Processing and analysis of freeform implants obtained by additive manufacturing from MRI data

This work introduces the processing steps for manufacturing implants in substitution of human body parts based on additive manufacturing. The parts were designed with data from Magnetic Resonance Imaging (MRI) of a defective cranium and the deviation analysis of the cranial implants was carried out to characterize the process. At the initial stage, the results of MRI exam of a defective patient’s skull were downloaded from internet in DICOM format. Next, segmentation was applied to separate the soft tissues from the bone one of the MRI data. The cranium bone CAD model was created and implemented in a 3D printer to manufacture the part in polymeric material. The produced part was measured in a 3D laser scanner to collect a surface cloud of points and the quality was evaluated by comparing data points with CAD model. Descriptive statistical analysis was applied to determine the behavior of the deviations. A statistical filter was proposed to remove the outliers using the boxplot graph and the filtered sample was analyzed again to define the statistical parameters of the implant surfaces. The proposed methodology is recommended to characterize the deviations of cranium implants manufactured by additive manufacturing and the determined deviations allow the execution of cranial surgeries with a minimal intervention of the surgeon.