Safety of Cardiac Pacemakers in 1.5T Tesla MRI
To evaluate short-term and long-term effects by MR imaging on the technical and functional status of Medtronic pacemakers.
|Study Design:||Observational Model: Defined Population
Observational Model: Natural History
Time Perspective: Longitudinal
Time Perspective: Prospective
|Official Title:||Studie Zur Sicherheit Von Medtronic Schrittmachern Bei Magnetresonanz-Bildgebungsverfahren an 1,5 Tesla-Systemen Study to Evaluate Safety Medtronic Pacemakers in MR Imaging at 1.5T Tesla)|
|Study Start Date:||December 2002|
|Estimated Study Completion Date:||January 2006|
The presence of a cardiac pacemaker (PM) is currently considered an absolute contraindication to MR imaging, and most patients with PM are excluded from having MRI. In 2002 there were approximately 2.4 million patients in the US with cardiac PM, and this number is growing by 80,000 annually. A previous study has shown that MRI is indicated in 17% of all patients with pacemakers within 12 months of device placement 1, demonstrating the need for a practical and safe approach for performing MRI on PM patients.
The aim of this study is to develop a strategy for safe performance of MR imaging at 1.5T, which included exclusion of pacemaker dependent patients and those requiring imaging of the thorax, restriction of specific absorption rate (SAR) values to minimize the risk of lead heating, and PM reprogramming to avoid interference from time varying gradient fields. The safety of this approach is then evaluated in a large group of PM patients including assessment of potential myocardial thermal injury by measuring serum troponin I and pacing capture thresholds, and performing a 3-month follow-up to evaluate long-term effects.
|University of Bonn, Department of Radiology|
|Bonn, NRW, Germany, 53127|
|Principal Investigator:||Torsten Sommer, MD||University of Bonn, Department of Radiology|