Contrast-enhanced magnetic resonance angiography of the great arteries in patients with congenital heart disease: an accurate tool for planning catheter-guided interventions

Background: Catheter-guided interventions are increasingly used for relief of lesions in patients with congenital heart disease. Exact anatomical imaging with measurement of the vascular structures is crucial in the planning of such interventions. This can be provided non-invasively and without radiation by contrast-enhanced MR angiography (CE-MRA). Aim: To evaluate the accuracy of the measurements of the vessels obtained by CE-MRA in comparison to those obtained by conventional X-ray angiography (XRA). Methods: Measurements of the diameters of aorta and pulmonary arteries were performed retrospectively and blinded on the CE-MRA and XRA images, in comparable locations. The limits of agreement between the two methods were calculated. Results: Twenty-one CE-MRA and XRA were performed in 20 children with congenital heart disease, median age 4years (1day-13years), weight 18kg (3.2-74kg). The time interval between CE-MRA and XRA was 2.6 ± 2.3months. A total of 98 measurements, 38 of the aorta and 60 of the pulmonary arteries were performed on the images obtained by each technique. The correlation between CE-MRA and XRA measurements was excellent, r=0.97, p < 0.0001. The mean difference between the two techniques was 0.018 ± 1.1mm; the limits of agreement −2.14 and + 2.18mm. Similar agreement was found for measures of the aorta (r=0.97, mean difference 0.20 ± 1.08mm) and of the pulmonary arteries (r=0.97, mean difference 0.048 ± 0.89mm). Conclusions: CE-MRA provides accurate quantitative anatomical information, which highly agrees with XRA data, and can therefore be used for planning catheter-guided procedure