Impact of post prostate biopsy hemorrhage on multiparametric magnetic resonance imaging

Introduction: Hemorrhage induced by prostate biopsy can interfere with the interpretation of prostate magnetic resonance imaging (MRI). Materials and methods: We reviewed 101 patients who had prostate multiparametric MRI (MP-MRI) and radical prostatectomy. Results: On MRI obtained within 4 weeks following the biopsy, hemorrhage was seen in 26/36 (72.2%) patients. Patients having a MRI between 4-6 weeks of the biopsy had hemorrhage in 8/14 (57.1%) cases. After 6 weeks, hemorrhage was less common but still present in 24/46 (52%) patients. There were five patients who had prostate MRI prior to biopsy and served as a control group. There was no significant correlation between the length of time beyond 6 weeks and the likelihood of having prostate hemorrhage on MRL The overall sensitivity and specificity of MRI for predicting extracapsular extension (ECE) were 78.6% and 89%, respectively. However, if the analysis was limited to patients with MRI within 6 weeks from the time of biopsy, the sensitivity and specificity were similar: 80% and 90%, respectively. For patients with MRI obtained after 6 weeks, the sensitivity and specificity were 76.9% and 87.9%. Conclusions: Prostate hemorrhage is seen in the majority of cases within 6 weeks of biopsy and can be seen in nearly half the patients even beyond 6 weeks. However, hemorrhage within 6 weeks of a biopsy does not interfere with assessment for BCE.