Technical limitations and error propagation in the 3D printing pipeline for congenital heart disease: an integrative review—a narrative synthesis

Figures

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  Figure 1. Central illustration: flowchart summarizing different error types for major milestone steps within modelling workflow.

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  Figure 2. Image showcasing a post-operative Rastelli-Senning patient with dynamic obstruction of the outflow pathway. This model was created from a diastolic image; however, on echocardiography, the pathway was seen to be further narrowed during systole from septal muscle contraction. The empty space with the label highlights where the ventricular septum would be.

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  Figure 3. Two segmented images of a patient, one from an MRI (A) and one from a CT scan (B). It is noticeable that the level of detail in the trabeculations of the ventricles and finer details is more appreciable in the segmentation from the CT scan (B).

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  Figure 4. Figure depicting cardiac MRI that showcased a resampling error during DICOM export, leading to poor generation of the coronal view due to the reference image set being only the axial scan.

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  Figure 5. A mask-level comparison of two different operators undertaking a thresholding task for the same image set, with mask 1 as the reference mask from the primary operator and the as the secondary operator (A). Panel (B) showcases the difference in masks at a visual level, with the green mask indicating the union area of both operators, the blue mask indicating the area under-segmented by operator 2, and the red area indicating the area over-segmented by operator 2.

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  Figure 6. An example of a case with a double outlet right ventricle and ventricular septal defect where, during part generation from the mask, software approximations of the internal surface during hollowing can lead to inadvertent smoothing of the surface, making the defect appear potentially wider than it is.

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  Figure 7. An example of a case where a patent arterial duct and aortic arch were printed from a segmented heart, but during removal of support material from the print, it led to distortion and damage to the walls; stringing and material warping are also seen given the thin nature of the wall in a neonatal segmentation.

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  Figure 8. A case of congenitally corrected transposition of the great arteries and ventricular septal defect where there was a question regarding the ventricular septal defect size, relation to the aorta, and a chordal insertion from the left-sided atrioventricular valve. The first two questions could be answered with the segmentation; however, the question of the chordal insertion could not be answered due to the inability to clearly depict the subvalvular apparatus using cross-sectional imaging and the inability to integrate echocardiographic data within the segmentation at the time.