Abstract 14364: Off-Resonance Insensitive LGE MRI for Imaging Ventricular Scar Without Image Artifacts Induced by Cardiac Devices
Introduction: Radiofrequency (RF) ablation procedure for treating ventricular tachycardia (VT) requires identification of ventricular scar or arrhythmia substrate. Late gadolinium enhanced (LGE) MRI is routinely used to identify myocardial scar for guiding VT ablation. Many patients with VT have an implantable cardioverter-defibrillator (ICD), which generate severe MRI artifacts. We developed a novel cardiac device insensitive LGE MRI method by using an adiabatic secant inversion pulse with a wide frequency bandwidth = 4.0 kHz and evaluated its performance against the standard LGE MRI method with a frequency bandwidth = 1.1 kHz in the challenging setting of 3T.
Methods: In a canine model (n=4) RF ablation was carried out in the left and right ventricle using an RF ablation catheter (Biosense Webstter, Diamond Bar, CA). After infusion of a gadolinium contrast agent (0.15 mmol/kg, Gd-BOPTA), standard LGE images were acquired at 3T (Siemens, Verio) to identify the ablation lesions. Next, an ICD was placed approximately 10 cm from the heart and both standard and the new device insensitive LGE pulse sequences were performed with identical imaging parameters, including the inversion time to null the normal myocardium. To test the clinical utility, both standard and the new LGE pulse sequences were performed in a male volunteer with the ICD placed 10 cm from the heart.
Results: Figure 1 shows standard and the new device insensitive LGE images of a dog with RF ablation lesions and the volunteer without any lesions. In all 4 animals, standard LGE MRI yielded large artifacts while the new device insensitive LGE MRI exhibited no significant artifacts and enabled complete identification of RF ablation lesions.
Conclusions: The novel LGE MRI pulse sequence is insensitive to image artifacts induced by an ICD and may be useful for identification of ventricular substrate in patients with cardiac devices.
- Magnetic resonance imaging
- Ablation, radiofrequency
- Implantable cardioconvert defibrillator
- Ventricular tachycardia
- © 2013 by American Heart Association, Inc.