MRI motion artifact mitigation methodologusing Spin Echo pulse sequences on a 4.7 T scanner

摘要

The movement caused by respiration is one of the most common sources of artifacts in Magnetic Resonance imaging (MRI). In this work, a methodology to mitigate artifacts related to respiratory movement is proposed using sequences of SE (Spin Echo) pulses in a 4.7 Tesla scanner for small animals without a commercial electronic module for detection of respiratory signals. In this methodology, the RF (Radio Frequency) pulses produced by the scanner in each sequence are detected synchronously with the respiration signal using the respiratory gating technique. To validate the methodology, images of a mechanism built to simulate the respiratory movement are collected and compared to the still images using objective metrics: PSNR (Peak Signal-to-noise-ratio), RMSE (Root Mean Square) and SSIM (Structural Similarity Index Measure). The results showed that the mitigation methodology of the simulated respiratory motion artifacts was efficient and can be used, in future experiments, to mitigate respiratory movement artifacts from abdominal organs of small animals, such as rats and mice.