gms | German Medical Science

61st Annual Meeting of the German Society of Neurosurgery (DGNC) as part of the Neurowoche 2010
Joint Meeting with the Brazilian Society of Neurosurgery on the 20 September 2010

German Society of Neurosurgery (DGNC)

21 - 25 September 2010, Mannheim

MRI safety of a programmable shunt sssistant (proSA) at 3 and 7 Tesla

Meeting Abstract

  • M. Javad Mirzayan - Neurochirurgische Klinik, Medizinische Hochschule Hannover, Deutschland
  • Joerg Knebel - Christoph Miethke GmbH & Co. KG, Potsdam, Deutschland
  • Petra M. Klinge - Neurochirurgische Klinik, International Neuroscience Institute Hannover, Deutschland
  • Madjid Samii - Neurochirurgische Klinik, International Neuroscience Institute Hannover, Deutschland
  • Friedrich Goetz - Institut für Diagnostische und Interventionelle Neuroradiologie, Medizinische Hochschule Hannover, Deutschland
  • Christoph Miethke - Christoph Miethke GmbH & Co. KG, Potsdam, Deutschland
  • Joachim K. Krauss - Neurochirurgische Klinik, Medizinische Hochschule Hannover, Deutschland

Deutsche Gesellschaft für Neurochirurgie. 61. Jahrestagung der Deutschen Gesellschaft für Neurochirurgie (DGNC) im Rahmen der Neurowoche 2010. Mannheim, 21.-25.09.2010. Düsseldorf: German Medical Science GMS Publishing House; 2010. DocP1808

DOI: 10.3205/10dgnc279, URN: urn:nbn:de:0183-10dgnc2792

Published: September 16, 2010

© 2010 Mirzayan 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: Several new shunt technologies have been developed to optimize hydrocephalus treatment within the past few years. Overdrainage, however, still remains an unresolved problem. One new technology which may avoid this complication is the use of a programmable shunt assistant (proSA). The aim of this in-vitro study was to investigate whether the proSA is safe at a field strength of 3 and 7 Tesla.

Methods: We exposed the proSA device in an ex vivo protocol to MR systems operating at 3 and 7 Tesla. The device is inactive in a horizontal position, it impedes CSF flow in a vertical position according to a prescribed pressure level ranging from 0 to 40 cm H2O. Twenty proSA valves adjusted at a pressure level of 16 cm H2O were exposed to the magnetic field of a commercially available 3 Tesla MR system (Allegra, Siemens, Erlangen, Germany). Another twenty valves were investigated at a field strength of 7 Tesla in a small animal MR unit (Pharmascan 70/16; Bruker Biospin MRI GmbH, 76256 Ettlingen, Germany). Four valves each were bonded on a plastic frame in order to be placed inside the magnet in a reproducible configuration. The frame was positioned in the center of the magnet perpendicular to the z-component of the main magnetic field. T1-weighted spin echo sequences was carried out. Following the MR studies functional testing of the valves was obtained by evaluation of the performance of the readjustment procedure. For measurement of the deflection angle the valves were hung up from a cord that was attached at the bore of the MR system. The deflection angle was determined as the angle between the plumb line and the displacement of the valve toward the MRI bore.

Results: After exposure to 3 Tesla no changes in valve settings were noted. Adjustment to any pressure level was possible thereafter. The mean deflection angle was 23±3°. Following 7 Tesla exposure the valves lost their functional capability.

Conclusions: The programmable shunt assistant (proSA) which has been introduced recently is safe and reliable for 3 Tesla MRI examinations in the in-vitro enviroment. Unintended changes of pressure settings and serious displacement within the body should not occur. Exposure to 7 Tesla affects the valve settings and the functional capability of the valves.