OBJECTIVES In this study, we compared the magnetic resonance (MR) image artifacts caused by a conventional metal-based cochlear implant and a newly developed liquid crystal polymer (LCP)-based device. METHODS The metal-based cochlear implant system (Nurobiosys Co.) was attached to side of the head of a subject and the LCP-based device was attached to opposite side. In both devices, alignment ...

Background Dental hardware produces streak artifacts on computed tomography (CT) images reconstructed with the standard weighted filtered back projection (wFBP) method. Purpose To perform a preliminary evaluation of an iterative metal artifact reduction (IMAR) technique to assess its ability to improve anatomic visualization over wFBP in patients with dental amalgam or other hardware. Mater...

BACKGROUND AND PURPOSE Developments in flat panel angiographic C-arm systems have enabled visualization of both the neurovascular stents and host arteries in great detail, providing complementary spatial information in addition to conventional DSA. However, the visibility of these structures may be impeded by artifacts generated by adjacent radio-attenuating objects. We report on the use of a m...

BACKGROUND AND PURPOSE Metal-related artifacts from spine instrumentation can obscure relevant anatomy and pathology. We evaluated the ability of CT images reconstructed with and without iterative metal artifact reduction to visualize critical anatomic structures in postoperative spines and assessed the potential for implementation into clinical practice. MATERIALS AND METHODS We archived CT ...

A maximum a posteriori algorithm for reduction of metal streak artifacts in x-ray computed tomography is presented. The algorithm uses a Markov random field smoothness prior and applies increased sampling in the reconstructed image. Good results are obtained for simulations and phantom measurements: streak artifacts are reduced while small, line-shaped details are preserved.

BACKGROUND Metal implants, surgical clips and other foreign bodies may cause 'streaking' or 'star' artifacts in computed tomography (CT) reconstructions, for example in the vicinity of dental restorations or hip implants. The deteriorated image quality complicates contouring and has an adverse effect on quantitative planning in external beam therapy. METHODS The potential to reduce artifacts ...

Background: Simultaneous EEG and VASO (Vascular Space Occupancy) imaging can be used to characterize CBV (cerebral blood volume) changes during interictal epileptic discharges (IED’s). However, the VASO sequence causes more RF pulse artifacts in the EEG than spin-echo or gradient-echo functional MRI (fMRI) sequences, because the global inversion pulses in the VASO sequence require higher RF pow...

Tepe Sagzabad, a site situated on the Qazvin Plain of north-central Iran, was excavated from 1970 to 1998 by the Institute ofArchaeology of Tehran University. Recent excavations by H. Tala’i (1997-1999) yielded some metal artifacts dating to theEarly Iron Age. Ten of these copper-based samples were investigated using inductively coupled plasma optical emissionspectroscopy (ICP-OES), scanning el...

Metal objects in the body such as hip prostheses cause artifacts in CT images. When CT images degraded by artifacts are used for treatment planning of radiotherapy, the artifacts can yield inaccurate dose calculations and, for particle beams, erroneous penetration depths. A metal artifact reduction software (O-MAR) installed on a Philips Brilliance Big Bore CT has been tested for applications i...