Mammography. Woman undergoing breast screening by X-ray mammography, a technique which reveals the fine details of internal breast tissues. The breast is compressed into a flat plane between a plastic sheet and a metal X-ray plate. Breast tissue is then exposed to low-dose X-rays from the X-ray machine (upper centre) to obtain a mammogram. Mammography is used to routinely screen women in order to detect breast tumours at an early stage. Once a tumour has been located, other techniques are employed to identify it. Biopsy (tissue sampling) of the tumour will confirm whether it is cancerous. Photographed at the European Institute of Oncology in Milan, Italy.