Aim: The aim of our study was to assess diagnostic value of magnetic resonance cholangiography (MRC) in patients with suspected common bile duct (CBD) stones focusing on the capability of this noninvasive method to replace invasive diagnostic procedures in these patients and to limit the use of endoscopic retrograde cholangiography (ERC) to the patients who need simultaneous therapeutic intervention.
Materials and methods: Single-shot fast-spin-echo rapid-acquisition thick-section MRC images were obtained in 310 patients recruited into this prospective study. There were 136 male and 174 female patients aged 21-95 years [mean +/- standard deviation (SD) 64.9 +/- 13.6 years]. Patients were subsequently classified into different risk groups (high, moderate, low) according to biochemical abnormalities or morphological features on abdominal ultrasonography and computed tomography. Direct cholangiography was the reference method of CBD evaluation.
Results: CBD stones were diagnosed in 115 (37%) patients; 86 of 175 patients in the high-risk group, 24 of 83 patients in the moderate-risk group, and 5 of 50 patients in the low-risk group. In dependent risk groups, the mean CBD caliber was 9.7 +/- 4.5, 7.1 +/- 2.0, and 4.8 +/- 1.2 mm, respectively. The difference was significant between all three groups (P < 0.05). The median size of CBD stones was 7 mm (range 3-21 mm). MRC achieved accuracy and positive and negative predictive values of 97%, 94%, and 98%, respectively.
Conclusions: MRC has a potential to substitute diagnostic ERC in all patients with suspected choledocholithiasis due to its high accuracy, reducing invasive direct cholangiography to patients who require therapeutic intervention.