali, Wang, Dingxin
• Granted Patent: US 8,103,076 B2
• Time in Patent Office: Days
• US Class Current: 382/128
• CPC Class Codes: G06T 2207/10088 Magnetic resonance imaging [MRI]
• CPC Class Codes: G06T 2207/30104 Vascular flow; Blood flow; Perfusion
• CPC Class Codes: G06T 7/0016 involving temporal comparison
• CPC Class Codes: Y10S 128/922 including image analysis

Abstract

A method to serially determine changes in perfusion to tissues is provided. This method involves injecting contrast material into a catheter that is positioned in the blood supply proximal to the targeted tissue of interest, acquiring a time series of images that depicts the uptake of this contrast material within the tissue, deriving semi-quantitative or quantitative perfusion metrics based upon the time series of perfusion images, altering perfusion to the targeted tissue by means of injecting pharmacologic agents or embolic agents into the blood vessels supplying the targeted tissue, repeating the acquisition of perfusion images to serially monitor changes in tissue perfusion after each alteration, and calculating changes in perfusion metrics after each series of perfusion images. This method is used to monitor changes in perfusion to various tissues, including a diverse array of tumors. The perfusion imaging method can be acquired using magnetic resonance, x-ray computed tomography, or radionuclide imaging. The perfusion metric is serially measured during an embolization procedure as a means of measuring changes in tissue perfusion or to target an endpoint based upon a specific alteration in the calculated perfusion metric.

Claims

1. A method for serially determining changes in perfusion to tissues, comprising the steps of:

injecting contrast material into a catheter that is positioned in a blood vessel supplying a targeted tissue of interest;

acquiring a time series of images that depicts an uptake of the contrast material within the targeted tissue;

deriving semi-quantitative or quantitative perfusion metrics based upon the time series of images;

altering perfusion to the targeted tissue by injecting pharmacologic agents or embolic agents into the blood vessel supplying the targeted tissue;

acquiring a further time series of perfusion images to serially monitor changes in tissue perfusion after each altering perfusion step;

repeating said altering perfusion step and said acquiring further images step; and

calculating changes in perfusion metrics after said acquiring of the further series of perfusion images.

2. A method as claimed in claim 1, wherein said steps of altering perfusion to the targeted tissue and monitoring changes with perfusion imaging are halted upon detection of a predetermined reduction in perfusion.

3. A method as claimed in claim 1, wherein said perfusion image acquisition is a perfusion magnetic resonance image acquisition.

4. A method as claimed in claim 1, wherein said steps of acquiring the perfusion images is a perfusion x-ray computed tomography image acquisition.

5. A method as claimed in claim 1, wherein said steps of acquiring the perfusion images is a perfusion radionuclide image acquisition.

6. A method as claimed in claim 3, wherein said steps of acquiring the perfusion images is a transcatheter intra-arterial perfusion magnetic resonance image acquisition.

7. A method as claimed in claim 1, further comprising the step of:

determining an area-under-curve parameter for each said acquiring further images step.

8. A method as claimed in claim 1, further comprising the step of:

determining a maximum up-slope parameter for each said acquiring further images step.

9. A method as claimed in claim 1, further comprising the step of:

determining a time-to-peak parameter for each said acquiring further images step.

10. A method as claimed in claim 1, further comprising the step of:

determining a k-trans parameter for each said acquiring further images step.

11. A method as claimed in claim 1, further comprising the step of:

determining a k_ep parameter for each said acquiring further images step.

12. A method as claimed in claim 1, further comprising the step of:

determining an absolute tissue blood flow (mL/mg/min) for each said acquiring further images step.

13. A method as claimed in claim 1, wherein the targeted tissue is a tumor.

14. A method as claimed in claim 13, wherein the tumor is a hepatocellular carcinoma.

15. A method as claimed in claim 13, wherein the tumor is a tumor selected from the following:

a colon cancer, a pancreas cancer, a breast cancer, a kidney cancer, a lymphoma, a uterine fibroid, a bone cancer, a sarcoma, a cholangiocarcinoma, a brain tumor, a meningioma, a gynecologic cancer, a prostate cancer, and a neuroendocrine cancer.

16. A method for determining an embolic endpoint during an embolization procedure of a tumor, comprising the steps of:

inserting a catheter into a blood vessel supplying the tumor using x-ray or magnetic resonance imaging guidance;

imaging a region of the tumor using transcatheter intra-arterial perfusion magnetic resonance image acquisition to establish a baseline value, the contrast material being injected via the catheter;

injecting an embolic agent via the catheter as a first embolization stage;

imaging the region of the tumor using transcatheter intra-arterial perfusion magnetic resonance image acquisition in a post embolization imaging stage;

determining at least one perfusion metric from the post embolization imaging stage; and

performing further embolizing stages and further post embolization imaging stages until a serial reduction in perfusion is determined by said perfusion metric from the respective post embolization imaging stages.

17. A method as claimed in claim 16, wherein said at least one perfusion metric is at least one of area-under-curve parameter, maximum up-slope parameter, time-to-peak parameter, k-trans parameter, and a k_ep parameter.

18. A method for determining an endpoint of an embolizing procedure of a tumor, comprising the steps of:

inserting a catheter into a blood vessel supplying the tumor;

performing a first transcatheter intra-arterial perfusion magnetic resonance image acquisition of a region of interest of the tumor;

injecting an embolic agent into the blood vessel via the catheter in a first transcatheter arterial embolization stage;

performing a second transcatheter intra-arterial perfusion magnetic resonance image data acquisition of the region of interest;

determining a change in signal intensity of image data for the region of interest from the first image data acquisition and the second image data acquisition;

injecting an embolic agent into the blood vessel via the catheter in a second transcatheter arterial embolization stage;

performing a third transcatheter intra-arterial perfusion magnetic resonance image data acquisition of the region of interest;

determining a change in signal intensity of image data for the region of interest from the second data image acquisition and the third image data acquisition;

calculating a perfusion metric from the changes in signal intensity; and

repeating the steps of injecting, performing, determining and calculating until the said perfusion metric reaches a threshold value, then halting the injection of the embolizing agent.

19. A method as claimed in claim 18, wherein said perfusion metric is at least one of area-under-curve parameter, maximum up-slope parameter, time-to-peak parameter, k-trans parameter, and a k_ep parameter.