Evaluation of the spatial resolution of multiplanar reconstruction images

We present a simple method for evaluating the spatial resolution of multi-slice computed tomography (MSCT) multiplanar reconstruction images (MPRs). We scanned a bead phantom to obtain the three-dimensional point spread function (PSF), and bead-centric MPRs were generated. The modulation transfer function (MTF) was calculated from the MPRs via a two-dimensional Fourier transform (2DFFT) of the PSF. The results showed that, when MPRs were reconstructed using axial images less than or equal to a nominal 1.0-mm slice-width with a standard kernel for the abdomen, the MTF in the longitudinal direction (z-direction) was superior to that in the in-plane (x-y plane) direction. It was also found that the arbitrary-angle MTFs of MPRs were between the MTFs of the in-plane and longitudinal directions. It was confirmed that this method can be used to evaluate MPR spatial resolution.