System and method for moving table MRI
View Patent ↗The present invention provides an MRI system for imaging of a subject over extended field-of-view (FOV) that employs both accelerated data acquisition, which is employed while the subject is stationary, and traditional data acquisition, which is employed while the subject is moved through the MRI system. This approach provides improved spatial resolution and time efficiency compared to traditional extended FOV imaging techniques.
1. A method for producing an image over an extended field-of-view (FOV) of a magnetic resonance imaging (MRI) system having a predefined FOV that is smaller than the extended FOV, the method comprising the steps of:
a) determining a set of imaging stations at which to image a subject over the extended FOV;
b) performing a prescan at the set of imaging stations using receiver coil elements to acquire a prescan data set;
c) determining sensitivity profiles of the receiver coil elements at each of the set of imaging stations from the prescan data set;
d) moving the subject to a first station in the set of imaging stations;
e) performing a stationary, parallel imaging acquisition using the sensitivity profiles determined at step c) while the subject is at the first station to acquire a first set of NMR data from the subject;
f) moving the subject toward a next station in the set of imaging stations;
g) performing an intermediate imaging acquisition while the subject is being moved toward the next station in the set of imaging stations to acquire a next set of NMR data;
h) performing a stationary, parallel imaging acquisition using the sensitivity profiles determined at step c) while the subject is at the next station to acquire a next set of NMR data from the subject;
i) repeating steps f) through h) until the last station to acquire a series of NMR data from the subject; and
j) a reconstructing and processing the series of NMR data to produce images of the subject over the extended FOV.
2. The method of claim 1 wherein step g) includes performing the intermediate imaging acquisition with a degree of acceleration of substantially unity.
3. The method of claim 1 wherein step i) includes performing the stationary, parallel imaging acquisition with a degree of acceleration varied at the imaging stations.
4. The method of claim 1 wherein step i) includes reconstructing real-time images and monitoring a timing and velocity of the subject during movement by analyzing the real-time images to identify a selected tracking feature.
5. The method of claim 4 wherein step h) includes reconstructing the real-time images from the first and next sets of NMR data.
6. The method of claim 4 wherein the tracking feature includes a leading edge of a contrast agent bolus administered to the subject approaching a distal end of the predefined FOV.
7. The method of claim 1 wherein step i) includes registering the series of NMR data to increase a spatial resolution during the intermediate imaging acquisition.
8. The method of claim 1 wherein step f) is performed according to a continuous moving table (CMT) technique.
9. A method for producing an image over an extended field-of-view (FOV) of a magnetic resonance imaging (MRI) system having a predefined FOV that is smaller than the extended FOV, the method comprising the steps of:
a) determining a plurality of imaging stations within the extended FOV at which to image a subject;
b) performing a prescan at each of the plurality of imaging stations using a receiver coil having a plurality of elements to acquire a prescan data set;
c) determining sensitivity profiles of the receiver coil at each of the plurality of imaging stations from the prescan data set;
d) sequentially moving the subject through each of the plurality of imaging stations;
e) at each of the plurality of imaging stations, performing a stationary, parallel imaging acquisition using the sensitivity profiles determined at step c) to acquire a corresponding, accelerated imaging data set;
f) between each of the plurality of imaging stations, performing an intermediate imaging acquisition while the subject is moving to acquire a corresponding, non-accelerated imaging data set; and
g) reconstructing the corresponding, accelerated imaging data set and, non-accelerated imaging data set to produce images of the subject over the extended FOV.
10. The method of claim 9 wherein step e) includes performing the stationary, parallel imaging acquisition with a degree of acceleration varied at each of the plurality of imaging stations.
11. The method of claim 9 wherein steps d) through f) include reconstructing real-time images and monitoring a timing and velocity of the subject during movement by analyzing the real-time images to identify a selected tracking feature.
12. The method of claim 11 wherein steps d) through f) include reconstructing the real-time images from the accelerated imaging data set and the non-accelerated imaging data set.
13. The method of claim 11 wherein the tracking feature includes a leading edge of a contrast agent bolus administered to the subject approaching a distal end of the predefined FOV.
14. The method of claim 9 wherein step g) includes registering the accelerated imaging data set and the non-accelerated imaging data set to increase a spatial resolution during the intermediate imaging acquisition.
15. The method of claim 9 wherein step d) includes performing a continuous moving table (CMT) technique between imaging stations.