Sensitivity and Specificity of Ultrasonography in Predicting Etiology of Azoospermia

Scrotal US was more sensitive in detecting functional azoospermia and more specific in detecting obstructive azoospermia. However, transrectal US was more sensitive in detecting obstructive azoospermia and more specific in detecting functional azoospermia. Both tests had greater specificity than sensitivity for obstructive azoospermia, indicating that US has the ability to exclude more than to diagnose cases of obstructive azoospermia. However, US is unlikely to completely replace testicular biopsy.