title: Three-dimensional printing of intracardiac defects from three-dimensional echocardiographic images: feasibility and relative accuracy.
abstract: BACKGROUND
  With the advent of three-dimensional (3D) printers and high-resolution cardiac imaging, rapid prototype constructions of congenital cardiac defects are now possible. Typically, source images for these models derive from higher resolution, cross-sectional cardiac imaging, such as cardiac magnetic resonance imaging or computed tomography. These imaging methods may involve intravenous contrast, sedation, and ionizing radiation. New echocardiographic transducers and advanced software and hardware have optimized 3D echocardiographic images for this purpose. Thus, the objectives of this study were to confirm the feasibility of creating cardiac models from 3D echocardiographic data and to assess accuracy by comparing 3D model measurements with conventional two-dimensional (2D) echocardiographic measurements of cardiac defects.
  
  
  METHODS
  Nine patients undergoing 3D echocardiography were identified (eight with ventricular septal defects, one with three periprosthetic aortic valve leaks). Raw echocardiographic image data were exported anonymously and converted to Digital Imaging and Communications in Medicine format. The image data were filtered for noise reduction, imported into segmentation software to create a 3D digital model, and printed. Measurements of the defects from the 3D model were compared with defect measurements from conventional 2D echocardiographic data. Meticulous care was taken to ensure identical measurement planes.
  
  
  RESULTS
  Long- and short-axis measurements of eight ventricular septal defects and three perivalvar leaks were obtained. Mean ± SD values for the 3D model measurements and conventional 2D echocardiographic measurements were 7.5 ± 6.3 and 7.1 ± 6.2 mm respectively (P = .20), indicating no significant differences between the standard 2D and 3D model measurements. The two groups were highly correlated, with a Pearson correlation coefficient of 0.988. The mean absolute error (2D - 3D) for each measurement was 0.4 ± 0.9 mm, indicating accuracy of the 3D model of <1 mm.
  
  
  CONCLUSIONS
  Three-dimensional printed models of echocardiographic data are technically feasible and may accurately reflect ventricular septal defect anatomy. Three-dimensional models derived from 3D echocardiographic data sets represent a new tool in procedural planning for children with congenital heart disease.
authors: Division of Cardiology, Children's National Medical Center, Washington, District of Columbia; Sheikh Zayed Institute for Pediatric Surgical Innovation, Children's National Medical Center, Washington, District of Columbia. Electronic address: lolivier@childrensnational.org.
authors: Laura J
authors: LJ
authors: Olivieri
authors: Sheikh Zayed Institute for Pediatric Surgical Innovation, Children's National Medical Center, Washington, District of Columbia.
authors: Axel
authors: A
authors: Krieger
authors: Division of Cardiology, Children's National Medical Center, Washington, District of Columbia.
authors: Yue-Hin
authors: YH
authors: Loke
authors: Sheikh Zayed Institute for Pediatric Surgical Innovation, Children's National Medical Center, Washington, District of Columbia; Division of Cardiovascular Surgery, Children's National Medical Center, Washington, District of Columbia.
authors: Dilip S
authors: DS
authors: Nath
authors: Sheikh Zayed Institute for Pediatric Surgical Innovation, Children's National Medical Center, Washington, District of Columbia.
authors: Peter C W
authors: PC
authors: Kim
authors: Division of Cardiology, Children's National Medical Center, Washington, District of Columbia.
authors: Craig A
authors: CA
authors: Sable
mesh_terms: D003198:Computer Simulation; D019560:Echocardiography, Three-Dimensional / Q000379:methods*; D005240:Feasibility Studies; D006330:Heart Defects, Congenital / Q000000981:diagnostic imaging* / Q000473:pathology*; D006801:Humans; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D008953:Models, Anatomic; D008955:Models, Cardiovascular; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
keywords: 3D echocardiography; 3D model; Cardiovascular surgery; Congenital heart disease