Technical assessment of artifact procution from neuro endovascular coil at 3 tesla MRI : an in vitro study

Abstract

Magnetic resonance imaging (MRI) is an essential part in diagnostic radiology and post-treatment valuation. MRI 3 Tesla is becoming more and more widespread due to high signal to noise ratio (SNR). The artifact in magnetic resonance imaging results from endovascular coils. Susceptibility artifacts and geometric distortions caused by magnetic field inhomogeneity- related signal loss is used to refer to an artifact in magnetic resonance images. It consists of a region of signal void with a surrounding area of an increased signal intensity that appears to be considerably larger than the actual size of the device causing the artifact. RF metal interaction effects were investigated systematically at B0 = 3 Tesla, analyzing correlated image artifacts for endovascular coils. The objective of the study is to compare the size of the artifact on the MR image to the actual size of endovascular coils using a 3 Tesla magnetic resonance imaging system, in vitro study. Endovascular coils were made from detachable platinum coils and aneurysm models were constructed by using catheters. A drop of gadolinium in normal saline solution was injected into each catheter.MRI 3 Tesla Philips Model Achieva. Pulse sequence selections were: Spin echo (conventional), fast spin echo, Inversion Recovery, Fast Gradient echo while additional parameters were Echo time and Turbo Factor. Improved visualization of peri-aneurysmal soft tissues is best accomplished by Spin echo for Fast spin echo sequences are even better suited to reduce metal artifact. Furthermore, shorter turbo factor and shorter effective TE in the latter sequences are beneficial for the same reason as sequences having shorter TE. Sequences with a shorter TE are preferred because there is less time for dephasing and frequency shifting. Imaging at gradient echo series increases susceptibility artifacts. In this in vitro study, we have defined some of the major characteristics related to MRI imaging of coil packs. conclusions from this study are; 1) Pulse sequence Spin echo is best reduce susceptibility artifact; 2) Reducing the TE is the main factor in improving peri-aneurysmal visualization on MRI images; 3) The use of small field of view, high resolution matrix and thin slice can help reduce susceptibility artifacts. Artifacts are also produced in the frequency encoding.