Color flow Doppler sonography (CFDS) has been used to evaluate the blo
od flow to the testes, because of its ability to visualize small vesse
ls with low flow. A total of 39 infertile men, 18 with clinical varico
cele and 21 without, were examined using CFDS to assess the clinical u
sefulness of this technique. In patients with varicocele, venous diame
ter in the pampiniform plexus was greater than 2 mm, whereas those wit
hout varicocele showed diameters of less than 1.8 mm. Of 21 patients w
ithout varicocele on physical examination, 13 were found to have reflu
x by CFDS. According to clinical and CFDS findings, patients were divi
ded into five groups: varicocele negative, suspicious subclinical vari
cocele, subclinical varicocele, manifest varicocele with Valsalva-indu
ced reflux, and manifest varicocele. These data suggest that the CFDS
technique is a simple, sensitive and noninvasive modality for the accu
rate diagnosis of varicocele.