|Budget Amount *help
¥3,200,000 (Direct Cost : ¥3,200,000)
Fiscal Year 2000 : ¥700,000 (Direct Cost : ¥700,000)
Fiscal Year 1999 : ¥600,000 (Direct Cost : ¥600,000)
Fiscal Year 1998 : ¥1,900,000 (Direct Cost : ¥1,900,000)
Purpose of this research is to develop a new method for true quantitation of tissue characteristics in contrast-enhanced CT with iodinated contrast medium by using compartment-model analysis. Following studies were performed.
1. Basic assessment to design a program for the compartment-model analysis
Correlation between myocardial contrast enhancement and presumed microscopic architecture of the tissue was assessed in cardiac CT.The results revealed that myocardial enhancement reflected relative volumes of vascular bed, interstitium and cellular components, and speed of transition of the contrast medium between vascular bed and interstitium.
2. Basic assessment to apply the compartment-model analysis for tumorous lesions
Correlation between contrast enhancement of mediastinal tumors and tissue characteristics was evaluated in thoracic CT.Degree of enhancement was consistent with presumed histo-patology of the tumors, indicating the analysis to be applicable to tumorous lesions.
ment and application of a program for the compartment-model analysis
The following program was developed ; dM/dt= A^*F+B^*M, A=(a^2/3/b)^*(a^*k2+b^*k1), B=-a^2/3/b^*k2 ; where, M : incremental CT# of the myocardium, F : CT# of cardiovascular lumen, a : vascular bed volume, b : interstitial volume, k1, k2 : transition coefficients of the contrast medium.
We applied the program to the normal and infarcted myocardium in electron-beam CT.The results (mean values) were ; a : 8%, b : 36% for the normal and a : 3%, b : 58% for infarction. Calculated values of the parameters representing tissue structure agreed well with those reported in anatomy, physiology and patology, and acceptable accuracy of the program was confirmed.
4. Comparison of the parameters in compartment analysis with M/Ls
The parameters for myocardium in the compartment-model analysis were well correlated (R ; 0.71 to 0.92) with corresponding M/L values ; a ratio of incremental CT# of the myocardium (M) to that of cardiovascular lumen (L), which is a normalized parameter for myocardial enhancement in CT, showing the possibility of easy quantitation of the tissue characteristics in contrast-enhanced CT.