Figure 4.

Two breast malignancies missed by rs-EPI DWI in two patients. (a–d) DCE-MRI, time-signal intensity curve (TIC), rs-EPI DWI (b-value, 1,000 s/mm²), and ADC map of a 55-year-old woman with the right breast ductal carcinoma in situ. (a) DCE-MRI shows a lobulated and spiculated nodule (8.7 mm) (arrow) with initial fast enhancement followed by a washout (b) classified as BI-RADS 4. No lesion was found on corresponding rs-EPI DWI (c) and ADC map (d). (e–h) DCE-MRI, TIC, rs-EPI DWI (b-value, 1,000 s/mm²), and ADC map of a 42-year-old woman with the right breast ductal carcinoma in situ. (e) DCE-MRI shows non-mass-like enhancement along the parenchyma surface (arrow) with initial fast enhancement followed by plateau (f) classified as BI-RADS 4. No lesion can be identified on corresponding rs-EPI DWI (g) and ADC map (h). Slight high signal can be retrospectively observed for both cases on rs-EPI DWI (c,g, respectively) (arrow), but it was not considered sufficient to confirm the presence of lesions. The latter finding may be attributable to the inferior spatial resolution (5 mm) of our rs-EPI DWI protocol relative to DCE-MRI protocol.