Comparison Of Three-dimensional Reconstructions At Low Dose And Conventional Dose CT In The Evaluation Of Pulmonary Nodules

Purpose: To determine the optimal scan parameters in multislice helical CT (MSCT) of the lung nodules for both axial scanning and three-dimensional reconstructions. Material and Methods: lung nodules which was found in the routine examination (120mV,230mA), repeatedly perform scan with the same scan parameters except tube current, which is low to 30mA and 10mA. Record the dose of X ray that patients have been exposed. Multiplanar reconstructions in coronal and sagittal planes and volume render with different tube current were evaluated in visualization of lung nodules containing the terms of lung-nodules interface, internal composition and relationship with adjacent tissues; Use ALA software to calculate the volume of lung nodules. Results: The doses of X ray that patients have been exposed with low tube current decrease obviously. The total numbers of pulmonary nodules detected in 39 patients with conventional spiral CT and low-dose were 784, 783 and 772, respectively. There was no statistically significant difference. There is no obvious difference in visualization of lung nodules with different tube current (p>0.05); There is difference among whether can use ALA software to calculate the volume of lung nodules (p<0.05); There is no difference in 230mA group and 30mA group; There is no difference in 30mA group and 10mA group; 230mA group is different to 10mA group. Conclusions: Low-dose MSCT (30mA and 10mA) can not only detect the nodules, but also show the visualization of lung nodules very clearly, which meet the demand of clinical with low dose.