Characterization of Radiofrequency Ablation Lesions With Gadolinium-Enhanced Cardiovascular Magnetic Resonance Imaging
Timm Dickfeld, MD, PhD*,
Ritsushi Kato, MD, PhD,
Menekhem Zviman, PhD,
Shenghan Lai, PhD,
Glenn Meininger, MD,
Albert C. Lardo, PhD,
Ariel Roguin, MD, PhD,
David Blumke, MD, PhD,
Ronald Berger, MD, PhD,
Hugh Calkins, MD and
Henry Halperin, MD, MA
Division of Cardiology, Department of RadiologyJohns Hopkins School of Medicine, and the Division of Cardiology, University of Maryland, Baltimore, Maryland
View larger version (63K):
[in a new window]
|
Figure 1 Gadolinium enhancement of a radiofrequency ablation lesion. The time-course (1 to 600 min) after injection of 0.225 mmol/kg gadolinium demonstrates four characteristic phases of enhancement: (A) Schematic of magnetic resonance (MR) images (30-W radiofrequency [RF] and 40-W RF = 30- and 40-W RF ablation lesions; Myo = right ventricular myocardial wall; EP = epicardial side; EN = endocardial side; RV-C = right ventricular cavity). (B) Phase 1 with a contrast void. (C and D) Phase 2 displaying an increasing peripheral enhancement (white arrows). (E) Phase 3 showing "very" delayed enhancement with high signal intensity throughout the ablation lesion. (F) Phase 4 displaying loss of enhancement with decreasing signal intensity and lesion size. (G) Corresponding pathological specimen.
|
|
View larger version (35K):
[in a new window]
|
Figure 2 Contrast-to-noise-ratio during the four phases of gadolinium-enhanced imaging between the radiofrequency lesion and the adjacent myocardium (A). Signal-to-noise ratio of radiofrequency lesions during the four phases of gadolinium enhancement in lesion center, lesion periphery, and adjacent myocardium (B).
|
|
View larger version (34K):
[in a new window]
|
Figure 3 Correlation of radiofrequency lesion size and peripheral enhancement. Shown is the lesion size assessed in the pathological specimen compared with the lesion size assessed by magnetic resonance imaging (MRI) during the Phase 1 of contrast void (A), Phase 2 of peripheral enhancement (B), and Phase 3 of "very" delayed enhancement (C). Increasing thickness of peripheral enhancement over time observed as a rim of high signal intensity surrounding a center of low signal after the injection of 0.225 mmol/kg of gadolinium (D).
|
|
View larger version (93K):
[in a new window]
|
Figure 4 Evaluation of discontinuous ablation line. Gap (dotted arrow) observed in ablation line between two ablation lesions (solid arrows). Pathological specimen after chloraldehyde preparation (left panel) and with gadolinium-enhanced magnetic resonance imaging (right panel).
|
|
View larger version (89K):
[in a new window]
|
Figure 5 Radiofrequency ablation lesion. Masson's trichrome stain. (A) AM = adjacent myocardium; CAN = coagulation necrosis; CBN = contraction band necrosis. (B) Blue center core with severe coagulation necrosis, necrotic cavity, and complete loss of cellular structure. (C) Light purple periphery demonstrating contraction band necrosis with erythrocytes and cell debris in vasculature. (D) Adjacent viable myocardium. Calibration bars are presented in millimeters (mm).
|
|
|
