Imaging system, computer, program product and method for detecting changes in rates of water diffusion in a tissue using magnetic resonance imaging (MRI)

• US 6,567,684 B1
• Filed: 12/06/2000
• Issued: 05/20/2003
• Est. Priority Date: 11/08/2000
• Status: Active Grant

• Current Assignee: Board of Regents of the University of Michigan (University of Michigan)
• Original Assignee: Board of Regents of the University of Michigan (University of Michigan)
• Inventors: Chenevert, Thomas L., Ross, Brian D., Rehemtulla, Alnawaz
• Primary Examiner(s): Vo, Hieu T.
• Application Number:
  US09/732,362
• Time in Patent Office: 895 Days
• Field of Search: 600/410, 600/411, 600/427, 600/419, 600/544, 600/545, 324/307, 324/306, 324/309
• US Class Current: 600/410
• CPC Class Codes: A61B 5/055 involving electronic [EMR] or nuclear [NMR] magnetic resonance, e.g. magnetic resonance imaging
• CPC Class Codes: A61B 5/4076 Diagnosing or monitoring particular conditions of the nervous system A61B5/4821, A61B5/4824 take precedence

Abstract

The invention provides a computer-implemented method for detecting changes in rates of water diffusion in a tissue. The invention also provides a computer program product for use in the detection of changes in rates of water diffusion in a tissue using magnetic resonance imaging (MRI) comprising a computer useable medium comprising a computer readable program code embodied therein, wherein the computer program product is capable of storing and analyzing data input from a MRI device. The invention also provides a computer system, comprising a processor and a computer program product of the invention. The invention also provides a tissue imaging system, comprising a magnetic resonance imaging (MRI) device capable of outputting data to a processor; a processor; and, a computer program product of the invention embodied within the processor.

Claims

1. A computer program product for use in the detection of changes in rates of water diffusion in a tissue using magnetic resonance imaging (MRI) comprising a computer useable medium comprising a computer readable program code embodied therein, wherein the computer program product is capable of storing and analyzing data input from a MRI device by a process comprising the following steps:

(a) providing a magnetic resonance imaging (MRI) device capable of outputting data to a computer;

(b) providing a computer capable of storing and analyzing data input from the MRI device comprising a computer program product embodied therein;

(c) projecting a sequence of magnetic field gradient pulses and radiofrequency pulses to the tissue of interest by the MRI device and collecting a first set of MRI signals from the tissue and outputting this data to the computer, wherein the MRI device collects MRI signals from the tissue of interest at multiple diffusion sensitivities and diffusion directions;

(d) analyzing the first set of diffusion-sensitive MRI signal readings by the computer program product to calculate an apparent diffusion coefficient (ADC) value for each diffusion direction, wherein an ADC value corresponds to a spatial origin of the signals used to determine the ADC value, and to generate a first spatial map of ADC values;

(e) projecting at least a second sequence of magnetic field gradient pulses and radiofrequency pulses and analyzing at least a second set of diffusion-sensitive MRI readings in the same tissue of interest as in steps (c) and (d) to generate at least a second subsequent spatial map of ADC values; and

(f) compare the first and subsequent spatial maps of ADC values to generate a spatial map that reflects the changes in ADC values over the time the several readings were taken by the MRI, wherein the changes in ADC values reflect the changes in spin diffusion properties which reflect changes in rates of water diffusion in the tissue.

2. A computer system, comprising:

(a) a processor; and

(b) a computer program product as set forth in claim 1.

3. A tissue imaging system, comprising:

(a) a magnetic resonance imaging (MRI) device capable of outputting data to a processor;

(b) a processor; and

(c) a computer program product as set forth in claim 1 embodied within the processor.

