Three dimensional reconstruction of thigh muscle groups by computer graphics

The purpose of this study is to develop the non-invesive method for three dimensional analysis of knee extensor and knee flexor muscle groups of the thigh part in human subjects. Our system consisted of magnetic resonance imaging (MRI) to get cross-sectional images of muscle and a computer graphics system which reconstructs three dimensional image of each muscle. The subjects chosen for this study were four healthy male adults, aged from 21 to 30 years. MRI scan was carried out from head of the femur to the upper border of the patella along thigh. Three dimensional (3 D) muscular image was reconstructed based on the data from MRI. Referring to the anatomic feature, contour information of knee extensor muscles (KEM) and knee flexor muscles (KFM) was identified on MRI and those muscles were reconstructed to 3 D images using the computer graphics system. This system also provided information on the quantitative volume and cross-sectional area (CSA) of each muscle. The structure of each muscle of KEM and KFM was displayed by a wireframe model or a surface model on the CRT. It was revealed that 3 D muscular images of the surface model using coloring and shadowing were highly effective to understand their shapes and relative location of muscles. CSA and volume of KEM were 86.84±8.38 cm2 and 2044.25 ±168.28 cm3 and those of KFM were 38.48±5.90 cm2 and 751.95±50.56 cm3 respectively. These results indicate that not only the anatomical information but also the volume and maximum CSAs of KEM and KFM can be measured quantitatively by this method using three dimensional analysis.