Clinics in diagnostic imaging (33). Missed testicular torsion

A 13-year-old boy presented with a painful scrotal swelling. On examination, the left testis was enlarged and tender. Ultrasound scan showed diffuse hypoechogenicity, with absent intra-testicular but increased peri-testicular blood flow. The diagnosis of missed testicular torsion was confirmed at surgery. The role of imaging in differentiating among other causes of painful scrotal swelling, such as infection, trauma and tumour, are discussed.