4. A computer-implemented method for detecting changes in rates of water diffusion in a tissue comprising the following steps:

(a) providing a magnetic resonance imaging (MRI) device capable of outputting data to a computer;

(b) providing a computer capable of storing and analyzing data input from the MRI device comprising a computer program product embodied therein;

(c) projecting a sequence of magnetic field gradient pulses and radiofrequency pulses to the tissue of interest by the MRI device and collecting a first set of MRI signals from the tissue and outputting this data to the computer, wherein the MRI device collects MRI signals from the tissue of interest at multiple diffusion sensitivities and diffusion directions;

(d) analyzing the first set of diffusion-sensitive MRI signal readings by the computer program product to calculate an apparent diffusion coefficient (ADC) value for each diffusion direction, wherein an ADC value corresponds to a spatial origin of the signals used to determine the ADC value, and to generate a first spatial map of ADC values;

(e) projecting at least a second sequence of magnetic field gradient pulses and radiofrequency pulses and analyzing at least a second set of diffusion-sensitive MRI readings in the same tissue of interest as in steps (c) and (d) to generate at least a second subsequent spatial map of ADC values; and

(f) compare the first and subsequent spatial maps of ADC values to generate a spatial map that reflects the changes in ADC values over the time the several readings were taken by the MRI, wherein the changes in ADC values reflect the changes in spin diffusion properties which reflect changes in rates of water diffusion in the tissue.

5. The computer-implemented method of claim 4, wherein the computer program product uses the spatial map that reflects the changes in ADC values over the time the several readings were taken by the MRI to generate a histogram.

6. The computer-implemented method of claim 4, wherein the tissue is brain or spinal cord tissue.

7. The computer-implemented method of claim 4, wherein the tissue is internal organ, skeletal or muscle tissue.

8. The computer-implemented method of claim 4, wherein the tissue is a diseased tissue.

9. The computer-implemented method of claim 8, wherein the diseased tissue is a cancer.

10. The computer-implemented method of claim 4, wherein the diseased tissue is an injured or inflamed tissue.

11. The computer-implemented method of claim 4, wherein the tissue has been exposed to a drug, a biological agent, hyperthermia, hypothermia, a radiation or a combination thereof.

12. The computer-implemented method of claim 11, wherein the tissue has been exposed to an antivascular therapy.

13. The computer-implemented method of claim 11, wherein radiation is a radiotherapy or a photodynamic therapy or a combination thereof.

14. The computer-implemented method of claim 4, wherein an increase in the rate of water diffusion as shown by the spatial map that reflects the changes in ADC values over the time indicates cell damage or tissue microvasculature damage.

15. The computer-implemented method of claim 4, wherein a rate of water diffusion higher or lower than considered normal for the tissue of interest indicates cell damage or tissue microvasculature damage.

16. The computer-implemented method of claim 4, wherein the method is applied to determine the effectiveness of an organ or a tissue transplant.

17. The computer-implemented method of claim 4, wherein the method is applied to determine the effectiveness of a therapy for a condition or a disease or an injury.

18. The computer-implemented method of claim 17, wherein the therapy is for a cancer and an increase in diffusion indicates tumor cell damage or tumor microvasculature damage, thereby indicating the effectiveness of the cancer therapy.

19. The computer-implemented method of claim 17, wherein the therapy is for an injured or inflamed tissue and a charge in diffusion indicates tissue repair or decreased inflammation, thereby indicating the effectiveness of the therapy.

20. The computer-implemented method of claim 4, wherein a change in diffusion indicates tissue repair.

21. The computer-implemented method of claim 4, wherein ADC values from a defined spatial subsection of the tissue taken over time is used to generate a statistical data reduction of data in that spatial subsection.

22. The computer-implemented method of claim 21, wherein the statistical data reduction comprises a mean standard deviation, a pixel count or a volume of tissue or a combination thereof.

23. The computer-implemented method of claim 21, wherein a histogram is generated from the statistical data reduction.

24. The computer-implemented method of claim 23, wherein a histogram reflecting changes in statistical data reduction sets over time is generated.

25. The computer-implemented method of claim 4, wherein the first set of diffusion-sensitive MRI signal readings is generated before initiation of a therapy.

26. The computer-implemented method of claim 25, wherein a subsequent set of diffusion-sensitive MRI signal readings is generated after initiation of a therapy.

27. The computer-implemented method of claim 26, wherein a subsequent set of diffusion-sensitive MRI signal readings is generated at a time appropriate for a therapeutic change in tissue.