Ovarian masses: MR imaging with T1-weighted 3-dimensional gradient-echo IDEAL water-fat separation sequence at 3T.
OBJECTIVE
We retrospectively compared the efficacy of 3-dimensional (3D) gradient-echo magnetic resonance T(1)-weighted sequence using the iterative decomposition of water and fat with echo asymmetry and least-squares estimation (IDEAL) technique with the efficacy of conventional 3D gradient-echo sequences for diagnosing ovarian masses at 3T.


METHODS
In images of 32 women (mean age, 45.3 years) with ovarian masses who underwent T(1)-weighted imaging with both IDEAL and conventional techniques, we quantitatively analyzed signal-to-noise ratio (SNR) and contrast between gluteal muscle and T(1)-weighted high-signal materials within lesions and assessed image quality. Two radiologists independently evaluated fat detection.


RESULTS
Mean SNR of subcutaneous fat did not differ significantly between IDEAL and conventional techniques for both fat-suppressed (P=.32) and non-fat-suppressed (P=.85) images. Mean absolute contrast between gluteal muscle and T(1)-weighted high signal materials within teratomas (n=15) was significantly higher with IDEAL on fat-suppressed images (P=.002) and lower with IDEAL on non-fat-suppressed images (P=.010). Fat suppression was significantly superior with IDEAL (P<.0001). Readers' assessments of fat detection did not differ between IDEAL and conventional sequences.


CONCLUSIONS
The quality of T(1)-weighted fat-suppressed images of ovarian masses was better with 3D gradient-echo IDEAL than conventional 3D gradient-echo sequences.
Department of Radiology, Osaka University Graduate School of Medicine, Suita, Osaka, Japan. mhori@radiol.med.osaka-u.ac.jp
Masatoshi
M
Hori
Tonsok
T
Kim
Hiromitsu
H
Onishi
Atsushi
A
Nakamoto
Takahiro
T
Tsuboyama
Mitsuaki
M
Tatsumi
Noriyuki
N
Tomiyama
D000273:Adipose Tissue / Q000473:pathology*; D000328:Adult; D000368:Aged; D000465:Algorithms; D001834:Body Water / Q000737:chemistry*; D005260:Female; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D021621:Imaging, Three-Dimensional / Q000379:methods*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008875:Middle Aged; D010051:Ovarian Neoplasms / Q000737:chemistry* / Q000473:pathology*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity