Single-session photon-counting CT protocol for simultaneous screening of coronary and carotid artery disease and lung...

Preventive imaging for cardiothoracic risk is fragmented across separate pathways. Photon-counting CT (PCCT) may consolidate coronary, aortic-carotid, and pulmonary assessment into a single session while maintaining diagnostic performance and controlling dose.

ACTA is an ongoing, general-practitioner-initiated, risk-enriched screening study (age 45-75 years; diabetes ≥10 years, current/recent smoking, or Framingham hard coronary artery disease risk ≥10%). The protocol integrates non-contrast calcium scoring, ultra-high-resolution coronary CT angiography, a high-pitch thoraco-cervical sweep, and brief late iodine enhancement (LIE). Incidental findings trigger predefined, guideline-concordant referrals. The primary endpoint is the prevalence of obstructive (≥50%) and/or extensive (≥2-vessel) coronary artery disease. This interim analysis includes participants imaged 11 January to 21 June 2025. Of 223 invited, 172 underwent PCCT; all completed without complications. Mean dose-length product was ∼740 mGy·cm; the effective dose was 12.6 mSv (IQR 10.5-17.1 mSv), and weight-adapted contrast equalled ∼0.44-0.48 gI/kg. Any coronary atherosclerosis was present in 129/172 (75%); the primary endpoint was met in 98/172 (57%). Carotid plaques occurred in 94/170 (55%); lung-RADS 3-4 in 16/172 (9%); emphysema in 41/172 (24%). Management actions included invasive coronary angiography in 8/172 (5%), targeted vascular and pulmonary referrals, initiation/intensification of prevention therapies, and structured follow-up. Incidental extracardiac findings were common but managed via protocolized pathways.

Single-session PCCT feasibly consolidates comprehensive cardiothoracic assessment with controlled radiation/iodine exposure and structured downstream care. Preliminary yield suggests actionable information in high-risk, asymptomatic adults; ongoing follow-up and prespecified economic analyses will determine clinical outcomes and cost-effectiveness.