Sarty G E, Kendall E J, Pierson R A
Department of Obstetrics and Gynecology, Royal University Hospital, Saskatoon, Saskatchewan, Canada.
MAGMA. 1996 Sep-Dec;4(3-4):205-11. doi: 10.1007/BF01772008.
A sample of 20 bovine ovaries were imaged in vitro using nuclear magnetic resonance (NMR) techniques to determine the visibility of various physiologic structures. In particular, the possibility of using NMR imaging to differentiate atretic follicles from physiologically selected and ovulatory follicles was examined. Five of the 20 ovaries were preserved in formalin, whereas the remaining 15 were preserved in a saline solution and imaged within 18 hours of death. Images weighted by T1 and T2 proton spin relaxation rates were obtained along with some three-dimensional (3-D) data sets acquired via a fast imaging with steady-state precession technique. Physiologically different structures were easily identified in the images from their morphology, especially in the 3-D images. Weighting by T1 and T2 was able to separate structures in the fresh ovaries in the following manner. Atretic and "cohort" follicles appear dark in T1-weighted images and bright in T2-weighted images. Ovulatory follicles appear bright in both T1- and T2-weighted images, whereas prephysiologic selection follicles present an intermediate brightness in T1-weighted images and appear dark in T2-weighted images. The corpus luteum appears bright in T1-weighted images and dark in T2-weighted images, whereas cysts in the corpus luteum appear dark in T1-weighted images and bright in T2-weighted images. The varying brightness of the follicles at different stages of development is hypothesized to be related to different hormone and protein concentrations in the follicular fluid. For example, it is known that physiologically selected preovulatory follicles contain high concentrations of estrogens in a viscous follicular fluid. The increased viscosity may occur only when the follicle fluid contains high concentrations of estrogen and contributes to bright T1-weighted images. The possibility of using nuclear relaxation-weighted NMR imaging for the study of follicular dynamics and other ovarian biology therefore shows great promise.
使用核磁共振（NMR）技术对20个牛卵巢样本进行体外成像，以确定各种生理结构的可视性。特别地，研究了使用NMR成像区分闭锁卵泡与生理选择卵泡及排卵卵泡的可能性。20个卵巢中的5个保存在福尔马林中，其余15个保存在盐溶液中，并在死亡后18小时内进行成像。获取了T1和T2质子自旋弛豫率加权的图像，以及通过稳态进动快速成像技术获得的一些三维（3-D）数据集。从形态学上很容易在图像中识别出生理上不同的结构，尤其是在三维图像中。T1和T2加权能够以下列方式区分新鲜卵巢中的结构。闭锁卵泡和“卵泡群”在T1加权图像中呈暗色，在T2加权图像中呈亮色。排卵卵泡在T1和T2加权图像中均呈亮色，而生理选择前的卵泡在T1加权图像中呈中等亮度，在T2加权图像中呈暗色。黄体在T1加权图像中呈亮色，在T2加权图像中呈暗色，而黄体中的囊肿在T1加权图像中呈暗色，在T2加权图像中呈亮色。据推测，卵泡在不同发育阶段亮度的变化与卵泡液中不同的激素和蛋白质浓度有关。例如，已知生理选择的排卵前卵泡在粘性卵泡液中含有高浓度的雌激素。只有当卵泡液含有高浓度的雌激素并有助于形成明亮的T1加权图像时，粘度才会增加。因此，使用核弛豫加权NMR成像研究卵泡动力学和其他卵巢生物学的可能性显示出巨大的前景。
