Application and research of increasing noise on simulation of the chest scan with low-dose CT
Cao Hui-zhi · Tianjin Yike Daxue xuebao · 2010
Objective: To assess the feasibility, fidelity and applicability of adding noise on raw data for simulation of low dose CT scan of chest. Methods: Three sets of raw data were studied, including conventional chest CT scan of ten patients, thin -section high resolution CT scan of ten patients, and conventional CT scan of lung nodule mannequin. Noise was added to simulate conventional CT scan with tube current of 60 mA and 30 mA, thin-section high resolution CT scan with tube current of 160 mA and 80 mA. For mannequin data, a series of noise were added to simulate tube current from 270 mA to 10 mA with interval of 10 mA. Noise index (NI) on levels of aortic arch and liver was measured and compared by paired t test and Pearson correlation analysis. Results: NI was different between scan data and simulated data of mannequin (P0.05), which had linear correlation;For conventional CT scan, NI was different on liver level (P0.05),while not different on aortic arch level,there had linear correlation;For high resolution CT scan, NI was different on both levels (P 0.05),which had linear correlation too. Conclusion: For conventional CT scan, the noise between scan data and simulated data is comparable, and adding noise can be used for low dose CT study.