Krings T, Schreckenberger M, Rohde V, Spetzger U, Sabri O, Reinges M H T, Hans F J, Meyer P T, Möller-Hartmann W, Gilsbach J M, Buell U, Thron A
Department of Neurosurgery, and the Interdisciplinary Center for Clinical Research, Central Nervous System, University Hospital of the Technical University, Aachen, Germany.
Acta Neurochir (Wien). 2002 Sep;144(9):889-99; discussion 899. doi: 10.1007/s00701-002-0992-8.
In patients with mass lesions near "eloquent" cortical areas different preoperative mapping techniques can be used. Two of the most widely used approaches include positron emission tomography (PET) and functional MRI (fMRI). We employed both methods in the same patients undergoing presurgical evaluation and compared the results to those obtained by direct electrical cortical stimulation (DECS).
22 patients with tumours of different aetiology near the central region were investigated. FMRI was performed using a T2(*)-weighted gradient-echo BOLD sequence at 1.5 T, PET was performed after injection of 122-301 MBq (18)F-Fluorodeoxyglucose (18-FDG) under rest and activation conditions. DECS was performed in all patients with recordings of muscles primarily involved in the investigated tasks.
In 19 patients all three modalities could be compared, 1 patient demonstrated discordance between fMRI and PET with DECS speaking in favour of fMRI, 6 patients had neighbouring results of PET and fMRI (between 1-2 cm distance), 12 patients had overlapping results.
The high incidence of neighbouring results is presumably related to fMRI specific artefacts. Advantages of fMRI are: Higher spatial and temporal resolution, more and different functional runs, shorter examination time, wider availability, longitudinal examinations, non-invasiveness and cost-effectiveness, easy registration to anatomical images. Advantages of PET are: higher signal-to-noise ratio, lesser susceptibility to artefacts (motion, draining veins), evaluation of tumour metabolism. It is our opinion that the neurosurgeon has to decide on a case-by-case basis which study suits his specific needs in the presurgical evaluation of his patient.
对于“明确功能”皮质区域附近有占位性病变的患者，可采用不同的术前定位技术。两种最常用的方法包括正电子发射断层扫描（PET）和功能磁共振成像（fMRI）。我们在接受术前评估的同一批患者中同时使用了这两种方法，并将结果与通过直接皮质电刺激（DECS）获得的结果进行比较。
对22例中央区附近不同病因肿瘤的患者进行研究。使用1.5T的T2（*）加权梯度回波BOLD序列进行fMRI，在静息和激活状态下注射122 - 301MBq的（18）F - 氟脱氧葡萄糖（18 - FDG）后进行PET检查。对所有患者进行DECS，并记录主要参与所研究任务的肌肉活动。
19例患者可对所有三种模式进行比较，1例患者fMRI与PET结果不一致，DECS结果支持fMRI；6例患者PET和fMRI结果相邻（距离在1 - 2厘米之间），12例患者结果重叠。
相邻结果的高发生率可能与fMRI特定的伪影有关。fMRI的优点包括：更高的空间和时间分辨率、更多且不同的功能运行、检查时间短、可用性更高、可进行纵向检查、无创性和成本效益高、易于与解剖图像配准。PET的优点包括：更高的信噪比、对伪影（运动、引流静脉）的敏感性较低、可评估肿瘤代谢。我们认为，神经外科医生必须根据具体情况决定哪种检查适合其患者术前评估的特定需求。
