Parenchymal echotexture changes as a predictor of viability in testicular torsion

Preoperative test that can predict the salvageability of the torsed testis may add essential information to the surgeon managing testicular torsion (TT), this can assist with patients' and parents' expectations, particularly with nonviable testes. We aimed to examine if parenchymal echotexture changes in preoperative ultrasound can predict irreversible hemorrhagic necrosis.

Preoperative ultrasound studies of 154 patients with TT were reviewed by 3 raters (2 radiologists and 1 urologist). The raters were asked to categorize the affected testicular parenchymal echotexture into one of the following categories: (1) normal (identical to the contra-lateral testis), (2) homogenous hypoechoic, or (3) focal heterogeneous echotexture. Testis non-viability was defined macroscopically during surgical exploration and correlated with the US results. Sensitivity, specificity, and positive and negative predicting values of the proposed diagnostic test were calculated. Cohen's kappa coefficient was used to determine inter-rater agreement.

A total of 54/154 patients had a nonviable testis. Mean of 59.5% cases was classified as category 1, 27.3% cases as category 2, and 13.2% cases as category 3. Testicular necrosis was 12%, 34%, and 92% in each category, respectively. Category 3 classified non-viability with a mean specificity of 99.3% and with a high inter-rater agreement level (Cohen's kappa coefficient of 0.830). Mean positive predictive value of 97% and mean negative predictive value of 74.3%. The mean sensitivity of this test however was low 39.7%.

Ultrasound finding of focal parenchymal echotexture heterogeneous changes is highly specific although not sensitive, for nonviable testis. The presence of this finding reassures non-viability in over 99%.