Document Detail

Characterization of acute and subacute radiofrequency ablation lesions with nonenhanced magnetic resonance imaging.
MedLine Citation:
PMID:  17275759     Owner:  NLM     Status:  MEDLINE    
BACKGROUND: Magnetic resonance imaging (MRI) has the potential to visualize radiofrequency (RF) ablations, which have become the preferred strategy for treatment of many arrhythmias. However, MRI patterns after RF ablation have not been well investigated.
OBJECTIVE: The purpose of this study was to define the characteristic appearance and the effect of time and energy on noncontrast-enhanced MRI of RF ablation.
METHODS: Using a power-controlled, cooled-tip ablation system, RF ablation lesions (5-50 W for 45 seconds) were created on the right ventricular epicardium in 10 mongrel dogs. T1- and T2-weighted MR images were obtained during 12-hour follow-up and compared with gross anatomy and histopathology.
RESULTS: Lesions were successfully visualized with T2- and T1-weighted images 30 minutes to 12 hours after RF ablation. T2 images were more consistent and displayed a characteristic elliptical, high-signal core (contrast-to-noise-ratio [CNR] = 18.9 +/- 8.4) with a surrounding 0.5-mm low-intensity rim that on histopathology corresponded to the central tissue necrosis and the transition zone, respectively. T1 images showed a less remarked increase in signal intensity (CNR = 9.6 +/- 7.4) without a surrounding rim. Lesion size and appearance were well defined and unchanged during the 12-hour follow-up (analysis of variance). CNR was independent of applied RF energy and allowed accurate assessment of RF ablation at all time points (r = 0.87 and r = 0.83 for T2 and T1 images, respectively). Transmural lesions, interlesional gaps, and intralesional pathology could be reliably predicted in >90%.
CONCLUSION: Noncontrast-enhanced MRI allows accurate assessment of RF ablation and its intralesional pathology during 12-hour follow-up. This finding confirms a possible role of MRI in guiding and evaluating RF application during electrophysiologic ablation procedures.
Timm Dickfeld; Ritsushi Kato; Menekem Zviman; Saman Nazarian; Jun Dong; Hiroshi Ashikaga; Albert C Lardo; Ronald D Berger; Hugh Calkins; Henry Halperin
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Publication Detail:
Type:  Journal Article; Research Support, N.I.H., Extramural; Research Support, Non-U.S. Gov't     Date:  2006-11-01
Journal Detail:
Title:  Heart rhythm : the official journal of the Heart Rhythm Society     Volume:  4     ISSN:  1547-5271     ISO Abbreviation:  Heart Rhythm     Publication Date:  2007 Feb 
Date Detail:
Created Date:  2007-02-05     Completed Date:  2007-12-20     Revised Date:  2013-06-06    
Medline Journal Info:
Nlm Unique ID:  101200317     Medline TA:  Heart Rhythm     Country:  United States    
Other Details:
Languages:  eng     Pagination:  208-14     Citation Subset:  IM    
Division of Cardiology, Johns Hopkins School of Medicine, Baltimore, Maryland 21201, USA.
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MeSH Terms
Acute Disease
Analysis of Variance
Catheter Ablation*
Linear Models
Magnetic Resonance Imaging / methods*
Pericardium / pathology*,  surgery
Grant Support
Comment In:
Heart Rhythm. 2007 Feb;4(2):215-7   [PMID:  17275760 ]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine

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