Artifacts are commonly encountered in clinical computed tomography (CT), and may obscure or simulate pathology. There are many different types of CT artifacts, including noise, beam hardening, scatter, pseudoenhancement, motion, cone beam, helical, ring, and metal artifacts. We review the cause and appearance of each type of artifact, correct some popular misconceptions, and describe modern tec...

BACKGROUND Metal artifacts appearing as streaks and shadows often compromise readability of computed tomography (CT) images. Particularly in a dental CT in which high resolution imaging is crucial for precise preparation of dental implants or orthodontic devices, reduction of metal artifacts is very important. However, metal artifact reduction algorithms developed for a general medical CT may n...

In computed tomography (CT), metal implants increase the inconsistencies between the measured data and the linear assumption made by the analytical CT reconstruction algorithm. The inconsistencies appear in the form of dark and bright bands and streaks in the reconstructed image, collectively called metal artifacts. The standard method for metal artifact reduction (MAR) replaces the inconsisten...

BACKGROUND AND PURPOSE Metal artifacts from dental fillings and other devices degrade image quality and may compromise the detection and evaluation of lesions in the oral cavity and oropharynx by CT. The aim of this study was to evaluate the effect of iterative metal artifact reduction on CT of the oral cavity and oropharynx. MATERIALS AND METHODS Data from 50 consecutive patients with metal ...

For decades, computed tomography (CT) images have been widely used to discover valuable anatomical information. Metallic implants such as dental fillings cause severe streaking artifacts which significantly degrade the quality of CT images. In this paper, we propose a new method for metal-artifact reduction using complementary magnetic resonance (MR) images. The method exploits the possibilitie...

Subject was to evaluate techniques for the reduction of metal artifacts in X-ray computed tomographies (CT). Compared to simulated CT projection data, real measurements allowed less improvements in image quality. Neither could metal artifacts be eliminated completely, nor was there a signiicant gain regarding the presentation of anatomical structures in the immediate neighbourhood of metal obje...

Spectroscopy of cervical diskectomy specimens obtained from sheep demonstrated that metallic susceptibility artifacts are produced by microscopic amounts of nickel, copper, and zinc. Sufficient quantities of metals to produce artifacts are deposited only by contact of metal drill bits and suction tips. If these instruments do not come in contact during surgery, susceptibility artifacts are not ...

BACKGROUND AND PURPOSE Image quality and diagnostic reliability of T2-weighted MR images of the cervical spine are often impaired by several kinds of artifacts, even in cooperative patients. The aim of this study was to evaluate if BLADE sequences might solve these problems in a routine patient collective. MATERIALS AND METHODS TSE and BLADE sequences were compared in 60 patients for T2-weigh...

PURPOSE To investigate effects of metal artifacts on the dose calculation accuracy of three dose calculation algorithms on CT and cone-beam CT images. METHODS A phantom with and without metal objects was scanned using CT simulator and on-board kV CBCT. Conformal 5-field treatment plans with identical physical and dosimetric parameters were created in the Eclipse™ treatment planning system for...