Use of BMI guidelines and individual dose tracking to minimize radiation exposure from low-dose helical chest CT scanning in a lung cancer screening program

Acad Radiol. 2012 Jan;19(1):84-8. doi: 10.1016/j.acra.2011.09.015.


Rationale and objectives: The increasing use of computed tomography (CT) has been accompanied by rising concerns over potential radiation-related health risks, especially cancer, and a need to minimize such risks.

Materials and methods: We conducted 2186 low-dose helical chest CT scans among 1235 nuclear weapons workers at elevated risk of lung cancer, setting the CT scanner tube current at 30 mAs for all participants with BMI <35 kg/m(2) and permitting technologists to raise mAs levels for participants with BMI ≥35 kg/m(2). Dose-length product (DLP) was recorded from the CT scanner, permitting calculation of effective dose. Phantom-based estimates of effective dose were also made. A chest radiologist recorded acceptability of image quality.

Results: The study population was significantly overweight: 79% exceeded a body mass index (BMI) >25 kg/m(2) and 37.1% exceeded a BMI ≥30 kg/m(2). Nearly 90% of CT scans were performed using a tube current setting of 30 mAs and had a mean DLP-based effective dose of 1.3 mSv. The phantom-based estimate of effective dose was lower at 1.1 mSv. Among participants with a BMI ≥35 kg/m(2), 92% were scanned at 40 or 50 mAs, which was associated with a DLP-based effective dose of 1.6 and 2.0 mSv, respectively. Image quality was satisfactory in 99.8% of scans.

Conclusion: Application of simple BMI-based guidelines and DLP tracking of low-dose helical chest CT scans in a lung cancer screening program minimizes radiation dose, even in a largely overweight population.

Publication types

  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Body Burden*
  • Body Mass Index*
  • Female
  • Humans
  • Lung Neoplasms / diagnostic imaging*
  • Lung Neoplasms / epidemiology
  • Middle Aged
  • Neoplasms, Radiation-Induced / diagnostic imaging*
  • Neoplasms, Radiation-Induced / epidemiology
  • New York / epidemiology
  • Nuclear Weapons
  • Practice Guidelines as Topic
  • Radiation Dosage
  • Radiation Protection / methods*
  • Radiation Protection / standards
  • Radiation Protection / statistics & numerical data
  • Radiography, Thoracic / standards
  • Radiography, Thoracic / statistics & numerical data
  • Radiometry / standards*
  • Radiometry / statistics & numerical data
  • Tomography, Spiral Computed / standards
  • Tomography, Spiral Computed / statistics & numerical data*