Abe Keiichi, Taira Takaomi
Department of Neurosurgery, Tokyo Women's Medical University.
Neurol Med Chir (Tokyo). 2017 Aug 15;57(8):386-391. doi: 10.2176/nmc.ra.2017-0024. Epub 2017 Jun 28.
The discovery that ultrasound waves could be focused inside the skull and heated to high temperatures at a focal point goes back to 1944. However, because the skull causes the ultrasound waves to attenuate and scatter, it was believed that application of this technology would be difficult, and that it would be impossible to use this approach in the surgical treatment of intracranial diseases. Eventually, magnetic resonance image guided focused ultrasound (MRgFUS) surgery began being used to treat uterine fibroids, breast cancer and bone metastasis and locally confined prostate cancer. In the first ten years of the 21st century, new developments in this technology have been achieved, broadening the scope of practical application, and treatment is now being performed in various countries around the world. In 2011, third-generation transcranial focused ultrasound made it possible to use thermocoagulation and create intracranial lesions measuring 2 to 6 mm in diameter with a precision of around 1 mm. It was also possible to produce MR images which relay information of temperature changes in real time, enabling a shift from reversible test heating to irreversible therapeutic heating. This gave rise to the possibility of a minimally-invasive treatment with outcomes similar to those of conventional brain surgery. This method is paving the way to a new future not only in functional neurosurgery, but in cranial neurosurgery targeting conditions such as epilepsy and brain tumors, among others. In this paper, we describe the current state and future outlook of magnetic resonance image guided focused ultrasound, which uses computed tomography (CT) bone images in combination with MRI monitoring of brain temperature.
超声波能够聚焦于颅骨内部并在焦点处加热至高温这一发现可追溯到1944年。然而，由于颅骨会使超声波衰减和散射，人们认为应用这项技术会很困难，并且不可能将这种方法用于颅内疾病的外科治疗。最终，磁共振成像引导聚焦超声（MRgFUS）手术开始用于治疗子宫肌瘤、乳腺癌、骨转移瘤以及局部局限型前列腺癌。在21世纪的头十年里，这项技术取得了新进展，拓宽了实际应用范围，目前世界各国都在开展相关治疗。2011年，第三代经颅聚焦超声实现了热凝治疗，并能够精确制造直径为2至6毫米的颅内病变，精度约为1毫米。还能够生成实时传递温度变化信息的磁共振图像，从而实现从可逆性试验加热到不可逆性治疗加热的转变。这使得微创治疗成为可能，其效果与传统脑外科手术相似。这种方法不仅在功能神经外科领域，而且在针对癫痫和脑肿瘤等病症的颅脑神经外科领域都为新的未来铺平了道路。在本文中，我们描述了结合计算机断层扫描（CT）骨图像与大脑温度磁共振成像监测的磁共振成像引导聚焦超声的现状和未来展望。
