Introduction: Acute scrotal pain is an important clinical presentation that necessitates rapid and precise imaging techniques to differentiate between urgent surgical cases and non-surgical cases. Radioisotope testicular scintigraphy is a very helpful imaging modality to assess testicular blood flow. However, until now, all scrotal scintigraphy studies have no standard values to compare with the other testicle and increase its diagnostic accuracy. In this study we are going to find a standard fixed-comparison region of interest.

Methods: Scrotal scintigraphy was done for 40 patients with acute scrotal pain after intravenous technetium pertechnetate injection. Time-activity curve data was created and analyzed to create standard numeric data to calculate the ratio between the testicular radioactivity count rate/background radioactivity count rate.

Results: Forty male patients between the ages of 7 to 21 years (mean 13.5 ± 5.3) were included. Their main complaint was acute testicular pain. Twenty-four cases (60%) had left side pain and 16 cases (40%) had right side pain. Twenty-two cases (45%) had a past history of similar attacks. A history of trauma was encountered in 9 cases (22.5%), 9 cases (22.5%) had a past history of recurrent inflammatory processes proved by previous ultrasonography, 6 cases (18%) were known to have varicoceles, and 13 cases (32.5%) had testicular torsion after surgical exploration. The numeric data showed that there was a correlation and a significant critical cut-off ratio between the testicular radioactivity count. A background radioactivity count was determined by drawing symmetrical regions of interest at both the testis and the medial aspect of the ipsilateral thigh, with a cut-off figure of 1.45 for normal testicular radiotracer uptake and with a mean ratio of <1.2 (found in 12 cases) for acute testicular torsion in which impaired vascular flow to the testis and impaired testicular uptake of radioactivity was noticed. This correlated with the clinical sonographic data and operative data, as well as postoperative histopathological results (p.value = 0.00041). Via this technique, we conclude that the sensitivity of this technique reach was 92.3%, specificity was 96.4%, and diagnostic accuracy was 95.1%, in the diagnosis of acute testicular torsion.

Conclusion: Scrotal scintigraphy using quantitative imaging techniques is a highly significant tool with diagnostic accuracy of 95%, which indicates its importance as an emergency imaging modality in managing patients with acute scrotal pain.