RESUMO
Objective:To measure CT linearity and evaluate if it would show linear relationship between coefficient and attenuation.Methods:The Catphan phantom was used to measure CT linearity in 18 computed tomography equipments,and the results were calculated.Results:(1)The CT linearity were qualified in 14 equipment but 4.Conclusion:(1)There are many factors which affect CT linearity.The artifact will be produced if the CT linearity is unqualified.(2)CT linearity must be calibrated periodically to assure the stability of the CT linearity and to make for the accurate diagnoses.
RESUMO
Objective:To measure CT linearity and evaluate if it would show linear relationship between coefficient and attenuation.Methods:The Catphan phantom was used to measure CT linearity in 18 computed tomography equipments,and the results were calculated.Results:(1)The CT linearity were qualified in 14 equipment but 4.Conclusion:(1)There are many factors which affect CT linearity.The artifact will be produced if the CT linearity is unqualified.(2)CT linearity must be calibrated periodically to assure the stability of the CT linearity and to make for the accurate diagnoses.