Figure 6.

A 65 year old female with diagnosis of biopsy-proven left breast cancer in the upper inner left breast adjacent to the chest wall. Maximum intensity projection image of a sagittal diffusion weighted imaging sequence (B800 series) demonstrates bright diffusion weighted imaging signal in the lesion with slightly less bright diffusion weighted imaging signal (arrow) in the chest wall (a). This was interpreted as diffusion weighted imaging restriction in the chest wall qualitatively. The apparent diffusion coefficient value in the chest wall was 2.5. Subsequent diffusion weighted imaging image after neoadjuvant chemotherapy demonstrates resolution of previously seen diffusion restriction within the mass and in the chest wall (b). Initial magnetic resonance imaging prior to neoadjuvant chemotherapy demonstrates enhancing mass in the left breast with enhancement extending into the pectoralis muscle (arrow), compatible with chest wall invasion (c). Subsequent magnetic resonance imaging demonstrates resolution of the mass and enhancement in the pectoralis muscle (d). The pathology in this case was negative for skeletal muscle involvement but patient had received neoadjuvant chemotherapy.