Evaluation of percutaneous biopsies of renal masses under MRI-guidance: a retrospective study about 26 cases

Objective To determine whether MRI allows safe and accurate guidance for biopsies of renal masses. Materials and methods Between May 2010 and September 2013, 26 patients (15 men and 11 women) with 26 renal masses underwent MRI-guided percutaneous biopsy. For each patient, we retrospectively collected the epidemiological, procedural and histopathological data. Results Mean size of tumour was 3.6 cm (range 0.6 – 9 cm). Mean procedure time was 48 minutes (range 37 – 70 min). Malignancy was found in the percutaneous samples in 81 % (21/26) of the masses. All these cases were considered as true positive biopsies. Benignity was found in the percutaneous samples in 5/26 (19 %) of the masses but was confirmed only in 3 cases. The other 2 cases included one false negative case and one undetermined biopsy, as patient was lost to follow-up. The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and accuracy of this study were 95.4 %, 100 %, 100 %, 75 % and 96 %, respectively Conclusion MRI-guidance is safe and accurate to target renal masses. Key Points • Percutaneous interventions can be performed with MRI - guidance • MRI offers real - time multiplanar imaging capabilities without radiation • MRI - guidance allows to target renal tumours