gms | German Medical Science

60th Annual Meeting of the German Society of Neurosurgery (DGNC)
Joint Meeting with the Benelux countries and Bulgaria

German Society of Neurosurgery (DGNC)

24 - 27 May 2009, Münster

Article

Send article

Dynamic susceptibility perfusion MRI to detect residual tumour intraoperatively

Meeting Abstract

Search Medline for

  • S. Ulmer - Institut für Neuroradiologie, Campus Kiel, Universitätsklinikum Schleswig-Holstein, Kiel
  • A. Nabavi - Klinik für Neurochirurgie, Campus Kiel, Universitätsklinikum Schleswig-Holstein, Kiel
  • M. Helle - Institut für Neuroradiologie, Campus Kiel, Universitätsklinikum Schleswig-Holstein, Kiel
  • O. Jansen - Institut für Neuroradiologie, Campus Kiel, Universitätsklinikum Schleswig-Holstein, Kiel
  • H.M. Mehdorn - Klinik für Neurochirurgie, Campus Kiel, Universitätsklinikum Schleswig-Holstein, Kiel

Deutsche Gesellschaft für Neurochirurgie. 60. Jahrestagung der Deutschen Gesellschaft für Neurochirurgie (DGNC), Joint Meeting mit den Benelux-Ländern und Bulgarien. Münster, 24.-27.05.2009. Düsseldorf: German Medical Science GMS Publishing House; 2009. DocMO.07-04

doi: 10.3205/09dgnc039, urn:nbn:de:0183-09dgnc0390

Published: May 20, 2009

© 2009 Ulmer et al.
This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by-nc-nd/3.0/deed.en). You are free: to Share – to copy, distribute and transmit the work, provided the original author and source are credited.

Outline

Text

Objective: Intraoperative MRI has the potential to identify and localize residual tumour. However, the non-specific nature of contrast enhancement, and the gradual “spreading enhancement” over time demand special scrutiny. In addition to our standard protocol, we have investigated dynamic susceptibility contrast-weighted perfusion MRI. This DSC-MRI enables calculation of relative blood volume and flow, depicting neovascularization. Primarily employed in conventional diagnostics, we have investigated its applicability and clinical utility for intraoperative MRI.

Methods: After phantom studies we proceeded to intraoperative cases. The patients were operated on within an integrated MRI-OR (with a 1.5 Tesla MR), which permitted MRimaging at the surgeon's discretion during surgery. Intraoperative Imaging is performed with a flexible two-channel coil system.

In addition to the standard protocol used during imaging of malignant gliomas, a dynamic susceptibility contrast T2*-weighted EPI sequence was performed in 6 patients. After an initial baseline period of this iDSC-MRI sequence, a bolus of contrast agent was administered intravenously. Maps of relative regional blood flow (rCBF), blood volume (rCBV) and the mean transit time (MTT) were calculated. These maps were compared to preoperatively acquired DSC-MRI data. The extent of the resection was compared with the postoperative MRI performed 24 h after the operation.

Results: In five patients complete tumour removal was already achieved at the time of iDSC-MRI and no areas of elevated perfusion values adjacent to the resection cavity were found. Complete removal was verified on the postoperative MRI. In one case there was residual tumour which showed both contrast enhancement and identical perfusion ratios as in the preoperatively acquired data. Subsequently this remainder was removed.

Conclusions: With conventional intraoperative MRimaging, we find contrast enhancement, which dilutes over time, yielding a slow spread of contrast medium into the surrounding tissue. This mitigates the information provided by contrast enhanced MRI.

iDSC-MRI is not susceptible to this phenomenon, since it detects regional blood flow changes. It is technically applicable intraoperatively and yields comparable results to preoperatively acquired data. This sequence has the potential to provide accurate intraoperative information on the neovascularized areas of malignant glioms.