PMC:6019327 / 173616-175422 JSONTXT

{"project":"2_test","denotations":[{"id":"28506916-20601148-29308003","span":{"begin":219,"end":222},"obj":"20601148"},{"id":"28506916-20601148-29308003","span":{"begin":219,"end":222},"obj":"20601148"},{"id":"28506916-19307477-29308004","span":{"begin":223,"end":226},"obj":"19307477"},{"id":"28506916-19307477-29308004","span":{"begin":223,"end":226},"obj":"19307477"},{"id":"28506916-24363354-29308005","span":{"begin":227,"end":230},"obj":"24363354"},{"id":"28506916-24363354-29308005","span":{"begin":227,"end":230},"obj":"24363354"},{"id":"28506916-19307477-29308006","span":{"begin":355,"end":358},"obj":"19307477"},{"id":"28506916-19307477-29308006","span":{"begin":355,"end":358},"obj":"19307477"},{"id":"28506916-24363354-29308007","span":{"begin":359,"end":362},"obj":"24363354"},{"id":"28506916-24363354-29308007","span":{"begin":359,"end":362},"obj":"24363354"},{"id":"28506916-24496537-29308008","span":{"begin":615,"end":618},"obj":"24496537"},{"id":"28506916-24496537-29308008","span":{"begin":615,"end":618},"obj":"24496537"},{"id":"T79169","span":{"begin":219,"end":222},"obj":"20601148"},{"id":"T10842","span":{"begin":219,"end":222},"obj":"20601148"},{"id":"T77561","span":{"begin":223,"end":226},"obj":"19307477"},{"id":"T41924","span":{"begin":223,"end":226},"obj":"19307477"},{"id":"T76773","span":{"begin":227,"end":230},"obj":"24363354"},{"id":"T18499","span":{"begin":227,"end":230},"obj":"24363354"},{"id":"T87686","span":{"begin":355,"end":358},"obj":"19307477"},{"id":"T59268","span":{"begin":355,"end":358},"obj":"19307477"},{"id":"T97379","span":{"begin":359,"end":362},"obj":"24363354"},{"id":"T74102","span":{"begin":359,"end":362},"obj":"24363354"},{"id":"T21866","span":{"begin":615,"end":618},"obj":"24496537"},{"id":"T12165","span":{"begin":615,"end":618},"obj":"24496537"},{"id":"T49613","span":{"begin":219,"end":222},"obj":"20601148"},{"id":"T7051","span":{"begin":219,"end":222},"obj":"20601148"},{"id":"T50672","span":{"begin":223,"end":226},"obj":"19307477"},{"id":"T13245","span":{"begin":223,"end":226},"obj":"19307477"},{"id":"T46061","span":{"begin":227,"end":230},"obj":"24363354"},{"id":"T55846","span":{"begin":227,"end":230},"obj":"24363354"},{"id":"T94003","span":{"begin":355,"end":358},"obj":"19307477"},{"id":"T40640","span":{"begin":355,"end":358},"obj":"19307477"},{"id":"T64173","span":{"begin":359,"end":362},"obj":"24363354"},{"id":"T44823","span":{"begin":359,"end":362},"obj":"24363354"},{"id":"T35365","span":{"begin":615,"end":618},"obj":"24496537"},{"id":"T69254","span":{"begin":615,"end":618},"obj":"24496537"}],"text":"Recently, the utility of delayed enhancement (DE) MRI has been introduced for detecting, quantifying, and localizing atrial fibrosis, including the definition of four categories of structural changes (Utah stages I–IV).130,560,561 The tissue characterization of the LA wall on DE MRI correlated with EAVM and with histology from surgical biopsy specimens.560,561 The association of atrial tissue fibrosis and AF catheter ablation outcomes, with more extensive fibrosis associated with lower efficacy, was confirmed in the multicenter Delayed Enhancement MRI and Atrial Fibrillation Catheter Ablation (DECAAF) study.365 On the other hand, these MRI findings at this point in time require extensive MRI experience, including specification of image contrast and continuity, required to set boundaries for the various degrees of fibrosis. The reproducibility of this approach is still under investigation. A major limitation of this approach is that the degree of scar identified depends strongly on the above thresholds used to define scar. At the present time, no uniform standard has been developed. This limitation hinders the reader-to-reader and day-to-day reproducibility of MRI-determined measurements of atrial scar. Once established, however, the DE MRI quantification and localization of atrial fibrosis might be used effectively to guide individually tailored substrate elimination comparable to EAVM-guided substrate modification. Finally, tissue visualization before and also during and directly after RF catheter ablation is the target for introducing real-time MRI into the clinical electrophysiological laboratory. Currently, the DECAAF-2 trial has been launched to test the hypothesis that ablation of scar detected on MRI improves ablation outcomes for persistent AF compared with PVI alone."}