In vivo evaluation of focused ultrasound ablation surgery (FUAS)-induced coagulation using echo amplitudes of the therapeutic focused ultrasound transducer

• Published in: International journal of hyperthermia Vol. 41; no. 1; p. 2325477
• Main Authors: Zhou, Yufeng, Gong, Xiaobo, You, Yaqing
• Format: Journal Article
• Language: English
• Published: England Taylor & Francis Group 2024
• Subjects: Animals; Blood Coagulation; coagulation prediction; coagulative necrosis; echo amplitude; focused ultrasound (FUS) transducer; Focused ultrasound ablation surgery FUAS; Kidney - diagnostic imaging; Kidney - surgery; Liver - diagnostic imaging; Liver - surgery; sonography; Transducers; Ultrasonic Therapy; coagulative necrosis; echo amplitude; Focused ultrasound ablation surgery FUAS; coagulation prediction; focused ultrasound (FUS) transducer; sonography
• ISSN: 0265-6736; 1464-5157
• DOI: 10.1080/02656736.2024.2325477

Monitoring sensitivity of sonography in focused ultrasound ablation surgery (FUAS) is limited (no hyperechoes in ∼50% of successful coagulation in uterine fibroids). A more accurate and sensitive approach is required. The echo amplitudes of the focused ultrasound (FUS) transducer in a testing mode (short pulse duration and low power) were found to correlate with the coagulation. To further evaluate its coagulation prediction capabilities, experiments were carried out. The liver, kidney, and leg muscles of three adult goats were treated using clinical FUAS settings, and the echo amplitude of the FUS transducer and grayscale in sonography before and after FUAS were collected. On day 7, animals were sacrificed humanely, and the treated tissues were dissected to expose the lesion. Echo amplitude changes and lesion areas were analyzed statistically, as were the coagulation prediction metrics. The echo amplitude changes of the FUS transducer correlate well with the lesion areas in the liver (  = 0.682). Its prediction in accuracy (94.4% vs. 50%), sensitivity (92.9% vs. 35.7%), and negative prediction (80% vs. 30.8%) is better than sonography, but similar in specificity (80% vs. 100%) and positive prediction (100% vs. 100%). In addition, the correlation between tissue depth and the lesion area is not good (| | < 0.2). Prediction performances in kidney and leg muscles are similar. The FUS echo amplitudes are sensitive to the tissue properties and their changes after FUAS. They are sensitive and reliable in evaluating and predicting FUAS outcomes.