background and aims. cone-beam computed tomography (cbct) is an imaging system which has many advantages over computed tomography (ct). in ct scan, hounsfield unit (hu) is proportional to the degree of x-ray attenuation by the tissue. in cbct, the degree of x-ray attenuation is shown by gray scale (voxel value). the aim of the present study was to investigate the relationship between gray scale...

A cone-beam image reconstruction algorithm using spherical harmonic expansions is proposed. The reconstruction algorithm is in the form of a summation of inner products of two discrete arrays of spherical harmonic expansion coefficients at each cone-beam point of acquisition. This form is different from the common filtered backprojection algorithm and the direct Fourier reconstruction algorithm...

PURPOSE This aim of this paper is to revisit the parallel-beam/cone-beam or fan-beam/cone-beam imaging configuration, and to investigate whether this configuration has any advantages. METHODS Twenty years ago, it was suggested to simultaneously use a parallel-beam (or a fan-beam) collimator and a cone-beam collimator to acquire single photon emission computed tomography data. The motivation w...

discussion in this patient we preferred following up. afterwards, total surgical lesion resection can be performed. after a long-term follow-up, the area may receive an implant. case presentation a 40-year-old female patient presented an opaque lesion at the left mandibular side of face, in a cone-beam computerized tomography (cbct) view, during the implant placement evaluations. the patient ha...

introdouction: cone beam computed tomography (cbct) is a relatively new three-dimensional imaging technology, which has been widely used in dental and maxillofacial imaging. materials and methods: cbct scans of 506 maxillary sinuses of 253 individuals (39.9% male and 60.1% female) were evaluated retrospectively for assessing the relationship between sinus mucosal thickening (mt) and dental and ...

conclusion the cbct may be safe to use in determining root canal wl. because lower radiation dose, a pre-existing cbct can be useful to detect the root canal wl more precisely. results the cbct was the most accurate method to evaluate the root canal wl, with accuracy of 70%. accuracy for the apex locator and periapical radiograph were 40% and 30%, respectively. materials and methods totally, 30...

conclusion the determination of the presence of mb2 in the maxillary first molars may be carried out using cbct scans. if the ∠mdp was 91 degrees or greater, there was considered to be a higher probability that mb2 canals would be found in the endodontic cavity. due to the positive correlation between the ∠mdp and the ∠mdmb2, the localization of mb2 canals may be easily performed in relation to...

abstract background and aim: cone beam computed tomography (cbct) produces high-quality data in periodontal diagnosis and treatment planning. the aim of this study was to compare the accuracy of cbct with intraoral digital and conventional radiography in the measurement of periodontal bone defects.  methods and materials: in this diagnostic research, two hundred and eighteen artificial osseous ...