Department of Radiology, Dokkyo Medical University, 880 Kitakobayashi Mibu, Tochigi, 321-0293, Japan.
Department of Urology, Dokkyo Medical University Koshigaya Hospital, 2-1-50 Minamikoshigaya, Koshigaya, Saitama, 343-8555, Japan.
Eur Radiol. 2018 Mar;28(3):1009-1015. doi: 10.1007/s00330-017-5077-4. Epub 2017 Oct 6.
To analyse the quantitative changes of the prostate and seminal vesicles (SV) on magnetic resonance imaging (MRI) after ejaculation.
Ten healthy young males were enrolled for T2-weighted and T2 mapping MRI before and after two consecutive ejaculations. T2 values of the peripheral zone (PZ) and the central gland (CG) at the midgland of the prostate were compared before and after ejaculation, respectively. T2 values of the PZ at the apex and base were also compared before and after, respectively. Pre- and post-ejaculation SV volumes were compared. The Wilcoxon's signed rank test with Bonferroni adjustment was used for comparison.
After ejaculation, T2 values of the PZ significantly decreased (mean, 119±20 vs. 105±21, p=0.002) while those of the CG did not significantly change at the midgland. At the apex, T2 values of the PZ also decreased significantly (mean, 114±9 vs. 94±7, p=0.002). On the other hand, T2 values of the PZ did not change at the base. SV volumes were significantly reduced after ejaculation (mean, 11.1±7.7mL vs. 7.2±6.7mL, p=0.002).
Ejaculation decreases T2 values of the PZ at the midgland and apex, and reduces SV volumes. Abstinence periods should be considered in evaluating the prostate and SV on MRI.
• T2 values decrease after ejaculation in the apical-mid peripheral zone. • Ejaculation does not affect T2 values of the central gland. • Volume of the seminal vesicles decreases after ejaculation. • An abstinence period should be considered before pelvic MRI in men.
分析射精后前列腺和精囊（SV）在磁共振成像（MRI）上的定量变化。
招募了 10 名健康的年轻男性，在连续两次射精前后进行 T2 加权和 T2 映射 MRI。比较射精前后前列腺中央腺体中部外周带（PZ）和中央腺体（CG）的 T2 值。比较前列腺尖部和底部 PZ 的 T2 值。比较射精前后 SV 体积。采用带有 Bonferroni 调整的 Wilcoxon 符号秩检验进行比较。
射精后，PZ 的 T2 值显著降低（平均 119±20 与 105±21，p=0.002），而 CG 的 T2 值在中央腺体无明显变化。在尖部，PZ 的 T2 值也显著降低（平均 114±9 与 94±7，p=0.002）。另一方面，PZ 的 T2 值在底部没有变化。射精后 SV 体积显著减少（平均 11.1±7.7mL 与 7.2±6.7mL，p=0.002）。
射精降低了中央腺体和尖部的 PZ 的 T2 值，并减少了 SV 体积。在 MRI 评估前列腺和 SV 时应考虑禁欲期。
• 射精后，尖部-中部外周带 T2 值降低。• 射精对中央腺体的 T2 值没有影响。• 射精后精囊体积减少。• 男性行盆腔 MRI 前应考虑禁欲期。
