Mimics 20

Given the rarity of complete and well preserved skulls of C. checchiai, the non-destructive method of CT scanning^{36 –39 (link)} was chosen to observe and analyse the internal anatomical features of the specimen sn813/lj. The fossil was scanned in its entirety in the coronal slice plane from front to back using a Philips Brilliance CT 64-channel scanner at M.G. Vannini Hospital (Rome). The scanning resulted in 670 slices with dimensions of 531 × 531 pixels. The slice thickness is 0.8 mm with an interslice space of 0.4 mm. The CT data were processed using OsiriX 5.5.2 and Materialise Mimics 20.0. The final 3D model was rendered with ZBrush 4R6.

CBCT was taken for both the flat and curved defects (Alphard3030, Asahi Roentgen Ind., Co. Ltd., Kyoto, Japan), under a voltage of 70 KV, current of 3 mA, voxel size of 0.30 mm, 154 mm × 154 mm FOV and 360° rotation. The images were exported as digital imaging and communication in medicine (DICOM) files. The DICOM files were converted into stereolithographic (STL) files using image processing software (Materialise Mimics 20.0, Materialise, Leuven, Belgium). Then, CAD software (3-MaticMaterialise Mimics 20.0, Materialise, Leuven, Belgium) was used to design the customized BCP and PMMA blocks, which were adapted to the defect model without a space for the cement between the surfaces of the block and the defect (Figure 1b).

The CT scan Digital Imaging and Communication in Medicine (DICOM) files were imported into Mimics 20.0 software (Materialise Inc., Belgium). Referring to the method described by Yang et al. and Xie et al. [12 (link), 15 (link)], a 3D model reconstruction was produced in which different fracture segments were distinguished in different colors. The 3D models were exported to 3-matic 12.0 software (Materialise Inc., Belgium). Using the sacrum and contralateral hip as a template, a mirrored hemipelvis was generated. All segments were manually reduced and automatically calibrated by “registration” to finish the reduction of the fracture.

Specimens were scanned using a SkyScan 1276 high-resolution micro-CT scanner (SkyScan, Kontich, Belgium). The parameters were set at 100 kV, 200µA, spatial resolution of 6 μm, and rotation step of 0.25°. The cross-section images were obtained through SkyScan CT analysis software (SkyScan, Kontich, Belgium). Mimics 20.0 (Materialise, Leuven, Belgium) was used for three-dimensional visualization analysis and the volumetric measurement of voids and filling materials (gutta-percha and sealer) for each specimen. The whole root was divided into 3 equal parts (coronal, middle and apical) with each 4 mm long. The volumetric percentages of voids in the whole root canal and each canal part were calculated separately. The distribution of voids was analyzed and compared among groups. Additionally, in groups E ∼ H, voids were classified as closed voids (confined in the filling material) and open voids (communicating with the root canal wall), and their volumetric percentages in the whole and each part of root canal were further calculated respectively. The volumetric percentage of voids (total, closed or open) = volume of voids (total, closed or open) / (volume of total voids + volume of fillings) * 100%. To avoid observer bias, the above analysis and calculation processes were independently conducted by a single experienced examiner .

The 3D geometry of coronary arteries and plaques was reconstructed from the CCTA images using the software MIMICS 20.0 (Materialise N.V., Belgium). The reconstruction method was semiautomatic, using the Coronary Segmentation Tool of Mimics Medical Suite. Firstly, the position of the aorta was marked. Then, with start and end points marked on the CCTA image dataset, an arterial segment can be automatically reconstructed with the result saved in an independent set (a “mask” in MIMICS). For the left coronary artery tree, artery segments were extracted from the left main coronary artery (LM) to major branches, including the left anterior descending artery (LAD) and left circumflex artery (LCX), and, finally, the distal branches. The small branches (diameter <1 mm, or blurred structure) were trimmed off. The left coronary artery tree was derived by connecting artery segments using the union operation of different sets.

Sixty-four-row contrast-enhanced volumetric CT (Discovery CT750 HD; General Electric, Boston, MA, USA) data were used for reconstruction of 3-D subject-specific PA models in Mimics 20.0 (Materialize, Leuven, Belgium) and surface smoothing in 3-Matic 11.0 (Materialize, Leuven, Belgium). Figure 1 shows the lateral and anterior views of the 3-D-reconstructed PA geometries of these 20 patients.
The maximum diameter of the main PA (D_MPA), left PA (D_LPA), and right PA (D_RPA) was measured. Subject-specific aorta models were reconstructed to obtain the maximum diameter of the aorta (D_AO). These vascular parameters were normalized by BSA to control for age-related deviation. The D_MPA/D_AO and D_MPA/D_(LPA+RPA) ratios were calculated to compare morphologic differences among different vessel segments.