Skip to main content
Advertisement

Main menu

  • Home
  • Content
    • Current Issue
    • Publication Preview--Ahead of Print
    • Past Issue Archive
    • Case of the Week Archive
    • Classic Case Archive
    • Case of the Month Archive
  • For Authors
  • About Us
    • About AJNR
    • Editors
    • American Society of Neuroradiology
  • Submit a Manuscript
  • Podcasts
    • Subscribe on iTunes
    • Subscribe on Stitcher
  • More
    • Subscribers
    • Permissions
    • Advertisers
    • Alerts
    • Feedback
  • Other Publications
    • ajnr

User menu

  • Subscribe
  • Alerts
  • Log in

Search

  • Advanced search
American Journal of Neuroradiology
American Journal of Neuroradiology

American Journal of Neuroradiology

  • Subscribe
  • Alerts
  • Log in

Advanced Search

  • Home
  • Content
    • Current Issue
    • Publication Preview--Ahead of Print
    • Past Issue Archive
    • Case of the Week Archive
    • Classic Case Archive
    • Case of the Month Archive
  • For Authors
  • About Us
    • About AJNR
    • Editors
    • American Society of Neuroradiology
  • Submit a Manuscript
  • Podcasts
    • Subscribe on iTunes
    • Subscribe on Stitcher
  • More
    • Subscribers
    • Permissions
    • Advertisers
    • Alerts
    • Feedback
  • Follow AJNR on Twitter
  • Visit AJNR on Facebook
  • Follow AJNR on Instagram
  • Join AJNR on LinkedIn
  • RSS Feeds
ReplyLetter

Reply:

S. Moskowitz and B. Davros
American Journal of Neuroradiology November 2010, 31 (10) E89; DOI: https://doi.org/10.3174/ajnr.A2323
S. Moskowitz
  • Find this author on Google Scholar
  • Find this author on PubMed
  • Search for this author on this site
B. Davros
  • Find this author on Google Scholar
  • Find this author on PubMed
  • Search for this author on this site
  • Article
  • Info & Metrics
  • References
  • PDF
Loading

We thank Mamourian et al for their comments about the radiation exposure in subarachnoid hemorrhage (SAH). We understand that there are significant limitations to the methods we applied. As we understand, there are 2 lines of comment that they are addressing.

The first relates to the fundamental measurements that we reported. Air kerma is a measurement of the exposure to air at a fixed distance from a radiation source. This is the value returned for all C-arm and biplanar equipment. Biologically relevant doses are, however, a related but different item. Air kerma does not account for scatter, angle of inclination to the skin, 2D distribution over an area, and so forth. Because the head is, in fact, usually a complex nonspheric shape, the real skin entry dose seen from imaging studies is not equal to the air kerma reported by the software. Even with a conversion applied, the real life use of radiation is not perfectly represented. Nonetheless, for the purposes of a retrospective analysis, the best (and only) data available for exposure are those gathered by that measure, and hence we used it for our review.

The second concern relates to the measurements that we used to calculate exposure from the variety of sources. The measurements were obtained from regularly scheduled quality and safety checks from all equipment. The doses were consistent with prior measurements and have been since that time. The doses were within the acceptable range for each such study, so we are not concerned with the safety of the equipment or the accuracy of the numbers used for our calculations.

In summary, we have 2 fundamental comments about our article. The first reflects on the overall comments made by Mamourian et al. Air kerma is not a perfect metric to measure skin entry radiation dose. Many factors impact the absorbed dose and the biologic response to any radiation source, including scatter, shape of the head, distribution over the skin, angle of inclination, actual distance of the skin to the source, and so forth. The actual dose a patient receives may be many factors less or more than the air kerma reported by quality assurance studies and software included with the fluoroscopy equipment. A better measure would be direct analysis of the skin entry dose. The use of GafChromic film (Specialty Products, Wayne, New Jersey) would account for many of the variables, even if not a perfect solution itself. Already underway are future endovascular studies that use this to measure total and peak skin entry dose, with consideration of distribution over the skin and eyes. We anticipate that this will control for some of the distinctively high doses seen, and it will demonstrate that the peak skin dose will not be represented reliably by air kerma.

