Repeated 3D coronary MR angiography with navigator echo gating: Technical quality and consistency of image interpretation

The purpose of this study was to evaluate the technical quality of 3D coron ary MR angiography (CMRA) with navigator echo and the consistency of image interpretation in repeated imaging sessions. Fourteen subjects underwent CM RA, 10 of whom were imaged twice. The coronary arteries (96 segments) were analyzed twice for hemodynamically significant stenoses. Signal-to-noise an d contrast-to-noise ratios varied considerably between the two imagings. Fa t saturation was poor or satisfactory in 37%; in 15% of the slabs, the seve rity of artifacts was moderate; and the overall quality was good to excelle nt in only 42% of the imagings. The intraobserver reproducibility was good (kappa = 0.54), but the consistency of interpretation for repeated CMRA was only satisfactory (kappa = 0.43). Sensitivities of 84 and 84% and specific ities of 70 and 62% were obtained for the two readings. Although the reprod ucibility of image reading is good, 3D CMRA with navigator echo provides on ly fair technical consistency, and the frequently compromised image quality impairs the clinical utility of this technique.