Comparison Between EPI DWI and PROPELLER DWI in Brain MR Imaging.

OBJECTIVE: EPI DWI is a routinely used sequence in brain imaging but it has limitations when it comes to SNR and artifact reduction. PROPELLER DWI has the benefit of improving image quality compared to EPI DWI. The aim of this study is to compare the EPI DWI sequence in brain MR imaging with the PROPELLER DWI sequence. The objective is to identify which sequence is more beneficial in brain imaging by evaluating image quality and the depiction of pathologies. MATERIALS AND METHODS: A total of 101 patients (55 females and 46 males, mean age 56 years) underwent brain MRI examination on a 1.5 T scanner. EPI DWI and PROPELLER DWI sequences were acquired in every exam and were reviewed by 2 radiologists. The images were evaluated by performing a quantitative analysis based on Relative Contrast and a qualitative analysis (overall image quality, conspicuousness of lesions, artifact reduction, etc.). RESULTS: In both the qualitative and quantitative analysis PROPELLER DWI achieved better results than EPI DWI. PROPELLER DWI showed statistical significance in the overall image quality (P < 0.001), the elimination of susceptibility (P < 0.001) and flow pulsation artifacts (P < 0.001), as well as in the contrast between CSF with white (P < 0.001) and grey matter (P < 0.001). Also, PROPELLER DWI presented better delineation of pathologies like ischemic strokes, metastasis, tumors and vasogenic edemas than conventional EPI DWI. CONCLUSION: PROPELLER DWI was the preferred sequence during the image evaluation. Compared to EPI DWI, PROPELLER DWI managed to reduce susceptibility and flow pulsation whilst achieving higher image quality and lesion delineation and earlier depiction of ischemic strokes than the conventional EPI DWI. PROPELLER DWI may be incorporated in brain MR imaging replacing EPI DWI.

Brain imaging: Comparison of T1W FLAIR BLADE with conventional T1W SE.

INTRODUCTION: Although T1 weighted spin echo (T1W SE) images are widely used to study anatomical details and pathologic abnormalities of the brain, its role in delineation of lesions and reduction of artifacts has not been thoroughly investigated. BLADE is a fairly new technique that has been reported to reduce motion artifacts and improve image quality. OBJECTIVE: The primary objective of this study is to compare the quality of T1-weighted fluid attenuated inversion recovery (FLAIR) images with BLADE technique (T1W FLAIR BLADE) and the quality of T1W SE images in the MR imaging of the brain. The goal is to highlight the advantages of the two sequences as well as which one can better reduce flow and motion artifacts so that the imaging of the lesions will not be impaired. MATERIALS AND METHODS: Brain examinations with T1W FLAIR BLADE and T1W SE sequences were performed on 48 patients using a 1.5T scanner. These techniques were evaluated by two radiologists based on: a) a qualitative analysis i.e. overall image quality, presence of artifacts, CSF nulling; and b) a quantitative analysis of signal-to-noise ratios (SNR), contrast-to-noise ratios (CNR) and Relative Contrast. The statistical analysis was performed using the Kruskal-Wallis non-parametric system. RESULTS: In the qualitative analysis, BLADE sequences had a higher scoring than the conventional sequences in all the cases. The overall image quality was better on T1W FLAIR BLADE. Motion and flow-related artifacts were lower in T1W FLAIR BLADE. Regarding the SNR measurements, T1W SE appeared to have higher values in the majority of cases, whilst T1W-FLAIR BLADE had higher values in the CNR and Relative Contrast measurements. CONCLUSION: T1W FLAIR BLADE sequence appears to be superior to T1W SE in overall image quality and reduction of motion and flow-pulsation artifacts as well as in nulling CSF and has been preferred by the clinicians. T1W FLAIR BLADE may be an alternative approach in brain MRI imaging.