Abstract:

Objectives: To investigate the causes, differential diagnosis, and clinical significance of absent blood flow (ABF) in the testis detected by color Doppler ultrasound (CDU) in acute scrotum.
Methods: A total of 263 patients with ABF in the testis detected by CDU in our hospital were reviewed retrospectively. However, only 111 patients who underwent surgery were included in this study. The ultrasonographic features of the testis and paratesticular tissue were analyzed. The surgical or surgical-pathologic results were taken as the reference standard to determine the causes of ABF in the testis.
Results: The causes of ABF in the testis were testicular torsion (n = 98, torsion group) and non-testicular torsion related diseases (n = 13, non-torsion group, including 8 testicular rupture, 3 epididymitis-orchitis combination with testicular necrosis, and 2 tumors). Tunica albuginea of the testis, diffuse enlarged epididymis, whirlpool sign, and internal echo of the testis were the better parameters for diagnosing the causes of ABF in the testis detected by CDU. And the accuracies of these approaches were 93.7%, 91%, 83.8%, and 81.1%, respectively. Whirlpool sign had a 100% positive predictive value (PPV), and disrupted tunica albuginea of the testis and diffuse enlarged epididymis each had 100% specificity for predicting testicular torsion. When the ultrasonographic findings were combined with these methods to determine the causes, the accuracy was 96.4% (107/111).
Conclusion: ABF in the testis detected by CDU is not always indicative of testicular torsion in acute scrotum; Analyzing ultrasound findings of the testis and paratesticular tissue can help with differential diagnosis of the causes of ABF in the testis and guide clinical decision-making.

Key words: Testicular torsion; Epididymitis; Ultrasound; Color Doppler