Normal adult epididymis: evaluation with color Doppler US.

Abstract

With current ultrasound imaging technology, epididymal flow was demonstrated not only in the head but also in the body and tail of the epididymides of all of our healthy volunteers. Thus, detection of flow in the epididymis at color Doppler imaging can be a normal finding and does not necessarily imply epididymitis.

Ultrasonography Evaluation of Scrotal Masses

“…15,16 The spectral waveforms of the intratesticular arteries, as well as the waveforms within the epididymis, typically have a lowresistance pattern. 12,14 Fig. 1.…”

Sonographic Findings of Typical and Atypical Scrotal Trauma

“…26 Color Doppler US has been shown to be a reliable method of evaluating intratesticular and epididymal blood flow. 10,11,24,27,28 During the evaluation of the acute scrotum, the asymptomatic side should be scanned first to set the gray scale and Doppler gains to facilitate accurate comparison with the injured/painful side. For increased sensitivity to hypoperfusion, power Doppler US can be used.…”

Imaging of the Epididymis

“…Color Doppler US can reliably demonstrate intraepididymal flow within the normal epididymis. 10 The spectral waveform of the epididymal artery, a branch of the testicular artery, characteristically has a similar arterial spectral pattern to that of the testicular artery, which is a high-flow, low-resistance pattern. 11 Conversely, the cremasteric artery, which is joined by anastomosis with the deferential and testicular arteries, demonstrates a low-flow, high-resistance pattern.…”

“…The resistive index of a normal epididymis ranges from 0.46 to 0.68. 10 The venous drainage of the testis and epididymis is via the pampiniform plexus. It is formed around the upper half of the epididymis in a variable fashion and continues as the testicular vein through the deep inguinal ring.…”

“…With modern US machines, blood flow can be seen in the normal epididymis on color Doppler sonography, as observed in 100% of healthy volunteers in 1 study. 10 Therefore, it is important to compare the vascularity in both epididymii. In acute epididymitis, there is an increased number and concentration of identifiable vessels with hyperemia, resulting in a high-flow, lowresistance pattern.…”