Abstract 17420: First Clinical Experience of Novel MRI Artifact Suppression Sequence in ICD Patients Undergoing Scar Delineation for Ventricular Tachycardia (VT) Ablation

Background: Recent studies have suggested that CMR imaging can be safely performed in selected patients with implanted ICDs. However, metal artifacts significantly impact the evaluation of myocardial fibrosis when using standard late gadolinium enhanced (LGE) protocols. Methods: 10 continuous patients scheduled for VT ablation underwent LGE CMR imaging (1.5T Siemens Avanto) for scar delineation using either the standard clinical late gadolinium enhancement (LGE) sequences (n=5) or a novel MR pulse sequence that used an inversion preparation pulse with a wide inversion bandwidth of 2.4kHz (n=5). Results: Standard LGE MR sequences produced a large central signal void with surrounding hyperintensity due to voxel dephasing. The new wide inversion bandwidth sequence reduced the artifact in the right ventricle from 21±7% to 1.2±1.3% (p<.001). Similarly, the new MRI sequence reduced the artifact in the LV from 44±9% to 4.5±5.7% (p<.001). LV artifact location changed from 100% (inferior), 100% (septal), 100% (lateral) and 100% (anterior) to 0%, 0%, 0% and 60%, respectively. Similarly, the LV artifact present was present in the basal, mid and apical segment in 100%, 100%, and 100% in the old sequence but was reduced to 0%, 60%, and 20% in the new sequence (Fig.1). While the artifact of the standard sequence prevented the reliable predictions of the voltage-defined scar during VT ablation, no significant low voltage area outside the imaged LGE areas were found in the patients imaged with the new MRI sequence. Conclusions: Widening the inversion bandwidth achieves a dramatic reduction in ICD metal artifact during LGE CMR imaging and allows a near completely evaluation of the whole myocardium. This allowed the reliable prediction of low voltage areas during VT ablation despite presence of ICD.