Dependence of T2* Relaxation Time of Cardiac Cryo and RF Lesions on Time after Ablation: A New Approach to Non-contrast MRI of Cardiac Ablation Lesions

RF and Cryo ablations are being increasingly used for treatment of cardiac arrhythmias. LGE-MRI is widely used for characterization of RF and Cryo lesions. However, LGE-MRI requires contrast injection. Recently proposed native T1w techniques are only useful for visualization of acute (< 3 days) RF lesions. T2* relaxation time of RF and Cryo lesions significantly changes with time after ablation. T2* time of ablated myocardium is considerably lower that T2* time of normal myocardium after 1 week post-ablation. A native T2*-weighted MRI technique which can be used to visualize both RF and Cryo lesions has been developed and validated in animal studies.