Diffusion-weighted EPI of cystic ovarian lesions: evaluation of cystic contents using apparent diffusion coefficients.
Diffusion-weighted echoplanar imaging (EPI) was performed to evaluate the contents of cystic ovarian lesions [33 endometrial cysts, 16 ovarian cysts, 5 serous cystadenomas, 6 mucinous cystadenomas, 13 malignant cystic ovarian tumors, and 3 benign cystic lesions mimicking malignant cystic ovarian tumor (BMMs)]. Apparent diffusion coefficient (ADC) values were calculated for the cystic contents. Many lesions showed unrealistically high ADC greater than water at body temperature (0.00324 mm(2)/sec), especially in lesions more than 12 cm in diameter. The higher ADC values were attributed to the sloshing effect: intermittent compression of large ovarian lesions by abdominal breathing before the breath-hold scan. When limited to lesions with ADC less than 0. 00324 mm(2)/sec, endometrial cysts and malignant cystic ovarian tumors showed lower ADC values than ovarian cysts and serous cystadenomas (P < 0.03). When further limited to lesions less than 12 cm in axial diameter, an additional ADC difference between malignant cystic ovarian BMMs was demonstrated (P < 0.03). Diffusion-weighted EPI showed the possibility that calculated ADC values might be useful in evaluating small to medium cystic ovarian lesions. J. Magn. Reson. Imaging 2000;12:1014-1019.
Moteki
T
T
Department of Diagnostic Radiology, Gunma University Hospital, 3-39-15, Showa-machi, Maebashi, 371 Gunma, Japan. tmmoteki@m12.alpha-net.ne.jp
Ishizaka
H
H
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003937:Diagnosis, Differential; D004058:Diffusion; D017352:Echo-Planar Imaging / Q000379:methods*; D005260:Female; D006801:Humans; D008875:Middle Aged; D010048:Ovarian Cysts / Q000175:diagnosis*; D010051:Ovarian Neoplasms / Q000175:diagnosis*; D010053:Ovary / Q000473:pathology