OBJECTIVES To evaluate the influence of exposure parameters and raw-data-based iterative reconstruction (IR) on computer-aided segmentation and quantitative analysis of the tracheobronchial tree on multidetector computed tomography (MDCT). MATERIAL AND METHODS 10 porcine heart-lung-explants were mounted inside a dedicated chest phantom. MDCT was performed at 120kV and 80kV with 120, 60, 30 an...

Recently, 3D image fusion reconstruction using a FDK algorithm along three-orthogonal circular isocentric orbits has been proposed. On the other hand, we know that 3D image reconstruction based on three-orthogonal circular isocentric orbits is sufficient in the sense of Tuy data sufficiency condition. Therefore the datum obtained from three-orthogonal circular isocentric orbits can derive an ex...

We have developed an image quality theory for reconstruction that we apply to filtered back-projection (FBP) and statistical reconstruction (OSEM) for Single Photon Emission Computed Tomography (SPECT). Quantitative measures of reconstruction performance are given in terms of signal and noise power spectra, SPS and NPS, that we derive from phantom images. This allows evaluating the properties o...

This paper concerns image reconstruction for helical x-ray transmission tomography (CT) with multi-row detectors. We introduce two approximate cone-beam (CB) filtered-backprojection (FBP) algorithms of the Feldkamp type, obtained by extending to three dimensions (3D) two recently proposed exact FBP algorithms for 2D fan-beam reconstruction. The new algorithms are similar to the standard Feldkam...

UNLABELLED Tissue attenuation results in nonuniform myocardial perfusion images with significant sex differences. New SPECT imaging protocols to correct attenuation are currently under investigation. This study was performed to assess the effects of attenuation correction (AC) on overall image uniformity compared with more conventional imaging protocols in both men and women. METHODS Thirty-n...

OBJECTIVE Gamma camera nonuniformity can result in the presence of ring artifacts in reconstructed SPECT images. The objective of this study is to compare the relationship between ring artifact magnitude and image noise in tomographic images reconstructed using FBP and OSEM. METHODS A cylindrical phantom was filled with water and (99m)TC: Seven tomographic acquisitions were performed, with to...

OBJECTIVES The objective of this study was to compare the image quality and radiation dose of chest CT images reconstructed with a blend of adaptive statistical iterative reconstruction (ASIR) and filtered back-projection (FBP) with images generated using conventional FBP. METHODS Patients with chest CT re-examinations were alternately assigned to two scanners with different reconstruction te...

PURPOSE Iterative reconstruction (IR) technique is growingly used in clinical CT imaging due to its ability to provide improved image quality at lower patient doses. However, the nonlinear frequency response of IR technique, which may affect quantitative analysis, is rarely explored. This study evaluates noise level and contrast dependent behavior of MTF in IR CT imaging with a multi-contrast s...

OBJECTIVE: The purpose of the current study was to evaluate the effect of an iterative reconstruction algorithm named advanced modeled iterative reconstruction (ADMIRE) on improving image quality and reducing the radiation dose. MATERIALS AND METHODS: The Catphan phantom (Phantom Lab, USA) was scanned on a SOMATOM Force CT scanner (Siemens Healthcare, Forchheim, Germany) with different exposure...

PURPOSE To evaluate nodule detection in an anthropomorphic chest phantom in computed tomography (CT) images reconstructed with adaptive iterative dose reduction 3D (AIDR(3D)) and filtered back projection (FBP) over a range of tube current-time product (mAs). METHODS Two phantoms were used in this study: (i) an anthropomorphic chest phantom was loaded with spherical simulated nodules of 5, 8, ...