MRI NON-CONTRAST TIME-SLIP ANGIOGRAPHY USING VARIABLY POSITIONED CINE SUB-SEQUENCE

• US 20110080170A1
• Filed: 11/15/2010
• Published: 04/07/2011
• Est. Priority Date: 09/18/2009
• Status: Active Grant

• Current Assignee: Toshiba Medical Systems Corporation (Canon Inc.)
• Original Assignee: Toshiba Medical Systems Corporation (Canon Inc.), Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Inventors: MIYAZAKI, Mitsue
• Granted Patent: US 8,581,582 B2
• Time in Patent Office: Days
• US Class Current: 324/309
• CPC Class Codes: A61B 5/055 involving electronic [EMR] or nuclear [NMR] magnetic resonance, e.g. magnetic resonance imaging
• CPC Class Codes: G01R 33/4833 using spatially selective excitation of the volume of interest, e.g. selecting non-orthogonal or inclined slices
• CPC Class Codes: G01R 33/543 Control of the operation of the MR system, e.g. setting of acquisition parameters prior to or during MR data acquisition, dynamic shimming, use of one or more scout images for scan plane prescription G01R33/546 takes precedence
• CPC Class Codes: G01R 33/5601 involving use of a contrast agent for contrast manipulation, e.g. a paramagnetic, super-paramagnetic, ferromagnetic or hyperpolarised contrast agent
• CPC Class Codes: G01R 33/5608 Data processing and visualization specially adapted for MR, e.g. for feature analysis and pattern recognition on the basis of measured MR data, segmentation of measured MR data, edge contour detection on the basis of measured MR data, for enhancing measured MR data in terms of signal-to-noise ratio by means of noise filtering or apodization, for enhancing measured MR data in terms of resolution by means for deblurring, windowing, zero filling, or generation of gray-scaled images, colour-coded images or images displaying vectors instead of pixels image data processing or generation, in general G06T
• CPC Class Codes: G01R 33/5635 Angiography, e.g. contrast-enhanced angiography [CE-MRA] or time-of-flight angiography [TOF-MRA]
• CPC Class Codes: G01R 33/56366 Perfusion imaging

Abstract

A magnetic resonance imaging (MRI) system using an MRI gantry and controlling computer system includes at least one programmed computer configured to effect a cardiac-triggered time-SLIP (spatial labeling inversion pulse) MRI data acquisition sequence for imaging blood perfusion in imaged patient tissue and employing therewithin an MRI cine sub-sequence. The sub-sequence is positioned in the time domain to encompass at least part of a predetermined (e.g., diastolic) cardiac time interval of the patient. Processing acquired data from the time-SLIP data acquisition sequence generates a sequence of MRI cine frame images having respectively associated different effective BBTI (black blood time to inversion) time intervals. Identifying one of the MRI cine frame images as acceptable, thereby effectively also determines an appropriate BBTI time interval for the patient. The system then outputs a time-SLIP image based on the determined appropriate BBTI time interval to at least one of (a) a display, (b) a remote system or (c) a non-transitory storage medium.

Claims

1. A magnetic resonance imaging (MRI) system comprising an MRI gantry and controlling computer system including at least one programmed computer configured to:

effect a cardiac-triggered time-SLIP (spatial labeling inversion pulse) MRI data acquisition sequence for imaging blood perfusion in imaged patient tissue and employing therewithin an MRI cine sub-sequence, which cine sub-sequence is positioned in the time domain to encompass at least part of a predetermined cardiac time interval of the patient;

process acquired data from the time-SLIP data acquisition sequence to generate a sequence of MRI cine frame images having respectively associated different effective BBTI (black blood time to inversion) time intervals;

identify one of said MRI cine frame images as acceptable, thereby effectively also determining an appropriate BBTI time interval for the patient; and

output a time-SLIP image based on said determined appropriate BBTI time interval to at least one of (a) a display, (b) a remote system or (c) a non-transitory storage medium.

2. An MRI system as in claim 1, wherein the position of said MRI cine sub-sequence in the time domain is determined, at least in part, by at least one operator input defining at least one time interval occurring after a cardiac triggering event within the time-SLIP MRI data acquisition sequence.

3. An MRI system as in claim 2, wherein said at least one operator input includes specification of a plurality of:

(a) an initial triggering delay which occurs immediately after said cardiac triggering event, (b) duration of said MRI cine sub-sequence, (c) a recovery time which occurs after said MRI cine sub-sequence and prior to a subsequent time-SLIP data acquisition sequence, and (d) an initial BBTI-related time delay before the start of the MRI cine sub-sequence.

4. An MRI system as in claim 1, wherein said time-SLIP data acquisition sequence is defined and executed based, at least in part, upon at least one operator input defining at least one of the following sequence parameters:

(a) use of spatially selective and/or spatially non-selective SLIP RF tag pulses, (b) use of plural data acquisition sequences with alternating on/off tagging and subtraction image processing, and (c) inflow or outflow MRA mode.

5. An MRI system as in claim 4 wherein said subtraction image processing includes at least one of:

(a) pixel-by-pixel subtraction of the magnitude of pixel values in one image from the magnitude of corresponding pixel values in another image, and (b) pixel-by-pixel subtraction of complex-valued pixels in one image from corresponding complex-valued pixels in another image.

6. An MRI system as in claim 1, wherein said identification of one of said MRI cine frame images as acceptable is based, at least in part, on a display of plural MRI cine frame images and a selective operator input identifying a cine frame image considered to be acceptable.

