Preliminary observations and diagnostic value of lipid peak in ovarian thecomas/fibrothecomas using in vivo proton MR spectroscopy at 3T.

PURPOSE

To retrospectively evaluate the significance of lipid peak in in vivo proton magnetic resonance (MR) spectroscopy for the diagnosis of ovarian thecomas/fibrothecomas in patients with solid gynecologic tumors exhibiting totally or partially low signal intensity on T2-weighted images.

MATERIALS AND METHODS

MR spectroscopy was performed in patients with pathologically diagnosed gynecologic tumors at 3T MRI. Single-voxel MR spectroscopy data were collected from a single square volume of interest that encompassed the gynecologic masses. The lipid concentration level was classified into three classes (high; low; none).

RESULTS

A total of 20 gynecologic tumors in 20 patients were evaluated in this study. High lipid peak was observed in all seven thecomas/fibrothecomas, whereas low lipid peak was observed in only one fibroma in 13 nonthecomatous tumors (six benign ovarian tumors and seven subserosal uterine leiomyomas). The presence of lipid peak for the diagnosis of thecomas/fibrothecomas had a sensitivity of 100%, specificity of 92%, positive predictive value of 88%, and negative predictive value of 100%.

CONCLUSION

The high lipid peak reflecting abundant intracellular lipid contents is considered a specific metabolite concentration for thecomas/fibrothecomas. Demonstration of high lipid peak may contribute to the diagnosis of thecomas/fibrothecomas in distinguishing from other benign ovarian fibrous tumors or subserosal uterine leiomyomas.