Mammography. View of a woman's breast undergoing X-ray screening. Mammography is an X-ray technique which reveals fine details of internal breast tissues. The breast is compressed into a relatively flat plane between a plastic sheet and a metal X-ray plate. Breast tissue is then exposed to low-dose X-rays to obtain a mammogram image. Mammography is mainly used in the early detection of breast tumours, whether they are benign lumps, cysts or malignant cancer. Once a tumour has been located on a mammogram, other techniques are employed to identify it. Biopsy (tissue sampling) of the tumour will confirm cancer. Photographed at King's College Hospital, London.