Scrotal disorders: Evaluation of testicular enhancement patterns at dynamic contrast-enhanced subtraction MR imaging

PURPOSE: To evaluate testicular enhancement patterns in various scrotal dis orders at dynamic contrast medium-enhanced subtraction magnetic resonance ( MR) imaging. MATERIALS AND METHODS: Forty-two patients with scrotal symptoms (22 testicu lar diseases, 20 extratesticular scrotal disorders) underwent three-dimensi onal (3D) fast field-echo or fast spin-echo dynamic subtraction MR imaging after injection of paramagnetic contrast medium. The relative percentages o f peak height and mean slope of the testes on the affected side were compar ed with those on the unaffected side by using time-signal intensity curves. RESULTS: Extratesticular scrotal disorders (time-signal intensity curve mea n peak height, 93.1%; mean slope, 89.8%) showed gradual and progressive inc rease in homogeneous testicular contrast enhancement in all normal testes. Relative percentages of peak height and mean slope of testicular torsion (m ean peak height, 17.3%; mean slope, 10.6%), infarction (mean peak height, 3 0.4%; mean slope, 19.8%), traumatic hemorrhagic necrosis (mean peak height, -3.5%; mean slope, -12.0%), and epidermoid cyst (mean peak height, -6.6%; mean slope, -14.2%) were significantly lower than those of extratesticular scrotal disorders. Acute mumps orchitis (mean peak height, 135.1%; mean slo pe, 307.5%) and malignant testicular tumor (mean peak height, 178.7%; mean slope, 467.6%) showed higher relative percentages of peak height and mean s lope. CONCLUSION: Dynamic contrast-enhanced subtraction MR imaging can provide in formation about testicular perfusion on the basis of contrast enhancement a nd can be used to differentiate testicular diseases from scrotal disorders.