About FDA

Nationwide Evaluation of X-Ray Trends (NEXT) Computed Tomography Dataset

A Nationwide Evaluation of X-ray Trends (NEXT) survey of clinical facilities performing computed tomography (CT) examinations was conducted during 2005-06. This survey was planned and conducted under the leadership of the Conference of Radiation Control Program Directors’ (CRCPD) H-4 Committee on the Nationwide Evaluation of X-Ray Trends. This committee is composed of State volunteers, resource volunteers from the medical physics community, and FDA staff serving as technical consultants. The committee plans the survey, generates the protocol, conducts surveyor training and secures the cooperation of states to conduct the survey.

Approximately 260 facilities participated in the voluntary survey. The survey consisted of two components: a site visit by trained surveyors and a questionnaire completed by facility staff. Trained state radiation personnel conducted each site visit, gathering data regarding CT workload volumes, equipment data, scanning parameters for clinical exams, and radiation measurements from CT equipment. Surveyors also used a specially designed phantom to characterize CT equipment scan features that adjust radiation output during scanning to optimize dose based on patient size. In addition to the onsite visit facility staff were requested to complete a questionnaire that gathered additional information regarding CT equipment inventory and examination workloads, aspects of quality assurance and quality control, and scanning parameters for a selection of commonly performed CT examinations on the surveyed CT unit.

Provided below as Microsoft Excel spreadsheets are the original, unedited data gathered by participating state programs during the 2005-06 NEXT CT survey. Their contents are as follows.

  1. NEXT CT0506 Surveyor Dataset.xls contains the original data gathered by surveyors during their site visits.
  2. NEXT CT0506 Facility Dataset.xls contains the original data reported by facilities on the questionnaire. This file contains three spreadsheets of data that can be accessed by clicking on the appropriate tab at the bottom of the Excel screen.


These data have not been reviewed and validated! These values represent the unedited responses collected by surveyors during the site visit, and reported by facilities on the survey questionnaire. The Food and Drug Administration and the Conference of Radiation Control Program Directors make no claims regarding the accuracy of these data. Users are responsible for ensuring that the data are thoroughly validated and used appropriately. You are strongly encouraged to review the survey protocol procedures and accompanying data forms, which are available for download from http://www.crcpd.org/Pubs/NEXT_Protocols/NEXT-2005CT-Protocol.pdf.

Some facilities that participated in the onsite portion of the survey did not return a completed questionnaire form. Therefore the number of populated entries (rows of data) in the facility questionnaire data set does not match the number of entries in the surveyor data set. To aid users in accurately matching individual entries between the two Excel files, a survey identifier field was created to anonymously and uniquely identify each survey entry. The first column of each spreadsheet contains these identifier values.

These datasets are made possible by the voluntary participation of state radiological health agencies, and particularly through the tremendous efforts by state surveyors to conduct site visits. By downloading these data you agree to acknowledge this collaborative effort by appropriate reference. The following is a suggested citation for inclusion in publications and other professional product releases which make use of these data.

CRCPD H-4 Committee on Nationwide Evaluation of X-ray Trends (NEXT) 2005-06 Survey of Computed Tomography. Online Webpage, Food and Drug Administration; Silver Spring MD: 2010. Available at http://www.fda.gov/AboutFDA/CenterOffices/CDRH/CDRHTransparency/ucm202868.htm Accessed DD month YYYY.

The FDA and CRCPD are currently conducting analyses of these data and will publish a statistical summary of findings. For more information on the NEXT program and statistical summaries of past surveys visit http://www.crcpd.org/pubs/next.aspx.

Page Last Updated: 06/03/2014
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