A METHOD FOR INNER VOLUME MAGNETIC RESONANCE IMAGING
Publication Date: 2004-Dec-29
The IP.com Prior Art Database
In an embodiment, a method for inner volume magnetic resonance imaging includes implementing an inner volume acquisition algorithm corresponding to a parallel-imaging inner volume scan while performing a calibration scan. In another embodiment, the method includes using an inner volume RF pulse, which has a sharp slice profile.
FIELD OF THE INVENTION
 This invention relates generally, to magnetic resonance imaging (MRI), and more particularly to, inner volume magnetic resonance imaging, e.g. cardiac imaging.
BACKGROUND OF THE INVENTION
 In MRI, the prescribed field-of-view (FOV) is usually set larger than an object e.g. organ to be visualized, in order to avoid “aliasing”, or “wrap-around”, artifacts. This poses a limitation that causes inefficiency in scan time and spatial resolution, especially in cardiac imaging, particularly when the organ of interest is very small compared to the patient’s total size. The use of the “inner volume” (IV) technique  with a spin echo pulse sequence allows small FOV imaging without aliasing. For fast imaging, inner volume (IV) technique is particularly useful with a single-shot version of the fast spin echo (FSE) sequence namely, single-shot fast spin echo (SSFSE)) [2-4].
 Higher spatial resolution FSE and SSFSE require use of long echo train length (ETL), which in turn results in image blurring due to motion, such as cardiac motion, during the long acquisition window, as well as T2-decay.
 Although the use of the IV technique helps reducing the ETL, there exists a need for further reduction in ETL to obtain high spatial resolution.
SUMMARY OF THE INVENTION
 In an embodiment, a method for inner volume magnetic resonance imaging, includes implementing an inner volume acquisition algorithm corresponding to a parallel-imaging inner volume scan while performing a calibration scan.
 In an embodiment, the method includes using an inner volume RF pulse, which has a sharp slice profile.
 In another embodiment, the inner volume FOV is maintained slightly larger than the inner volume RF pulse’s excitation bandwidth, to allow for any residual imperfection of the slice profile of the inner volume RF pulse.
BRIEF DESCRIPTION OF THE DRAWINGS
 FIG. 1 shows an example of a series of images being reconstructed according to one embodiment of this invention.
 FIG. 2 shows an example of a series of images illustrating the effect of number of phase coding lines according to one embodiment of this invention.
 FIG. 3 shows a comparative example of an in vivo cardiac image obtained with parallel imaging and predetermined number of phase encoding lines according to one embodiment of this invention.
DETAILED DESCRIPTION OF THE INVENTION
 Various embodiments of the present invention provide a method for inner volume magnetic resonance imaging especially for cardiac imaging.
 In an embodiment, a method of inner volume magnetic resonance imaging according to this invention includes combining parallel imaging technique such as, for example, SENSE, SMASH [5,6] with IV technique using FSE AND IV SSFSE sequence.
 For the purposes of illustration of this invention, for a successful r...