Radiology, Vol 179, 505-508, Copyright © 1991 by Radiological Society of North America

ARTICLES

Important considerations in measurement of attractive force on metallic implants in MR imagers

NJ Kagetsu and AW Litt
Department of Radiology, New York University Medical Center, NY 10016.

Almost all reported measurements of the attractive force exerted on metallic implants in magnetic fields of magnetic resonance imagers have been obtained at the portal. This study was done to determine whether the maximum force on an implant is at the portal. Horizontal attractive forces on needles were measured along the axis of the bore at various distances from the portal of a 0.3-T vertical-field magnet and 0.5- and 1.5-T solenoid magnets. Upward vertical forces along the top of the bore were also measured. The horizontal forces 40 cm in from the portals of the 0.5- and 1.5-T magnets were 70%-80% greater than the horizontal forces at the portal. The upward vertical force at the top of the 0.3-T magnet bore, 63 cm in from the portal, was 20 times the horizontal force at the portal and was twice the maximum force measured in the 0.5-T magnet. The maximum force was not at the portal.

This article has been cited by other articles:

				M. R. Patel, T. S. E. Albert, D. E. Kandzari, E. F. Honeycutt, L. K. Shaw, M. H. Sketch Jr, M. D. Elliott, R. M. Judd, and R. J. Kim Acute Myocardial Infarction: Safety of Cardiac MR Imaging after Percutaneous Revascularization with Stents Radiology, September 1, 2006; 240(3): 674 - 680. [Abstract] [Full Text] [PDF]

				C. T. Hennemeyer, K. Wicklow, D. A. Feinberg, and C. P. Derdeyn In Vitro Evaluation of Platinum Guglielmi Detachable Coils at 3 T with a Porcine Model: Safety Issues and Artifacts Radiology, June 1, 2001; 219(3): 732 - 737. [Abstract] [Full Text] [PDF]

				E. Kanal and F. G. Shellock Aneurysm Clips: Effects of Long-term and Multiple Exposures to a 1.5-T MR System Radiology, February 1, 1999; 210(2): 563 - 565. [Abstract] [Full Text]