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 p otential of creating polymer hard copies of echocardiographic data using st ereolithography. 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 echocardiog raphic data could enhance our spatial perception of cardiac anatomy and pat hology. METHODS Hard-copy replicas of water-filled latex balloon phantoms (n = 7) a nd porcine liver specimens (n = 12) were generated from echocardiographic i mages using stereolithography (computerized laser polymerization). In addit ion, we created 24 models of the mitral valve from 12 transesophageal studi es (normal = 6, mitral stenosis n = 4, prolapse/flail leaflet n = 8, annula r dilation n = 2, leaflet restriction n = 2 and following mitral valve repa ir 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 dimens ions (r = 0.99, SEE = 0.16 cm, mean difference = 0.03 +/- 0.16 cn) between phantoms and their corresponding replicas. Visual and tactile examination o f 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 feas ible and provides tangible polyacrylic models that are true to scale, shape and volume. Such models offer accurate depiction of mitral valve anatomy a nd pathology in patients studied with transesophageal echocardiography. Thi s technique could have substantial impact on diagnosis, management and preo perative planning in complex cardiovascular disorders. (C) 1999 by the Amer ican College of Cardiology.