Different calculating formulas for contrast-to-noise ratio of energy spectrum brain CT single energy imaging
10.13929/j.issn.1003-3289.2020.10.026
- VernacularTitle: 不同对比噪声比公式用于颅脑能谱CT单能量成像
- Author:
Jinlei YAO
1
Author Information
1. Department of CT, Liaocheng Hospital of Traditional Chinese Medicine
- Publication Type:Journal Article
- Keywords:
Brain;
Formula;
Quality control;
Tomography, X-ray computed
- From:
Chinese Journal of Medical Imaging Technology
2020;36(10):1537-1541
- CountryChina
- Language:Chinese
-
Abstract:
Objective: To analyze the application value of 6 common formulas for calculating contrast-to-noise ratio (CNR) of energy spectrum brain CT single energy imaging. Methods: Brain energy spectrum CT images were obtained in 52 patients, and single-energy images of 40-140 keV (10 keV interval) were reconstructed. CT values and the corresponding noises of white matter, temporal muscles, cerebrospinal fluid, subcutaneous fat and extracranial air were respectively measured, and formulas A (group A), B (group B), C (group C), Da (group Da), Db (group Db) and Dc (group Dc) were used to calculate CNR values. CNR values were compared among groups based on Optimal CNR curve (Optimal CNR group), and the relative correlation and consistency of CNR value of each group and Optimal CNR group were observed. Results: CNR values of each group at different energy levels were statistical different (all P<0.01). CNR values of group A, group B, group C, group Da, group Db, group Dc were all correlated with Optimal CNR group (r=0.97±0.02, 0.94±0.01, 0.94±0.01, 0.67±0.01, 0.39±0.01, 0.59±0.01, all P<0.05) and showed various degrees of consistency with Optimal CNR group (ICC=0.97±0.02, 0.89±0.01, 0.67±0.01, 0.54±0.02, 0.13±0.01, 0.47±0.02, all P<0.05). Conclusion: For brain energy spectrum CT single-energy imaging, CNR value calculated by formula A had the best consistency and correlation with the results of Optimal CNR software. CNR calculation formulas should be selected according to patient condition and research purposes in clinic practice.
