The critical appraisal of any medical test or strategy requires careful assessment of its potential risks, benefits, and costs. Accurate definition of the risks, benefits, and costs of the use of coronary artery calcium (CAC) scanning with computed tomography (CT) in asymptomatic individuals remains an elusive goal. In this issue of the Archives, Kim et al1 contribute to our knowledge about potential risks by reporting estimated radiation doses and excess lifetime risks of radiation-induced cancer from CAC scanning for a variety of CT scanners and scanning protocols that have been described in the literature. The authors report more than a 10-fold variation in effective radiation dose, from 0.8 to 10.5 mSv, with a median of 2.3 mSv. The data reflect well-established relationships between the specifics of CT scanner settings such as x-ray tube potential or tube current-time product on the one hand and radiation exposure and dose on the other.2 For their median radiation dose, Kim and colleagues estimate a lifetime excess cancer risk from a single examination at the age of 40 years of 9 cancers per 100 000 men and 28 cancers per 100 000 women.
Thank you for submitting a comment on this article. It will be reviewed by JAMA Internal Medicine editors. You will be notified when your comment has been published. Comments should not exceed 500 words of text and 10 references.
Do not submit personal medical questions or information that could identify a specific patient, questions about a particular case, or general inquiries to an author. Only content that has not been published, posted, or submitted elsewhere should be submitted. By submitting this Comment, you and any coauthors transfer copyright to the journal if your Comment is posted.
* = Required Field
Disclosure of Any Conflicts of Interest*
Indicate all relevant conflicts of interest of each author below, including all relevant financial interests, activities, and relationships within the past 3 years including, but not limited to, employment, affiliation, grants or funding, consultancies, honoraria or payment, speakers’ bureaus, stock ownership or options, expert testimony, royalties, donation of medical equipment, or patents planned, pending, or issued. If all authors have none, check "No potential conflicts or relevant financial interests" in the box below. Please also indicate any funding received in support of this work. The information will be posted with your response.
Some tools below are only available to our subscribers or users with an online account.
Download citation file:
Web of Science® Times Cited: 5
Customize your page view by dragging & repositioning the boxes below.
More Listings atJAMACareerCenter.com >
The Rational Clinical Examination: Evidence-Based Clinical Diagnosis
Evidence Summary and Review 2
All results at
Enter your username and email address. We'll send you a link to reset your password.
Enter your username and email address. We'll send instructions on how to reset your password to the email address we have on record.
Athens and Shibboleth are access management services that provide single sign-on to protected resources. They replace the multiple user names and passwords necessary to access subscription-based content with a single user name and password that can be entered once per session. It operates independently of a user's location or IP address. If your institution uses Athens or Shibboleth authentication, please contact your site administrator to receive your user name and password.