Coronary CT Angiography

ECG-gated contrast CT angiography of the coronary arteries (Koronar-CT) mapping stenosis, atherosclerotic plaque, and coronary anatomy in three dimensions without invasive catheterisation. Claraspital also performs TAVI-CT for pre-procedural transcatheter valve planning. Reported jointly by cardiologists and radiologists.

Coronary CT angiography (CCTA) — termed Koronar-CT at Claraspital — is the department's central non-invasive cardiac imaging examination. ECG gating synchronises image acquisition with the cardiac cycle so that the coronary arteries appear frozen mid-diastole, when they move least. Intravenous iodine contrast is injected as a timed bolus and tracked to peak coronary opacification; the Dual-Layer Spectral CT then captures the full coronary tree in a single breath-hold of approximately five to eight seconds. The resulting three-dimensional dataset allows cardiologists and radiologists to assess each coronary segment for narrowing (stenosis grade: non-obstructive <50%, moderate 50–70%, severe >70%), non-calcified and calcified plaque burden, coronary anomalies, and myocardial bridging. The Dual-Layer Spectral CT technology at Claraspital adds the ability to apply iodine maps and virtual monoenergetic reconstructions post-hoc — useful for clarifying equivocal segments in calcified vessels and for producing vascular 'clean images' to confirm patency beyond heavy plaque. Before the scan, heart rate is assessed and, where above approximately 65 beats per minute, rate-lowering medication may be offered to optimise image quality. Sublingual nitroglycerine spray is administered five minutes before acquisition to dilate the coronary arteries and maximise luminal opacification. The contrast injection produces a brief, intense warmth throughout the body lasting 20 to 30 seconds — expected and harmless. Creatinine and allergy history must be reviewed before any iodine contrast administration. For patients undergoing TAVI evaluation, the CT protocol is extended to include the aortic root, ascending aorta, and access vessels (iliac and femoral arteries), providing the anatomical measurements — annulus diameter, calcification pattern, coronary height, access vessel calibre and tortuosity — that interventional cardiologists need to select prosthesis size and plan the approach. This combined TAVI-CT is performed within the same appointment as standard Koronar-CT where clinically appropriate. The written report from Claraspital's joint cardiology–radiology team includes per-segment stenosis grading, plaque characterisation, overall CCTA risk category, and management recommendations. Results are typically available within 48 hours. Self-referring patients and those referred by external cardiologists are welcome; complex findings are reviewed by the Claraspital interdisciplinary heart team.