gms | German Medical Science

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

Low dose non-enhanced head to abdomen CT is a promising alternative to conventional radiographic shunt series

Meeting Abstract

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  • Hussam A. Hamou - Department of Neurosurgery, RWTH Aachen University, Aachen, Germany; Department of Neurosurgery, Gemeinschaftskrankenhaus, Herdecke, Germany
  • Hans R. Clusmann - Department of Neurosurgery, RWTH Aachen University, Aachen, 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. DocMI.22.05

doi: 10.3205/16dgnc374, urn:nbn:de:0183-16dgnc3746

Published: June 8, 2016

© 2016 Hamou et al.
This is an Open Access article distributed under the terms of the Creative Commons Attribution 4.0 License. See license information at



Objective: Many patients with shunt for hydrocephalus have to undergo repeated radiographic shunt series, resulting in a relatively high cumulative radiation exposure, with a recently reported dose of 1.57 ± 0.60 mSv per shunt series. In some cases even an additional regular CT is necessary. Especially in children, there is a high risk of long-term effects of ionizing radiation. The purpose of our study was to evaluate whether unenhanced low-dose-CT scan from head to abdomen could provide acceptable image quality, provide required information, and without radiation doses higher than with conventional standard imaging.

Method: 56 patients (mean age: 60 (0.5 to 85) yrs; 22 female and 34 male) were included. VP shunt surgery of hydrocephalus was due to various etiologies (22 normal pressure hydrocephalus, 16 posthemorrhagic, 12 congenital, 2 posttraumatic, 2 after stroke, 1 tumor-related, and 1 unknown). All patients had a routine postoperative low-dose-CT from head to abdomen using a 16-slice MD-CT scanner (Toshiba).19 low-dose-CTs were additionally performed in the later course to exclude shunt malformation. Whole body dose of 75 CT was calculated with an established computer model (Benchmarking MSCT). The axial and three dimensional (volume rendering technique) vp shunt visualisation was independently evaluated by one neuroradiologist (criteria of diagnostic image quality: excellent, satisfactory, insufficient) and one neurosurgeon.

Results: 60 (80%) of CT series were judged excellent and 15 (20%) satisfactory, none was insufficient, no repeated exam necessary. The average effective whole body dose was 1,56 ± 0,3 mSv in 75 low-dose-CT. More than the required information was obtained: beside a reliably evaluation of the shunt continuity early after surgery, one intracerebral hemorrhage was found. In the later course, 3 disconections and one case with abdominal cysts were found in 19 CT exams.

Conclusions: Low-dose head to abdomen CT scan provides diagnostically excellent or acceptable images without increasing the overall radiation exposure. It improves the diagnostic yield (hemorrhage, cysts, catheter placement, etc.) compared to plain x-ray shunt series. One disadvantage is that adjustment of some valves cannot be documented by CT, however, alternative non-invasive techniques are meanwhile available for most systems.