title: Contrast in intracardiac acoustic radiation force impulse images of radiofrequency ablation lesions.
abstract: We have previously shown that intracardiac acoustic radiation force impulse (ARFI) imaging visualizes tissue stiffness changes caused by radiofrequency ablation (RFA). The objectives of this in vivo study were to (1) quantify measured ARFI-induced displacements in RFA lesion and unablated myocardium and (2) calculate the lesion contrast (C) and contrast-to-noise ratio (CNR) in two-dimensional ARFI and conventional intracardiac echo images. In eight canine subjects, an ARFI imaging-electroanatomical mapping system was used to map right atrial ablation lesion sites and guide the acquisition of ARFI images at these sites before and after ablation. Readers of the ARFI images identified lesion sites with high sensitivity (90.2%) and specificity (94.3%) and the average measured ARFI-induced displacements were higher at unablated sites (11.23 ± 1.71 µm) than at ablated sites (6.06 ± 0.94 µm). The average lesion C (0.29 ± 0.33) and CNR (1.83 ± 1.75) were significantly higher for ARFI images than for spatially registered conventional B-mode images (C = -0.03 ± 0.28, CNR = 0.74 ± 0.68).
authors.affiliation: 1Department of Biomedical Engineering, Duke University, Durham, NC, USA.
authors.forename: Stephanie A
authors.initials: SA
authors.lastname: Eyerly
authors.forename: Tristram D
authors.initials: TD
authors.lastname: Bahnson
authors.forename: Jason I
authors.initials: JI
authors.lastname: Koontz
authors.forename: David P
authors.initials: DP
authors.lastname: Bradway
authors.forename: Douglas M
authors.initials: DM
authors.lastname: Dumont
authors.forename: Gregg E
authors.initials: GE
authors.lastname: Trahey
authors.forename: Patrick D
authors.initials: PD
authors.lastname: Wolf
mesh_terms: D000818:Animals; D006348:Cardiac Surgical Procedures / Q000379:methods; D017115:Catheter Ablation / Q000379:methods*; D004285:Dogs; D054459:Elasticity Imaging Techniques / Q000379:methods*; D006325:Heart Atria / Q000000981:diagnostic imaging; D007089:Image Enhancement / Q000379:methods*; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D008297:Male; D012680:Sensitivity and Specificity
keywords: acoustic radiation force impulse imaging; cardiac radiofrequency ablation; electroanatomical mapping; intracardiac echocardiography