Comparison of conventional and higher-resolution reduced-FOV diffusion-weighted imaging of breast tissue

Reduced FOV-diffusion-weighted imaging (rFOV-DWI) allows for acquisition of a tissue region without back-folding, and may have better fat suppression than conventional DWI imaging (c-DWI). The aim was to compare the ADCs obtained with c-DWI bilateral-breast imaging with single-breast rFOV-DWI.

Breasts of 38 patients were scanned at 3 T. The mean ADC values obtained for 38 lesions, and fibro-glandular (N = 35) and adipose (N = 38) tissue ROIs were compared between c-DWI and higher-resolution rFOV-DWI (Wilcoxon rank test). Also, the ADCs were compared between the two acquisitions for an oil-only phantom and a combined water/oil phantom. Furthermore, ghost artifacts were assessed.

No significant difference in mean ADC was found between the acquisitions for lesions (c-DWI: 1.08 × 10^-3 mm²/s, rFOV-DWI: 1.13 × 10^-3 mm²/s) and fibro-glandular tissue. For adipose tissue, the ADC using rFOV-DWI (0.31 × 10^-3 mm²/s) was significantly higher than c-DWI (0.16 × 10^-3 mm²/s). For the oil-only phantom, no difference in ADC was found. However, for the water/oil phantom, the ADC of oil was significantly higher with rFOV-DWI compared to c-DWI.

Although ghost artifacts were observed for both acquisitions, they appeared to have a greater impact for rFOV-DWI. However, no differences in mean lesions' ADC values were found, and therefore this study suggests that rFOV can be used diagnostically for single-breast DWI imaging.