Breast cancer pre and post surgery in a 68 year old woman. The tumour is shown at left in an ultrasound scan (top left, dark tumour) and a composite coloured positron emission tomography (PET) and computed tomography (CT) scan (bottom left, bright tumour). The PET, CT and magnetic resonance imaging (MRI) scans at right are after a left modified radical mastectomy (MRM), which removes the entire left breast, and chemotherapy. They show no evidence of metastasis (spread) of the cancer.