H Magnetic Resonance Spectroscopy of Cystic Ovarian Lesions

Most female ovarian lesions manifest as cystic masses contain variable contents of fluid. MR image is increasingly used to evaluate theses cystic lesions; malignancy can in some cases be predicted, however, sometimes it is nonspecific for differentiation of benign and malignant lesions. Solid component of ovarian cystic tumors visualized on ultrasonography, CT or MR images strongly supports the diagnosis for malignancy (1-4). Although the presence of tumor markers (CA-125, CA15.9, CEA, CASA and CA 72-4) for the differential diagnosis of ovarian tumors has been studied, there is compelling evidence that cyst fluid tumor marker levels cannot distinguish adequately between the different histologic types. In vivo MRS (magnetic resonance spectroscopy) is a powerful and a noninvasive chemical analysis. This essay illustrated the use of MRS in evaluating female ovarian cystic lesions. In vivo proton MRS was performed with a freebreathing multivoxel point-resolved spectroscopy (PRESS) sequence (TR/TE = 1500/135 msec or 1500/30 msec, 2048-point acquisition, 2500 Hz bandwidth eight averages). CHESS water suppression with 20 Hz bandwidth was obtained after semiautomated higher-order shimming. Outer volume suppression was achieved with six suppression bands placed three-dimensionally around the lesion. Post-processing was applied automatically with zero-order phase correction, zero-filling to 4096 points, and noise INTRODUCTION