MODEL RELEASED. Angiocardiography machine check. Engineer checking angiocardiography equipment. The machinery seen here will be used for X-ray examination of the chambers of the heart. During angiocardiography, a radio-opaque contrast medium is introduced into the blood in a patient's heart. The progress of this medium through the heart is followed on the screens at centre left by a rapid series of X-ray films, taken by the X-ray machine at centre. Angiocardiography is useful for diagnosing heart defects and planning their surgical repair. Photographed at a Siemens plant in Germany.