gms | German Medical Science

64th Annual Meeting of the German Society of Neurosurgery (DGNC)

German Society of Neurosurgery (DGNC)

26 - 29 May 2013, Düsseldorf

Artefacts of adjustable shunt valves in MRI – analysis of valve models, MRI- techniques and clinical consequences

Meeting Abstract

  • Timo Behm - Klinik für Neurochirurgie, Universitätsmedizin Göttingen
  • Claudia Kuhlbars - Klinik für Neurochirurgie, Universitätsmedizin Göttingen; Abteilung für Neuroradiologie, Universitätsmedizin Göttingen
  • Veit Rohde - Klinik für Neurochirurgie, Universitätsmedizin Göttingen
  • Florian Stockhammer - Klinik für Neurochirurgie, Universitätsmedizin Göttingen

Deutsche Gesellschaft für Neurochirurgie. 64. Jahrestagung der Deutschen Gesellschaft für Neurochirurgie (DGNC). Düsseldorf, 26.-29.05.2013. Düsseldorf: German Medical Science GMS Publishing House; 2013. DocP 004

doi: 10.3205/13dgnc429, urn:nbn:de:0183-13dgnc4290

Published: May 21, 2013

© 2013 Behm 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: Adjustability of hydrocephalus valves is performed by percutaneous magnetic interaction. Whereas changes of the valve setting during MR scans is solved in modern valves, the MR image is still vulnerable for susceptibility artefacts with increased magnetic field strength. Therefore, we set up a study for identification of sequences and valve type most prone to MR artefacts and the possible influence on patients care to evolve substitute examination protocols.

Method: From 2006 to 2011 all patients with implanted shunt valve who underwent cranial MRI examination were included in this retrospective study. All MR sequences were classified and analyzed for susceptibility artefacts. The volume and localization of the intradural artefact were determined. Additionally patient data including tumor history, valve type and localization as well as clinical consequences due to the artefact were compiled by chart analysis.

Results: Artefacts occurred in 154 MR examinations. Median intradural artefact volumes for 1.5 Tesla (T) was 9.67 ccm and 10.18 ccm for 3T. According to the sequence type median artefact volume was 10.91 ccm in FLAIR (n=54), 6.80 ccm in PD (n=59), 4.72 ccm in T2-SE (n=138), 4.30 ccm in T2-SE-3D (n=39), 7.80 ccm T2-SE-non-3D (n=99), 7.87 ccm in T1 (n=151) and 36.28 ccm in DWI (n=91). Concerning valve type the median artefact volume was 7.85 ccm in proGAV (n=32) , 15.54 ccm in proSA (n=19) and 9.35 ccm in Medos (n=87). The tumor site was affected in 2 patients, MRI scan failed to detect cerebral ischemia caused by artefacts in one patient. Artifacts were mostly located in the temporal and parietal lobe, less frequent in the cerebellum.

Conclusions: Extent of MRI artifacts by shunt valves depends on magnetic field strength, sequences and valve model. Artifacts may lead to wrong diagnosis in MRI examination. Especially in tumor patients the implantation site should be thoroughly planed. MRI examination protocols should be optimized to reduce artifacts and misdiagnosis.