Effect of the Phase Encoding Direction on the Image Quality of Breast Diffusion-Weighted Magnetic Resonance Images

Abstract Purpose The study aimed to evaluate the effect of reversing the phase encoding direction on the image quality of breast diffusion-weighted (DWI) magnetic resonance images (MRI). Methods A total of 100 patients attending our hospital for MRI breast examinations between February 2022 to July 2022 were enrolled in the study. The patients were randomly divided into the study group and the control group. The patients in the study group were scanned using the posterior-anterior (P-A) phase encoding direction, while those in the control group were scanned using the anterior-posterior (A-P) phase encoding direction. The geometric distortion rate on the axial DWI in relation to the T1-weighted images, the incidence of phase displacement artifacts, and the image signal-to-noise ratio (SNR) of the two groups were analyzed and statistically compared using either the 2 sample t-test or the Chi-square test. Results In the study group, the average breast stretch rate for the craniocaudal diameter was 6.75% for the right breast and 6.92% for the left breast, while the average breast stretch rate for the transverse diameter was 4.14% for the right breast and 3.79% for the left breast. In the control group, the average breast stretch rate in the craniocaudal direction was 13.82% for the right breast and 16.12% for the left breast, while the average stretch rate of the transverse breast diameter was 8.26% for the right breast and 9.56% for the left breast. The deformation rate of the study group was lower than that of the control group (PLength of right breast, PTransverse of right breast, PLength of left breast, PTransverse of left breast< 0.05). The incidence of phase displacement artifacts in the study group was lower than that of the control group (14.0% versus 62.0% p = 0.000 ). Similarly, the incidence of phase displacement artifacts in the study group was significantly lower than that of the control group (P < 0.05). The average SNR in the study group was slightly lower than that of the control group (2.30 versus 2.53, p = 0.278). Conclusion The P-A phase encoding direction provided a better image quality than the A-P phase coding direction, and it could facilitate the detection of breast lesions.