Construction Of Deformable Statistical Trunk Atlas Of Chinese Human

Digital human anatomy atlas has been an emerging research field since 1990 s.It hasbeen widely used in various areas including virtual surgery,physiological modeling and simulation,mechanical education and radiological simulation,computer diagnosis system,medical education and ergonomics.The development of medical imaging techniques provides image data for the construction of digital human anatomy atlas.In the last decade,large number of Chinese people have taken PET/CT health screening.In this study,we construct digital atlas of trunk region based on 79 sample sets,which will provide the technical foundation for the further construction of statistical atlas based on larger sample set.Compared to the traditional digital human atlases based on single or several subjects,the atlases of this study include anatomical information of inter-subject organ shape deformation across the population.The obtained models will provide data support for the Chinese anatomical morphology and knowledge database.The construction process of digital human atlas in this study was divided into three stages.The first stage is to segment the major organs and tissues including muscles,fat,skeleton,heart,lungs,liver,spleen and kidneys from the trunk region.The medical images were collected from four large hospitals in China.After organs segmentation,all the organs' segmentation results were converted to triangular surface mesh for the template matching in the next step.The second stage is point cloud matching.The correspondence of each vertex between the training subjects was obtained by registering the organs meshes of the reference anatomy model to each subject.The reference anatomy model of whole body male and female anatomy were purchased from the web.The last stage is to construct statistical shape model based on the registration results,then we obtain the inter-subject anatomical variations.From the result of the statistical shape model,we found the largest inter-subject deformation is from height,the second largest deformation is from the changes of abdominal volume which is caused by accumulation of subcutaneous fat and abdominal fat.The third largest inter-subject deformation is the motion of lungs and thoracic muscles caused by respiration.We also used z-scores to evaluate the deviation of model from normal Chinese organs weight.By comparison,we found the average mass of major organs(heart,liver,pancreas,kidneys,lungs,spleen and vertebras)in our model were less than twice plus orminus standard deviation.By now,the size of our sample set has reached a preliminary statistical significance.The outcomes of shape modeling show the change rule of anatomical morphology of Chinese population samples.we are still collecting and segmenting more PET/CT images.As the sample size keeps growing,more statistically significant results will be presented.Dedicated atlases will be constructed for each gender in the future.