High resolution MRI imaging of brain functions

• US 20010056231A1
• Filed: 03/13/2001
• Published: 12/27/2001
• Est. Priority Date: 03/13/2000
• Status: Abandoned Application

• Current Assignee: The MSW Research Foundation, Inc.
• Original Assignee: The MSW Research Foundation, Inc.
• Inventors: Jesmanowicz, Andrzej, Hyde, James S., Biswal, Bharat B.
• Application Number:
  US09/804,934
• Publication Number:
  US 20010056231A1
• Time in Patent Office: Days
• US Class Current: 600/410
• CPC Class Codes: A61B 5/0042 for the brain
• CPC Class Codes: A61B 5/055 involving electronic [EMR] or nuclear [NMR] magnetic resonance, e.g. magnetic resonance imaging
• CPC Class Codes: A61B 5/14553 specially adapted for cerebral tissue
• CPC Class Codes: G01R 33/4806 Functional imaging of brain activation

Abstract

An EPI pulse sequence is performed by an NMR system which acquires images of the brain over a time interval during which the subject performs a function or is stimulated in a pattern. The voxel size of acquired images corresponds to the anatomy of cortical microcirculation structures which range from 1 to 2 mm along all three axes. A centric view order is employed and one-half of k-space is sampled to reduce scan time for each image.

Claims

1. A method for producing a functional magnetic resonance image (fMRI) of a subject'"'"'s brain, the steps comprising:

a) operating a magnetic resonance imaging (MRI) system to perform a series of pulse sequences that acquire a series of NMR k-space data arrays over a period of time, during which the subject'"'"'s brain is caused to function in a preselected temporal pattern;

b) producing a time course NMR image data set of time domain voxel vectors from the series of k-space arrays, in which each time domain voxel vector indicates the NMR signal during said period of time from a substantially cubic region of the brain having a size from 1.0 to 8.0 mm³;

c) producing an image which indicates the amount of brain activity in each of said cubic regions.

2. The method as recited in

claim 1

in which each pulse sequence is performed by the MRI system in step a) by:

i) producing an RF excitation pulse in the presence of a slice select magnetic field gradient aligned along a first k-space axis to produce transverse magnetization in a slice perpendicular to said first k-space axis with a thickness of from 1.0 to 2.0 mm;

ii) producing a series of phase encoding magnetic field gradients directed along a second k-space axis in the plane of the slice;

iii) producing a series of readout magnetic field gradients directed along a third k-space axis perpendicular to the second k-space axis, the series of readout gradients being produced concurrently with the series of phase encoding gradients;

iv) acquiring a series of NMR signals in the presence of the readout gradient to produce k-space data which samples k-space as a series of views in centric view order.

3. The method as recited in

claim 2

in which the pulse sequence is performed such that a part of k-space is sampled by the acquired NMR signals and step a) includes:

v) calculating k-space samples for the unacquired part of k-space to form a complete k-space data array.

4. The method as recited in

claim 3

in which the acquired part of k-space is substantially one-half of k-space.

5. The method as recited in

claim 1

in which step a) acquires a series of NMR k-space data arrays from a plurality of substantially contiguous slices through the subject'"'"'s brain.

6. The method as recited in

claim 5

in which the period of time is from four to six minutes.

7. The method as recited in

claim 2

in which the pulse sequence is a multislice, partial k-space, gradient recalled echo planar imaging pulse sequence.

8. The method as recited in

claim 2

in which steps i) and iv) are performed using a local RF coil configured for imaging the human brain.

9. The method as recited in

claim 2

in which steps ii) and iii) are performed using a local gradient coil configured for imaging the human brain.

10. The method as recited in

claim 1

in which the pulse sequence is selected to detect changes in brain activity produced by the BOLD contrast mechanism.