Abstract
Background: Cystic renal masses (CRM) are found incidentally in many patients undergoing lumbar MRI. cysts. Objectives: The present study aimed to determine the diagnostic value of T2-weighted imaging features of CRM on lumbar spine MRI and their reliability in differentiating complex renal lesions from simple Methods: All lumbar MRIs performed between 2019 and 2021 were included in this prospective study. Patients with simple cysts on MRI underwent a renal ultrasound by an expert radiologist. Patients with complex or suspicious cysts, based on sonographic characteristics, were subjected to a CT scan with contrast. For complex cysts identified on MRI, patients underwent a CT scan with contrast without first undergoing an ultrasound examination. Finally, the sensitivity, specificity, and positive and negative predictive values of T2 lumbar MRI images were calculated to determine the nature of the cysts. Results: A total of 2,789 lumbar MRIs were performed during the study period. Of these, 169 cases (6.05%) were reported to have incidental kidney cysts. No significant differences were found between the age and sex of the patients. The size of the cysts differed significantly between complex and simple cysts. The sensitivity, specificity, and positive and negative predictive values of MRI in determining the nature of the cyst were calculated to be 100%, 98%, 83%, and 100%, respectively. Conclusions: The results of the present study showed that further examinations using ultrasound and CT scans in patients with simple renal cysts on lumbar MRI are not recommended, which can significantly reduce health care costs.