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A New 3D Topographic Device for Monitoring Scoliosis Progression in Children. Stud Health Technol Inform 2012;176:485



Pubmed ID



Introduction: The degree of curvature of the spine is defined by the Cobb angle measured by 2-D postero-anterior full length spine radiographs. Cumulative exposure to radiation from diagnostic radiographs increases patient risk for cancer development. Less exposure to radiation is desired for the patient's health and there is a need for non-invasive tools to measure spine deformity. Objectives: The aims of this study are to determine the reproducibility of the newly developed 3D Milwaukee topographic system (MTS) through inter- and intra-rater measurements, calculate the correlation between the 3D angle obtained by the device and the Cobb angle measured with radiographs, and establish the mean value of the normal range of 3D image parameters. Materials and methods: Two population groups are involved in this study. The control group has a normal patient population of ten children aged 6-18 years. The scoliosis group has twenty children with idiopathic scoliosis (IS) aged 6-18 years and with a range of Cobb angles. The MTS is composed of two wide-angle optical cameras, two electro-magnetic sensors, a light, a software package, a positioning frame, and a desktop computer. The device requires 4 scan sweeps (3 vertical and 1 horizontal) for each subject (5 seconds). Four measurements are performed by two investigators, alternatively. Reliability for the device is measured with intra-class correlation coefficient (ICC) controlling subject effect in a stratified model. Pearson correlations are calculated as well as mean values and confidence intervals for each metric. Results: A Pearson data analysis shows excellent intra-class correlation (ICC > 0.6) between investigators for 10 metrics, moderate ICC (ICC from 0.4 to 0.6) for 4 metrics, and poor ICC (ICC < 0.4) for 3 metrics, only for investigator 2 (P<0.05). A Pearson analysis of intra-investigator ICC demonstrated moderate to excellent ICC in almost all measured parameters (P<0.05). A Pearson correlation coefficient between the 3D angles obtained from the MTS and radiographs was calculated for the Cobb angle, kyphosis, and lordosis as 0.906, 0.675, and -0.014 with p-values of 0.000, 0.096, and 0.976 respectively. Conclusion and significance: The new MTS should be considered a reliable device because of the high intra- and inter-investigator values obtained from this study. It can be used as a desirable alternative to radiography to follow scoliosis progression.

Author List

Liu XC, Tassone JC, Thometz JG, Lyon RM, Tarima S, Lim CH, Paulsen LC


Sergey S. Tarima PhD Associate Professor in the Institute for Health and Equity department at Medical College of Wisconsin

jenkins-FCD Prod-486 e3098984f26de787f5ecab75090d0a28e7f4f7c0