The article analyzes the existing algorithms of cardiac imaging reconstructions using multidata segments and derives the ideal data segment conditions. A scheme of selectable velocity scanning is then proposed for cardiac computed tomography with a circular trajectory, which can cover any cardiac phase exactly or approximately to achieve a desirable temporal resolution. Numerical tests show tha...

Copyright © 2007 Massachusetts Medical Society. The advent of computed tomography (ct) has revolutionized diagnostic radiology. Since the inception of CT in the 1970s, its use has increased rapidly. It is estimated that more than 62 million CT scans per year are currently obtained in the United States, including at least 4 million for children.1 By its nature, CT involves larger radiation doses...

Triple-Source Computed Tomography (TSCT) improves the temporal resolution by three times the conventional Single-Source Computed Tomography (SSCT). The theories and implementations of TSCT have been well established in previous studies. However, whether additional X-ray tubes increase the dose remains unknown. To solve this problem, a TSCT system was simulated by Monte Carlo simulation. For com...

background: the purpose of this study was to evaluate the infl uence of ejection fraction (ef) on peak aortic time (pat) and  peak aortic enhancement (pae) during coronary computed tomography angiography (cta). materials and methods: one-hundred and twenty patients (64 men, 56 women) underwent measurement of coronary cta with a measurement of ef within 3 months of coronary cta.pearson’s correla...

introduction : to evaluate the efficacy of niti mechanical rotary instrumentation and hedstrom file for gutta-percha/sealer removal computed tomography (ct) was utilized in vitro . materials and methods: thirty extracted human single rooted teeth, each with a single canal were selected. the samples were decoronated with a double faced diamond disk to have 17-mm root; teeth roots were instrument...

abstract: cone-beam computed tomography (cbct) has been accepted as a useful tool for diagnosis and treatment in endodontics. despite a growing trend toward using cbct in endodontic practice the cbct images should be interpreted carefully. this case report presents a case that showed radiolucency inside and around a tooth which was free of pathologic changes under a dental operative microscope ...

introduction: this study aimed to perform a rigorous sample standardization and also evaluate the preparation of mesiobuccal (mb) root canals of maxillary molars with severe curvatures using two single-file engine-driven systems (waveone with reciprocating motion and oneshape with rotary movement), using micro-computed tomography (micro-ct). methods and materials: ten mb roots with single canal...

introduction: the aim of the present in vitro study was to compare the accuracy of cone-beam computed tomography (cbct) in determining root canal morphology of mandibular first molars in comparison with staining and clearing technique. methods and materials: cbct images were taken from 96 extracted human mandibular first molars and the teeth were then evaluated based on vertucci’s classificatio...

conclusion this study has highlighted the anatomical variations of npc regarding its dimension, location and morphological appearance. cylindrical was the most common shape followed by funnel-shape, hourglass, and spindle, which were the other canal shapes with less frequency, respectively. the results suggest significant relationship between npc, and gender and dental status. the influence of ...