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


METHODS
T(1)-weighted and T(2)-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 T(1)-weighted and T(2)-weighted fast spin-echo sequences. For T(1)-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.


CONCLUSIONS
Multipeak IDEAL fat-water separation provides improved fat suppression for T(1)-weighted and T(2)-weighted fast spin-echo imaging of the knee when compared to single-peak IDEAL and two widely used frequency-selected fat-saturation methods.
Kijowski
Richard
R
Department of Radiology, University of Wisconsin, Madison, Wisconsin, USA. r.kijowski@hosp.wisc.edu
Woods
Michael A
MA
Lee
Kenneth S
KS
Takimi
Kuya
K
Yu
Huanzhou
H
Shimakawa
Ann
A
Brittain
Jean H
JH
Reeder
Scott B
SB
D000273:Adipose Tissue / Q000473:pathology*; D000328:Adult; D002138:Calibration; D003288:Contusions / Q000473:pathology; D005260:Female; D006801:Humans; D007089:Image Enhancement / Q000379:methods*; D007091:Image Processing, Computer-Assisted; D007717:Knee / Q000473:pathology* / Q000601:surgery; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male