MAGNETIC RESONANCE IMAGING APPARATUS AND MAGNETIC RESONANCE IMAGING METHOD

• US 20110071382A1
• Filed: 04/20/2010
• Published: 03/24/2011
• 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.)
• Inventors: Miyazaki, Mitsue, Kuhara, Shigehide
• Granted Patent: US 9,474,455 B2
• Time in Patent Office: Days
• US Class Current: 600/413
• CPC Class Codes: A61B 5/0037 Performing a preliminary scan, e.g. a prescan for identifying a region of interest
• CPC Class Codes: A61B 5/0263 using NMR
• CPC Class Codes: A61B 5/029 Measuring or recording blood output from the heart, e.g. minute volume A61B8/065 takes precedence
• CPC Class Codes: A61B 5/318 Heart-related electrical modalities, e.g. electrocardiography [ECG]
• CPC Class Codes: A61B 5/7271 Specific aspects of physiological measurement analysis A61B5/316, A61B5/349 and A61B5/374 take precedence
• CPC Class Codes: A61B 5/742 using visual displays A61B5/339 takes precedence
• CPC Class Codes: G01R 33/385 using gradient magnetic field coils
• 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

According to one of the aspects of an MRI apparatus of the present invention, the MRI apparatus includes an imaging data acquiring unit and a blood flow information generating unit. The imaging data acquiring unit acquires imaging data from an imaging region including myocardium, without using a contrast medium, by applying a spatial selective excitation pulse to a region including at least a part of an ascending aorta for distinguishably displaying inflowing blood flowing into the imaging region. The blood flow information generating unit generates blood flow image data based on the imaging data.

Claims

1. A magnetic resonance imaging apparatus comprising:

an imaging data acquiring unit which acquires a plurality of 3-dimensional imaging data each corresponding to mutually different traveling time of inflowing blood flowing into an imaging region including myocardium in synchronization with a heartbeat without administration of a contrast medium, by applying a spatial selective excitation pulse plural times for distinguishably displaying the inflowing blood and by changing a time interval from application timing of the spatial selective excitation pulse to acquisition timing of the imaging data;

a blood flow image generating unit which generates a plurality of blood flow image data corresponding to the mutually different traveling time of the inflowing blood based on the plurality of imaging data; and

a cardiac function analysis unit which allows obtaining blood flow information indicative of cardiac function of the myocardium based on the plurality of blood flow image data.

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

wherein the cardiac function analysis unit is configured to generate profiles of blood signal intensity, corresponding to the plurality of blood flow image data as the blood flow information.

3. The magnetic resonance imaging apparatus according to claim 2,

wherein the cardiac function analysis unit is configured to generate 3-dimensional profiles of the blood signal intensity.

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

wherein the cardiac function analysis unit is configured to generate, as the blood flow information, a blood flow information image for performing piecewise display of “

signal intensity of an arbitrary cross-section of the plurality of blood flow image data”

or “

signal intensity difference between arbitrary cross-sections of the plurality of blood flow image data”

with a plurality of segments.

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

wherein the cardiac function analysis unit is configured to generate cross-sectional image data for distinguishably displaying a lesion area based on signal intensity difference between the plurality of blood flow image data, as the blood flow information.

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

wherein the cardiac function analysis unit is configured to generate “

a curve indicating a profile of signal intensity in an arbitrary linear region of interest of arbitrary one of the plurality of blood flow image data”

or “

a curve indicating a profile of signal intensity difference between arbitrary linear regions of interest of the plurality of blood flow image data”

, as the blood flow information.

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

wherein the cardiac function analysis unit is configured to generate “

a curve indicating a profile of signal intensity of arbitrary one of the plurality of blood flow image data in selected one of linear regions of interest set on a cross-section of the myocardium”

or “

a curve indicating a profile of signal intensity difference between the plurality of blood flow image data”

, as the blood flow information.

8. The magnetic resonance imaging apparatus according to claim 7,

wherein the cardiac function analysis unit is configured to perform positional correction of the plurality of blood flow image data by using a reference position set at a border part between right and left ventricles in each of myocardial cross-sections corresponding to the plurality of blood flow image data, and to calculate the signal intensity difference between the plurality of blood flow image data after the positional correction.

9. A magnetic resonance imaging apparatus comprising:

an imaging data acquiring unit which acquires at least one of imaging data from an imaging region including myocardium without using a contrast medium, by applying a spatial selective excitation pulse to a region including at least a part of an ascending aorta for distinguishably displaying inflowing blood flowing into the imaging region; and

a blood flow information generating unit which generates at least one of blood flow image data based on the imaging data.

