Stereolithographic biomodeling to create tangible hard copies of cardiac structures from echocardiographic data - In vitro and in vivo validation

OBJECTIVES This study investigated the feasibility, accuracy and clinical potential of creating polymer hard copies of echocardiographic data using stereolithography. BACKGROUND Three-dimensional (3D) echocardiography has so far been limited by the need to display reconstructed 3D objects on a two-dimensional screen. Thus, tangible stereolithographic polymer models created from echocardiographic data could enhance our spatial perception of cardiac anatomy and pathology. METHODS Hard-copy replicas of water-filled latex balloon phantoms (n = 7) and porcine liver specimens (n = 12) were generated from echocardiographic images using stereolithography (computerized laser polymerization). In addition, we created 24 models of the mitral valve from 12 transesophageal studies (normal = 6, mitral stenosis n = 4, prolapse/flail leaflet n = 8, annular dilation n = 2, leaflet restriction n = 2 and following mitral valve repair n = 2). RESULTS Excellent agreement was found for comparison of volumes (r = 0.98, SEE = 3.46 mm(3), mean difference = 0.25 +/- 3.33 mm(3)) and maximal dimensions (r = 0.99, SEE = 0.16 cm, mean difference = 0.03 +/- 0.16 cn) between phantoms and their corresponding replicas. Visual and tactile examination of mitral valve models by two blinded observers allowed correct depiction of mitral valve anatomy and pathology in all cases. CONCLUSIONS Stereolithographic modeling of echocardiographic images is feasible and provides tangible polyacrylic models that are true to scale, shape and volume. Such models offer accurate depiction of mitral valve anatomy and pathology in patients studied with transesophageal echocardiography. This technique could have substantial impact on diagnosis, management and preoperative planning in complex cardiovascular disorders. (C) 1999 by the American College of Cardiology.