MRI use for atrial tissue characterization in arrhythmias and for EP procedure guidance

Acute enhancement of necrotic radio‐frequency ablation lesions in left atrium and pulmonary vein ostia in swine model with non‐contrast‐enhanced T1‐weighted MRI

“…A small number of target points (1-3) were ablated in the LA to test conspicuity in MRI. A larger number of points (10)(11)(12)(13)(14)(15)(16)(17)(18)(19)(20) were ablated circumferentially around the RSPV ostium to simulate a pulmonary vein isolation (PVI) procedure. 39 Electrical isolation was confirmed after ablation using conventional methods of EAM and pacing.…”

“…Acute imaging of tissue necrosis could reveal gaps for targeting of additional ablations to complete treatment and reduce recurrence. 6,[8][9][10][11][12][13][14] Several groups have reported MRI studies to visualize myocardial ablation lesions acutely, some using contrast-enhanced (CE) imaging with early gadolinium enhancement (EGE) or late enhancement (LGE) techniques. [15][16][17] Non-CE imaging with T 1 -weighted (T1w) [18][19][20][21][22][23] or T 2 -weighted (T2w) 18,19,22,24,25 pulse sequences have also been investigated.…”

“…MRI has been considered for years in this role, with its soft‐tissue contrast to indicate damaged or necrotic myocardium. Acute imaging of tissue necrosis could reveal gaps for targeting of additional ablations to complete treatment and reduce recurrence . Several groups have reported MRI studies to visualize myocardial ablation lesions acutely, some using contrast‐enhanced (CE) imaging with early gadolinium enhancement (EGE) or late enhancement (LGE) techniques .…”

Cardiovascular imaging 2018 in the International Journal of Cardiovascular Imaging

“…The use of CMR for atrial tissue characterization in arrhythmias and guidance for electrophysiology procedure guidance was reviewed [82]. Time-resolved contrastenhanced MRA was found to have superior image quality compared to traditional contrast-enhanced MRA in patients with atrial fibrillation being evaluated for ablation procedures [83].…”

Real-time photoacoustic assessment of radiofrequency ablation lesion formation in the left atrium

“…Thus far, Magnetic Resonance Imaging (MRI) and ultrasound elastography were the only two imaging modalities shown to assess RF ablation lesions in humans. However, both face challenges in monitoring lesion formation during RF energy delivery due to device compatibility, temporal resolution and motion artefacts caused by an asynchrony of acquisitions in an irregular heart rhythm [12,13]. Ultrasound imaging studies [14,15] showed promising results in monitoring RF ablation lesions in animal models but the small field of view of the imaging catheters that were used limits the assessment of the lesion as a whole.…”