Correlation of radionuclide imaging and diagnostic ultrasound in scrotal diseases.

A retrospective study was performed to evaluate the comparative usefulness of scrotal ultrasound imaging (SU) and radionuclide scrotal imaging (RSI) in 46 patients. The final diagnosis included four late phase and one early testicular torsion (TT), 11 acute epididymitis (AE), four subacute epididymitis (SE), six malignant tumors, ten hydroceles or other cystic lesions, and ten miscellaneous lesions. In patients with scrotal pain, 3/4 with late phase TT were correctly diagnosed by SU, while one with early TT and 11/15 with AE or SE were not diagnosed. All of them were correctly diagnosed with RSI except one with scrotal cyst. SU was able to separate cystic masses (n = 10) from solid masses (n = 9), but could not separate malignant from benign lesions. RSI had difficulty in separating cystic from solid lesions. We concluded that SU is useful in patients with scrotal mass to separate solid from cystic lesions. However, SU is unable to differentiate acute epididymitis from early testicular torsion. Therefore, in patients with acute scrotal pain, RSI should still be the first study performed.