TY - JOUR
T1 - Visualization of acute edema in the left atrial myocardium after radiofrequency ablation
T2 - Application of a novel high-resolution 3-dimensional magnetic resonance imaging sequence
AU - Zghaib, Tarek
AU - Akhavan Malayeri, Ashkan
AU - Ipek, Esra G.
AU - Habibi, Mohammadali
AU - Huang, Dong
AU - Balouch, Muhammad A.
AU - Bluemke, David Alan
AU - Calkins, Hugh
AU - Nazarian, Saman
AU - Zimmerman, Stefan L.
N1 - Funding Information:
This study was funded by National Institutes of Health Grants K23HL089333 and R01HL116280; and by a Biosense Webster grant to Dr. Nazarian. Dr. Malayeri was funded by a 2013 Radiological Society of North America Research Fellow Grant. Dr. Nazarian has received research grant funding from Biosense Webster during the conduct of the study. All other authors have reported they have no relationships relevant to the contents of this paper to disclose. Drs. Zghaib and Malayeri contributed equally to this work.
Publisher Copyright:
© 2018 Heart Rhythm Society
PY - 2018/8
Y1 - 2018/8
N2 - Background: Ablation-induced left atrial (LA) edema may result in procedural failure due to reversible pulmonary vein isolation. Conventional T2-weighted magnetic resonance edema imaging is limited by low spatial resolution. Objective: The purpose of this pilot study was to optimize and validate a 3-dimensional (3D) sampling perfection with application-optimized contrasts using different flip-angle evolution (SPACE) sequence for quantification of T2 signal in the LA, and to apply it in recently ablated patients, comparing myocardial edema on T2-SPACE to tissue damage on late gadolinium enhancement (LGE) imaging. Methods: Phantom studies were performed to identify 3D-SPACE parameters for optimal contrast between normal and edematous myocardium. Fourteen AF patients were imaged with both 3D-SPACE and dark-blood turbo-spin echo (DB-TSE) to compare image quality and signal intensity between the 2 techniques. Eight patients underwent pre- and postablation 3D-SPACE and 3D-LGE imaging. Ablation points were co-registered with corresponding myocardial sectors, and ablation-induced changes in T2 and LGE signal intensities were measured. Results: Signal-to-noise ratio and contrast-to-noise ratio were higher on SPACE vs DB-TSE (65.5 ± 33.9 vs 35.7 ± 17.9; P =.01; and 59.4 ± 33.0 vs 32.9 ± 17.7; P =.04, respectively). T2-signal correlated well on 3D-SPACE and DB-TSE, such that each unit increase in TSE intensity correlated with a 0.69-unit increase in SPACE intensity (95% confidence interval 0.56–0.82; P <.001). T2 and LGE signal intensities were acutely increased at ablation sites. The extent of postablation edema was higher compared to LGE, although the spatial distribution of hyperenhancement around pulmonary veins seemed similar in both modalities. Conclusion: T2-SPACE can be used to map the extent of acute postablation edema in the thin LA myocardium, with improved resolution and lower artifact compared to traditional DB-TSE.
AB - Background: Ablation-induced left atrial (LA) edema may result in procedural failure due to reversible pulmonary vein isolation. Conventional T2-weighted magnetic resonance edema imaging is limited by low spatial resolution. Objective: The purpose of this pilot study was to optimize and validate a 3-dimensional (3D) sampling perfection with application-optimized contrasts using different flip-angle evolution (SPACE) sequence for quantification of T2 signal in the LA, and to apply it in recently ablated patients, comparing myocardial edema on T2-SPACE to tissue damage on late gadolinium enhancement (LGE) imaging. Methods: Phantom studies were performed to identify 3D-SPACE parameters for optimal contrast between normal and edematous myocardium. Fourteen AF patients were imaged with both 3D-SPACE and dark-blood turbo-spin echo (DB-TSE) to compare image quality and signal intensity between the 2 techniques. Eight patients underwent pre- and postablation 3D-SPACE and 3D-LGE imaging. Ablation points were co-registered with corresponding myocardial sectors, and ablation-induced changes in T2 and LGE signal intensities were measured. Results: Signal-to-noise ratio and contrast-to-noise ratio were higher on SPACE vs DB-TSE (65.5 ± 33.9 vs 35.7 ± 17.9; P =.01; and 59.4 ± 33.0 vs 32.9 ± 17.7; P =.04, respectively). T2-signal correlated well on 3D-SPACE and DB-TSE, such that each unit increase in TSE intensity correlated with a 0.69-unit increase in SPACE intensity (95% confidence interval 0.56–0.82; P <.001). T2 and LGE signal intensities were acutely increased at ablation sites. The extent of postablation edema was higher compared to LGE, although the spatial distribution of hyperenhancement around pulmonary veins seemed similar in both modalities. Conclusion: T2-SPACE can be used to map the extent of acute postablation edema in the thin LA myocardium, with improved resolution and lower artifact compared to traditional DB-TSE.
KW - Atrial fibrillation
KW - Late gadolinium enhancement
KW - Left atrial edema
KW - Left atrial fibrosis
KW - Left atrial imaging
KW - Radiofrequency ablation
KW - T2-weighted imaging
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U2 - 10.1016/j.hrthm.2018.03.010
DO - 10.1016/j.hrthm.2018.03.010
M3 - Article
C2 - 29530833
AN - SCOPUS:85046169076
SN - 1547-5271
VL - 15
SP - 1189
EP - 1197
JO - Heart Rhythm
JF - Heart Rhythm
IS - 8
ER -