| Popis: |
The aim of this paper is to present linearity studies and quality control charts for changes in the computed tomography (CT) number of water and contrast scales for two CT scanners over one year. Linear regression relates the attenuation coefficient to CT number. The CT number for water and the contrast scale values as obtained from the fit are: CT1 = (-0.13 +/- 1.3) Hounsfield units (HU), CT2 = (-1.8 +/- 1.6) HU and contrast scale (CS)1 = (1.80 +/- 0.03) 10(-4) cm-1 HU-1, CS2 = (1.82 +/- 0.02) 10(-4) cm-1 HU-1 for Picker International scanner models 600SE and 1200SX, respectively. Direct measurements of CT numbers are compared with fitted results, providing a necessary preliminary steps in the development of objective CT interpretation. |
Plný text