Image Quality Improvement of SENSE Parallel Imaging MRI Post-Acquisition Using Denoising Non-Local Mean Filter Technique

Abstract

Abstract. Magnetic Resonance Imaging (MRI) is a medical tool that is used to form images of organs, soft tissues, bones and almost all internal body structures. The MRI image acquisition process takes a long time. One of the efforts to shorten the examination acquisition time is using the parallel imaging technique, namely SENSE. However, SENSE has a weakness, namely reducing the Signal Noise to Ratio (SNR). One of the denoising methods that can increase SNR is the Nonlocal mean filter (NLM). Post-image acquisition denoising becomes a cheaper and more effective alternative to use. The aim of this research is to measure the increase of SNR value in MRI SENSE images between before the denoising technique and after the denoising technique. This research is expected to produce a faster scanning time and maintain the quality of the MRI image. This experimental research was carried out by applying the SENSE parallel imaging technique to R-factors 2 and 4. The sequence used is T2WI TSE on axial slice phantom. The T2WI TSE SENSE phantom MRI image was corrected with the NLM denoising technique to produce a better quality image. Each variation is measured image information before and after the denoising technique. Image information is assessed quantitatively by measuring SNR. The results of the parametric test showed that there was an increase in the SNR value after the application of the denoising technique on the Phantom T2WI TSE SENSE MRI image at r-factor 2 and r-factor 4. The different test on the SNR assessment resulted in a p value < 0.001.