Teratomas versus cystic hemorrhagic adnexal lesions: differentiation with proton-selective fat-saturation MR imaging

To assess the value of proton-selective fat-saturation magnetic resonance (MR) imaging in differentiating teratomas from cystic hemorrhagic masses, 38 patients with 48 lesions (21 teratomas, 27 cystic hemorrhagic masses) detected at prior ultrasound or computed tomography were imaged with standard T1- and T2-weighted spin-echo (SE) sequences. Twenty-one patients with 28 lesions (13 teratomas, 15 cystic hemorrhagic masses) were imaged with an additional T1-weighted fat-saturation sequence. On standard T1- and T2-weighted SE images, 43% of the teratomas and 52% of the cystic hemorrhagic masses were characterized correctly with signal intensity criteria. Sixty-two percent of the teratomas and 100% of the cystic hemorrhagic masses were characterized correctly with chemical shift artifact criteria. With fat-saturation images alone, the characterization sensitivity for teratomas and cystic hemorrhagic masses increased to 92% and 100%, respectively. Fat-saturation MR imaging was statistically superior to standard T1- and T2-weighted imaging in characterizing teratomas.