gms | German Medical Science

55. Jahrestagung der Deutschen Gesellschaft für Neurochirurgie e. V. (DGNC)
1. Joint Meeting mit der Ungarischen Gesellschaft für Neurochirurgie

Deutsche Gesellschaft für Neurochirurgie (DGNC) e. V.

25. bis 28.04.2004, Köln

Intraoperative imaging with MRI and ultrasound

Meeting Abstract

  • corresponding author Christian Rainer Wirtz - Ruprecht-Karls-Universität Heidelberg, Neurochirurgische Universitätsklinik, Heidelberg
  • V. M. Tronnier - Ruprecht-Karls-Universität Heidelberg, Neurochirurgische Universitätsklinik, Heidelberg
  • R. Metzner - Ruprecht-Karls-Universität Heidelberg, Neurochirurgische Universitätsklinik, Heidelberg
  • A. Unterberg - Ruprecht-Karls-Universität Heidelberg, Neurochirurgische Universitätsklinik, Heidelberg
  • M. M. Bonsanto - Ruprecht-Karls-Universität Heidelberg, Neurochirurgische Universitätsklinik, Heidelberg

Deutsche Gesellschaft für Neurochirurgie. Ungarische Gesellschaft für Neurochirurgie. 55. Jahrestagung der Deutschen Gesellschaft für Neurochirurgie e.V. (DGNC), 1. Joint Meeting mit der Ungarischen Gesellschaft für Neurochirurgie. Köln, 25.-28.04.2004. Düsseldorf, Köln: German Medical Science; 2004. DocJM II.02

Die elektronische Version dieses Artikels ist vollständig und ist verfügbar unter: http://www.egms.de/de/meetings/dgnc2004/04dgnc0002.shtml

Veröffentlicht: 23. April 2004

© 2004 Wirtz et al.
Dieser Artikel ist ein Open Access-Artikel und steht unter den Creative Commons Lizenzbedingungen (http://creativecommons.org/licenses/by-nc-nd/3.0/deed.de). Er darf vervielf&aauml;ltigt, verbreitet und &oauml;ffentlich zug&aauml;nglich gemacht werden, vorausgesetzt dass Autor und Quelle genannt werden.


Gliederung

Text

Objective

Neuronavigation is subject to intraoperative changes of anatomy leading to increasing inaccuracies as the operation progresses. Intraoperative imaging seems to be the best method to counter these problems since mew images depict these intraoperative changes. Principally there are several imaging modalities as MRI, ultrasound (US) and CT available. Two of these (MRI and US) were applied intraoperatively to evaluate their use to depict intraoperative changes, residual tumor and update neuronavigation.

Methods

A low-field MRI (Siemens Magnetom Open, 0,2T) installed in the neurosurgical OP and new device integrating a neuronavigation with a high-end US machine (SonoWand, Mison, Trondheim, Norway) were used for intraoperative imaging. MRI was used in 215 and US in 83 cranial cases with microsurgical tumor resection. Initial navigation from planning to craniotomy was performed with preoperative MRI datasets. Intraoperatie MRI was acquired at the end of the resection to evaluate radicality. With US 3D datasets were acquired with a registered 4-8 MHz phased-array US probe before and after dural incision and displayed along with the MRI. When applicable, another acquisition after tumor resection was used to evaluate radicality.

Results

For the intraoperative MRI a failure to obtain intraoperative images was noted in 3.5% only, whereas diagnostic yield regarding residual tumor at the end of resection was found to be 85.5%. In 56% of the procedures residual tumour could be identified. In 158 cases navigation could be updated with an accuracy of 1.3±0.6mm. For US, the acquisition of an intraoperative 3D US-dataset and with that the update of navigation was always possible, although image quality was variable. Brain shift was hardly observed prior to dural incision but in an increasing number of cases with ongoing operation. At the time of resection control all of the datasets showed discrepancies to preoperative MRI and the first US-acquisition. A clear definition of tumor borders with US was possible only in 75% of the gliomas. Due to the deterioration of US imaging quality, a resection control could be performed in only in 66% of the gliomas but still in 86% of the metastases. Cases with prior irradiation were particularly difficult to interpret in US-images but less problematic with intraoperative MRI.

Conclusions

Both, intraoperative MRI and intraoperative 3D navigated ultrasound offer an intraoperative imaging for intracranial operations with the possibility to update navigation and display brain shift. A substantial help to interpret the US-images is the congruent display of coregistered preoperative MRI. Surgical manipulations however lead to deteriorated image quality impairing resection control in both modalities but seemingly more pronounced in US. The choice of intraoperative US versus intraoperative MRI is dependent on availability and the individual case. The value of both methods in regard to cost/benefit ratio, the potential to update navigation and resection control still remains to be determined finally.