Comparison of Radionuclide Imaging and Ultrasonography in the Differentiation of Acute Testicular Torsion and Inflammatory Testicular Disease

Purpose: Torsion of the testis is a urologic emergency that requires early diagnosis and prompt surgical treatment for testicular survival. However, the early differential diagnosis of acute testicular torsion from epididymitis or orchitis is often difficult. The aim of this retrospective study was to evaluate and compare the value of Tc-99m pertechnetate radionuclide imaging and ultrasonography in the differentiation of acute testicular torsion and inflammatory testicular diseases.

Methods: Twenty patients (age range, 5 to 38 years) with possible acute testicular torsion from July 2000 to July 2001 were enrolled in this study. Ultrasonography was performed in all patients in the emergency room. Within 3 hours of ultrasonography, radionuclide imaging was also performed after intravenous injection of 5 to 15 mCi Tc-99m pertechnetate in the forearms. All of the patients with clinically suspected acute testicular torsion underwent surgery. The surgical findings and pathologic reports of these patients were reviewed and definite diagnoses were established. None of the other patients had surgery and were followed clinically for at least 1 month after ultrasonography and radionuclide imaging.

Results: Four patients with testicular torsion, 13 patients with inflammatory testicular disease, and three healthy persons had a final surgical and pathologic diagnosis or clinical follow-up, and all were accurately diagnosed by Tc-99m pertechnetate radionuclide imaging. In contrast, ultrasonography was less accurate in the diagnosis and differentiation of acute testicular torsion from inflammation. Only 1 of 4 patients with testicular torsion, 5 of 13 patients with inflammatory testicular disease, and 2 of 3 healthy persons were diagnosed by ultrasonography.

Conclusions: The results indicate that Tc-99m pertechnetate radionuclide imaging is a more useful and accurate imaging method than ultrasonography in the detection and differentiation of acute testicular torsion from inflammatory testicular disease in patients with acute scrotal pain.