Computed tomography (CT) scans provide detailed internal images of the body. Cardiac CT specifically evaluates the heart and its surrounding vessels.
Heart Conditions Revealed by CT
Cardiac CT scans detect various heart problems, especially coronary artery disease (CAD), which involves plaque buildup in heart arteries. CT identifies calcified and non-calcified plaque, showing atherosclerosis extent, blockages, or narrowings.
CT imaging also detects issues with the aorta, the body’s largest artery, including aneurysms (bulges) and dissections (tears). It can also diagnose coarctation, a narrowing.
Pericardial diseases, affecting the sac surrounding the heart, are detected by CT, including inflammation (pericarditis), fluid accumulation (pericardial effusion), or thickening. CT also identifies congenital heart defects (structural abnormalities present from birth) and cardiac masses like tumors.
Understanding Cardiac CT
Cardiac CT scans use X-rays to generate cross-sectional images of the heart. These “slices” are compiled by a computer to create detailed 2D and 3D views. An iodine-based contrast dye enhances visualization of blood vessels and heart chambers.
Two types are used. Coronary CT Angiography (CCTA) provides detailed images of the coronary arteries. This non-invasive procedure identifies blockages or narrowing without a catheter. Coronary Artery Calcium (CAC) Scoring, a non-contrast CT scan, measures calcium in coronary arteries, indicating atherosclerosis and predicting future heart disease risk.
Indications for Cardiac CT
Cardiac CT scans are recommended for diagnosis and treatment planning, commonly evaluating chest pain when other non-invasive tests (e.g., stress tests) are inconclusive or unsuitable. CT also assesses coronary artery disease risk, especially in intermediate-risk individuals.
Scans are performed for pre-surgical planning before complex cardiac procedures, such as valve replacement or atrial fibrillation treatment. It is also valuable for following up on known conditions, like monitoring aortic aneurysms or congenital heart defects. When other tests haven’t identified heart-related symptom causes, CT provides additional diagnostic information.
What to Expect and Safety
Preparing for a cardiac CT scan involves instructions for optimal image quality. Patients may fast for a few hours and avoid caffeine. Beta-blockers may be given to slow heart rate for clearer images.
During the procedure, patients lie on a movable table that slides into a doughnut-shaped scanner. The scanner rotates, taking rapid images, and patients may hold their breath briefly to minimize motion artifacts. While cardiac CT involves radiation, doses are generally low, and diagnostic benefits outweigh risks for appropriate indications. Rare reactions to the contrast dye, such as allergic responses, can occur.