Symphony 1.5 t scanner

MRCP was performed before diagnosing of PBM in all cases. Before MRCP, all subjects were maintained in jejunitas for 4 h then MRCP was performed with sedation for subjects 10 years-of-age or younger. A Symphony 1.5 T scanner (Siemens, Erlangen, Germany) with an abdominal phased array coil was used as follows: T1-weighted and T1-weighted fast spin series (field of view 24–28 cm, repetition time [TR] 173 ms, echo time [TE] 2.64 ms, flip angle 70, matrix 256 * 128, radiofrequency (RF) bandwidth 260 Hz/Px) and a T2-weighted sequence (TR 1,000 ms, TE 60 ms, RF bandwidth 230 Hz/Px). For MRCP, half-Fourier acquisition single shot turbo spin echo (HASTE) was used with multilayer thin coronal and axial T2-weighted imaging (TR 1,200 ms, TE 80 ms, slice thickness 4 mm). Oblique thick slabs were acquired in the planes of the common bile and pancreatic ducts. For multi-angle imaging, TR was 4,500 ms, TE 950 ms and slice thickness 60 mm were used.
Two radiologists who were unaware of the pathological findings independently reviewed the images and reached consensus through discussion. A diagnosis of PBM was established if the common channel is longer than 5 mm. They also assess the shape of the intrahepatic bile duct and gallbladder, pancreatitis, surgical pathology, symptom profiles, operative notes and pathological records were compared with the imaging findings.

The patient was admitted for MRI including T1-weighted, T2-weighted, FLAIR, and diffusion tensor imaging (DTI) at four times points (day 41, 75, 173 and 284 after CPA) using a Symphony 1.5 T scanner (Siemens, Erlangen, Germany). For DTI we used single shot echo planar imaging (EPI) with 6 diffusion directions [b-factors 0 and 1000 s/mm², TR = 9.8 s/TE = 95 ms, acquisition matrix: 128×128, voxel size: 1.8×1.8×3.6 mm³, two averages]. All EPI images have been smoothed by using a Gaussian kernel of 2 mm×2 mm×4 mm FWHM. An experienced neuroradiologist evaluated findings on conventional MRI. DTI processing was performed by using the “Münster Neuroimaging Evaluation System (EVAL)” [5] (link)–[7] (link). The employed EVAL-DTI processing pipeline incorporated multi-contrast image registration and correction for eddy currents [7] (link), [8] . Registered fractional anisotropy (FA) images corresponded to the MNI coordinate space. For quantitative comparisons FA was averaged in various regions of interest (ROI), for details see Table 1. All ROIs were created automatically by the EVAL pipeline on the output images from the registration toolbox for the patient and controls, as previously described [5] (link), [9] (link). The patient's mean FA values of the ROIs were compared longitudinally and with the control group by inferential statistics (t-tests, corrected for multiple comparisons).