Yrjänä S K, Katisko J P, Ojala R O, Tervonen O, Schiffbauer H, Koivukangas J
Department of Neurosurgery, Neurosurgical Research Unit, Oulu University Hospital, Finland.
Acta Neurochir (Wien). 2002 Mar;144(3):271-8; discussion 278. doi: 10.1007/s007010200035.
Several models for the application of intra-operative magnetic resonance imaging (IMRI) have recently been reported, most of them unique. Two fundamental issues need to be addressed: optimal use of the scanner to ensure a wide base for research, development and clinical application, and an organisational model that facilitates such use.
While in our setting the IMRI project was initiated by the neurosurgeons, the need for wider use of the facilities was recognised since the beginning of the planning phase in 1996. An organisational model was developed that allowed for development of neurosurgical applications, radiological imaging, and radiological interventions and for the research and development work of the vendor. A resistive 0.23 T MR scanner was installed in a dedicated operating room environment. Unique to this scanner is the ability to turn off the magnet, allowing for normal OR activities and devices, and to turn on the magnet as needed with a relatively short six-minute ramp up time. A staged surgical technique was perfected, allowing for transfer of data to the neuronavigator outside the scanner during surgery. In neurosurgery, IMRI was used as one part of a neuronavigational system that included ultrasound imaging, intra-operative cortical stimulation during awake procedures, electrocorticography and two neuronavigators.
34 neurosurgical cases included 27 brain tumour resections, 5 brain tumour biopsies, 1 extirpation of an arterio-venous malformation, and 1 haematoma evacuation. The scanner could also be used for normal clinical imaging where obese patients, children, claustophobic patients and postoperative control examinations were the major groups. The radiologists performed 110 interventions, including bone and abdominal biopsies, nerve root infiltrations and local pain therapies, with the optical needle tracking system under continuous MRI guidance. The organisational model allowed frequent use of the facilities for both neurosurgery and radiology and continuous development of the facilities. Intra-operative ultrasound was used in 20 tumour resections and in two open brain biopsies. This resulted in reduction of the number of MR imaging sessions during surgery. Five of the 27 resections were performed as awake craniotomies with cortical stimulation. For two of the resections, electrocorticography and depth electrode registrations were used. Furthermore, various non-MRI-compatible instruments and devices were used.
Intra-operative MRI is an imaging tool that can be useful especially in the context of neuronavigation. A scanner that can be turned off during surgery is particularly appropriate for neurosurgery. The concept of joint use of such facilities with other clinicians is mutually worthwhile.
最近报道了几种术中磁共振成像（IMRI）的应用模式，其中大多数独具特色。有两个基本问题需要解决：扫描仪的最佳使用方式，以确保为研究、开发和临床应用提供广泛基础；以及促进这种使用的组织模式。
在我们的机构中，IMRI项目由神经外科医生发起，自1996年规划阶段开始就认识到需要更广泛地使用这些设备。开发了一种组织模式，允许开展神经外科应用、放射成像、放射介入以及供应商的研发工作。一台0.23T的电阻式磁共振扫描仪安装在专用手术室环境中。该扫描仪的独特之处在于能够关闭磁体，以便进行正常的手术室活动和使用设备，并可根据需要在相对较短的6分钟升温时间内开启磁体。完善了一种分阶段手术技术，允许在手术期间将数据传输到扫描仪外的神经导航仪。在神经外科手术中，IMRI被用作神经导航系统的一部分，该系统包括超声成像、清醒手术期间的术中皮质刺激、皮质脑电图以及两台神经导航仪。
34例神经外科病例包括27例脑肿瘤切除术、5例脑肿瘤活检、1例动静脉畸形切除术和1例血肿清除术。该扫描仪还可用于正常临床成像，主要对象为肥胖患者、儿童、幽闭恐惧症患者以及术后对照检查。放射科医生在连续MRI引导下，使用光学针跟踪系统进行了110次介入操作，包括骨活检和腹部活检、神经根浸润以及局部疼痛治疗。这种组织模式允许神经外科和放射科频繁使用这些设备，并持续对设备进行改进。20例肿瘤切除术和2例开放性脑活检中使用了术中超声。这减少了手术期间的磁共振成像检查次数。27例切除术中的5例是在清醒开颅手术中进行皮质刺激。其中2例切除术使用了皮质脑电图和深度电极记录。此外，还使用了各种与MRI不兼容的仪器和设备。
术中磁共振成像是一种成像工具，尤其在神经导航背景下可能很有用。一种在手术期间可关闭的扫描仪特别适合神经外科手术。与其他临床医生联合使用此类设备的理念是互利的。
