Improved fat suppression using multipeak reconstruction for IDEAL chemical shift fat-water separation: Application with fast spin echo imaging

• Published in: Journal of magnetic resonance imaging Vol. 29; no. 2; pp. 436 - 442
• Main Authors: Kijowski, Richard, Woods, Michael A., Lee, Kenneth S., Takimi, Kuya, Yu, Huanzhou, Shimakawa, Ann, Brittain, Jean H., Reeder, Scott B.
• Format: Journal Article
• Language: English
• Published: Hoboken Wiley Subscription Services, Inc., A Wiley Company 01.02.2009
• Subjects: Adipose Tissue - pathology; Adult; Calibration; Contusions - pathology; fat suppression; fat-water separation; Female; Humans; IDEAL; Image Enhancement - methods; Image Processing, Computer-Assisted; knee; Knee - pathology; Knee - surgery; Magnetic Resonance Imaging - methods; Male; MRI
• ISSN: 1053-1807; 1522-2586
• DOI: 10.1002/jmri.21664

Purpose To evaluate and quantify improvements in the quality of fat suppression for fast spin‐echo imaging of the knee using multipeak fat spectral modeling and IDEAL fat‐water separation. Materials and Methods T1‐weighted and T2‐weighted fast spin‐echo sequences with IDEAL fat‐water separation and two frequency‐selective fat‐saturation methods (fat‐selective saturation and fat‐selective partial inversion) were performed on 10 knees of five asymptomatic volunteers. The IDEAL images were reconstructed using a conventional single‐peak method and precalibrated and self‐calibrated multipeak methods that more accurately model the NMR spectrum of fat. The signal‐to‐noise ratio (SNR) was measured in various tissues for all sequences. Student t‐tests were used to compare SNR values. Results Precalibrated and self‐calibrated multipeak IDEAL had significantly greater suppression of signal (P < 0.05) within subcutaneous fat and bone marrow than fat‐selective saturation, fat‐selective partial inversion, and single‐peak IDEAL for both T1‐weighted and T2‐weighted fast spin‐echo sequences. For T1‐weighted fast spin‐echo sequences, the improvement in the suppression of signal within subcutaneous fat and bone marrow for multipeak IDEAL ranged between 65% when compared to fat‐selective partial inversion to 86% when compared to fat‐selectivesaturation. For T2‐weighted fast spin‐echo sequences, the improvement for multipeak IDEAL ranged between 21% when compared to fat‐selective partial inversion to 81% when compared to fat‐selective saturation. Conclusion Multipeak IDEAL fat‐water separation provides improved fat suppression for T1‐weighted and T2‐weighted fast spin‐echo imaging of the knee when compared to single‐peak IDEAL and two widely used frequency‐selected fat‐saturation methods. J. Magn. Reson. Imaging 2009;29:436–442. © 2009 Wiley‐Liss, Inc.