Inaccurate placement of the ablation catheter and the inability to monitor the real-time temperature within the tissue of interest such as veins curbs the treatment efficacy of laser ablation procedures during thermal therapies. Our previous studies have validated the efficacy of photoacoustic (PA) imaging during endovenous laser ablation (EVLA) procedures. However, the PA-guided therapies suffer from low temporal resolution, due to the low pulse repetition rates of pulsed lasers, which could cause a problem during fast catheter motion and rapid temperature changes. Herein, to enhance the accuracy and sensitivity for tracking the ablation catheter tip and temperature monitoring, we proposed to develop a high frame rate (500 Hz), combined ultrasound (US), and PA-guided ablation system. The proposed PA-guided ablation system was evaluated in a set of ex vivo tissue studies. The developed system provides a 2 ms temporal resolution for tracking and monitoring the ablation catheter tip’s location and temperature, which is 50 times higher temporal resolution compared to the previously proposed 10 Hz system. The proposed system also provided more accurate feedback about the temperature variations during rapid temperature increments of 10°C per 250 ms. The co-registered US and PA images have an imaging resolution of about 200 μm and a field of view of 45 × 40 mm². Tracking the ablation catheter tip in an excised tissue layer shows higher accuracy during a relatively fast catheter motion (0.5–3 mm/s). The fast US/PA-guided ablation system will potentially enhance the outcome of ablation procedures by providing location and temperature feedback.

消融导管的不准确放置和无法监测感兴趣的组织（例如静脉）内的实时温度会抑制热疗期间激光消融程序的治疗效果。我们之前的研究已经验证了光声 (PA) 成像在静脉内激光消融 (EVLA) 过程中的功效。然而，由于脉冲激光的脉冲重复率低，PA 引导疗法的时间分辨率低，这可能会在导管快速运动和快速温度变化期间引起问题。在此，为了提高跟踪消融导管尖端和温度监测的准确性和灵敏度，我们建议开发高帧率 (500 Hz)、组合超声 (US) 和 PA 引导的消融系统。在一组离体组织研究中评估了提议的 PA 引导的消融系统。开发的系统提供 2 毫秒的时间分辨率，用于跟踪和监测消融导管尖端的位置和温度，与之前提出的 10 Hz 系统相比，时间分辨率高 50 倍。在每 250 毫秒 10°C 的快速温度增量期间，提议的系统还提供了关于温度变化的更准确反馈。联合配准的 US 和 PA 图像的成像分辨率约为 200 μm，视场为 45 × 40 mm 在每 250 毫秒 10°C 的快速温度增量期间，提议的系统还提供了关于温度变化的更准确反馈。联合配准的 US 和 PA 图像的成像分辨率约为 200 μm，视场为 45 × 40 mm 在每 250 毫秒 10°C 的快速温度增量期间，提议的系统还提供了关于温度变化的更准确反馈。联合配准的 US 和 PA 图像的成像分辨率约为 200 μm，视场为 45 × 40 mm² . 在相对较快的导管运动 (0.5–3 mm/s) 期间，在切除的组织层中跟踪消融导管尖端显示出更高的准确性。通过提供位置和温度反馈，快速 US/PA 引导的消融系统将潜在地提高消融程序的结果。