1. Department of Radiology, West China Second University Hospital of Sichuan University, Chengdu Sichuan 610041, China|
2. Key Laboratory of Obstetric and Gynecologic and Pediatric Diseases and Birth Defects of Ministry of Education (Sichuan
University),
Chengdu Sichuan 610041, China
Abstract：Objective To investigate the effect of monochromatic imaging on image quality and radiative agent in children’s
emergency head CT plan scanning compared with conventional axial scanning, so as to evaluate the ability of energy spectrum imaging to improve image quality. Methods A total of 80 pediatric patients who underwent emergency head CT plan scan were divided into energy spectrum imaging group and conventional imaging group, 40 cases in each group. The energy spectrum imaging group were reconstructed a total of 8 groups of monochromatic imaging on different energy levels and poly chromatic imaging. Conventional imaging group ?xed tube voltage 100 kVp, and used the same mAs scanning as energy spectrum imaging group. CT value and Noise value of 3 region of interestand region of background in each group images were measured and recorded. Signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) of the same region organization of each group image were calculated. The overall quality of each group was scored by blind subjective method. Variance analysis and Kappa test were used to compare the data of each group and analyze the consistency of subjective scores. Results Within the increasing of keV, the CT value and noise value of the measured area gradually decreased in monochromatic imaging group. Calculating the SNR and CNR values, the 65 keV to 80 keV group in the monochromatic group was higher than that in the poly chromatic group, and higher than conventional group the difference was statistically signi?cant (P<0.001). The subjective scores of 65 keV and 70 keV group were superior to those in the poly chromatic group and the conventional group (P<0.001). The mean effective dose of energy spectrum imaging group was lower than that of conventional group (P<0.001). Conclusion The children’s emergency brain CT plan scanning, using energy spectrum scanning mode, monochromatic imaging, especially 65 keV and 70 keV group, can effectively reduce total image noise, posterior fossa and subdural artifacts depressed. The image quality is improved and the radiation dose is decreased.
