How We Convert CT Scans into Patient-Specific 3D Printed Models

July 18, 2026

In contemporary orthopedic surgery and medical training, two-dimensional cross-sectional imaging poses challenges for visualization of spatial relationships in three planes. Although multi-planar reconstruction (MPR) and 3D rendering on PACS screens have considerable value, they do not offer any tangible experience with tactile sensation and real depth perception.

The trend towards the use of physical, patient-specific 3D biomodels is becoming increasingly popular in preoperative planning and anatomical education. Here at Pegasus Prints Bharat, we employ an extensive engineering process to transform radiological images into highly accurate 1:1 anatomical models.

The Digital-to-Physical Translation Process

In order to translate raw X-ray absorption data into an accurate physical representation, strict attention must be paid to the data integrity process. Any misstep along the way may lead to artifacts or geometric errors in translation.

1. DICOM Image Acquisition and Data Integrity:Input Specifications.

The process starts with high-quality DICOM images (Digital Imaging and Communications in Medicine) images, which have been acquired using computer tomography (CT). To ensure maximum geometric accuracy, particularly in very articulated areas such as the midfoot, wrist, or pediatric spine, we use thin slice imaging (less than or equal to 1.0 mm slice thickness) in a 512x512 matrix.

2. Density-Based Segmentation and Thresholding:Hounsfield Unit (HU) Selection.

The image is processed through medical imaging software to threshold the images based on the targeted structures. In cases of orthopedic imaging, we select a certain Hounsfield Unit (HU) threshold, usually above 226 HU for cortical bone, in order to segment the bony elements away from the soft tissue, muscle, and vasculature around it.

3. Isosurface Creation and Mesh Optimization:STL/OBJ Optimization.

The ROI after segmentation is turned into a 3D surface mesh, which takes the form of an STL or OBJ file. The unoptimized meshes in medical applications exhibit noise and stepping at slice junctions due to slicing. Non-manifold mesh repair, mesh decimation, and Laplacian smoothing techniques are applied to reduce the file size and remove artifacts from slicing without violating any tolerances of the underlying geometry.

4. Slicing Setup and Material Matrix:Tool Pathing.

The mesh is then imported into the slicing engine that creates G-code. Physical characteristics of materials are chosen for optimal performance according to the requirements of the clinical use case: we use advanced PLA or PETG filaments. The optimal print orientation, tool pathing and infill percentage (from 15% up to 100%, depending on whether tactile suturing or screw-fixation is tested) along with water soluble or break-away supports are provided to protect the bone-like geometry.

5. Precision Manufacturing & Quality Control : Post Manufacturing & Validation.

The models are manufactured in a layer-by-layer process using high resolution additive manufacturing technology. Once manufacturing is done, the support structures are removed mechanically or by chemical means. Post manufacturing involves microabrasion or chemical finishing resulting in a sterile-ready/learning ready model. Each model goes through a cycle of checking its dimensions from digital to physical for 100% 1:1 ratio.

Orthopedic Clinical Data Fidelity

In pre-surgical planning where there is need to plan for trajectory of bone fixation and/or sizing specific cutting guides, dimensional inaccuracy is not an option. Our manufacturing process guarantees sub-millimeter dimensional accuracy of the physical model with respect to the digital DICOM data set.

Clinical Uses and Teaching of Medicine

The physical biomodels reduce the mental effort of interpreting the two-dimensional screens into three-dimensional thinking and have definite benefits within both institutional and clinical settings:

Pre-operative Planning and Simulation: Allows for the tangible manipulation of the reconstruction plates, the trial placement of implants, and the visualization of difficult surgical paths before any first incision is made. This effectively decreases the intraoperative duration.

Medicine and Residency Teaching: Supplies the trainees with realistic specimens of pathological conditions (e.g., a specific tumor border or rare congenital anomalies) that are not available in traditional anatomic laboratories.

Patient Informed Consent: Functions as a touchable educational tool, which facilitates the understanding of a specific pathology and its risks to the patient.

Partner With Pegasus Prints Bharat

Integrate the use of highly precise anatomical models in your operating rooms, research labs, or courses. Choose from our selection of pre-designed anatomical collections or upload anonymized patient data sets to order customized products through website for institutional purchases