CT radiation dose for computer-assisted endoscopic sinus surgery: dose survey and determination of dose-reduction limits

Nauer, C B; Eichenberger, A; Dubach, P; Gralla, J; Caversaccio, M (2009). CT radiation dose for computer-assisted endoscopic sinus surgery: dose survey and determination of dose-reduction limits. American journal of neuroradiology AJNR, 30(3), pp. 617-22. Oak Brook, Ill.: American Society of Neuroradiology 10.3174/ajnr.A1378

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BACKGROUND AND PURPOSE: Computer-assisted navigation is increasingly used in functional endoscopic sinus surgery (FESS) to prevent injury to vital structures, necessitating preparative CT and, thus, radiation exposure. The purpose of our study was to investigate currently used radiation doses for CT in computer-assisted navigation in sinus surgery (CAS-CT) and to assess minimal doses required. MATERIALS AND METHODS: A questionnaire inquiring about dose parameters used for CAS-CT was sent to 30 radiologic institutions. The feasibility of low-dose registration was tested with a phantom. The influence of CAS-CT dose on technical accuracy and on the practical performance of 5 ear, nose, and throat (ENT) surgeons was evaluated with cadaver heads. RESULTS: The questionnaire response rate was 63%. Variation between minimal and maximal dose used for CAS-CT was 18-fold. Phantom registration was possible with doses as low as 1.1 mGy. No dose dependence on technical accuracy was found. ENT surgeons were able to identify anatomic landmarks on scans with a dose as low as 3.1 mGy. CONCLUSIONS: The vast dose difference between institutions mirrors different attitudes toward image quality and radiation-protection issues rather than being technically founded, and many patients undergo CAS-CT at higher doses than necessary. The only limit for dose reduction in CT for computer-assisted endoscopic sinus surgery is the ENT surgeon's ability to cope with impaired image quality, whereas there is no technically justified lower dose limit. We recommend, generally, doses used for the typical diagnostic low-dose sinus CT (120 kV/20-50 mAs). When no diagnostic image quality is needed, even a reduction down to a third is possible.

Item Type:

Journal Article (Original Article)


04 Faculty of Medicine > Department of Radiology, Neuroradiology and Nuclear Medicine (DRNN) > Institute of Diagnostic and Interventional Neuroradiology
04 Faculty of Medicine > Department of Head Organs and Neurology (DKNS) > Clinic of Ear, Nose and Throat Disorders (ENT)

UniBE Contributor:

Nauer, Claude; Dubach, Patrick; Gralla, Jan and Caversaccio, Marco






American Society of Neuroradiology




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Date Deposited:

04 Oct 2013 15:01

Last Modified:

04 May 2014 23:18

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https://boris.unibe.ch/id/eprint/26695 (FactScience: 85918)

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