RR-PO-0486

Wednesday 15:00, Palau de Congressos, Exhibition Hall  [Display No. 373]

MEASUREMENTS OF THE LIVING HUMAN LIMB VOLUME, MASS AND CENTER OF MASS USING PET TRANSMISSION SCANNING. Hidaka M, Itoh M, Kobayashi T, Oi N, Iwaya T; Division of Physical Therapy. Kohnan Hospital. Sendai. Japan. PURPOSE: The purpose of this study was to validate the estimations of the living human limb volume, mass and center of mass (COM) using positron emission tomography (PET) transmission scanning. RELEVANCE: Body segment masses and COMs are essential data for calculations of joint moments required in kinematic and kinetic analysis of human movement. SUBJECTS: Nine healthy males, aged 19-27 years, participated in this study. METHODS: Transaxial whole body images with slice thickness of 3.125 mm were obtained by PET transmission scanning, using a ^68Ge/^68Ga rod source. The volumes, masses, and COMs of left upper arm, forearm, hand, thigh, shank, foot and whole body were measured by counting pixel numbers of the transmission scanning images. The regions of interest were defined using an automatic threshold selection method. ANALYSES: The association between the values by PET transmission scanning and actual values was measured by correlation coefficient. The masses and COMs of limbs were compared with values reported by Dempster (1955). RESULTS: The limb volumes by transmission scanning and actual values by the water displacement method showed significant positive correlation. The masses and the COMs of the whole body by transmission scanning showed a significant positive correlation with actual values. Each mean mass ratios of forearm, shank and foot to whole body mass were in good agreements with values reported by Dempster respectively. The locations of COM of forearm, shank and foot were also similar to his values. CONCLUSION: We conclude that PET transmission scanning is a reliable method for estimating the living human limb volume, mass and COM.