Published online Nov 28, 2019. doi: 10.4329/wjr.v11.i11.134
Peer-review started: June 29, 2019
First decision: August 2, 2019
Revised: August 26, 2019
Accepted: September 25, 2019
Article in press: September 25, 2019
Published online: November 28, 2019
Processing time: 148 Days and 17 Hours
Diffusion-weighted imaging (DWI) in the body has several technical challenges. This include ghosting artifacts, mis-registration and susceptibility artifacts.
New DWI sequences have been developed to overcome some of these challenges. Our goal is to evaluate 3 new DWI sequences for liver imaging.
To compare the image quality and quantitative apparent diffusion coefficients (ADC) of 3 DWI sequences for in vivo liver imaging: Free-breathing (FB)-DWI, simultaneous multislice (SMS)-DWI, and prospective acquisition correction (PACE)-DWI.
Magnetic resonance imaging (MRI) of the abdomen was performed at 1.5 T on 20 patients with liver lesions in this Institutional Review Board-approved prospective study. The MR study included 3 separate DWI sequences: FB-DWI, SMS-DWI, and PACE-DWI. The image quality, mean ADC values, standard deviations (SD) of the ADC, and quality of the ADC histogram were compared. Wilcoxon signed-rank tests were used to compare qualitative image quality scores. A linear mixed model was used to compare the mean ADC values and the SDs of the ADC values. All tests were 2-sided and P values of 0.05 or less were considered statistically significant.
PACE-DWI had the highest mean image quality score (4.48), followed by SMS-DWI (4.22) and FB-DWI (3.15). The image quality of PACE-DWI was rated superior to that of SMS-DWI and FB- DWI (P < 0.03). The quality of the PACE-DWI ADC histograms were better than the SMS-DWI and FB-DWI. The SD of the ADC values was not statistically significant in terms of difference for PACE-DWI and SMS-DWI (P = 0.18), whereas FB-DWI had significantly more variation in the SD of its ADC.
PACE-DWI and SMS-DWI are equivalent in their ability to measure ADC. Compared to FB-DWI, both PACE-DWI and SMS-DWI provide better image quality and decreased variability in the quantitative diffusion measurement of liver lesions.
Therefore, this technique may provide a better characterization of the intrinsic diffusion characteristics of the tumor than that provided by FB-DWI and SMS-DWI. However, both PACE-DWI and SMS-DWI provided better image quality with fewer artifacts and less variability in the ADC values. These are valuable in assessing tumor treatment response and comparably better than the FB-DWI technique.