Diffusion Weighted Imaging on a 3 Tesla Magnetic Resonance Scanner as a Diagnostic Tool in Early Detection of Prostate Cancer

Abstract

Introduction: Multiparametric Magnetic Resonance Imaging (MRI) of prostate including Diffusion Weighted Imaging (DWI) is greatly evolving as a diagnostic tool in prostate cancer. Incidence of prostate cancer in India is on rise with most of the cases been diagnosed in late stages. In this scenario, DWI imaging can pick up the cases at an earlier stage causing a significant impact in the patient management. Aim: To assess the role of DW-MRI as a non invasive initial investigation tool in prostate carcinoma prior to biopsy. Materials and Methods: The study was a prospective observational study conducted during April 2014 to March 2015 in the Department of Radiodiagnosis in collaboration with Department of Urology in a hospital in Kolkata. A total of 34 patients with a clinical suspicion of prostate cancer underwent prostate DWI-MRI by a 3T scanner before Transrectal Ultrasound (TRUS)-guided biopsies. IBM Statistical Package for Social sciences (SPSS) version 17.0 was used for statistical analysis and the sensitivity, specificity, Positive Predictive Value (PPV) and Negative Predictive Value (NPV) were determined. Results: All patients (100%) with biopsy proven adenocarcinoma showed diffusion restriction. A total of 95.8% were PI-RADS 5. False positive results were found in two patients. The sensitivity, specificity, PPV and NPV were 100% (95% CI=85.75% to 100.00%), 80% (95% CI=44.39% to 97.48%), 92.31% (95% CI=74.87% to 99.05%) and 100% (95% CI=63.06% to 100.00%) Conclusion: From the present study, it was noted that sensitivity of DWI is very high (100%). DWI also has a high specificity and positive predictive value. Hence, DWI is one of the most effective adjunct non invasive tools for initial investigation in prostate carcinoma which improves the diagnostic performance and helps in performing targeted biopsies from the suspicious prostatic lesion.