Clinical evaluation of patient misalignment during CT scans for computer assisted implantology - a new approach for compensation

摘要

Computer assisted implantology relies on good CT data. Therefore a strict protocol for acquiring the CT scan has to be adhered to. Most errors are introduced by misalignment and movement of the patient during scanning. We introduce a new method in terms of software algorithms and of clinical protocol changes, which allows for an optimal patient positioning to reduce movement artefacts and for compensating patient positioning misalignments. After CT scanning a 3D volume data set is reconstructed from DICOM slices. Then the user moves an 3D template of a jaw arc and standard dental planes (occlusion/median/frontal) interactively through the data set to define its optimal position (Fig. la-c). This is subsequently used for compensating all alignment errors and for initialising standard views when reconstructing secondary views, e.g. 'cross sectionals'.