Fig. 6
From: Development and validation of a four-dimensional registration technique for DCE breast MRI
Case history of a 48-year-old patient with ductal carcinoma in situ (DCIS) of 18-mm diameter. Tumor histopathology showed a G1 tumor, 10% progesterone receptor expression, and 100% estrogen receptor expression. The patient was not considered a high-risk patient. Images show subtractions of the same axial plane at three different time points (the first [t1], third [t3] and fifth [t5] time point after contrast administration), first in full-size and beneath by zooming in on the tumor. The left column shows images before registration and the right column after registration. In subjective assessment, the case was assigned to motion category 3 with an NRS (numerical ranking scale) value of 9 (defined as “nondiagnostic image quality”). After registration, the previously undetectable tumor in the subtracted images is unveiled (indicated by arrows in full-size images). Following registration, the images were assigned to motion category 1 with a NRS of 1. Quantitative analysis showed for the 90th percentile of intralesional motion, a 0.021 reduction in residual errors. Median Ktrans decreased from 0.0482 (IQR 0.0561) before registration to 0.0438 (IQR 0.0423) after registration