Role of diffusion weighted magnetic resonance imaging in a rat model of testicular torsion.

Objective: The purpose of this study was to investigate the usefulness of diffusion-weighted imaging (DWI) in the detection of different degrees of testicular torsion (TT) at the 8th hour and testicular salvageability at the 24th hour of torsion. Methods: 31 rats were randomly classified into 4 groups. In Group 1 (sham-control group), the left testicle was kept outside and replaced. Left testicles were kept outside and twisted 360 degrees in Group 2, 720 degrees in Group 3 and 1080 degrees in Group 4. Later, DWI was performed at 8th and 24th hours. After DWI, bilateral radical orchiectomy and histopathological examination were performed. Apparent diffusion coefficient (ADC) maps were obtained with b-factors of 0 and 800 s mm(-2). Comparisons of ADC values and damage in testicles were performed with Kruskal-Wallis test. Results: Sensitivity of DWI in the diagnosis of TT was 12.5% for 360 degrees torsion, 100% for 720 degrees torsion and 1080 degrees torsion at the 8th hour of torsion. Mean ADC values of the left testicles increased significantly at the 24th hour of torsion in Groups 3 and 4. All testicles in Groups 3 and 4 were observed to be irrecoverable on histopathological examination. Conclusion: Increased ADC values in the affected testicle may represent irreversible tissue damage. So, immediate surgery is not required at this stage, which may reduce morbidity and mortality caused by immediate surgery and anaesthesia. Advances in knowledge: TT can be diagnosed easily by DWI without administrating any contrast material. DWI findings in the affected testicle may represent testicular salvageability.