Free-breathing, blood-flow-independent, three-dimensional relaxation-enhanced angiography without contrast and triggering (REACT) for aorta measurement and diagnosis in patients with aortic disease: a comparison with computed tomography angiography.

BACKGROUND: Patients with aortic diseases require precise quantitative assessment and long-term regular follow-up monitoring. Computed tomography angiography (CTA) is widely used for evaluation; however, its application is limited by ionizing radiation exposure and iodinated contrast administration. This study aimed to evaluate the feasibility and accuracy of a novel technique-free-breathing, blood-flow-independent, three-dimensional (3D), relaxation-enhanced angiography without contrast and triggering (REACT)-for the assessment of aortic disease as an alternative to CTA. METHODS: A total of 101 patients were included in this single-center prospective study, comprising 54 patients with aortic aneurysm (AA), 30 patients with aortic dissection (AD), and 17 patients who had previously undergone endovascular aortic repair (EVAR). All the patients underwent both REACT and CTA examinations. An intraindividual assessment was performed by measuring aortic diameters at 11 levels. Overall image quality was evaluated independently by three readers using a 5-point scale. Additionally, for AA, AD, and EVAR, diagnostic confidence using different criteria was assessed. Differences and consistency between REACT and CTA were analyzed. RESULTS: There was no significant difference in aortic diameter assessment between REACT and CTA (all P>0.05). REACT had lower overall image quality than CTA (3.77±0.52 vs. 4.29±0.57, P<0.001). REACT showed comparable diagnostic confidence to CTA for the assessment of aneurysm morphology and intraluminal thrombus (ILT). However, REACT showed lower diagnostic confidence than CTA for AD and EVAR evaluation. Interobserver consistency was high for the two imaging methods in subjective scoring (range, 0.67-0.88). CONCLUSIONS: REACT can accurately display aortic morphology and is valuable for diagnosing aortic disease, especially AA. It could serve as an alternative to CTA for repeated aortic imaging.