[Monitoring radiofrequency ablation by ultrasound temperature imaging and elastography under different power intensities].
OBJECTIVE
To evaluate the reliability of diagnostic ultrasound-based temperature and elasticity imaging during radiofrequency ablation (RFA) through ex vivo experiments.


METHODS
Procine liver samples (n=7) were employed for RFA experiments with exposures of different power intensities (10 and 50w). The RFA process was monitored by a diagnostic ultrasound imager and the information were postoperatively captured for further temperature and elasticity image analysis. Infrared thermometry was concurrently applied to provide temperature change calibration during the RFA process.


RESULTS
Results from this study demonstrated that temperature imaging was valid under 10 W RF exposure (r=0.95), but the ablation zone was no longer consistent with the reference infrared temperature distribution under high RF exposures. The elasticity change could well reflect the ablation zone under a 50 W exposure, whereas under low exposures, the thermal lesion could not be well detected due to the limited range of temperature elevation and incomplete tissue necrosis.


CONCLUSIONS
Diagnostic ultrasound-based temperature and elastography is valid for monitoring thr RFA process. Temperature estimation can well reflect mild-power RF ablation dynamics, whereas the elastic-change estimation can can well predict the tissue necrosis. This study provide advances toward using diagnostic ultrasound to monitor RFA or other thermal-based interventions.
School of Electronic and Information Engineering, Tianjin University, Tianjin 300072, China.E-mail: xiaonan_geng@hotmail.com.
Xiaonan
X
Geng
Qiang
Q
Li
Pohsiang
P
Tsui
Chiaoyin
C
Wang
Haoli
H
Liu
D000818:Animals; D017115:Catheter Ablation / Q000379:methods*; D054459:Elasticity Imaging Techniques; D008099:Liver / Q000000981:diagnostic imaging*; D013552:Swine; D013696:Temperature