A preliminary study was done of Fourier analysis of high-resolution computed tomographic (CT) images of normal pulmonary parenchyma. A two-dimensional fast Fourier transform was applied to 20 regions of interest (64 x 64 pixels) obtained from CT images of six lungs. A qualitative analysis of the spectra and the application of filters in the frequency domain allowed the characterization and removal of reconstruction artifacts. Selective application of a low-pass filter removed these parasitic frequencies and clearly enhanced the quality of the image.