Patient monitoring during a scan

An imaging system for capturing images of a patient during a medical scan using a scanner having a scanning system and a patient support, the imaging system comprising:

• a set of one or more cameras for mounting in a fixed position relative to the scanning system directed towards the patient support for capturing images, wherein each camera of the set has an optical axis orthogonal to a direction of the patient support displacement in use of the scanner, and wherein pixel rows of images captured by each camera correspond to locations along an axis parallel to the direction of patient support movement;
• a processor, wherein the processor is configured to:
• perform image post-processing to correct distortions within the captured images resulting from the width of the field of view of the camera or cameras and to provide perspective correction;
• identify patient motion based only on image movements in the pixel column direction between sequential captured images;
• and
• output a measure of patient motion.