5T Non-Contrast One-Stop MRA for Thoracic Aorta and Coronary Arteries: A Prospective Feasibility Study in Healthy Volunteers

Background/Objectives: This prospective study evaluated the feasibility of a non-contrast 5T one-stop MRA protocol for simultaneous assessment of the thoracic aorta and coronary arteries and examined the effect of heart rate (HR) on image quality. Methods: Thirty-four healthy volunteers underwent 5T MRA and were stratified by median HR into Low-HR (≤70 bpm, n = 17) and High-HR (>70 bpm, n = 17) groups. Subjective image quality was assessed using a 4-point scale, and signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR), and vessel edge sharpness (VES) were measured in predefined aortic and proximal coronary segments. Results: The protocol was successfully completed in all participants, and all evaluated segments were evaluable. Interobserver and intraobserver agreement was excellent (kappa ≥ 0.90; ICC ≥ 0.85). Subjective aortic scores did not differ between HR groups, whereas several coronary segments had lower scores in the High-HR group. SNR, CNR, and VES were higher in the Low-HR group across all objectively assessed segments. Conclusions: These findings support the technical feasibility of integrated 5T non-contrast MRA in healthy volunteers and suggest that the subjective effect of higher HR is more evident in the coronary arteries than in the thoracic aorta, warranting further validation in patients with cardiovascular disease.