J Korean Radiol Soc.  1995 Jun;32(6):947-951.

Assessment of Resistive Index in Acute Epididymitis on Doppler Sonography

• Lee MG
• Auh YH
• Cho KS
• Choi HK
• Jung SM
• Kim CS

Abstract

PURPOSE
This study was aimed to review findings of gray-scale ultrasonography and to assess the diagnostic value of the resistive index (RI) in patients with acute epididymitis by comparing with that in normal volunteers. MATERIALS & METHODS: Gray-scale ultrasonogram was reviewed in nine patients with acute epididymitis for echogenicity, size and reactive hydrocele. Normal values of resistive index (RI) were obtained in 20 epididymides from 10 volunteers (aged 20-28, mean 23.7). Nine patients of epididymitis (aged 18-67, mean 37.2) were examinated with color Doppler sonography and RI was measured at 11 sites on epididymal arteries. For the prediction of acute epididymitis, accuracy, sensitivity and specificity were calculated at the cut-off value of RI in 0.65 and 0.70.
RESULTS
Gray-scale ultrasonography showed echogenicity that was variable among the 9 cases (hype- rechoic 2 cases, isoechoic 2, hypoechoic 5), enlargement of epididymis in 8, and reactive hydrocele in 8 cases. Normal volunteers displayed color Doppler signals in 14 out of 20. The range of RI in normal volunteers were between 0.64 and 1.00 (mean, 0.79 +/- SD 0.10). In patients with acute epididymitis, color Doppler signals were detected in all patients. The range of RI in epididymitis were 0.40-0.68 (mean, 0.56 +/- SD 0.10). At cut-off RI value of 0.65, accuracy was 88%, sensitivity 81.8%, and specificity 92.7%. At cut-off value of 0.70, accuracy was 92%, sensitivity 100%, and specificity 85.7%.
CONCLUSION
In addition to the findings of gray-scale ultrasonography, resistive index and color flow changes are valuable in diagnosing acute epididymitis.

MeSH Terms

Arteries
Epididymis
Epididymitis*
Healthy Volunteers
Humans
Male
Reference Values
Sensitivity and Specificity
Ultrasonography
Volunteers