Diffusion weighted magnetic resonance imaging of rat testes: A method for early detection of ischemia

Purpose: We investigated the feasibility of diffusion weighted magnetic resonance imaging (MRI) for the early detection of ischemia in the testis. Materials and Methods: Circulation to the right testis in Wistar rats was occluded by surgical ligation of the right funicle. The left side was sham operated and served as a control. The diffusion and T2-weighted MRI images of the 2 testes was performed postoperatively by a 1.5 Tesla MRI unit using a knee coil. On apparent diffusion coefficient images and T2-weighted images the region of interest values in the 2 testes were measured and statistically compared. Results: At 1 hour after testicular funicle ligation the apparent diffusion coefficient was 18% lower in the ischemic than in the sham operated testis (p < 0.0098). At 2 hours the difference was 20% (p < 0.0017). In the signal-to-noise ratio on T2-weighted images there was no difference in the left and right testes. Conclusions: Altered diffusion occurs in an ischemic testis, which can be measured on MRI at 1.5 Tesla. Thus, diffusion-weighted MRI may be a helpful method for the differential diagnosis of acute testicular torsion.