| 摘要 |
A method of forming an image representing fat distribution in a tissue based on the fat constitution from the tomographic data. The method comprises: the steps (D1 and D7) of obtaining two tomographic data by scanning a subject and a phantom under different tube voltages, said phantom being charged with a standard fat substance in addition to a bone-salt equivalent, the steps (D2 and D8) of detecting the CT value of each pixel in the whole or target region of the tomographic data as alpha wf (CT value of tissue including fat), the steps (D3 and D9) of detecting the CT value of the bone-salt equivalent to calculate the regression line between the CT value and the density of the bone-salt equivalent, thus defining the CT value as alpha nf (CT value of tissue not including fat), the steps (D4 and D10) of detecting alpha ff (CT value of standard fat substance), the steps (D5 and D11) of detecting the CT value of the blood part as alpha st (CT value of standard soft tissue substance), the steps (D6 and D12) of correlating each CT value with the formula alpha wt = alpha nf + beta .{ alpha ff- alpha st} (formula A), wherein beta serves as a fat rate parameter, the step (D13) of calculating the beta value of each pixel in the whole or target region of the tomographic data from the regression line and the formula A with attention paid to the fact that the density of the bone-salt equivalent remains constant even in the scanning under different tube voltages, and the step (D14) of forming the image based on the parameter beta . <IMAGE> |
