Introduction
Three-dimensional (3D) printing technology, which was defined as the
process of creating solid, 3D objects from a collection of images in the
form of a digital file, has been applied to the medical field and played
an increasingly significant role in the diagnosis and treatment of
cardiac diseases due to the continuous advancement of materials, medical
imaging technology, and the vigorous development of individualized
cardiac therapy1. As a bridge between physical and
imaging data, the 3D printed models can display the complex intracardiac
pathological anatomy with a more comprehensive, intuitive way and
provide preoperative exercise opportunities for individualized surgery
as well. Scholars have reported the application of 3D printing
technology in the diagnosis and treatment of cardiac disease for such
procedures as valve replacement and formation, complex congenital heart
disease 2,3 .
CT (computed tomography) is the mainstream data source of 3D printing
technology, but it may involve intravenous contrast and ionizing
radiation, the image quality is affected by heart rate4,5. Three-dimensional echocardiography is another
imaging modality with strong linear correlation with CT,new
echocardiographic transducers and advanced software and hardware have
optimized 3D echocardiographic images. Moreover, because of its
portability, safety, none radiation exposure, high spatial and temporal
resolution, superior ability to image fast moving
structure6, involves no sedation or general
anesthesia, echocardiography images may be more advantageous as the data
source in the procedure of printing 3D models7,8.
Atrial septal defect (ASD) is one of the most common congenital heart
diseases, accounting for 20% to 30% of adult congenital heart disease.
As the effective therapeutic methods, ASD occlusion has been widely
applied. Imaging data provided by different techniques always play a
significant role in the diagnosis and treatment of ASD. However, they
are lack of comprehensive, real touch and visual experience that can be
obtained by a patient-specific physical model 9. 3D
printed models based on echocardiography images may show the anatomical
details of the pathological structure clearly and act as the guidance
for individualized treatment.
Feasibility and fidelity are prerequisites and guarantees for the
ultrasound-derived 3D printing ASD models to be fully utilized. Whether
it can highly retain and replicate the original image information is the
basis for the 3D printed model to fully combine the advantages of
three-dimensional transesophageal echocardiography (3D-TEE images) and
3D printing technology. Only when fidelity was guaranteed will the 3D
printed model considered as an accurate measurement tool as the
conventional 3D-TEE images and provide visual and tactile perception
well. However, steps of creating 3D ASD model from an echocardiogram to
a tangible 3D model are so complex that errors may be brought in, there
is a risk of introducing design errors and manipulating the original
source data in order to generate oversimplified 3D
models10. Focused on process-oriented outcomes, which
means analysis the parameters in each step of the printing process, is
an efficient method to assess the fidelity of the 3D models in some
studies2,11.
This study aims to evaluate the feasibility and fidelity of 3D printed
ASD models from echocardiographic images. Moreover, our study intends
providing evidence for potential applications of 3D printing technology
based on echocardiographic data in ASD therapy, especially
individualized ASD occlusion.