Feasibility of real-time magnetic resonance imaging for catheter guidance in electrophysiology studies.
BACKGROUND
Compared with fluoroscopy, the current imaging standard of care for guidance of electrophysiology procedures, magnetic resonance imaging (MRI) provides improved soft-tissue resolution and eliminates radiation exposure. However, because of inherent magnetic forces and electromagnetic interference, the MRI environment poses challenges for electrophysiology procedures. In this study, we sought to test the feasibility of performing electrophysiology studies with real-time MRI guidance.


RESULTS
An MRI-compatible electrophysiology system was developed. Catheters were targeted to the right atrium, His bundle, and right ventricle of 10 mongrel dogs (23 to 32 kg) via a 1.5-T MRI system using rapidly acquired fast gradient-echo images (approximately 5 frames per second). Catheters were successfully positioned at the right atrial, His bundle, and right ventricular target sites of all animals. Comprehensive electrophysiology studies with recording of intracardiac electrograms and atrial and ventricular pacing were performed. Postprocedural pathological evaluation revealed no evidence of thermal injury to the myocardium. After proof of safety in animal studies, limited real-time MRI-guided catheter mapping studies were performed in 2 patients. Adequate target catheter localization was confirmed via recording of intracardiac electrograms in both patients.


CONCLUSIONS
To the best of our knowledge, this is the first study to report the feasibility of real-time MRI-guided electrophysiology procedures. This technique may eliminate patient and staff radiation exposure and improve real-time soft tissue resolution for procedural guidance.
Nazarian
Saman
S
Department of Medicine, Division of Cardiology, Johns Hopkins Hospital, Carnegie 592C, 600 N Wolfe St, Baltimore, MD 21287, USA. snazarian@jhmi.edu
Kolandaivelu
Aravindan
A
Zviman
Menekhem M
MM
Meininger
Glenn R
GR
Kato
Ritsushi
R
Susil
Robert C
RC
Roguin
Ariel
A
Dickfeld
Timm L
TL
Ashikaga
Hiroshi
H
Calkins
Hugh
H
Berger
Ronald D
RD
Bluemke
David A
DA
Lardo
Albert C
AC
Halperin
Henry R
HR
D000818:Animals; D002036:Bundle of His; D006328:Cardiac Catheterization / Q000009:adverse effects / Q000295:instrumentation / Q000379:methods*; D002304:Cardiac Pacing, Artificial; D002404:Catheterization; D003199:Computer Systems; D004285:Dogs; D017352:Echo-Planar Imaging; D004594:Electrophysiology / Q000379:methods*; D005240:Feasibility Studies; D006325:Heart Atria; D006358:Hot Temperature; D006801:Humans; D053783:Magnetic Resonance Imaging, Interventional / Q000009:adverse effects