Clinical research Reproducibility of 3D free-breathing magnetic resonance coronary vessel wall imaging

Aims Although the coronary artery vessel wall can be imaged non-invasively using magnetic resonance imaging (MRI), the in vivo reproducibility of wall thickness measures has not been previously investi-gated. Using a refined magnetization preparation scheme, we sought to assess the reproducibility of three-dimensional (3D) free-breathing black-blood coronary MRI in vivo. Methods and results MRI vessel wall scans parallel to the right coronary artery (RCA) were obtained in 18 healthy individuals (age range 25–43, six women), with no known history of coronary artery disease, using a 3D dual-inversion navigator-gated black-blood spiral imaging sequence. Vessel wall scans were repeated 1 month later in eight subjects. The visible vessel wall segment and the wall thickness were quantitatively assessed using a semi-automatic tool and the intra-observer, inter-observer, and inter-scan reproducibilities were determined. The average imaged length of the RCA vessel wall was 44.5+ 7 mm. The average wall thickness was 1.6+ 0.2 mm. There was a highly significant intra-observer (r 0.97), inter-observer (r 0.94), and inter-scan (r 0.90) correlation for wall thickness (all P, 0.001). There was also a significant agreement for intra-observer, inter-observer, and inter-scan measurements on Bland–Altman analysis. The intra-class correlation coefficients for intra-observe