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67th Annual Meeting of the German Society of Neurosurgery (DGNC)
Joint Meeting with the Korean Neurosurgical Society (KNS)

German Society of Neurosurgery (DGNC)

12 - 15 June 2016, Frankfurt am Main

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Postoperative diffusion-weighted magnetic resonance imaging for detection of intracranial pyogenic abscesses in neurosurgical patients

Meeting Abstract

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  • Christoph Schwartz - Department of Neurosurgery, Ludwig-Maximilians-University Munich, Germany
  • Robert Forbrig - Department of Neuroradiology, Ludwig-Maximilians-University Munich, Germany
  • Markus Lenski - Department of Neurosurgery, Ludwig-Maximilians-University Munich, Germany
  • Christian Schichor - Department of Neurosurgery, Ludwig-Maximilians-University Munich, Germany
  • Hendrik Janssen - Department of Neuroradiology, Ludwig-Maximilians-University Munich, Germany
  • Niklas Thon - Department of Neurosurgery, Ludwig-Maximilians-University Munich, Germany

Deutsche Gesellschaft für Neurochirurgie. 67. Jahrestagung der Deutschen Gesellschaft für Neurochirurgie (DGNC), 1. Joint Meeting mit der Koreanischen Gesellschaft für Neurochirurgie (KNS). Frankfurt am Main, 12.-15.06.2016. Düsseldorf: German Medical Science GMS Publishing House; 2016. DocP 052

doi: 10.3205/16dgnc427, urn:nbn:de:0183-16dgnc4271

Published: June 8, 2016

© 2016 Schwartz et al.
This is an Open Access article distributed under the terms of the Creative Commons Attribution 4.0 License. See license information at http://creativecommons.org/licenses/by/4.0/.

Outline

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Objective: Despite modern surgical techniques and stringently applied sterility measures, postoperative intracranial pyogenic infections still remain a considerable concern in neurosurgical patients. Besides clinical evaluation, diffusion-weighted magnetic resonance imaging (MRI) is the modality of choice for detecting intracranial abscesses. However, it is still unclear to what extent postoperative artefacts (i.e. edema, hemorrhage, hemostatic agents) influence the diagnostic accuracy of apparent diffusion coefficient (ADC) values for the detection of local intracranial infection after prior neurosurgical procedures.

Method: 22 patients undergoing revision surgery due to clinically and diffusion-weighted imaging (DWI) suspected intracranial abscess after intracranial surgery (11 meningiomas, 4 traumatic brain injuries, 3 metastases, 2 gliomas, 2 cavernomas) were retrospectively identified. The control group consisted of 40 patients receiving routine postoperative cranial MRI including DWI after intracranial tumor surgery (28 gliomas, 9 metastases, 3 meningiomas). Concerning MRI data analysis, mean ADC and T1-weighted ± gadolinium values within the resection cavity as well as perifocal edema were measured for each patient in both groups.

Results: Mean time span between initial surgery and MRI prior to revision surgery was 82.7 ± 97.1 days in patients with suspected local infection, and 2.1 ± 1.0 days in the control group (p<0.01). Suspicion of an intraparenchymal abscess was confirmed intraoperatively in 21/22 patients, resulting in a sensitivity of 100% and specificity of 97.6% of DWI for both groups to detect a local infection after prior surgery. In 18 out of these 21 patients the respective pathogen was identified; 2 of the remaining 3 patients had already undergone extensive prior antibiotic therapy. The mean ADC value was significantly lower in the abscess group (780.8 ± 244.5 mm2/s vs. 2951 ± 237.4 mm2/s, p<0.01). In both groups, no significant contrast enhancement was found within the resection cavity, whereas the perifocal edema increased in 9/22 patients in the abscess group.

Conclusions: DWI represents a robust MRI sequence for the identification of intracranial abscesses after prior intracranial neurosurgical procedures.