[Utility of fixed-quantity analysis in evaluating image noise and resolution in multi-slice CT].

We analyzed the spatial frequency of images generated with multi-slice CT (Z-axis) and estimated the definition and noise characteristics. The noise characteristics were calculated with Wiener spectra from multi planar reconstruction (MPR) images, and, in the evaluation of definition characteristics, the modulation transfer function (MTF) was calculated using section sensitivity profile (SSP) with the base method. The Wiener spectra showed a tendency for noise to decrease from a low frequency domain as the effective slice thickness increased. In addition, Wiener spectra were not much different in helical pitch because effective slice thickness became thicker with increases in helical pitch. Examination results suggest that quantitative analysis of the characteristics of image noise and resolution in multi-slice CT images may provide an optical parameter for improving the quality of images in clinical data.