Reference Korean human models: Past, present and future

Tomographic models provide currently the most realistic representation of human anatomy for radiation dosimetry calculation since they are based on medical tomography data obtained from a real human subject. Since the dose distribution in a body is affected by the physical and anatomical characteristics of the body, it is worthwhile for each racial group to have its specific human model. The project on “Formulation of the Reference Korean for Radiation Protection Purpose” has been performed by the authors since 1999. The construction of the reference Korean tomographic model was an essential part of the project. Three male models (KORMAN, KTMAN1 and KTMAN-2), and one female model (KORWOMAN) have been developed from tomography data of typical Korean healthy volunteers. The male and female subjects whose body dimension was close to average Korean values were recruited for this work. This article was intended to introduce several techniques and results accumulated at the moment. Acquisition and manipulation of medical tomographic images, CT (computed tomography) and MR (magnetic resonance), and semi-automated segmentation of organs and tissues from the images were explained. Mass of organs and tissues of the resulting Korean models were tabulated, and compared with those of Korean and Caucasian reference data. The selected results of organ dose conversion coefficients computed using Monte Carlo method were presented, and compared with those from reference Caucasian stylized model. Four Korean models are just “typical” Korean models, not “reference” models yet. In order to establish the reference Korean models, three requirements should be satisfied: body dimension and organ mass should be closer to Korean average values, voxel resolution should be so high as to represent small organs and tissues, and organ segmentation should be more sophisticated and automated. To address these requirements, 4 th male tomographic model is being constructed from whole body sectional photographs with the vertical interval of 0.2 mm, which were obtained by medical doctors in Ajou University. The authors are convinced that faster computing machine, advanced whole body scanning modality, and automated segmentation techniques will accelerate a variety of applications.