Magnetic Resonance Imaging of Plaques in Cylindrical Channel

Abstract

The detection of blockage in cylindrical pipes using diffusion magnetic resonance equation has been carried out in previous works. In this study, magnetic resonance imaging (MRI) has been employed to image the materials causing fluid blockage in a cylindrical pipe. The Bloch Nuclear Magnetic Resonance (NMR) flow equation is solved analytically in cylindrical coordinates for flow of fluid in a radially symmetric cylindrical pipe. Based on the appropriate boundary conditions, the radial axis was varied to depict blockage in the pipe. The gradient pulse is designed such that it undergoes exponential rise and fall. The results show that the graphical pattern changed from vertical orientation (free flow) to horizontal orientation (partial blockage) – which is an indication of presence of materials that may cause obstruction to the fluid flow. Also, coagulation of colours indicates that obstruction caused is becoming more immense than previously noted. One similarity between the plaques imaged is that as the time is varied, they both show a drop in magnetization. This seems to lay credence to the fact that the model registers signal in its first few seconds or micro-seconds.