7. An MRI system as in claim 1, wherein said at least one programmed computer is configured to also:

effect a further time-SLIP data acquisition sequence for imaging blood perfusion in said imaged patient tissue using the BBTI time interval associated with said identified acceptable MRI cine frame image.

8. An MRI system as in claim 6, wherein said at least one programmed computer is configured to effect said further time-SLIP data acquisition sequence for three spatial dimensions.

9. An MRI system as in claim 1, wherein said at least one programmed computer is configured to effect image position registration when processing said acquired data to generate a sequence of MRI cine frame images.

10. An MRI system as in claim 1, wherein the imaged blood perfusion is in imaged patient myocardium tissue.

11. An MRI system as in claim 1, wherein said at least one programmed computer is configured to output a quantified measurement of MRI signal intensity versus cine frame image time occurrence.

12. A magnetic resonance imaging (MRI) method comprising use of an MRI gantry and controlling computer system including at least one programmed computer configured to:

effect a cardiac-triggered time-SLIP (spatial labeling inversion pulse) MRI data acquisition sequence for imaging blood perfusion in imaged patient tissue and employing there-within an MRI cine sub-sequence which cine sub-sequence is positioned in the time domain to encompass at least part of a predetermined cardiac time interval of the patient;

process acquired data from the time-SLIP data acquisition sequence to generate a sequence of MRI cine frame images having respectively associated different effective BBTI (black blood time to inversion) time intervals;

identify one of said MRI cine frame images as acceptable, thereby effectively also determining an appropriate BBTI time interval for the patient; and

output a time-SLIP image based on said determined appropriate BBTI time interval to at least one of (a) a display, (b) a remote system, or (c) a non-transitory storage medium.

13. An MRI method as in claim 12, wherein the position of said MRI cine sub-sequence in the time domain is determined, at least in part, by at least one operator input defining at least one time interval occurring after a cardiac triggering event within the time-SLIP MRI data acquisition sequence.

14. An MRI method as in claim 13, wherein said at least one operator input includes specification of a plurality of:

(a) an initial triggering delay which occurs immediately after said cardiac triggering event, (b) duration of said MRI cine sub-sequence, (c) a recovery time which occurs after said MRI cine sub-sequence and prior to a subsequent time-SLIP data acquisition sequence, and (d) an initial BBTI-related time delay before the start of the MRI cine sub-sequence.

15. An MRI method as in claim 12, wherein said time-SLIP data acquisition sequence is defined and executed based, at least in part, upon at least one operator input defining at least one of the following sequence parameters:

(a) use of spatially selective and/or spatially non-selective SLIP RF tag pulses, (b) use of plural data acquisition sequences with alternating subtraction on/off tagging and image processing, and (c) inflow or outflow MRA.

16. An MRI method as in claim 15 wherein said subtraction image processing includes at least one of:

(a) pixel-by-pixel subtraction of the magnitude of pixel values in one image from the magnitude of corresponding pixel values in another image, and (b) pixel-by-pixel subtraction of complex-valued pixels in one image from corresponding complex-valued pixels in another image.

17. An MRI method as in claim 12, wherein said identification of one of said MRI cine frame images as acceptable is based, at least in part, on a display of plural MRI cine frame images and a selective operator input identifying a cine frame image considered to be the acceptable.

18. An MRI method as in claim 12, wherein said at least one programmed computer is configured to also:

effect a further time-SLIP data acquisition sequence for imaging blood perfusion in said imaged patient tissue using the BBTI time interval associated with said identified acceptable MRI cine frame image.

19. An MRI method as in claim 18, wherein said at least one programmed computer is configured to effect said further time-SLIP data acquisition sequence for three spatial dimensions.

20. An MRI method as in claim 12, wherein said at least one programmed computer is configured to effect image position registration when processing said acquired data to generate a sequence of MRI cine frame images.

21. An MRI method as in claim 12, wherein the imaged blood perfusion is in imaged patient myocardium tissue.

22. An MRI method as in claim 12, wherein said at least one programmed computer is configured to output a quantified measurement of MRI signal intensity versus cine frame image time occurrence.

23. A non-transitory computer memory medium containing computer program control code which, when executed by at least one programmed computer in a magnetic resonance imaging (MRI) system:

effects a cardiac-triggered time-SLIP (spatial labeling inversion pulse) MRI data acquisition sequence for imaging blood perfusion in imaged patient tissue and employing there-within an MRI cine sub-sequence which cine sub-sequence is positioned in the time domain to encompass at least part of a predetermined cardiac time interval of the patient;

processes acquired data from the time-SLIP data acquisition sequence to generate a sequence of MRI cine frame images having respectively associated different effective BBTI (black blood time to inversion) time intervals;

identifies one of said MRI cine frame images as acceptable, thereby effectively also determining an appropriate BBTI time interval for the patient; and

outputs a time-SLIP image based on said determined appropriate BBTI time interval to at least one of (a) a display, (b) a remote system, or (c) a non-transitory storage medium.

24. A non-transitory computer memory medium as in claim 23 wherein said processes include at least one of:

(a) pixel-by-pixel subtraction of the magnitude of pixel values in one image from the magnitude of corresponding pixel values in another image, and (b) pixel-by-pixel subtraction of complex-valued pixels in one image from corresponding complex-valued pixels in another image.