10. The magnetic resonance imaging apparatus according to claim 9,

wherein the imaging data acquired and the blood flow image data generated are both plural;

the imaging data acquiring unit is configured to apply the spatial selective excitation pulse plural times, and to acquire the plurality of imaging data in 3-dimensional form, each corresponding to mutually different traveling time of the inflowing blood, in synchronization with a heartbeat by changing a time interval from application timing of the spatial selective excitation pulse to acquisition timing of the plurality of imaging data; and

the blood flow information generating unit is configured to generate the plurality of blood flow image data, each corresponding to the mutually different traveling time, based on the plurality of imaging data.

11. The magnetic resonance imaging apparatus according to claim 10,

wherein the imaging data acquiring unit is configured to acquire the plurality of imaging data in diastole.

12. The magnetic resonance imaging apparatus according to claim 10,

wherein the imaging data acquiring unit is configured to set at least one of delay times of electrocardiogram synchronization automatically in order for the plurality of imaging data to be acquired in an arbitrary cardiac phase, and to acquire the plurality of imaging data by using at least one of the delay times automatically set.

13. The magnetic resonance imaging apparatus according to claim 12,

wherein the imaging data acquiring unit is configured to use “

a condition of a pulse sequence for acquiring imaging data corresponding to criterion traveling time of the inflowing blood” and

“

a condition as to which time parameter is preferentially used to determine a pulse sequence”

, in order to automatically set a delay time from a reference wave of an electrocardiogram signal in a pulse sequence for acquiring imaging data corresponding to other traveling time of the inflowing blood.

14. The magnetic resonance imaging apparatus according to claim 10,

wherein the imaging data acquiring unit is configured to apply a labeling pulse as the spatial selective excitation pulse.

15. The magnetic resonance imaging apparatus according to claim 10,

wherein the imaging data acquiring unit is configured to acquire the plurality of imaging data by changing Black Blood Traveling Time of a spatial selective inversion recovery pulse of Time Spatial Labeling Inversion Pulse method used as the spatial selective excitation pulse.

16. The magnetic resonance imaging apparatus according to claim 15,

wherein the imaging data acquiring unit is configured to set the Black Blood Traveling Time long enough to extend for plural heartbeats, in data acquisition of at least one of the plurality of imaging data.

17. The magnetic resonance imaging apparatus according to claim 10,

wherein the imaging data acquiring unit is configured to apply a saturation pulse as the spatial selective excitation pulse.

18. The magnetic resonance imaging apparatus according to claim 10,

wherein the imaging data acquiring unit is configured to apply a labeling pulse as the spatial selective excitation pulse to a region deferent from the imaging region, and to acquire the plurality of imaging data for distinguishably displaying blood labeled by the labeling pulse.

19. The magnetic resonance imaging apparatus according to claim 18,

wherein the imaging data acquiring unit is configured to apply the labeling pulse to a region including a coronary artery.

20. The magnetic resonance imaging apparatus according to claim 18,

wherein the imaging data acquiring unit is configured to apply the labeling pulse to a region including only one of a right coronary artery, a left main coronary trunk, a left circumflex artery, and a left anterior descending artery.

21. The magnetic resonance imaging apparatus according to claim 18,

wherein the imaging data acquiring unit is configured to apply the labeling pulse to a slab set inside a ventricle.

22. The magnetic resonance imaging apparatus according to claim 18,

wherein the imaging data acquiring unit is configured to apply the labeling pulse to a region set on a scout image indicating a right ventricle, a left ventricle and a left atrium.

23. The magnetic resonance imaging apparatus according to claim 18,

wherein the imaging data acquiring unit is configured to apply the labeling pulse to a region set based on 3-dimensional vessel image data of a coronary artery in a sagittal plane of a heart.

24. The magnetic resonance imaging apparatus according to claim 18,

wherein the imaging data acquiring unit is configured to apply a spatial non-selective inversion recovery pulse to the imaging region.

25. The magnetic resonance imaging apparatus according to claim 24,

wherein the imaging data acquiring unit is configured to apply an imaging region selective inversion recovery pulse to excite the imaging region selectively after applying the spatial non-selective inversion recovery pulse and the labeling pulse.

