The overarching goal of this project is the development of a novel computed tomography imaging system allowing for an analysis of the knee cartilage and menisci under weight-bearing conditions. The articular cartilage deformation under different weight-bearing conditions reveals information about abnormal motion patterns, which can be an early indicator for arthritis. This can help to detect the medical condition at an early stage.

To allow for a scan in standing or squatting position, we opted for a C-arm CT device that can be almost arbitrarily positioned in space. The standard application area for C-arm CT is in the interventional suite, where it usually acquires images using a vertical trajectory around the patient. For the recording of the knees in this project, a horizontal trajectory has been developed.

Scanning in standing or squatting position makes an analysis of the knee joint under weight-bearing conditions possible. However, it will also lead to involuntary motion of the knees during the scan. The motion will result in artifacts in the reconstruction that reduce the diagnostic image quality. Therefore, the goal of this project is to estimate the patient motion during the scan to reduce these artifacts. One approach is to compute the motion field of the knee using surface cameras and use the result for motion correction. Another possible approach is the design and evaluation of a biomechanical model of the knee using inertial sensors to compensate for movement.

After the correction of the motion artifacts, the reconstructed volume is used for the segmentation and quantitative analysis of the knee joint tissue. This will give information about the risk or the progression of an arthrosis disease.