Pitch Optimizing Combination of Thoracic and Abdominal CTA Image Quality and Radiation Dose Discussion

Abstract：Objective：To evaluate the pitch of the thoracic and abdominal MSCT CTA image quality,and compare the radiation dose.Materials and Methods：Collection of clinical suspected thoracic and abdominal vascular lesions in 90 patients,according to the different pitch were randomly divided into 3 groups（n=30）,group A：a pitch of 1.375：1,55 mm/s bed velocity;group B：a pitch of 0.984：1,39.37 mm/s bed velocity;group C：pitch,0. 516：1 bed velocity 20.62 mm/s,using the same injection rate and dose of contrast contrast tracking trigger scanning.After obtaining data from imaging director and supervisor technician in a AW4.4 workstation for image quality evaluation.Results：Through the pitch after optimization,A,B,C 3 groups average each patient scan time respectively：（12.60±0.54）s,（17.40±0.44）s,（33.10±1.48）s,DLP respectively：（1 462.50±71.56）mGy.cm, （2 010.55±62.14）mGy.cm,（3 821.58±198.50 the difference between mGy.cm）,which was statistically significant（P0.05）, recombinant vascular definition and display of vascular branching number also no difference.Conclusion：The groups A pitch optimization,fast bed velocity scanning parameters can significantly reduce the patient radiation dose,so as to ensure the image quality and meet the requirements of diagnosis.