Background: Visual confirmation of radiofrequency ablation (RFA) lesions during clinical cardiac ablation procedures could improve procedure efficacy, safety, and efficiency. It was previously shown that acoustic radiation force impulse (ARFI) imaging can identify RFA lesions in vitro and in vivo in an animal model. This is the "first-in-human" feasibility demonstration of intracardiac ARFI imaging of RFA lesions in patients undergoing catheter ablation for atrial flutter (AFL) or atrial fibrillation (AF).
Methods And Results: Patients scheduled for right atrial (RA) ablation for AFL or left atrial (LA) ablation for drug refractory AF were eligible for imaging. Diastole-gated intracardiac ARFI images were acquired using one of two equipment configurations: (1) a Siemens ACUSON S2000™ ultrasound scanner and 8/10Fr AcuNav™ ultrasound catheter, or (2) a CARTO 3™ integrated Siemens SC2000™ and 10Fr SoundStar™ ultrasound catheter. A total of 11 patients (AFL = 3; AF = 8) were imaged. ARFI images were acquired of ablation target regions, including the RA cavotricuspid isthmus (CTI), and the LA roof, pulmonary vein ostia, posterior wall, posterior mitral valve annulus, and the ridge between the pulmonary vein and LA appendage. ARFI images revealed increased relative myocardial stiffness at ablation catheter contact sites after RFA and at anatomical mapping-tagged RFA treatment sites.
Conclusions: ARFI images from a pilot group of patients undergoing catheter ablation for AFL and AF demonstrate the ability of this technique to identify intra-procedure RFA lesion formation. The results encourage further refinement of ARFI imaging clinical tools and continued investigation in larger clinical trials.
Download full-text PDF |
Source |
---|---|
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4399801 | PMC |
http://dx.doi.org/10.1111/jce.12514 | DOI Listing |
J Magn Reson Imaging
January 2025
Department of Radiology and Imaging Sciences, University of Utah, Salt Lake City, Utah, USA.
This review covers the theoretical background, pulse sequence considerations, practical implementations, and multitudes of applications of magnetic resonance acoustic radiation force imaging (MR-ARFI) described to date. MR-ARFI is an approach to encode tissue displacement caused by the acoustic radiation force of a focused ultrasound field into the phase of a MR image. The displacement encoding is done with motion encoding gradients (MEG) which have traditionally been added to spin echo-type and gradient recalled echo-type pulse sequences.
View Article and Find Full Text PDFInt J Hyperthermia
December 2025
Department of Mechanical Engineering, Brigham Young University, Provo, UT, USA.
Purpose: In magnetic resonance-guided focused ultrasound (MRgFUS) breast therapies, the focal location must be characterized to guide successful treatment. Focal characterization is difficult because heterogeneous breast tissues introduce phase aberrations that blur and shift the focus and traditional guidance methods do not work in adipose tissues. The purpose of this work is to evaluate numerical simulations of MRgFUS that predict the focal location.
View Article and Find Full Text PDFArq Gastroenterol
January 2025
Universidade Federal de São Paulo, São Paulo, SP, Brasil.
Background: Liver biopsy (LB) is still the gold standard method for assessing hepatic fibrosis (HF), associated diseases, and liver inflammation. Nowadays, noninvasive techniques such as Acoustic radiation force impulse (ARFI) elastography have been introduced instead of liver biopsy. However, there are controversies about the time it should be performed after treatment for hepatitis C virus (HCV).
View Article and Find Full Text PDFMed Biol Eng Comput
January 2025
Department of Biomedical Engineering, Indian Institute of Technology, Ropar, Punjab, India.
Blood pressure (BP) is one of the vital physiological parameters, and its measurement is done routinely for almost all patients who visit hospitals. Cuffless BP measurement has been of great research interest over the last few years. In this paper, we aim to establish a method for cuffless measurement of BP using ultrasound.
View Article and Find Full Text PDFUltrason Imaging
January 2025
Department of Biomedical Engineering, Duke University, Durham, NC, USA.
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!