The Application Of The Three-dimensional CT Volume-based Measurement In The Study Of The Brain Atrophy

Purpose To investigate the application of the three-dimensional CT volume-based measurement in the study of the brain atrophy with ageingMaterials and Methods 1. Three experienced readers independently make three serial measurements of each of 40 head images that have been observed on standard-dose multi-section CT images obtained in 40 patients. To calculate the Intra-class Correlation Coefficients (ICC) of intra- and inter- rater reliability. 2. To calculate different brain parachymal volume that comes separately from volume-based multi-section CT images and MRI images obtained in 20 volunteers. Use Intra-class Correlation Coefficients (ICC) to compare the consistency of the two methods. 3. After 403 volunteers are scanned with brain CT, the result is carried on 3D rebuild , then calculate total intracranial volume, brain volume, brain parenchyma volume, ventricular cerebrospinal fluid volume and total cerebrospinal fluid volume. To calculate every brain parenchymal fraction(BPF): brain parenchymal fraction ( absolute parechymal-to-brain BPF), brain-to-intracranial cavity volume ratio (BICVR),absolute parechymal-to-intracranial cavity volume ratio (APICVR).Results 1.The Intra-class Correlation Coefficients(ICC) for readers 1, 2 and 3 are 0.91,0.88,0.92 ; 0.45,0.48,0.41 ; 0.78, 0.78, 0.83 (P<0.001) respectively . The Intra-class Correlation Coefficients ICC for readers 1,2,1,3,2,3are 0.84,0.92,0.92 ; 0.36,0.61,0 .63 ;0.81,0.86,0.89(P<0.001) respectively . 2.The Intra-class Correlation Coefficient (ICC) of the absolute parechymal-to-brain(BPF) between three-dimensional volume-based CT measurement and MRI measurement is 0.94. 3.Three BPF decrease with ageing. For the age stage 40-60 years old, there is statistically significant difference between BPF and BICVR, but for the remaining age stages there is no statistically significant difference between BPF and BICVR. 4.There is no significant difference between BPF and BICVR on the level of sex.Conclusion 1.Because of the ill intra- and inter- rater agreement, two-dimensional linear CT measurement is inaccurate in the appraise of the brain atrophy with ageing.