Using Spin-labeled MR Imaging to Depict Slow Pancreatic Juice Flow

This study evaluated the dependence of the signal characteristics of time-spatial labeling inversion pulse (time-SLIP) on flow velocity and tag thickness to depict the pancreatic juice flow by analyzing signal profile using a tube phantom study. The tag edge property was evaluated by edge rise distance (ERD). For various slow flow velocities and tag thicknesses, the signal profile characteristics were evaluated using two indices: the tag center value (R(TCV)) reduction rate and the total signal value along the tube (T(SVT)). ERD, which was about 10% of the tag thickness, was higher for thicker tags, making slow flow detection difficult. T(SVT) was proportional to the thickness of the tag and was preserved irrespective of the flow velocity. R(TCV) became lower with higher flow velocity and decreased significantly with thinner tags. These results suggest that the visualization of pancreatic juice flow might improve stability by considering the appropriate tag thickness.