Blood signal suppressed enhanced magnetic resonance imaging

Patent metadata

Field	Value
Publication number	US-9149203-B2
Application number	US-201113100272-A
Country	US
Kind code	B2
Filing date	May 3, 2011
Priority date	May 5, 2010
Publication date	Oct 6, 2015
Grant date	Oct 6, 2015

Abstract

Methods for achieving suppression of blood pool signal to image contrast-enhanced organs and vascular walls using magnetic resonance (MR) imaging technology. After administration of e.g., an intravenous contrast agent, an RF pulse sequence is applied that includes a preparatory section designed to modify signal from organ tissue differently than blood pool signal, followed by an inversion RF pulse. MR signals are then allowed to evolve during a wait time that is sufficiently long to permit tissue species with dissimilar T1 relaxation times to separate in signal yet short enough so that blood signal has greater negative magnetization than other tissues of interest. MRI data is then acquired with phase sensitive reconstruction so that blood pool signal is suppressed compared with the tissues of interest.

First claim

I claim:

1. A method of black-blood magnetic resonance imaging (MRI) with blood signal suppression that is independent of blood flow velocity and blood exchange, comprising:
a. administering an MRI contrast agent;
b. waiting for the MRI contrast agent to arrive at the organ tissue of interest; then
c. using an RF transmitter, applying an RF pulse sequence having (i) a preparatory section that reduces the MRI magnetization of the organ tissue more than the MRI magnetization of blood pool, and (ii) following the preparatory section with an inversion RF pulse;
d. after applying the RF pulse sequence, waiting for a period of time which is independent of blood flow, the wait time period selected so that (i) the MRI magnetization of healthy organ tissue will be different than the MRI magnetization of diseased organ tissue due to differences in organ tissue accumulation of the MRI contrast agent, and (ii) the MRI magnetization of blood pool will have a more negative signal vector than the MRI magnetization of healthy organ tissue;
e. after waiting the period of time, acquiring magnetic resonance data from the organ tissue of interest; and
f. generating a black blood image based on said acquired magnetic resonance data with a phase sensitive reconstruction.

2. The method according to claim 1 , wherein the preparatory section comprises one or more RF pulses that imparts weighting selected from the group consisting of T2 weighting, T1rho weighting, magnetization transfer weighting, and combinations thereof.

3. The method according to claim 1 , wherein the preparatory section comprises one or more RF pulses that imparts T2 weighting.

4. The method according to claim 1 , wherein the preparatory section comprises one or more RF pulses that imparts T1rho weighting.

5. The method according to claim 1 , wherein the preparatory section comprises one or more RF pulses that imparts magnetization transfer weighting.

6. The method according to claim 1 , wherein the inversion RF pulse comprises a flip angle between 90 and 180 degrees.

7. The method of claim 1 wherein acquiring uses a steady-state free precession (SSFP).

8. The method of claim 1 wherein acquiring uses a gradient-recalled echo (GRE) readout.

9. The method of claim 1 wherein acquiring uses a turbo-spin (TSE) readout.

10. The method of claim 1 wherein acquiring uses an echo planar (EPI) readout.

11. The method of claim 1 wherein acquiring uses a 2-dimensional readout.

12. The method of claim 1 wherein acquiring uses a 3-dimensional readout.

13. The method of claim 1 wherein acquiring uses a segmented acquisition so that data acquired for an image comes from at least two cycles of the pulse sequence.

14. The method of claim 1 wherein acquiring uses a single-shot acquisition so that data acquired for an image comes from once cycle of the pulse sequence.

15. The method of claim 1 wherein acquiring uses parallel imaging.

16. The method of claim 1 wherein acquiring uses a Cartesian, radial, spiral or elliptical readout.

17. The method according to claim 1 , wherein acquiring uses a technique comprising at least one of gradient-recalled echo (GRE) readout, turbo-spin echo (TSE readout, echo planar (EPI) readout, 2-dimensional readout, 3-dimensional readout, segmented acquisition so that data acquired for an image comes from at least two cycles of the pulse sequence, a single-shot acquisition so that data acquired for an image comes from one cycle of the pulse sequence, parallel imaging, Cartesian readout, radial readout, spiral readout, elliptical readout, and combinations thereof.

18. The method according to claim 1 , further including timing readout to occur during a specific phase of an electrocardiogram after the wait time period expires.

19. The method according to claim 1 , wherein the phase sensitive reconstruction is also based on obtaining a reference set of data.

20. The method according to claim 1 , wherein the phase sensitive reconstruction is also based on estimating the phase from local statistics or region growing approaches.

21. The method of claim 1 wherein the preparatory section is not required to have any slice-selective RF pulses.

22. The method of claim 1 wherein the preparatory section does not have any slice-selective RF pulses.

23. A system for black-blood magnetic resonance imaging (MRI) when administering an MRI contrast agent and waiting for the MRI contrast agent to arrive at the organ tissue of interest, the system providing blood signal suppression that is independent of blood flow velocity and blood exchange, the system comprising:
an RF transmitter configured to apply an RF pulse sequence having (i) a preparatory section that reduces the MRI magnetization of the organ tissue more than the MRI magnetization of blood pool, and (ii) an inversion RF pulse following the preparatory section;
a sequencer coupled to the RF transmitter that, after controlling the RF transmitter to apply the pulse sequence, is configured to wait a wait time period which is independent of blood flow, the wait time period selected so that (i) the MRI magnetization of healthy organ tissue will be different than the MRI magnetization of diseased organ tissue due to differences in organ tissue accumulation of the MRI contrast agent, and (ii) the MRI magnetization of blood pool will have a more negative signal vector than the MRI magnetization of healthy organ tissue;
an RF receiver coupled to the sequencer, the receiver acquiring magnetic resonance data after waiting the selected wait time period; and
at least one computer operatively coupled to the RF receiver, the computer using a phase sensitive reconstruction to generate a black blood image based on said acquired magnetic resonance data the RF receiver acquires after the sequencer waits the wait time period.

24. The system of claim 23 wherein the RF transmitter is configured to generate the preparatory pulse signal without any slice-selective RF pulses.

25. The system according to claim 23 , wherein sequencer times the receiver to acquire the magnetic resonance echoes during a specific phase of an electrocardiogram after the wait time period has expired.

Assignees

• Kim Raymond J
• Univ Duke

Inventors

• Kim Raymond J

Classifications

• G01R33/5602

  by filtering or weighting based on different relaxation times within the sample, e.g. T1 weighting using an inversion pulse · CPC title

• G01R33/5607

  by reducing the NMR signal of a particular spin species, e.g. of a chemical species for fat suppression, or of a moving spin species for black-blood imaging · CPC title

• A61B5/055 Primary

  involving electronic [EMR] or nuclear [NMR] magnetic resonance, e.g. magnetic resonance imaging · CPC title

• G01R33/5601

  involving use of a contrast agent for contrast manipulation, e.g. a paramagnetic, super-paramagnetic, ferromagnetic or hyperpolarised contrast agent · CPC title