From the Department of Radiology, University of Chicago, 5841 S Maryland Ave, MC 2026, Chicago, IL 60637.
Radiology. 2014 May;271(2):452-60. doi: 10.1148/radiol.14131374. Epub 2014 Feb 1.
To determine the possibility of obtaining high-quality magnetic resonance (MR) images before, during, and immediately after ejaculation and detecting measurable changes in quantitative MR imaging parameters after ejaculation.
In this prospective, institutional review board-approved, HIPAA-compliant study, eight young healthy volunteers (median age, 22.5 years), after providing informed consent, underwent MR imaging while masturbating to the point of ejaculation. A 1.5-T MR imaging unit was used, with an eight-channel surface coil and a dynamic single-shot fast spin-echo sequence. In addition, a quantitative MR imaging protocol that allowed calculation of T1, T2, and apparent diffusion coefficient (ADC) values was applied before and after ejaculation. Volumes of the prostate and seminal vesicles (SV) were calculated by using whole-volume segmentation on T2-weighted images, both before and after ejaculation. Pre- and postejaculation changes in quantitative MR parameters and measured volumes were evaluated by using the Wilcoxon signed rank test with Bonferroni adjustment.
There was no significant change in prostate volumes on pre- and postejaculation images, while the SV contracted by 41% on average (median, 44.5%; P = .004). No changes before and after ejaculation were observed in T1 values or in T2 and ADC values in the central gland, while T2 and ADC values were significantly reduced in the peripheral zone by 12% and 14%, respectively (median, 13% and 14.5%, respectively; P = .004).
Successful dynamic MR imaging of ejaculation events and the ability to visualize internal sphincter closure, passage of ejaculate, and significant changes in SV volumes were demonstrated. Significant changes in peripheral zone T2 and ADC values were observed.
在射精前、中、后确定获得高质量磁共振（MR）图像的可能性，并检测射精后定量 MR 成像参数的可测量变化。
在这项前瞻性、机构审查委员会批准、符合 HIPAA 规定的研究中，8 名年轻健康志愿者（中位年龄 22.5 岁）在知情同意后，通过自慰达到射精点进行 MR 成像。使用 1.5-T MR 成像仪，配备 8 通道表面线圈和动态单次快速自旋回波序列。此外，还应用了一种定量 MR 成像方案，允许在射精前后计算 T1、T2 和表观扩散系数（ADC）值。在射精前后，通过 T2 加权图像的全容积分割计算前列腺和精囊（SV）的容积。使用 Wilcoxon 符号秩检验和 Bonferroni 校正评估射精前后定量 MR 参数和测量容积的变化。
射精前后的前列腺容积无明显变化，而 SV 平均收缩 41%（中位数 44.5%；P =.004）。中央腺体的 T1 值、T2 值和 ADC 值在射精前后均无变化，而外周带的 T2 值和 ADC 值分别显著降低 12%和 14%（中位数分别为 13%和 14.5%；P =.004）。
成功进行了射精事件的动态 MR 成像，并能够可视化内括约肌闭合、精液通过和 SV 容积的显著变化。观察到外周带 T2 和 ADC 值的显著变化。
