Medical X-ray machines are grouped by how they capture images. The main diagnostic modalities that use ionizing X-rays are radiography (conventional still X-rays), fluoroscopy (continuous real-time X-ray video), and computed tomography (CT), which builds cross-sectional slices from many projections.
Mammography is a specialized form of radiography used to image breast tissue. Related systems include dental X-ray units and mobile or C-arm equipment used for bedside or interventional imaging.
Source: Medical X-ray Imaging — U.S. Food and Drug Administration (FDA)