The Applicability of Gd-DTPA Magnetic Resonance Imaging Contrast Agent for the Evaluation of Blood Compartment Flow Distribution in Hollow Fiber Hemodialyzers

Observation of flow distribution pattern in the hemodialyzers is significant as it is a valuable indication of the performance of these modules. Therefore, in this study, a feasible non-destructive Magnetic Resonance Imaging (MRI) technique is proposed to characterize the flow distribution in the blood compartment of hemodialyzers using Gd-DTPA MRI contrast agent. The distribution of flow is qualitatively observed in two commercial clinical dialyzers through an in-vitro experiment. The contrast enhanced T1 weighted images are acquired along the dialyzer length using Spin Echo (SE) pulse sequence after an injection of 0.5 mmol/L Gd-DTPA solution into the blood compartment. Although relatively uniform flow distribution pattern over the spatial volume of transverse images, close the dialyzer inlet is observed, the heterogeneity of flow distribution can be identified towards the blood outlet port. Furthermore, the signal intensity profiles formed by the injected Gd-DTPA are gradually decreased towards the outlet port. These results of the study suggest that although no advanced techniques and protocols available, MRI and Gd-DTPA contrast agent can be utilized to characterize the flow distribution within a dialyzer qualitatively.