gms | German Medical Science

57th Annual Meeting of the German Society of Neurosurgery
Joint Meeting with the Japanese Neurosurgical Society

German Society of Neurosurgery (DGNC)

11 - 14 May, Essen

Preliminary experience in glioma surgery using intraoperative low field MRI (Pole Star N 20, 0.15T)

Vorläufige Ergebnisse in der Gliomchirurgie unter Verwendung eines niedrig Feld intraoperativen Kernspintomographen (Pole Star N 20, 0.15T)

Meeting Abstract

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  • corresponding author V. Ntoukas - Neurochirurgische Klinik, Universitätsklinikum Frankfurt, Frankfurt/Main
  • V. Seifert - Neurochirurgische Klinik, Universitätsklinikum Frankfurt, Frankfurt/Main

Deutsche Gesellschaft für Neurochirurgie. Japanische Gesellschaft für Neurochirurgie. 57. Jahrestagung der Deutschen Gesellschaft für Neurochirurgie e.V. (DGNC), Joint Meeting mit der Japanischen Gesellschaft für Neurochirurgie. Essen, 11.-14.05.2006. Düsseldorf, Köln: German Medical Science; 2006. DocSA.03.03

The electronic version of this article is the complete one and can be found online at:

Published: May 8, 2006

© 2006 Ntoukas et al.
This is an Open Access article distributed under the terms of the Creative Commons Attribution License ( You are free: to Share – to copy, distribute and transmit the work, provided the original author and source are credited.



Objective: To present preliminary clinical experience with intraoperative imaging in glioma surgery using the Pole Star N20.

Methods: From June 2004 to November 2005, 61 neurosurgical procedures were performed with a 0.15-T magnetic resonance system (Pole Star N 20). Of the patients, who underwent these procedures, 31 cases with gliomas who had undergone craniotomy were investigated retrospectively. Completeness of tumor resection and possible limitations using this technology were assessed.

Results: We did not observe any complications attributable to intraoperative MR imaging. Image quality was sufficient to evaluate the extent of the tumor resection in the majority of cases. Intraoperative imaging revealed remaining tumor in 19 patients (61,3%). Ten (32,25%) of them did not have further resection because we wanted to spare eloquent brain areas. The other 9 (29%) patients receive further resection achieving total resection in 2 (6,45%) patients and extended subtotal resection in 7 (22,6%) patients. An additional morbidity was not noticed. Unfortunately, the borders of low grade gliomas which are often well seen in preoperative T2 imaging (1.5T scanner), were not easy to identify in the low field intraoperative T2 imaging. Resection control did not show a clear tumor-brain tissue border. T 2 imaging seems to be quite sensitive to RFI (Radio-Frequency-Interference) especially in a low magnet field. Since we discovered this limitation, we are in close contact and cooperation with Odin Medical Technologies trying to resolve that problem. We found out that intraoperative Flair imaging shows the borders of a low grade glioma more accurately than T2 imaging does.

Conclusions: Contrast enhancing gliomas can easily be resected in a low field (0,15T) open-MRI using T1 imaging with and without contrast medium. In low grade gliomas, the intraoperative quality of a low field T2 imaging is inadequate, therefore we recommend Flair imaging which allows a good control of the resection borders. The more complete resection due to intraoperative imaging did not lead to a higher morbidity. Thus, intraoperative MRI increases the radicality of tumor removal without additional morbidity.