The objective of this study was to investigate changes in magnetic resonance findings of the normal ovary during menstrual cycle on diffusion-weighted image (DWI).
Magnetic resonance imaging was performed in 9 healthy females at the menstrual, periovulatory, and luteal phases using a 1.5-T unit. Signal intensity (SI) of the ovary on DWI with a b value of 1000 s/mm2 was visually scored. The ovary-to-muscle contrast ratios on DWI and apparent diffusion coefficient (ADC) values were also evaluated.
All the ovaries were identified, and higher SI than the nerve root was identified in 70% (38/54) of the ovaries, although visual scores did not show significant difference among menstrual phases. The mean ADC values (10−3 mm2/s) were 1.71 (SD, 0.27), 1.71 (SD, 0.22), and 1.67 (SD, 0.19) in menstrual, periovulatory, and luteal phases, respectively. No phase-dependent change was observed in contrast ratios and ADC values.
The normal ovary in fertile period shows high SI enough to be identified on DWI, and observed values are independent of the menstrual cycle.
From the *Department of Diagnostic Imaging and Nuclear Medicine, Graduate School of Medicine, Kyoto University, Kyoto; †Department of Diagnostic Radiology, Osaka Red Cross Hospital, Osaka; and ‡Department of Radiology, Kyoto Katsura Hospital, Kyoto, Japan.
Received for publication January 25, 2012; accepted March 14, 2012.
Reprints: Nobuko Morisawa, MD, Department of Diagnostic Imaging and Nuclear Medicine, Graduate School of Medicine, Kyoto University, 54 Kawahara-cho, Shogoin, Sakyo-ku, Kyoto 606–8507, Japan (e-mail: firstname.lastname@example.org).
The authors report no conflicts of interest.