PURPOSE: To validate the feasibility of real time kinematography with four-dimensional (4D) dynamic functional wrist joint imaging using dual source CT. MATERIALS AND METHODS: Two healthy volunteers performed radioulnar deviation and pronation-supination wrist motions for 10 s and 4 s per cycle in a dual source CT scanner. Scan and reconstruction protocols were set to optimize temporal resolution. Cine images of the reconstructed carpal bone of the moving wrist were recorded. The quality of the images and radiation dosage were evaluated. RESULTS: The 4D cine images obtained during 4 s and 10 s of radioulnar motion showed a smooth stream of movement with good quality and little noise or artifact. Images from the pronation-supination motion showed noise with a masked surface contour. The temporal resolution was optimized at 0.28 s. CONCLUSION: Using dual source CT, 4D cine images of in vivo kinematics of wrist joint movement were obtained and found to have a shorter scan time, improved temporal resolution and lower radiation dosages compared with those previously reported.
Adult ; Artifacts ; Biomechanical Phenomena ; Carpal Bones/radiography ; Female ; Humans ; Nontherapeutic Human Experimentation ; Radiation Dosage ; Radiographic Image Interpretation, Computer-Assisted/methods ; Tomography, X-Ray Computed/*methods ; Wrist Joint/*physiology/*radiography

OBJECTIVETo investigate three-dimensional kinematics of the superficial and deep portion of triangular fibrocartilage complex (TFCC) in different parts of the forearm rotation.

METHODSSix wrists of 6 volunteers were used to obtain CT scans at different positions of the wrist. The wrists were scanned from 90 degrees of pronation to 90 degrees of supination at an interval of 30 degrees. The 3-dimensional radius and ulna were reconstructed with customized software and changes in length of the superficial and deep portion of TFCC during forearm rotation.

RESULTSIn forearm pronation, the superficial dorsal portion and the deep palmar portion of the TFCC were tight. While the superficial palmar portion and the deep dorsal potion of the TFCC were lax. In supination, the changes in length of all these fibers were reverse.

CONCLUSIONSIn forearm rotation one portion fibers of dorsal TFCC and one portion fibers of palmar TFCC are tight, and this mechanism controls stability during DRUJ rotation.

Adult ; Biomechanical Phenomena ; Female ; Forearm ; physiology ; Humans ; Imaging, Three-Dimensional ; Male ; Pronation ; Radiography ; Radius ; diagnostic imaging ; Supination ; Triangular Fibrocartilage ; diagnostic imaging ; Ulna ; diagnostic imaging ; Wrist Joint ; diagnostic imaging ; Young Adult