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RACING1 and ELECTROPHYSIOLOGY www.ipej.org 197
Journal
Review Article
Magnetic Resonance Imaging in patients with ICDs and
Pacemakers
Prashant Nair MD, DM , Ariel Roguin MD, PhD
Department of Cardiology, Rambam Medical Center, B. Rappaport - Faculty of Medicine,
Technion - Israel Institute of Technology, Haifa, Israel.
Address for correspondence: Ariel Roguin MD PhD, Department of Cardiology, Rambam
Medical Center, B. Rappaport - Faculty of Medicine, Technion - Israel Institute of Technology,
Haifa 31096 Israel.E-mail: [email protected]
Abstract
Magnetic resonance (MR) imaging has unparalleled soft-tissue imaging capabilities. The
presence of devices such as pacemakers and implantable cardioverter/defibrillators (ICDs),
however, is historically considered a contraindication to MR imaging. These devices are now
smaller, with less magnetic material and improved electromagnetic interference protection. This
review summarizes the potential hazards of the device-MR environment interaction, and presents
updated information regarding in-vivo and in-vitro experiments. Recent reports on patients with
implantable pacemakers and ICDs who underwent MR scan shows that under certain conditions
patients with these implanted systems may benefit from this imaging modality. The data
presented suggests that certain modern pacemaker and ICD systems may indeed be MR safe.
This may have major clinical implications on current imaging practice.
Keywords: Imaging, MRI, safety, pacemaker, ICD
Introduction
Magnetic Resonance (MR) imaging is a diagnostic technique used to obtain high quality
images of the human body. The structure and abundance of water in the different tissues of the
human body is the key to clinical MR imaging. The basic concept of MR is the absorption or
emission of electromagnetic energy by atomic nuclei in a static magnetic field after excitation by
a radiofrequency (RF) pulse.1 A powerful magnet generates a magnetic field roughly 10,000
times stronger than the natural background magnetism from the earth. Various types of clinical
MR systems currently use the superconductive magnet which utilizes 0.5 Tesla to 3.0 Tesla.
Unlike conventional radiography and computed tomographic imaging, which make use of
potentially harmful radiation (X-rays), MR imaging has many advantages, including its
nonionizing nature and the unparallel ability to discriminate different soft tissues without contrast
media. MR imaging has now become the image modality of choice for imaging the brain, spine,
musculoskeletal system, head and neck, complex pediatric heart malformations and other tissue
structures.2
More recently, MR imaging has been applied successfully to assess myocardial structure, wall
motion, perfusion and viability. The number of MR scans performed annually has increased
dramatically over the past few years.—
Indian Pacing and Electrophysiology Journal (ISSN 0972-6292), 5(3): 197-209 (2005)