Magnetic resonance imaging apparatus and magnetic resonance imaging method

• US 9,804,245 B2
• Filed: 06/26/2008
• Issued: 10/31/2017
• 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.)
• Inventors: Ichinose, Nobuyasu, Yamashita, Yuichi
• Primary Examiner(s): KISH, JAMES M
• Application Number:
  US12/213,939
• Publication Number:
  US 20090005670A1
• Time in Patent Office: 3,414 Days
• 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 (MR) imaging apparatus comprising:

static and gradient magnetic field generators, at least one RF coil for transmitting and/or receiving RF signals to/from a patient when disposed within said magnetic field generators and at least one programmed computer system and associated memory connected to control the gradient magnetic field generators and RF transmitter and receiver circuits coupled to said at least one RF coil;

said at least one computer system being

configured (a) to accept an input individually designating at least one of position, shape and size for each of a plurality of tag regions, (b) to accept an input individually of a time period from an RF tag pulse to an imaging pulse for each of the plurality of tag regions, and (c) to respectively set the period for each of the plurality of tag regions, the plurality of tag regions being at least partially spatially located within an MR imaging region;

configured to apply the RF tag pulse to each tag region based on the respectively corresponding set period, apply the imaging pulse to the MR imaging region after applying the plurality of RF tag pulses to the plurality of tag regions, and acquire MR echo signals from the MR imaging region; and

configured to reconstruct an image of the MR imaging region based on said acquired MR echo signals,

wherein said acquired MR echo signals emanating from at least one of said MR tag regions are of different intensity compared to acquired MR echo signals emanating from elsewhere in said MR imaging region.

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, wherein:

the at least one computer system is configured to accept an input preventing the plurality of tag regions from overlapping with each other.

4. The magnetic resonance imaging apparatus according to claim 1, wherein:

the at least one computer system is configured to accept an input causing at least portions of the plurality of tag regions to overlap with each other.

5. The magnetic resonance imaging apparatus according to claim 1, wherein:

the at least one computer system is configured to accept an input designating at least one of the plurality of tag regions to include another tag region.

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

said at least one computer system being configured to designate a tag pulse flip angle or time lapse from application of the tag pulse to start of image data acquisition for each of the plurality of tag regions.

7. The magnetic resonance imaging apparatus according to claim 1, wherein:

the at least one computer system is configured to apply a tag pulse to a first of the plurality of tag regions and subsequently to a second of the plurality of tag regions, and to acquire MR imaging data from the imaging region, after said tag pulses have been applied to said first and second tag regions, using a common MR imaging sequence.

8. The magnetic resonance imaging apparatus according to claim 1, wherein:

each 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.

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

said at least one computer system being configured to accept inputs that set the plurality of tag regions and respectively associated time lapses from tag pulse application to the start of MR imaging data acquisition for each of the plurality of tag regions using a previously obtained positioning image; and

said at least one computer system being coupled to a display and configured to display thereon information including respective positions of the tag regions relative to the positioning image and a respectively corresponding time lapse from application of the tag pulse to the start of imaging data acquisition for each of the tag regions.

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

said memory is configured to store therein respective positions on the positioning image of the tag regions used in the acquisition of MR imaging data.

11. The magnetic resonance imaging apparatus according to claim 1,

wherein said at least one computer system is further configured to accept inputs setting information as to whether a tag pulse is to be applied or not for each of plural tag regions, and to acquire the imaging data based on information set for each of plural tag regions, as to whether a tag pulse is to be applied or not.

12. A magnetic resonance (MR) imaging method comprising:

accepting, individually designated for each of a plurality of tag regions, (a) at least one of the position, shape and size, (b) accepting an input individually of a period from an RF tag pulse an imaging pulse for each of the plurality of tag regions, and (c) to respectively set the time period for each of the plurality of tag regions, the plurality of tag regions being at least partially spatially located within an MR imaging region;

applying the RF tag pulse to each tag region based on the respectively corresponding set period, apply the imaging pulse to the MR imaging region after applying the plurality of RE tag pulses to the plurality of tag regions, and acquiring MR echo signals from the MR imaging region, and

reconstructing an image of the MR imaging region based on MR echo signals acquired as the MR imaging data,

said acquired MR echo signals emanating from at least one of said tag regions being of different intensity compared to acquired MR echo signals emanating from elsewhere in said MR imaging region.

13. A magnetic resonance (MR) imaging apparatus comprising:

static and gradient magnetic field generators, at least one RF coil for transmitting and/or receiving RF signals to/from a patient when disposed within said magnetic field generators and at least one programmed computer system and associated memory connected to control the gradient magnetic field generators and RF transmitter and receiver circuits coupled to said at least one RF coil;

said at least one computer system being

configured (a) to accept an input individually designating at least one of position, shape and size for each of a plurality of tag regions, (b) to accept an input individually of a period from an RF tag pulse to an imaging pulse for each of the plurality of tag regions, and (c) to respectively set the time period for each of the plurality of tag regions, the plurality of tag regions being at least partially spatially located within an MR imaging region;

configured to apply the RF tag pulse to each tag region based on the respectively corresponding set period, apply the imaging pulse to an MR imaging region after applying the plurality of RF tag pulses to the plurality of tag regions, and to acquire MR echo signals from the MR imaging region, and

configured to reconstruct an image of the MR imaging region based on said acquired MR echo signals,

said acquired MR echo signals emanating from at least one of said tag regions being of different intensity compared to acquired MR echo signals emanating from elsewhere in said MR imaging region.

14. A magnetic resonance (MR) imaging method comprising:

(a) individually designating at least one of the position, shape and size of tag regions for each of a plurality of tag regions, (b) individually setting a time period from an RF tag pulse to an imaging pulse for each of the plurality of tag regions, and (c) to respectively set the period for each of the plurality of tag regions, the plurality of tag regions being at least partially spatially located within an MR imaging region;

applying the RE tag pulse to each tag region based on the respectively corresponding set period, apply the imaging pulse to the MR imaging region after applying the plurality of RF tag pulses to the plurality of tag regions, and acquiring MR echo signals from the MR imaging region; and

reconstructing an image of the MR imaging region based on acquired echo signals,

said acquired MR echo signals emanating from at least one of said tag regions being of different intensity compared to acquired MR echo signals emanating from elsewhere in said MR imaging region.