Purpose: 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 two sequences in order to identify which sequence is more beneficial in brain imaging by evaluating the image quality and the depiction of pathologies.
Methods: 101 patients (55 females and 46 males, mean age 56 years) underwent brain MRI examination on a 1.5 T scanner. Both EPI DWI and PROPELLER DWI sequences were acquired in every examination and were reviewed by two radiologists. The images were evaluated by performing a quantitative analysis (Relative Contrast) and a qualitative analysis (overall image quality, conspicuousness of lesions, artifact reduction, etc).
Results: In both the qualitative and quantitative analyses, PROPELLER DWI achieved better results than EPI DWI. PROPELLER DWI showed statistically significant superior performance than conventional EPI DWI in the overall image quality, elimination of susceptibility and flow pulsation artifacts, as well as in the contrast between CSF with white and grey matter. PROPELLER DWI achieved better delineation of pathologies like ischemic strokes, metastasis, tumours and vasogenic oedemas. Additionally, in PROPELLER DWI we could distinguish the peripheral zone of a tumour with high signal, which was confirmed by a T1W SE sequence after contrast administration, whilst in EPI DWI the peripheral zone could not be presented with high signal.
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, better lesion delineation and earlier depiction of ischemic strokes than the conventional EPI DWI. PROPELLER DWI could be incorporated in brain MR imaging replacing EPI DWI.