PROCEEDINGS ARTICLE | March 6, 2013
Proc. SPIE. 8668, Medical Imaging 2013: Physics of Medical Imaging
KEYWORDS: CT reconstruction, Spatial frequencies, Medical imaging, Image quality, Solids, Visual system, Computed tomography, Reconstruction algorithms, Modulation transfer functions, Spatial resolution
Iterative reconstruction techniques (IRTs) are used to reduce the radiation dose significantly and suppress the noise in
computed tomography (CT) imaging. However, the image from IRTs is unacceptable to the human visual system due to
the presence of outlier and non-Gaussian noise structure. The conventional noise measurements, such as mean and
standard deviation, are limited to provide the information of noise characteristics of an image comprehensively when the
undesirable noise structure happens on the image. In this study, the images reconstructed by using Weighted filtered
back-projection (WFBP) and image-based IRTs (SAFIRE and SafeCT) were compared in terms of conventional noise
statistics, high-order noise statistics, modulation transfer function (MTF), and slice sensitivity profile (SSP) with
different levels of radiation dose. The results showed that the noise characteristics, which were considered with
conventional and high-order noise statistics, and spatial resolution characteristics were different for the IRTs,
reconstruction parameters, and levels of radiation dose. This study can contribute to the optimization of image quality
from IRT with the reduction of radiation dose and development of IRT which overcomes the issue caused by undesirable
noise structures.
