CCTA

Coronary computed tomography angiography (CCTA) is a non-invasive imaging modality that visualizes the coronary arteries using iodinated contrast material and ECG-gated CT scanning. By capturing high-resolution, three-dimensional images of the coronary lumen and arterial walls, CCTA can identify obstructive and non-obstructive atherosclerosis and characterize plaque.

CCTA is commonly used to evaluate patients with chest pain and suspected coronary artery disease, particularly those at low to intermediate pretest probability where a negative study can reliably exclude significant CAD. It also assists in planning revascularization, evaluating anomalous coronary arteries, and preoperative risk assessment in selected cases or when invasive angiography is unsuitable.

Technique involves intravenous contrast administration with a bolus tracking or timing method, followed by rapid, ECG-synchronized image acquisition. Modern scanners employ prospective ECG-triggered (single-heartbeat) or retrospective gating and may use high-pitch spiral modes to reduce radiation exposure. Images are reconstructed as axial, multiplanar, and three-dimensional reconstructions; plaque composition and stenosis severity can be graded, with some centers offering functional assessment such as FFR-CT.

Diagnostic performance is high for ruling out significant CAD in properly selected patients, with strong sensitivity and negative predictive value. Specificity declines with extensive calcification or motion artifacts. Limitations include radiation exposure, risk of contrast-induced nephropathy or allergic reactions, and reduced accuracy in high heart rates or arrhythmias.

In acute chest pain or suspected STEMI, invasive coronary angiography remains the standard when intervention is anticipated.