Visijet pxl

The 3D-printed hydroxyapatite scaffolds (3D-printed HA) were fabricated as described previously^{16 (link)}. First, calcium sulfate-based powder (Visijet PXL, 3D Systems, USA) was loaded into the powder-based three-dimensional printing machine (PROJET 160, 3D Systems, USA) to print the closed disc-shaped specimens with 5 mm in diameter and 2 mm in thickness without any designed pore channels in the specimen using a commercial liquid binder (Visijet PXL clear, 3D Systems, USA). Regarding the printing parameters, the layer thickness was set at 0.1 mm, and the disc sample was oriented to build the thickness in the Z direction. Next, the printed samples were phase transformed to hydroxyapatite using the dissolution–precipitation principle by immersing them in a 1 M disodium hydrogen phosphate solution (Sigma Aldrich, USA) at 100 °C for 24 h. Afterward, the scaffolds were cleaned with distilled water, oven-dried, and sterilized using an ethylene oxide sterilizer.

According to the STL-formatted 3D-IDM provided as the printing template, a 3D printer (ProJet CJP 260C, 3D Systems Inc., USA) equipped with double print heads was used in the physical additive manufacturing. Core material named VisiJet PXL (3D Systems Inc., USA) was spread in thin layers over the build platform with a roller. After each layer of core material was spread, color binder was selectively jetted from inkjet print heads over the core layer, causing the core to solidify. The build platform lowered with each subsequent layer of core and binder until the high-resolution model was complete.
The maximal printable size of this printer is 236 × 185 × 127 mm, which can satisfy the full-size fabrication demand of kidney perfectly (Fig. 2). A video demonstrating 3D-IDM demonstration and 3D-IPM fabrication accompanies this article (Additional file 1: Supplemental video).Fig. 2

The distinct spatial relationship between the tumor and the nearby vital structures, including renal pelvic, ureter and renal vascular network, can be presented intuitively (A–C). The intrarenal sophisticated vasculature featured the targeted arterial branch can be presented in the life-sized 3D-IPM by using different colors (D–F)

A set of CT images of the hip of a 22-year-old man with suspected osteoid osteoma on the left femur neck was used to design a completely symmetric hip model containing the pelvis and proximal femur.
The CT scan of the pelvis and proximal femur was reconstructed into a 3D model using MIMICS 20.0 (Materialise, Leuven, Belgium). The right hemipelvis, containing the proximal femur, was mirrored to the pelvic sagittal plane and fused to the right hemipelvis itself to form a symmetric hip model^{45 (link)}. The distance from the center of the femoral head to the sagittal plane was measured using 3-matic modeling software (Materialise, Leuven, Belgium) at 80.23 mm.
The 3D image was 3D printed (Projet360, 3D Systems Inc., Rock Hill, CA, USA) using plaster material that absorbs radiation (VisiJet PXL, 3D Systems Inc.). The accuracy of the output was within 100 μm, according to the information provided by the manufacturer.