High-resolution diffusion-weighted imaging compared with conventional diffusion-weighted imaging and dynamic contrast-enhanced magnetic resonance imaging with regard to image quality and assessment of breast cancer morphology

PURPOSETo evaluate the image quality and tumor morphology depiction ability of high resolution (HR) dif-fusion-weighted imaging (f-DWI) in comparison to conventional DWI (c-DWI) and dynamic con-trast-enhanced magnetic resonance imaging (DCE-MRI) in the primary breast cancer setting.METHODSThe f-DWI, c-DWI, and DCE-MRIs of 160 malignant breast masses were evaluated retrospectively by two independent radiologists. Data on image quality [sharpness, distortion, and perceived signal-to-noise ratio (SNR)], apparent diffusion coefficient (ADC) value, lesion size, and tumor morphology (shape, margin, and internal pattern) obtained on f-DWI, c-DWI, and DCE-MRI were compared. Con-sistency between the readers and imaging methods for morphological parameters was analyzed.RESULTSThe ADC values measured on f-DWI were significantly lower than those measured on c-DWI for both readers (P < 0.001 for each), whereas mean lesion size was significantly larger in c-DWI than in f-DWI and DCE-MRI for both readers (P < 0.001 for each). Higher consistency values were obtained for f-DWI compared with c-DWI when correlated with DCE-MRI for each morphological parame-ter. The least distorted images were obtained using DCE-MRI compared with c-DWI and f-DWI for both readers, whereas the highest distortion scores were obtained using c-DWI. Sharpness and per-ceived SNR scores were rated as significantly higher for f-DWI and DCE-MRI images compared with c-DWI by both readers (P < 0.001 for all). The concordance between c-DWI and DCE-MRI was fair to slight (& kappa; = 0.15 to 0.41), whereas concordance between f-DWI and DCE-MRI was significantly better (& kappa; = 0.68 to 0.87) for each reader and for all morphological parameters (P < 0.001). The highest con-cordance between the readers was achieved in margin assessment (& kappa; = 0.87 to 0.89) regardless of the MRI method, followed by shape and internal pattern parameters (& kappa; = 0.63 to 0.79).CONCLUSIONThe results demonstrated that f-DWI produces higher-quality images than c-DWI, enabling the morphological features to be identified in similar detail to that offered by HR DCE-MRI. Accordingly, f-DWI, as a method that highly correlates with DCE in determining the morphological character-istics of breast cancers, seems to have potential in the evaluation of breast tumors in patients for whom the use of contrast media is contraindicated.