title: Design, construction, and testing of a stereo-photogrammetric tool for the diagnosis of fetal alcohol syndrome in infants.
abstract: Stereo-photogrammetry provides a low cost, easy to use, and noninvasive alternative to traditional facial anthropometry for the diagnosis of fetal alcohol syndrome (FAS). We describe such a system for use in obtaining 3-D facial information in infants. The infant is photographed using three high resolution digital cameras simultaneously while seated in a car seat. The subject's head is enclosed in a control frame during imaging. Technical system tests, namely control frame interpolation, camera calibration reliability, and camera synchronization delay assessments were performed. Direct and stereo-photogrammetric measurements of a doll were compared. Of 275 inter-landmark distances, 100% were within a 1.5 mm error range and 92.36% within a 1 mm error range when the two modalities were compared. Stereo-photogrammetry proved to be highly precise with submillimeter error in landmark placement for all landmarks on the doll. An intra-modality comparison of inter-landmark distances using two sets of images of five subjects showed the stereo-photogrammetric system to be highly reliable, with an average 72.25% of distances within a 1 mm error range. The system has potential for large scale screening and surveillance studies for FAS.
authors.affiliation: MRC/UCT Medical Imaging Research Unit, Department of Human Biology, University of Cape Town, 7935 Cape Town, South Africa.
authors.forename: Tinashe E M
authors.initials: TE
authors.lastname: Mutsvangwa
authors.forename: Julian
authors.initials: J
authors.lastname: Smit
authors.forename: H Eugene
authors.initials: HE
authors.lastname: Hoyme
authors.forename: Wendy
authors.initials: W
authors.lastname: Kalberg
authors.forename: Denis L
authors.initials: DL
authors.lastname: Viljoen
authors.forename: Ernesta M
authors.initials: EM
authors.lastname: Meintjes
authors.forename: Tania S
authors.initials: TS
authors.lastname: Douglas