26. The magnetic resonance imaging apparatus according to claim 24,

wherein the imaging data acquiring unit is configured to set “

an inversion recovery time from application timing of the spatial non-selective inversion recovery pulse to acquisition timing of the plurality of imaging data” and

“

a time interval from application timing of the labeling pulse to the acquisition timing of the plurality of imaging data”

, changeably and independently each other.

27. The magnetic resonance imaging apparatus according to claim 26,

wherein the imaging data acquiring unit is configured to set the acquisition timing of the plurality of imaging data to a timing when both “

an absolute value of longitudinal magnetization of blood except the inflowing blood” and

“

an absolute value of longitudinal magnetization of the myocardium”

become equal to or less than a predetermined value.

28. The magnetic resonance imaging apparatus according to claim 27,

wherein the blood flow information generating unit is configured to inhibit a signal from the blood except the inflowing blood by performing image reconstruction processing with the use of real parts of the plurality of imaging data.

29. The magnetic resonance imaging apparatus according to claim 10,

wherein the imaging data acquiring unit is configured to acquire the plurality of imaging data for distinguishably displaying the inflowing blood by applying the spatial selective excitation pulse to the imaging region.

30. The magnetic resonance imaging apparatus according to claim 10,

wherein the imaging data acquiring unit is configured to acquire the plurality of imaging data each corresponding to the mutually different traveling time without application of the spatial selective excitation pulse, aside from acquiring the plurality of imaging data with application of the spatial selective excitation pulse;

and

the blood flow information generating unit is configured to generate the plurality of blood flow image data based on difference data between “

the plurality of imaging data acquired with application of the spatial selective excitation pulse” and

“

the plurality of imaging data acquired without application of the spatial selective excitation pulse”

.

31. The magnetic resonance imaging apparatus according to claim 10,

wherein the imaging data acquiring unit is configured to apply another spatial selective excitation pulse in a period between application timing of the spatial selective excitation pulse and acquisition timing of imaging data.

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

a prescan unit which acquires 2-dimensional data under application of the spatial selective excitation pulse by changing a delay time from application timing of the spatial selective excitation pulse to data acquisition timing, and displays a plurality of cross-sectional images based on the plurality of the 2-dimensional data; and

an imaging condition setting unit which selects at least two of the cross-sectional images based on input information, and sets “

the delay time corresponding to the cross-sectional images selected”

as a time interval from the application timing of the spatial selective excitation pulse to acquisition timing of the plurality of imaging data.

33. The magnetic resonance imaging apparatus according to claim 10,

wherein the imaging data acquiring unit is configured to acquire the plurality of imaging data by applying at least one of medicational stress and exercise stress to the imaging region.

34. The magnetic resonance imaging apparatus according to claim 10,

wherein the imaging data acquiring unit is configured to acquire the plurality of imaging data as first data by applying at least one of medicational stress and exercise stress to the imaging region, and to acquire the plurality of imaging data as second data by applying neither medicational stress nor exercise stress to the imaging region;

and

the blood flow information generating unit is configured to generate the plurality of blood flow image data based on difference data between the first data and the second data.

35. The magnetic resonance imaging apparatus according to claim 10,

wherein the imaging data acquiring unit is configured to acquire a magnetic resonance signal for measuring motion quantity caused by respiration prior to acquisition of the plurality of imaging data, and to correct the imaging region according to the motion quantity.

36. The magnetic resonance imaging apparatus according to claim 10,

wherein the imaging data acquiring unit is configured to acquire a magnetic resonance signal for measuring motion quantity caused by respiration prior to acquisition of the plurality of imaging data;

and

the blood flow information generating unit is configured to generate the plurality of blood flow image data by performing motion correction using the motion quantity.

37. The magnetic resonance imaging apparatus according to claim 10,

wherein the blood flow information generating unit is configured to generate the plurality of blood flow image data by performing correction to eliminate a signal component corresponding to a background of an image from the plurality of imaging data.

38. The magnetic resonance imaging apparatus according to claim 10,

wherein the blood flow information generating unit is configured to control a time interval from “

timing of a last reference wave of an electrocardiogram signal before acquisition of the plurality of imaging data”

to “

the acquisition of the plurality of imaging data”

by estimating a cyclic period of a heartbeat based on the electrocardiogram signal.

39. A magnetic resonance imaging method comprising the steps of:

acquiring imaging data from an imaging region including myocardium without using a contrast medium, by applying a spatial selective excitation pulse to a region including at least a part of an ascending aorta for distinguishably displaying inflowing blood flowing into the imaging region; and

generating blood flow image data based on the imaging data.