Abstract
Purpose: 4D-visualization of the human upper arm based on sequential or dynamic MRI may be useful in functional orthopedic disorders and surgical planning. A cascade of 4D-visualization approaches have been applied including deformation of the soft tissue surfaces and muscular
contraction. Skeletal structures and the epifascial tissue comprising vascular structures are included in the 4D-visualization.
Methods: Sequential MRI (T2-weighted spin echo sequences) scans of a healthy volunteer's upper
extremity were obtained. The skeletal, muscular, and epifascial tissues were segmented. For 4Drendering
of the elbow joint, surface models of the humerus, the ulna, and the radius, were displaced with respect to the movement. For 4D-visualization of the soft tissue, the processed MRI data were subjected to highly transparent direct volume rendering with special two tone transfer
functions designed with regard to the application, e.g., muscular inner structure or fasciae. For
rendering of time dependent behavior, the visualization was continuously updated.
Results: Continuous deformation of muscular inner structure and fasciae, and dynamics of muscle
fibers could be differentiated in 4D-visualizations of the upper extremity. Using sequential MRI
scans, this work was constrained by the high sagittal slice thickness and separation.
Conclusion: 4D-visualization of the upper extremity based on sequential MRI is feasible and
provides a realistic appearance in comparison with anatomical drawings and preparations. The
4D-visualization method may be useful for detecting and monitoring muscular pathologies and
lesion
Kober, C