**7. Ability of MRI to describe multifocality and the extent of the disease**

For women with newly diagnosed breast cancer, a single round of screening of the contralateral breast with MRI at the time of diagnosis might detect otherwise occult malignancy in approximately 3 % to 9 % of cases (Lee et al., 2010) (Figure 4).

MRI has been found to be more accurate in assessing tumor extent and multifocality in patients with dense breasts. MRI can improve the detection of cancer in the contralateral breast when added to a thorough clinical breast examination and mammographic evaluation at the time of the initial diagnosis of breast cancer. The increased rate of cancer

The Application of Breast MRI on Asian Women (Dense Breast Pattern) 33

**10. Lesion analysis using ESP image, kinetic curve patterns, color mapping,** 

In the DBMRI, for cases suspected of being malignant, an ESP image was obtained based on subtraction of the post-enhanced phase of images from 90 s non-enhanced images. Lesions that could be subtracted in the ESP (by subtraction of the post enhanced image at 90 s from the pre-contrast phase) were almost completely excluded from the possibility of being malignant (Figure 1b). Therefore, the lesions that could not be subtracted in the ESP

Using the mean percentage calculation and comparing pre- and post-contrast kinetic data (calculated from 0 s, 90 s, and 4.5 min), the threshold point for lesion enhancement was displayed. According to the diagnostic observations of Dr. Christane Kuhl (1999), curved patterns of the plateau and washout with bound protein water and free water represent possible lesions. A stabilized enhancement without change in signal intensity between 90 s and 4.5 min was termed a "plateau" pattern. A "washout" pattern was indicated by a decline in signal intensity between 90 s and 4.5 min after the injection of contrast. Each lesion was characterized according to the strongest enhancement pattern visible over the entire lesion. Figures 1c show magnetic resonance imaging for differentiating lesions that

Fig. 3. In normal tissue, the contrast medium equally permeates in and out through the normal gaps in the vascular endothelial cells and interstitial space. In benign neoplasms, contrast does not permeate out of the microvessel to interstitial space, and the progressive accumulate increases the concentration which manifests itself in a progressively increased

The washout curve represents the initial increase in contrast concentration in the interstitial space and then a decrease, as it reverse permeates back through the abnormal gaps in the vascular endothelial cells. A final decreased contrast concentration in the tumor interstitial

required further analysis to assess the risk of malignancy.

are normal, benign, or display a washout pattern.

**and morphology** 

MRI signal.

space can be detected.

detection comes with a false positive rate of 10.9 % and a relatively low risk of detecting benign disease on biopsy (9.4 %) (Lehman et al., 2007a).
