SU‐E‐I‐67: Multi‐Shot RESOLVE Compared to Single‐Shot EPI Diffusion‐ Weighted MR Imaging Acquisition Scheme

Purpose: The purpose of this project was to configure the parameters for optimal comparison of image quality differences between the prototype imaging technique, read‐out‐segmented EPI multi‐shot (RESOLVE) and the clinically used single‐shot EPI (SS‐EPI) MRI sequence for Diffusion Weighted Imaging (DWI) in a saline phantom, followed by a normal rat brain. Methods: Saline phantom (4.2 × 4.2 cm²) and a rat brain were imaged on the 1.5T ESPREE (Siemens, Germany) MRI magnet using a wrist coil. Both the SS‐EPI and RESOLVE DWI were optimized with equal imaging parameters such as slice thickness/slice gap = 3.0/0 mm, field of view = 210 mm, phase resolution = 100%, and diffusion b values = 0, 600 s/mm² while other parameters were given similar settings such as the base resolution, which had to be interpolated for the SS‐EPI to 96i to match the RESOLVE as it was unable to be set at 192. Image quality was compared in terms of signal intensity, distortion, % ghosting and Apparent Diffusion Co‐efficient (ADC) measurements from each sequence. Results: A marked enhancement of overall image quality with superior detail was observed in each of the scans from the RESOLVE sequence when compared to the SS‐EPI. Comparing the efficiency of both sequences in terms of image quality, RESOLVE demonstrated a better stable image with minimal distortion and ghosting. The phantom dimensions obtained from RESOLVE images matched the actual dimensions perfectly. RESOLVE images had signal intensities significantly higher than (2.4×) the SS‐EPI images (p=0.0008) and ∼0.6 % times less ghosting compared to SS‐EPI (p=0.82) which also exhibited distortion with reduced phantom dimensions (4.05 × 3.28 cm) from original. The ADC values computed were almost identical to be (p=0.32) from SS‐EPI (2.21mm²/sec) and RESOLVE (2.19mm²/sec). Conclusions: The RESOLVE sequence has significantly superior image quality compared to SS‐EPI at 1.5 T with reasonable scan times. DWI with RESLOVE acquisition scheme can be highly beneficial in obtaining distortion free images in routine clinical studies to characterize tumors and other pathological mechanisms with much greater detail than the current clinically used SS‐EPI.