Artifacts are commonly encountered in clinical computed tomography (CT), and may obscure or simulate pathology. There are many different types of CT artifacts, including noise, beam hardening, scatter, pseudoenhancement, motion, cone beam, helical, ring, and metal artifacts. We review the cause and appearance of each type of artifact, correct some popular misconceptions, and describe modern tec...

PURPOSE A computationally efficient algorithm (linear iterative type) based on singular value decomposition (SVD) of the Jacobian has been developed that can be used in rapid dynamic near-infrared (NIR) diffuse optical tomography. METHODS Numerical and experimental studies have been conducted to prove the computational efficacy of this SVD-based algorithm over conventional optical image recon...

The noise of low-dose computed tomography (CT) sinogram follows approximately a Gaussian distribution with nonlinear dependence between the sample mean and variance. The noise is statistically uncorrelated among detector bins at any view angle. However the correlation coefficient matrix of data signal indicates a strong signal correlation among neighboring views. Based on above observations, Ka...

OBJECTIVE The purpose of this study was to evaluate the influence of sinogram-affirmed iterative reconstruction (SAFIRE) on quantification of lung volume and pulmonary emphysema in low-dose chest computed tomography compared with filtered back projection (FBP). METHODS Enhanced or nonenhanced low-dose chest computed tomography was performed in 20 patients with chronic obstructive pulmonary di...

the aim of this study was to reveal biometric peculiarities of new zealand white rabbit antebrachium (radius and ulna) by means of three-dimensional (3d) reconstruction of multidetector computed tomography (mdct) images. under general anesthesia, the antebrachiums of a total of sixteen rabbits of both sexes were scanned with a general diagnostic mdct. biometric measurements of the reconstructed...

This study was aimed to evaluate the image quality and lacunar lesion detection of thin-slice brain computed tomography (CT) images with different reconstruction algorithms, including filtered back projection (FBP), hybrid iterative reconstruction (HIR), and iterative model reconstruction (IMR) by comparison of routine slice images with FBP reconstruction. Sixty-one patients underwent noncontra...

As has already been shown with 2D-models DIRECTT (Direct iterative reconstruction of computed tomography trajectories) exceeds the spatial resolution of the classical filtered back projection. In this work the DIRECTT algorithm is extended towards cone-beam projection including iterative 3D reconstruction. The improved speed is still overcompensated by the large amount of reconstruction space a...

OBJECTIVE Evaluation of a new iterative reconstruction algorithm (IMR) for detection/rule-out of pulmonary embolism (PE) in ultra-low dose computed tomography pulmonary angiography (CTPA). METHODS Lower dose CT data sets were simulated based on CTPA examinations of 16 patients with pulmonary embolism (PE) with dose levels (DL) of 50%, 25%, 12.5%, 6.3% or 3.1% of the original tube current sett...

Kisner, Sherman J. Ph.D., Purdue University, December 2013. Image Reconstruction for X-ray Computed Tomography in Security Screening Applications. Major Professor: Charles A. Bouman. X-ray tomographic systems have increasingly widespread use in security screening applications. For example, most major airports now utilize X-ray CT systems for efficient screening of baggage and cargo. While decad...