Effect of echo time, echo train length and flip angle of t2 weighted turbo spin echo in reduction chemical shift artifact

Abstract

Magnetic resonance imaging (MRI) is an essential part in diagnostic radiology. The effectiveness of magnetic resonance in evaluating the spine and intervertebral disks has become most favorite examination, as MRI can show anatomy of spine imaging better than other modality. Chemical shift artifact may cause pitfall of diagnostic. It occurs in the frequency encode direction. The MRI uses the frequency of the signal to indicate spatial position. Chemical shift artifact were occurred between fat and water interface. The objective of the study is to optimize echo time, echo train length and flip angle in T2 weighted Turbo spin echo for the chemical shift artifact reduction, in vitro study . Acrylic phantom was built and used by fill the water and vegetable oil in the phantom. Bandwidth, matrix size , field of view and frequency encoding direction were fixed in scanning.Turbo spin echo pulse sequence was used for compensation of magnetic field inhomogeneity due to rephrasing by 180 RF pulse. T2 weighted was used. Variable echo time, echo train length and flip angle were regarded for MRI 1.5 Tesla Siemens Model Magnetom Essenza. Chemical shift artifact distances were measured by image J program. Flip angle are revert proportional to chemical shift artifact distances. Center position of artifact distance between fat and water interface is less than right and left position in the same slice (image). At different slice, center of slice selection shows artifact distance less than border of slice selection. Echo time are directly proportional to chemical shift artifact distances but echo train length are not clearly related to chemical shift artifact distances.