Prostate vascular flow: the effect of ejaculation as revealed on transrectal power Doppler sonography

The objective of our study was to determine the effect of ejaculation on prostate vascular flow.

Using power Doppler technology, we performed four transrectal sonographic examinations before and immediately, 6 hr, and 24 hr after ejaculation in 10 healthy volunteers. Images were assessed by three independent observers.

Ninety-seven percent of the images ranked as having the least flow were from the baseline examination. There was a significant difference between the rankings when categorized into the four time sets (mean score for the baseline group was 1.1, whereas for the immediate, 6-, and 24-hr postejaculation groups it was 2.5, 2.9, and 2.4, respectively (p<0.0001). The only statistically significant difference was between the baseline and the three remaining groups. Interobserver agreement was high, with the chance-corrected measure of agreement of 0.78.

Transrectal sonography revealed that prostate vascular flow increases dramatically after ejaculation and remains elevated for at least 24 hr. This observation should be considered when power Doppler sonography is used to assess for potential hyperemia in patients suspected of having prostate abnormalities.