PURPOSE Investigate the possibility of reducing the number of PET detector elements per ring (introduce gaps) while maintaining image quality by employing compressed sensing techniques. METHODS A uniform Ge-68 phantom was imaged on a D-RX PET/CT scanner twice; once with all detectors operational (baseline) and once with 8 equidistant detector blocks turned off (partially sampled [PS], 11% det...

UNLABELLED Our purpose was to find out the cause of an unusual distinct break seen on a patient's sinogram despite within-tolerance results on all quality assurance tests during myocardial perfusion imaging (MPI) and corrective measures. METHODS SPECT quality control is a prerequisite to obtaining high-quality diagnostic images. Daily uniformity and energy-peaking tests and weekly center-of-r...

Purpose: This paper proposes a sinogram-consistency learning method to deal with beamhardening related artifacts in polychromatic computerized tomography (CT). The presence of highly attenuating materials in the scan field causes an inconsistent sinogram, that does not match the range space of the Radon transform. When the mismatched data are entered into the range space during CT reconstructio...

We propose a method, which treats metal artifact reduction in CT by sinogram restoration as a problem of scattered data interpolation. Corrupted sinogram entries are discarded and replaced with artificially generated values. The presented interpolation algorithm is based on the 2D non-equispaced fast Fourier transform (NFFT). Results are compared to two common polynomial interpolation schemes.

introduction in ct imaging, metallic implants inside the tissues cause metal artifact that reduce the quality of image for diagnosis. in order to reduce the effect of this artifact, a new method with more appropriate results has been presented in this research work. materials and methods the presented method comprised of following steps: a) image enhancement and metal areas extraction, b) sinog...

BACKGROUND Metal objects implanted in the bodies of patients usually generate severe streaking artifacts in reconstructed images of X-ray computed tomography, which degrade the image quality and affect the diagnosis of disease. Therefore, it is essential to reduce these artifacts to meet the clinical demands. METHODS In this work, we propose a Gaussian diffusion sinogram inpainting metal arti...

The non-stationary Poisson noise in single photon emission computed tomography (SPECT) sinogram is a major cause to compromise the quality of reconstructed images and challenge any compensation strategy for photon attenuation, scatter and collimator response. Research utilizing threedimensional Wiener filter after Anscombe transformation, which converts Poisson distributed noise into Gaussian d...

PURPOSE A CT scanner measures the energy that is deposited in each channel of a detector array by x rays that have been partially absorbed on their way through the object. The measurement process is complex and quantitative measurements are always and inevitably associated with errors, so CT data must be preprocessed prior to reconstruction. In recent years, the authors have formulated CT sinog...

The aim of this paper is to test and analyse a novel technique for image reconstruction in positron emission tomography, which is based on (total variation) regularisation on both the image space and the projection space. We formulate our variational problem considering both total variation penalty terms on the image and on an idealised sinogram to be reconstructed from a given Poisson distribu...

We propose filtering the PET sinograms with a constraint curvature motion diffusion. The edge-stopping function is computed in terms of edge probability under the assumption of contamination by Poisson noise. We show that the Chi-square is the appropriate prior for finding the edge probability in the sinogram noise-free gradient. Since the sinogram noise is uncorrelated and follows a Poisson di...