The second comment is that the purpose of this study was not to identify the highest skin dose possible. We were highlighting the fact that in a very sick population of neurovascular patients, repetitive radiation-based imaging studies can result in significant radiation exposure. We believe that great care must be applied to this patient population in this regard, and any technique to reduce unneeded exposure should be considered. We are aware that it is not possible today to expect no exposure at all through a prolonged hospitalization for SAH. However, we hope that the results of our study bring to light a need for conscientious use of imaging; they are not intended to define a standard by which individual patient care should be measured.

  • Copyright © American Society of Neuroradiology
PreviousNext
Back to top

In this issue

American Journal of Neuroradiology: 31 (10)
American Journal of Neuroradiology
Vol. 31, Issue 10
1 Nov 2010
  • Table of Contents
  • Index by author
Advertisement
Print
Download PDF
Email Article

Thank you for your interest in spreading the word on American Journal of Neuroradiology.

NOTE: We only request your email address so that the person you are recommending the page to knows that you wanted them to see it, and that it is not junk mail. We do not capture any email address.

Enter multiple addresses on separate lines or separate them with commas.
Reply:
(Your Name) has sent you a message from American Journal of Neuroradiology
(Your Name) thought you would like to see the American Journal of Neuroradiology web site.
CAPTCHA
This question is for testing whether or not you are a human visitor and to prevent automated spam submissions.
Citation Tools
Reply:
S. Moskowitz, B. Davros
American Journal of Neuroradiology Nov 2010, 31 (10) E89; DOI: 10.3174/ajnr.A2323

Citation Manager Formats

  • BibTeX
  • Bookends
  • EasyBib
  • EndNote (tagged)
  • EndNote 8 (xml)
  • Medlars
  • Mendeley
  • Papers
  • RefWorks Tagged
  • Ref Manager
  • RIS
  • Zotero
Share
Reply:
S. Moskowitz, B. Davros
American Journal of Neuroradiology Nov 2010, 31 (10) E89; DOI: 10.3174/ajnr.A2323
del.icio.us logo Digg logo Reddit logo Twitter logo Facebook logo Google logo Mendeley logo
  • Tweet Widget
  • Facebook Like
  • Google Plus One
Purchase

Jump to section

  • Article
  • Info & Metrics
  • References
  • PDF

Related Articles

  • No related articles found.
  • Google Scholar

Cited By...

  • No citing articles found.
  • Crossref
  • Google Scholar

This article has not yet been cited by articles in journals that are participating in Crossref Cited-by Linking.

More in this TOC Section

  • Pattern Recognition in Mitochondrial Leukodystrophies is Hampered by the Peculiarities of Mitochondrial Genetics
  • Callosal Angle Narrowing in Research Data Bases of the Cognitively Impaired
  • Reply:
Show more Letters

Similar Articles

Advertisement

News and Updates

  • Lucien Levy Best Research Article Award
  • Thanks to our 2021 Distinguished Reviewers
  • Press Releases

Resources

  • Evidence-Based Medicine Level Guide
  • How to Participate in a Tweet Chat
  • AJNR Podcast Archive
  • Ideas for Publicizing Your Research
  • Librarian Resources
  • Terms and Conditions

Opportunities

  • Share Your Art in Perspectives
  • Get Peer Review Credit from Publons
  • Moderate a Tweet Chat

American Society of Neuroradiology

  • Neurographics
  • ASNR Annual Meeting
  • Fellowship Portal
  • Position Statements

© 2022 by the American Society of Neuroradiology | Print ISSN: 0195-6108 Online ISSN: 1936-959X

Powered by HighWire