A convolution-backprojection formula is deduced for direct reconstruction of a three-dimensional density function from a set of two-dimensional projections. The formula is approximate but has useful properties, including errors that are relatively small in many practical instances and a form that leads to convenient computation. It reduces to the standard fan-beam formula in the plane that is p...

Purpose: With increasing cone angle the cone– beam artifacts in x–ray CT become more and more prominent. It is well known that cone–beam CT (CBCT) does not satisfy the data completeness condition for exact image reconstruction and therefore allows only for approximate image reconstruction [1]. Additionally, in clinical C–arm CT often only a short scan with less than a full rotation can be acqui...

Concrescence is a form of twinning, formed by the confluence of cementum of two teeth at the root level. The diagnosis of concrescence has largely relied on the conventional 2D imaging. The 2D imaging has inherent limitations such as distortion and superimposition. Cone-Beam CT eliminates these limitations. The aim of this article was to describe a case of dental abnormality using Cone-Beam CT ...

the presence of three root canals in the distal root of the mandibular fi rst permanent molars is rare; based on in vitro studies its incidence is reported to be between 0.2% and 3%. with the advent of cone beam computed tomography (cbct) as an adjunctive diagnostic aid, the determination of root canal anatomy in teeth with extra canals and complex canal confi gurations has become more precise....

Central granular cell odontogenic tumor) CGCOT) of the jaw is an exceedingly rare benign odontogenic neoplasm with 35 reported cases in the literature. Among these, very few studies have focused on the cone-beam CT features of CGCOT. Here, we report a case of an asymptomatic CGCOT in a 16-year-old girl and focus on the cone-beam CT features. Only 36 cases of this lesion, including this one, hav...

AIM To present a newly developed cone beam computerized tomography system (3DX Micro-CT) and its application in endodontic surgery. SUMMARY Cone beam CT has attracted considerable attention as a new diagnostic imaging technique in dentistry. The assessment of fractured endodontic instruments and the planning of endodontic surgery present challenges that conventional radiography cannot meet su...

Since cone-beam computed tomography (CT) has been adapted for use with a C-arm system it has brought volumetric CT capabilities in the interventional suite. Although cone-beam CT image resolution is far inferior to that generated by traditional CT scanners, the system offers the ability to place an access needle into position under tomographic guidance and use the access to immediately begin a ...

We report on a novel pumping scheme for stimulated Raman scattering (SRS) that uses a Bessel beam. We have used this scheme for SRS from molecular vibrations in acetone and from a polariton mode in a LiIO(3) crystal. A nearly diffraction-limited Stokes beam was observed along the cone axis of the Bessel beam. The generation mechanism of the Stokes beam is identified as being due to noncollinear...