The use of high-resolution magnetic resonance imaging in the management of patients presenting with priapism

OBJECTIVE To investigate the use of magnetic resonance imaging (MRI) of the penis during an episode of priapism and assess the viability of the corpus cavernosum (CC) smooth muscle, as prolonged ischaemic priapism is associated with a high rate of long-term erectile dysfunction (ED), and the viability of CC smooth muscle influences the subsequent management in ischaemic priapism. PATIENTS AND METHODS The study was set in a single centre based in a large university teaching hospital. We investigated the correlation of T2-weighted gadolinium- enhanced MRI with the histology from CC biopsies in the same patients. In all, 38 patients (mean age 42 years) presenting with priapism over a 3-year period had MRI of the penis. The scans were reported by two dedicated uro-radiologists who graded the MR images as showing viable or nonviable erectile tissue. One pathologist assessed the CC biopsies for necrosis. The findings were then correlated. Where no biopsies were taken a clinical follow-up was used to assess erectile function. RESULTS In 23 patients undergoing both a CC biopsy and MRI, the sensitivity of MRI in predicting nonviable smooth muscle was 100%. In a further 10 patients MRI showed nonviable CC smooth muscle, but no biopsy was taken in these patients; on clinical follow-up all of these patients subsequently developed ED. In a further five patients the imaging showed viable smooth muscle and these patients subsequently maintained erectile function on clinical follow up. CONCLUSIONS Penile MRI provides an accurate imaging method to assess smooth muscle viability in patients presenting with priapism.