MAGNETIC RESONANCE The diagnostic value of magnetic resonance urography using a balanced turbo field echo sequence Egemen Çifçi 1 & Gökçen Çoban 1 & Tufan Çiçek 2 & Umut Gönülalan 2 Received: 18 July 2015 /Revised: 22 January 2016 /Accepted: 28 January 2016 # European Society of Radiology 2016 Abstract Objectives The aim of the study was to compare the inter- observer variability and the accuracy of magnetic resonance urography (MRU) using a thin sectional balanced-turbo field echo (B-TFE) sequence for detecting ureteral calculi and to determine the effect of additional factors (size, density and location of the calculus) on the sensitivity and specificity of the MRU. Materials & methods MRU and CT images were evaluated independently by two radiologists according to presence, den- sity and localization of calculi. The degrees of inter-rater agreement for categorical items were evaluated by the Kappa coefficient. Results According to the 1st and 2nd observers, the sensitivity of MRU was 65.9 %, 71.8 % and the specificity of MRU was 95.9 %, 100 %, respectively. Inter-observer agreement was 84.6 % for stone detection. The larger size had a better effect on detectability (p <0.05). Also, the higher density had a bet- ter impact on detectability (p < 0.05). Conclusion Our study has shown that B-TFE MRU was use- ful to detect ureteral calculi. However, B-TFE MRU has low sensitivity and high specificity in comparison with CT images. MRU is a reasonable alternative imaging technique for follow-up periods of selective groups like patients with large urinary stones, children or pregnant patients when ionizing radiation is undesirable. Key Points • According to 1st and 2nd observers, sensitivity of MRU was 65.9 %, 71.8 %, respectively. • According to 1st and 2nd observers, MRU specificity was 95.9 %, 100 %, respectively. • Interobserver agreement was found to be over 84 % for stone detection. • B-TFE sequence provides calculus follow-up without radiation. • Larger calculi and more dense calculi individually have the better effect on detectability. Keywords Balanced-turbo field echo . Diagnosis . Flank pain . Magnetic resonance urography . Ureteral calculus Introduction Flank pain is a general medical complaint that affects approx- imately 12 % of the population throughout life [1]. Imaging techniques are critical in the evaluation and treatment of pa- tients diagnosed with urolithiasis. Intravenous pyelography (IVP), kidney ureter and bladder X-ray (KUB) of the kidneys, ureters and bladder, and ultrasound are performed to assess calculus burden. Currently, computed tomography (CT) is the gold standard technique to diagnose urolithiasis, with a sensi- tivity of nearly 100 % [2]. During the initial diagnosis and the management periods, patients frequently undergo multiple imaging modalities in which each examination has an inherent degree of radiation exposure. The biological effects of signif- icant radiation exposure are an active area of research [3]. The field of radiology has greatly improved the urologist’s ability to diagnose and treat patients. Although there are medical benefits to radiographic imaging, high radiation exposure due to diagnostic imaging carries the potential risk of induced * Egemen Çifçi drecifci@gmail.com 1 Department of Radiology, Baskent University Faculty of Medicine, Hocacihan mah. Saray cad., No:1 Selcuklu, Konya, Turkey 42080 2 Department of Urology, Baskent University Faculty of Medicine, Konya, Turkey Eur Radiol DOI 10.1007/s00330-016-4256-z