نتایج جستجو برای: metal artifact

تعداد نتایج: 215918  

Introduction: Metallic artifacts due to pacemaker/ implantable cardioverter defibrillator (ICD) leads in CT images can produce artifactual uptake in cardiac SPECT/CT images. The aim of this study was to determine the influence of the metallic artifacts due to pacemaker and ICD leads on myocardial SPECT/CT imaging. Methods: The study included 9 patients wh...

Journal: :Journal of X-ray science and technology 2011
Jiyoung Choi Kyung Sang Kim Min Woo Kim Won Seong Jong Chul Ye

Metal artifact removal (MAR) is one of the most important issues in x-ray CT reconstruction. Various methods have been suggested for metal artifact removal, among which projection modification and iterative methods are most popular. While those methods mainly focus on removing background artifacts, for some applications such as dental CT the correct reconstruction of metallic inserts is also im...

Journal: :journal of medical signals and sensors 0
parinaz mortaheb mehdi rezaeian

segmentation and three‑dimensional (3d) visualization of teeth in dental computerized tomography (ct) images are of dentists’ requirements for both abnormalities diagnosis and the treatments such as dental implant and orthodontic planning. on the other hand, dental ct image segmentation is a difficult process because of the specific characteristics of the tooth’s structure. this paper presents ...

2013
Tsutomu Gomi

We compared metal artifact in X-ray digital tomosynthesis (DT) and modern computed tomography (CT) reconstruction to improve the image quality. We compared the images of a prosthetic phantom (titanium) and a contrast-detail phantom obtained by DT using conventional filtered backprojection (FBP), metal artifact reduction (MAR) processing, and simultaneous iterative reconstruction technique (SIRT...

2011
Henry Wynn-Jones Rory Macnair James Wimhurst Nish Chirodian Brian Derbyshire Andoni Toms John Cahir

BACKGROUND AND PURPOSE Adverse reactions to metal debris have been reported to be a cause of pain in metal-on-metal hip arthroplasty. We assessed the incidence of both symptomatic and asymptomatic adverse reactions in a consecutive series of patients with a modern large-head metal-on-metal hip arthroplasty. METHODS We studied the early clinical results and results of routine metal artifact-re...

2014
Kevin K Whitehead Matthew A Harris Gary R McNeal Mark A Fogel

Background While CMR has become instrumental in imaging complex congential heart disease (CHD), limitations remain including significant flow and metal artifact on cine images. 2D dark blood imaging generally requires gating to diastole which may not capture the maximal vessel dimensions, is time consuming and dependent on precise plane positioning. Traditional 3D whole heart sequences are also...

Journal: :Medical physics 2016
Mehrsima Abdoli Abolfazl Mehranian Angeliki Ailianou Minerva Becker Habib Zaidi

PURPOSE Metal artifact reduction (MAR) produces images with improved quality potentially leading to confident and reliable clinical diagnosis and therapy planning. In this work, the authors evaluate the performance of five MAR techniques for the assessment of computed tomography images of patients with hip prostheses. METHODS Five MAR algorithms were evaluated using simulation and clinical st...

Journal: :Journal of magnetic resonance imaging : JMRI 2010
Brian A Hargreaves Weitian Chen Wenmiao Lu Marcus T Alley Garry E Gold Anja C S Brau John M Pauly Kim Butts Pauly

PURPOSE To demonstrate accelerated imaging with both artifact reduction and different contrast mechanisms near metallic implants. MATERIALS AND METHODS Slice-encoding for metal artifact correction (SEMAC) is a modified spin echo sequence that uses view-angle tilting and slice-direction phase encoding to correct both in-plane and through-plane artifacts. Standard spin echo trains and short-TI ...

2009
W. Lu K. B. Pauly G. E. Gold J. M. Pauly B. A. Hargreaves

Introduction: Slice encoding for metal artifact correction (SEMAC) [1] completely corrects metal-induced in-plane and through-plane distortions. The SEMAC imaging sequence (Fig. 1) augments a view-angle-tilting (VAT) [2] spin echo sequence with z-phase encoding. While the VATcompensation gradient suppresses the in-plane distortions, the throughplane distortions are corrected by combining multip...

2009
B. A. Hargreaves G. E. Gold J. M. Pauly K. B. Pauly

Introduction: Metallic implants can cause moderate or severe distortion artifacts in MR images depending on the shape, size, composition and orientation of the implant. Recentlyproposed methods correct image distortion due to susceptibility shifts near metallic implants by using excitation of limited bandwidths [1] or limited spatial slices [2], both followed by 3D imaging. Here we demonstrate ...

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