Digital subtraction angiography (DSA) is an imaging technique used to visualise blood vessels by subtracting pre-contrast images from post-contrast images. This process removes background anatomical structures and enhances the visibility of contrast-filled vessels.

DSA relies on rapid sequential image acquisition and digital image processing. Accurate image registration is essential because even small patient movements between acquisitions can produce subtraction artefacts.

The technique is widely used in interventional radiology to guide vascular procedures and assess blood flow dynamics.

DSA physics is occasionally examined in FRCR and ABR Core physics examinations, particularly in questions relating image subtraction techniques, temporal resolution, and artefact formation.

The questions in this section reinforce the physical and computational principles underlying digital subtraction imaging and vascular visualisation.

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