Journal of magnetic resonance imaging : JMRI
-
J Magn Reson Imaging · Jun 2009
Comparative StudySpiral imaging artifact reduction: a comparison of two k-trajectory measurement methods.
To compare an external sensor-based k-space calibration technique with a routine precalibration method for quantification of method accuracy and reduction of spiral imaging artifacts to obtain improved image quality. ⋯ We introduce MFM as an effective and accurate correction technique for spiral imaging, where a comparison of MFM and DCT has shown that both techniques are accurate correction techniques for spiral imaging.
-
J Magn Reson Imaging · Jun 2009
Improved time-of-flight magnetic resonance angiography with IDEAL water-fat separation.
To implement IDEAL (iterative decomposition of water and fat using echo asymmetry and least squares estimation) water-fat separation with 3D time-of-flight (TOF) magnetic resonance angiography (MRA) of intracranial vessels for improved background suppression by providing uniform and robust separation of fat signal that appears bright on conventional TOF-MRA. ⋯ By providing uniform suppression of fat, IDEAL TOF-MRA provides improved background suppression with improved image quality when compared to conventional TOF-MRA methods.
-
J Magn Reson Imaging · Jun 2009
Comparative StudyImproved arterial visibility using short-tau inversion-recovery (STIR) fat suppression in non-contrast-enhanced time-spatial labeling inversion pulse (Time-SLIP) renal MR angiography (MRA).
To evaluate whether short-tau inversion-recovery (STIR) fat suppression is worthwhile in non-contrast-enhanced respiration-triggered free-breathing time-spatial labeling inversion pulse (Time-SLIP) renal magnetic resonance angiography (MRA) compared with chemical shift selective (CHESS) fat suppression. ⋯ STIR fat suppression provides better renal artery contrast than CHESS fat suppression in non-contrast free-breathing Time-SLIP MRA; it is also an effective screening tool for renal artery stenosis because of the lack of interference from intestinal signals. However, close attention is needed if the patient has slow respiration. As the TI for the ssIR pulse decreases, the STIR method requires faster-paced respiration.
-
J Magn Reson Imaging · Jun 2009
Intermuscular adipose tissue (IMAT): association with other adipose tissue compartments and insulin sensitivity.
To quantify intermuscular adipose tissue (IMAT) of the lower leg as well as to investigate associations with other adipose tissue (AT) compartments. The relationship between IMAT and insulin sensitivity was also examined. ⋯ Quantification of IMAT is possible by standard MR techniques. AT distribution of the lower leg is comparable to the visceral compartment with males having higher IMAT/VAT but lower subcutaneous AT (SCAT). IMAT seems to be involved in the pathogenesis of insulin resistance, as shown by the significant negative correlation with GIR.
-
J Magn Reson Imaging · Jun 2009
Multiecho time-resolved acquisition (META): a high spatiotemporal resolution Dixon imaging sequence for dynamic contrast-enhanced MRI.
To evaluate a new dynamic contrast-enhanced (DCE) imaging technique called multiecho time-resolved acquisition (META) for abdominal/pelvic imaging. META combines an elliptical centric time-resolved three-dimensional (3D) spoiled gradient-recalled echo (SPGR) imaging scheme with a Dixon-based fat-water separation algorithm to generate high spatiotemporal resolution volumes. ⋯ META is a promising high spatiotemporal resolution imaging sequence for capturing the fast dynamics of hyperenhancing hepatic lesions and provides robust fat suppression even at 3T.