Additional Methods to Analyze Computer Tomography Data for Medical Purposes and Generatively Produced Technical Components

Abstract

The result of a computer tomography (CT) record is an image layer stack, which can be applied for medical diagnostic purposes, as well for virtual 3D object representation (e.g. for a skull bone) depending on the used threshold values. Based on these representations, medical 3D objects could be easily produced by generative manufacturing processes. The additive manufacturing of individual implants is also based on the use of CT data for the representation of the remaining bone. This knowledge was further used for the evaluation of industrial CT data.For technical applications, the industrial computer tomography becomes more and more important. Compared with devices from the medical area, industrial CT devices have a significantly higher radiation power and a much higher resolution. Thus, these data are not only suitable for the reconstruction of a 3D model in the sense of reverse engineering, but also for the inspection of components of metal workpieces (density differences, cavities, joint connection). The known CT evaluation procedures from medical use have been qualified and further modified in the research group. The developed software solution allows the generation of free-form sections through a layer image stack e.g. to evaluate the quality of a soldered connection in a tube. This procedure is also suitable to detect and determine density differences and the detachment of individual layers of a generative produced component. The topic is illustrated by selected practical examples.

3D printing of patient-specific implants for osteochondral defects: workflow for an MRI-guided zonal design

“…In addition to the implant design and generation, we presented a novel strategy for an optimized, bidirectional CAD/ CAM workflow (Fig. 4a): The main advantage of the CTinA software tool is the bidirectional interface [3,37] from the MRI data to the CAD system, which allows full freedom for reversibility and correction of previous editing steps. Thus, no information is lost during additional import/export steps between different software tools.…”

“…AM methods enable realization of a patient-specific design of implants or tissue-substituting structures. Certain techniques already allow the use of data applied for Digital Imaging and Communications in Medicine (DICOM data) from clinical imaging such as computed tomography (CT) or magnetic resonance imaging (MRI) [1] for the design of metal implants for bone replacement [2,3]. Methods such as selective laser sintering/melting are able to consider a pre-defined individual geometry and can contribute tremendously to any biomedical application [4].…”

“…This workflow should be easily transferable to other material combinations besides the model system selected. In addition to commercially available software solutions, we hoped to extend the applicability of a recently developed software tool CT data in CAx product development Applications (CTinA) [3,37] toward use for data obtained from MRI instead of CT.…”