objective: the aim of this study was to evaluate the influences of reconstruction and attenuation correction on the differences in the radioactivity distributions in 123i brain spect obtained by the hybrid spect/ct device. methods: we used the 3-dimensional (3d) brain phantom, which imitates the precise structure of gray mater, white matter and bone regions. it was filled with 123i solution (20...

Abstract Mathematical methods take an important part in reconstruction technologies of radiographic image. Back projection, iterative, and analytical (Two-dimensional Fourier, Filtered Projection) are the most procedures for image reconstruction. Whenever there exists numerous projections, have a great performance speed accuracy due to these advantages they comprehensively used X-ray imaging. O...

– Filtered back projection (FBP) is a commonly used image reconstruction scheme for parallel beam tomography. The algorithm implemented in this project, called fast hierarchical back projection (FHBP), was proposed in [1] as a fast approximation to the direct FBP technique. Through derivation, implementation and simulation results, I will show a complete picture on this novel algorithm for a cl...

To achieve approximately parallel projection geometry, traditional optical projection tomography (OPT) requires the use of low numerical aperture (NA) objectives, which have a long depth-of-field at the expense of poor lateral resolution. Particularly promising methods to improve spatial resolution include ad-hoc post-processing filters that limit the effect of the system's MTF and focal-plane-...

Algoritma Filtered Back Projection (FBP) telah menjadi algoritma standar untuk rekonstruksi citra dalam computed tomography (CT) selama bertahun-tahun, tetapi ini menciptakan kemungkinan artefak dan peningkatan noise gambar yang mencolok ketika dosis radiasi dikurangi secara berlebihan. Dengan kemajuan teknologi kapasitas komputasi, Adaptive Statistical Iterative Reconstruction (ASIR) muncul ke...

.. Objective: Myocardial perfusion imaging (MPI) with superior quality of images in least acquisition time is imperative for diagnostic purpose. The objective of this study was to compare the Filter Back Projection (FBP) and half time Astonish reconstruction techniques in diagnosis of coronary artery disease using cardiac catheterization as gold standard. Place and period of study: Study was co...

BACKGROUND Computed Tomography (CT) is a technology that obtains the tomogram of the observed objects. In real-world applications, especially the biomedical applications, lower radiation dose have been constantly pursued. To shorten scanning time and reduce radiation dose, one can decrease X-ray exposure time at each projection view or decrease the number of projections. Until quite recently, t...

OBJECTIVE The purpose of this study was to report preliminary results of an ongoing prospective trial of ultralow-dose abdominal MDCT. SUBJECTS AND METHODS Imaging with standard-dose contrast-enhanced (n = 21) and unenhanced (n = 24) clinical abdominal MDCT protocols was immediately followed by ultralow-dose imaging of a matched series of 45 consecutively registered adults (mean age, 57.9 yea...

UNLABELLED The high-resolution research tomograph (HRRT) is a dedicated human brain PET scanner. At present, iterative reconstruction methods are preferred for reconstructing HRRT studies. However, these iterative reconstruction algorithms show bias in short-duration frames. New algorithms such as the shifted Poisson ordered-subsets expectation maximization (SP-OSEM) and ordered-subsets weighte...