3D-shaded surface rendering of gadolinium-enhanced MR angiography in congenital heart disease

Background. Gadolinium-enhanced three-dimensional (3D) MR angiography is a useful imaging technique for patients with congenital heart disease. Objective. This study sought to determine the added value of creating 3D sh aded surface displays compared to standard maximal intensity projection (MI P) and multiplanar reformatting (MPR) techniques when analyzing 3D MR angio graphy data. Materials and methods. Seventeen patients (range, 3 months to 51 years old) with a variety of congenital cardiovascular defects underwent gadolinium-e nhanced 3D MR angiography of the thorax. Color-coded 3D shaded surface mode ls were rendered from the image data using manual segmentation and computer -based algorithms, Models could be rotated, translocated, or zoomed interac tively by the viewer. information available from the 3D models was compared to analysis based on viewing standard MIP/MPR displays, Results. Median postprocessing time for the 3D models was 6 h (range, 3-25 h) compared to approximately 20 min for MIP/MPR viewing. No additional diag nostic information was gained from 3D model analysis. All major findings wi th MIP/MPR postprocessing were also apparent on the 3D models. Qualitativel y, the 3D models were more easily interpreted and enabled adjacent vessels to be distinguished more readily. Conclusion. Routine use of 3D shaded surface reconstructions for visualizat ion of contrast enhanced MR angiography in congenital heart disease cannot be recommended. 3D surface rendering may be more useful for presenting comp lex anatomy to an audience unfamiliar with congenital heart disease and as an educational tool.