Magnetic resonance imaging apparatus and magnetic resonance imaging method

• US 20090005670A1
• Filed: 06/26/2008
• Published: 01/01/2009
• Est. Priority Date: 06/29/2007
• 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: Yamashita, Yuichi, Ichinose, Nobuyasu
• Granted Patent: US 9,804,245 B2
• Time in Patent Office: Days
• US Class Current: 600/410
• CPC Class Codes: A61B 5/05 Detecting, measuring or recording for diagnosis by means of electric currents or magnetic fields; Measuring using microwaves or radio waves impedance plethysmography A61B5/0295; measuring movement of the entire body or parts thereof A61B5/11; detecting, measuring or recording bioelectric or biomagnetic signals of the body or parts thereof A61B5/24
• CPC Class Codes: A61B 5/055 involving electronic [EMR] or nuclear [NMR] magnetic resonance, e.g. magnetic resonance imaging
• CPC Class Codes: G01R 33/20 involving magnetic resonance medical aspects A61B5/055; magnetic resonance gyrometers G01C19/60
• CPC Class Codes: G01R 33/48 NMR imaging systems
• CPC Class Codes: G01R 33/483 with selection of signals or spectra from particular regions of the volume, e.g. in vivo spectroscopy
• 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 33/4835 of multiple slices
• CPC Class Codes: G01R 33/4838 using spatially selective suppression or saturation of MR signals
• 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 33/5607 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 Class Codes: G01R 33/56308 Characterization of motion or flow; Dynamic imaging
• 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

An IR pulse is applied to a tag region B that is disposed at the upstream side of the ascending aorta relative to a tag region A at a timing with a second predetermined delay time TD2 (for example, 600 ms) from the application time of an IR pulse to the tag region A to thereby perform tagging. By this tagging, it is possible to suppress the MR signals derived from the substantial portions and the blood within the tag region B. Subsequently, an imaging scan is performed after a predetermined time lapse TIA (for example, 1200 ms) from the application time of the IR pulse to the tag region A or after a predetermined time lapse TIB (for example, 600 ms) from the application time of the IR pulse to the tag region B.

Claims

1. A magnetic resonance imaging apparatus, comprising:

an imaging unit that applies a tag pulse capable of inverting a nuclear spin in a subject to a plurality of tag regions, at least a portion of which is set in an imaging region of the subject, and that thereafter performs imaging on the imaging region; and

a reconstructing unit that reconstructs an image of the imaging region based on an echo signal obtained by the imaging.

2. The magnetic resonance imaging apparatus according to claim 1, wherein the plurality of tag regions are all set within the imaging region.

3. The magnetic resonance imaging apparatus according to claim 1, further comprising a designating unit for designating at least one of the position, shape and size of the tag regions in an individual manner for each of the plurality of tag regions.

4. The magnetic resonance imaging apparatus according to claim 3, wherein the designating unit is configured such that the plurality of tag regions will not overlap with each other.

5. The magnetic resonance imaging apparatus according to claim 3, wherein the designating unit is configured such that at least portions of the plurality of tag regions overlap with each other.

6. The magnetic resonance imaging apparatus according to claim 3, wherein the designating unit is configured such that at least some of the plurality of tag regions includes another tag region.

7. The magnetic resonance imaging apparatus according to claim 1, further comprising a designating unit for designating a flip angle of the tag pulse or a time lapse from the application of the tag pulse to the start of the imaging in an individual manner for each of the plurality of tag regions.

8. The magnetic resonance imaging apparatus according to claim 1, wherein the imaging unit applies the tag pulse to a first tag region of the plurality of tag regions and subsequently to a second tag region of the plurality of tag regions, and thereafter, performs the imaging on the imaging region using a common imaging sequence.

9. The magnetic resonance imaging apparatus according to claim 1, wherein the tag pulse is an IR (inversion recovery) pulse applied together with a selective gradient magnetic field, and the image of the imaging region is a non-contrast MRA (magnetic resonance angiography) image.

10. The magnetic resonance imaging apparatus according to claim 1, further comprising:

a setting unit that sets the plurality of tag regions and a time lapse from the application of the tag pulse to the start of the imaging for each of the plurality of tag regions using a positioning image; and

a display unit that displays information including respective positions of the tag regions relative to the positioning image and a time lapse from the application of the tag pulse to the start of the imaging for each of the tag regions.

11. The magnetic resonance imaging apparatus according to claim 1, further comprising a storage unit that stores therein respective positions on the positioning image, of the tag regions used in the imaging.

12. The magnetic resonance imaging apparatus according to claim 1, further comprising a setting unit that sets information as to whether the tag pulse is to be applied or not for each of the tag regions,

wherein the imaging unit performs the imaging based on the information set for each of the tag regions, as to whether the tag pulse is to be applied or not.

13. A magnetic resonance imaging method, comprising the steps of:

applying a tag pulse capable of inverting a nuclear spin in a subject to a plurality of tag regions, at least a portion of which is set in an imaging region of the subject, and thereafter performing imaging on the imaging region; and

reconstructing an image of the imaging region based on an echo signal obtained by the imaging.

14. A magnetic resonance imaging apparatus, comprising:

an imaging unit that applies a tag pulse capable of inverting a nuclear spin in a subject to a plurality of tag regions which are set outside an imaging region of the subject, and that thereafter performs imaging on the imaging region; and

a reconstructing unit that reconstructs an image of the imaging region based on an echo signal obtained by the imaging.

15. A magnetic resonance imaging method, comprising the steps of:

applying a tag pulse capable of inverting a nuclear spin in a subject to a plurality of tag regions which are set outside an imaging region of the subject, and thereafter performing imaging on the imaging region; and

reconstructing an image of the imaging region based on an echo signal obtained by the imaging.