Aim: To determine the effect of metallic implant positioning on magnetic resonance (MR) imaging artefacts, and to determine the optimal imaging parameters for minimization of metallic artefacts.
Materials And Methods: In a phantom and in three joints with non-ferromagnetic metallic implants imaged at 1.5 and/or at 0.2 T, we examined the influence of the static magnetic field (B(0)) strength and orientation, frequency-encoding direction, and type of imaging sequence on metallic artefacts.
Results: The impact of artefacts caused by metallic objects depends mainly on the relationship between the anatomy of interest and the orientation of the object relative to the direction of B(0). The main field strength plays a less important role, but its orientation depends on the type of MR imager.
Conclusion: MR artefacts can be easily minimized by optimally positioning patients with metallic implants in the magnet. Knowledge of how this influences MR imaging is helpful in patient selection and guiding limb positioning.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1016/s0009-9260(02)00540-8 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Magnetic vector field mapping of the stimulated abductor digiti minimi muscle with optically pumped magnetometers.
Biomed Phys Eng Express
January 2025
Children's Hospital of Eastern Switzerland, Claudiusstrasse 6, St.Gallen, 9006, SWITZERLAND.
Mapping the myomagnetic field of a straight and easily accessible muscle after electrical stimulation using triaxial optically pumped magnetometers (OPMs) to assess potential benefits for magnetomyography (MMG). Approach: Six triaxial OPMs were arranged in two rows with three sensors each along the abductor digiti minimi (ADM) muscle. The upper row of sensors was inclined by 45° with respect to the lower row and all sensors were aligned closely to the skin surface without direct contact.
View Article and Find Full Text PDFFullerenes are statically pleasant species featuring symmetric cages, which can be modified upon reduction. Here, we theoretically account for the variation of 13C-NMR patterns in C60 and C70 upon six-fold reduction and the overall variation of the enabled shielding/deshielding regions induced by π and σ electrons according to different orientations of the external field and the related anisotropy. Our results show a significant modification of the chemical shift given by the main variation of the σ33 (or δ33) shielding component under the principal axis system (PAS) of the chemical shift anisotropy (CSA) at the representative carbon nucleus.
View Article and Find Full Text PDFElectroacupuncture alleviates motor dysfunction after intracerebral hemorrhage via the PPARγ-EAAT2 pathway.
Neuroreport
January 2025
Department of Neurosurgery.
Nowadays, intracerebral hemorrhage (ICH) is the main cause of death and disability, and motor impairment is a common sequel to ICH. Electroacupuncture (EA) has been widely used for functional recovery after ICH. However, its role and associated regulatory mechanisms in rehabilitation after ICH remain poorly understood.
View Article and Find Full Text PDFFunctional independence trajectories over 5 years in older veterans with traumatic brain injury: A model systems study.
PM R
January 2025
Department of Psychology, University of Virginia, Charlottesville, Virginia, USA.
Background: Research on older adults who sustain a traumatic brain injury (TBI) has predominantly been on civilian, nonveteran populations. Military populations experience higher rates of TBI and often experience the additive effects of TBI and other comorbid disorders, including posttraumatic stress disorder and/or substance use that may increase disability over time.
Objective: To investigate predictors of functional independence trajectories over the 5 years after TBI in veterans 55 years or older at injury.
Effect of Pulsed Electromagnetic Field and Microwave Therapy on Pain and Physical Function in Older Adults With Knee Osteoarthritis: A Randomized Clinical Trial.
J Geriatr Phys Ther
January 2025
Toledo Physiotherapy Research Group (GIFTO), Faculty of Physiotherapy and Nursery, Universidad de Castilla-La Mancha, Toledo, Spain.
Background And Purpose: The objective was to examine the adjuvant effect of active pulsed electromagnetic field (PEMF) versus microwave (MW) therapy, as well as sham PEMF, in addressing pain and improving functionality for treating knee osteoarthritis (KOA).
Methods: This was a double-blind, placebo-controlled, randomized clinical trial. Individuals diagnosed with KOA were assigned to an intervention combining an exercise program (EX) with active PEMF, MW, or sham PEMF.
Want AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!