Sexual Medicine and Andrology Unit, Department of Clinical Physiopathology, University of Florence, Viale Pieraccini 6, Florence 50139, Italy.
Hum Reprod. 2012 Apr;27(4):974-82. doi: 10.1093/humrep/des032. Epub 2012 Feb 16.
Previous studies concerning ultrasound evaluation of the seminal vesicles (SV) were performed on a limited series of subjects, and considered few parameters, often only before ejaculation and without assessing the patients' sexual abstinence. The aim of this study was to evaluate the volume and the emptying characteristics of the SV and their possible correlations with scrotal and transrectal ultrasound features.
The SV of 368 men seeking medical care for couple infertility were evaluated by ultrasound. All patients underwent, during the same ultrasound session, scrotal and transrectal evaluation, before and after ejaculation, and the ejaculate was subjected to semen analysis. A new parameter, SV ejection fraction, calculated as: [(SV volume before ejaculation - SV volume after ejaculation)/SV volume before ejaculation] × 100, was evaluated.
After adjusting for sexual abstinence and age, both pre-ejaculatory SV volume and SV ejection fraction were positively associated with ejaculate volume. As assessed by receiver operating characteristic curve, a cut-off for SV ejection fraction of 21.6% discriminates subjects with normal ejaculate volume (≥1.5 ml) and pH (≥7.2 ml) with both sensitivity and specificity equal to 75%. Subjects with SV ejection fraction of <21.6% more often had a higher post-ejaculatory SV volume and ejaculatory duct abnormalities. Furthermore, a higher post-ejaculatory SV volume was associated with a higher prostate volume and SV abnormalities. Higher epididymal and deferential diameters were also detected in subjects with a higher post-ejaculatory SV volume or reduced SV ejection fraction. No association between SV and testis ultrasound features or sperm parameters was observed. Associations with SV ejection fraction were confirmed in nested 1:1 case-control analysis.
The SV contribute significantly to the ejaculate volume. A new parameter, SV ejection fraction, could be useful in assessing SV emptying. A SV ejection fraction of <21.6% was associated with prostate-vesicular and epididymal ultrasound abnormalities.
之前关于精囊（SV）超声评估的研究仅在有限数量的受试者中进行，且考虑了较少的参数，通常仅在射精前进行，而没有评估患者的禁欲时间。本研究旨在评估 SV 的体积和排空特征及其与阴囊和经直肠超声特征的可能相关性。
对 368 名因夫妻不孕而寻求医疗护理的男性的 SV 进行了超声评估。所有患者在同一超声检查过程中，在射精前和射精后进行了阴囊和经直肠评估，并对精液进行了精液分析。评估了一个新的参数，SV 射出分数，计算方法为：[(SV 射精前的体积 - SV 射精后的体积）/SV 射精前的体积]×100。
在调整了禁欲时间和年龄后，射精前的 SV 体积和 SV 射出分数与精液量呈正相关。通过接收者操作特征曲线评估，SV 射出分数的截断值为 21.6%，可区分具有正常精液量（≥1.5 ml）和 pH 值（≥7.2 ml）的受试者，其敏感性和特异性均为 75%。SV 射出分数<21.6%的受试者射精后 SV 体积更大且射精管异常更为常见。此外，射精后 SV 体积较大与前列腺体积较大和 SV 异常有关。在射精后 SV 体积较大或 SV 射出分数降低的受试者中，还检测到更高的附睾和输精管直径。SV 与睾丸超声特征或精子参数之间未观察到相关性。在嵌套的 1:1 病例对照分析中证实了与 SV 射出分数的相关性。
SV 对精液量有重要贡献。一个新的参数，SV 射出分数，可以用于评估 SV 的排空。SV 射出分数<21.6%与前列腺 - 精囊和附睾超声异常有关。
