Rationale Correct and timely diagnosis of choledochal cyst is a rather serious problem in paediatric surgery and radiology. The tool box of diagnostic possibilities has been significantly enriched since the development of medical technology. One of the methods to examine the bile ducts is magnetic resonance cholangiopancreatography (MRCP) enabling a sufficiently precise determination of anatomical features of the hepatobiliary system in children.

Aim of the study: To assess the informative value of MRCP in patients with cystic transformation of the common bile duct.

Materials and methods The study was carried out on the basis of the MRI Department. A total of 11 children aged from 6 months to 15 years have been examined. Apart from the MRI of the abdomen combined with the MRCP, all the patients underwent ultrasound examination and six of them – computed tomography. A 3.0 Tesla MRI scanner (Discovery 750, GE) and a 1.5 Tesla MRI scanner (Optima 450w, GE) were used. The whole-body MRI coil was exploited. Standard abdominal MRI examination involved T1- and T2-weighted pulse sequences, the FatSat technique, the diffusion weighted imaging (DWI) and the MRCP. Obtained MRI data were checked against those obtained on surgical interventions.

Results The MRCP has accurately identified all the type I choledochal cysts (Todani classification) in our patients. The anatomic structure of the biliary tree as seen on the MRCP was in line with the results obtained on surgical interventions. The noninvasive nature of the study (in contrast with the ERCP), no exposure to radiation, no need to use contrast enhancement and the possibility to obtain 3D images allowed carrying out the tests with no age restrictions in all the patients.

Conclusion Thus, the MRCP is an accurate noninvasive method to diagnose abnormalities of the biliary duct. It can be used as the initial method for preoperative diagnosis of choledochal cysts along with ultrasound examination in children.