Department of Internal Medicine II, Division of Cardiology, Medical University Vienna, Austria.
Ultraschall Med. 2013 Feb;34(1):51-7. doi: 10.1055/s-0032-1313083. Epub 2012 Aug 7.
Transtemporal sonothrombolysis is a tool for a more effective treatment in acute stroke patients. However, some reports revealed side effects, which might be potentially connected to temperature elevation. To gain better insight into cerebral temperature changes during transtemporal sonication, diagnostic and therapeutic ultrasound (US) applications were evaluated using an anthropomorphic skull model.
The impact of diagnostic (PW-Doppler, 1.8-MHz, 0.11 W/cm², TIC 1.2) and therapeutic (1-MHz and 3-MHz, 0.07 - 0.71 W/cm², continuous and pulsed mode) US application on temperature changes was evaluated at the level of muscle/temporal bone (TB), TB/brain, brain and at the middle cerebral artery (MCA) using 4 miniature thermocouples along the US beam. Sonication lasted 120 minutes.
Diagnostic ultrasound revealed a maximum temperature increase of 1.45°/0.60°/0.39°/0.41°C (muscle/TB, TB/brain, brain, MCA) after 120 minutes. Therapeutic-1-MHz ultrasound raised temperature by 4.33°/2.02°/1.05 °C/0.81°C (pulsed 1:20) and by 10.38°/4.95°/2.43°/2.08°C (pulsed 1:5) over 120 minutes. Therapeutic-3-MHz US raised temperature by 4.89°/2.56°/1.24/1.25°C (pulsed 1:20) and by 14.77°/6.59°/3.56°/2.86°C (pulsed 1:5) over 120 minutes, respectively. Continuous application of therapeutic US (1-MHz and 3-MHz) led to a temperature increase of 13.86°/3.63°/1.66°/1.48°C and 17.09°/4.28°/1.38/0.99°C within 3 minutes.
Diagnostic PW-Doppler showed only a moderate temperature increase and can be considered as safe. Therapeutic sonication is very powerful in delivering energy so that even pulsed application modes resulted in significant and potentially harmful temperature increases.
经颞骨超声溶栓是治疗急性脑卒中患者的一种更有效的手段。然而，一些报道显示其存在副作用，这可能与温度升高有关。为了更深入地了解经颞骨超声治疗过程中大脑温度的变化，本研究使用仿体颅骨模型评估了诊断和治疗超声（US）应用的影响。
在肌肉/颞骨（TB）、TB/脑、脑和大脑中动脉（MCA）水平上，使用沿 US 束的 4 个微型热电偶，评估诊断（PW-Doppler，1.8MHz，0.11W/cm²，TIC 1.2）和治疗（1MHz 和 3MHz，0.07-0.71W/cm²，连续和脉冲模式）US 应用对温度变化的影响。超声治疗持续 120 分钟。
诊断性 US 在 120 分钟后产生的最大温升分别为 1.45°C/0.60°C/0.39°C/0.41°C（肌肉/TB、TB/脑、脑、MCA）。治疗性 1MHz US 在 120 分钟内将温度升高 4.33°C/2.02°C/1.05°C/0.81°C（脉冲 1:20）和 10.38°C/4.95°C/2.43°C/2.08°C（脉冲 1:5）。治疗性 3MHz US 在 120 分钟内将温度升高 4.89°C/2.56°C/1.24°C/1.25°C（脉冲 1:20）和 14.77°C/6.59°C/3.56°C/2.86°C（脉冲 1:5）。治疗性 US（1MHz 和 3MHz）连续应用 3 分钟可分别导致 13.86°C/3.63°C/1.66°C/1.48°C 和 17.09°C/4.28°C/1.38°C/0.99°C 的温升。
诊断性 PW-Doppler 仅显示出适度的温升，可被认为是安全的。治疗性超声能量传递非常强大，即使是脉冲应用模式也会导致显著且潜在有害的温升。
