Ovarian cancer: staging with CT and MR imaging.

PURPOSE: To evaluate ovarian cancer staging and tumor resectability with computed tomography (CT) or magnetic resonance (MR) imaging. MATERIALS AND METHODS: Eighty-two women underwent CT (n = 43) or MR imaging (n = 50); eleven of these 82 underwent both. Imaging was performed within 4 weeks of surgical staging. Radiologic, surgical, and histopathologic findings were compared. RESULTS: Overall staging accuracy was similar for CT and MR imaging (77% [33 of 43] vs 78% [39 of 50]). Evaluation of pelvic cancer extent was better with MR imaging than with CT. There was no difference in detection of abdominal disease. Most mesenteric and small-bowel implants were not detected with either CT or MR imaging. For CT, the positive predictive value for cancer nonresectability was 100% (three of three patients); the negative predictive value was 92% (37 of 40 patients). The positive and negative predictive values for MR imaging were 91% (10 of 11 patients) and 97% (38 of 39 patients). CONCLUSION: While the staging accuracy of both CT and MR imaging is only moderate, prediction of tumor resectability is excellent.

MRI of a silicone breast implant surrounded by an enlarging hemorrhagic collection.

MRI yields cross-sectional image acquisition in multiple planes with very high contrast resolution. Additionally, in MRI of the breast, evaluation of the entire implant is possible. Not only is MRI very sensitive to loss of implant integrity and rupture, but also MRI can evaluate and characterize adjacent fluid collections or soft-tissue masses. Anatomic relationships of abnormalities and normal structures are well seen. In some situations, MRI may offer clinically relevant information not adequately addressed by other imaging modalities.

Differentiation of silicone gel from water and fat in MR phase imaging of protons at 0.064 T.

The authors present a method of identifying silicone at magnetic resonance (MR) imaging based on its chemical shift. The method relies on phase images reconstructed from a gradient-recalled-echo sequence that has an echo time chosen to maximize the phase offsets between water, fat, and silicone. Results from studies at 0.064 T of both phantoms and human subjects are presented. This technique was useful in identifying extracapsular silicone and may be applicable at other field strengths.

The ovary. Computed tomography and magnetic resonance imaging.

CT and MR imaging can both contribute valuable clinical information in women with benign and malignant ovarian masses; the superior soft tissue contrast and multiplanar capabilities provided by MR imaging make it a valuable tool to evaluate the normal ovary, polycystic ovaries, endometriosis, and disorders of sexual differentiation. CT is currently the recommended modality to stage ovarian carcinoma, and peritoneal implants as small as 5 mm can be visualized. With the addition of contrast-enhanced images to conventional MR sequences, however, improved visualization of intratumoral architecture has also allowed for accurate MR characterization of benign versus malignant ovarian masses. Fat saturation techniques used with conventional MR sequences can also be used for definitive characterization of benign fat-containing teratomas and differentiate these tumors from hemorrhagic ovarian cysts or endometriomas. Finally, the detailed visualization of the normal-sized ovary on MR images provided by both the body coil and the new phased-array coil allows detection of the normal ovaries, ovarian follicles, and ovarian cysts throughout the premenopausal and postmenopausal years. Findings of polycystic ovarian syndrome, which cannot be evaluated by CT, are characteristic on MR images. MR is unparalleled in the evaluation of disorders of sexual differentiation because MR images can depict ectopic and normally positioned gonads and provide multiplanar depiction of the other pelvic organs and perineum as well. CT and MR imaging can provide valuable and specific clinical information about the ovary and benign and malignant ovarian disease.