What is the radiation dose of an x-ray measured in milligray (mGy)?

From the Guidelines

The radiation dose of an X-ray is typically in the range of 0.01 to 10 milligrays (mGy), with chest X-rays delivering around 0.1 mGy, as supported by recent guidelines 1. When considering the radiation dose of X-ray examinations, it's essential to note that the dose varies depending on the body part being imaged.

• Chest X-rays generally deliver about 0.1 mGy
• Dental X-rays around 0.005 mGy
• Abdominal X-rays approximately 0.7 mGy, as mentioned in the context of CT examinations 1. These doses are considered low and safe for most patients. The variation in dose occurs because different tissues require different amounts of radiation for adequate imaging - denser structures like bones need more radiation than softer tissues like lungs. Medical facilities follow the ALARA principle (As Low As Reasonably Achievable) to minimize exposure while still obtaining diagnostically useful images. Modern digital X-ray equipment typically requires less radiation than older film-based systems. For context, we receive about 3 mGy annually from natural background radiation sources. While X-rays do carry a small theoretical risk of cellular damage, the diagnostic benefits generally far outweigh these minimal risks for patients who need these examinations, as emphasized in the 2018 expert consensus document on optimal use of ionizing radiation in cardiovascular imaging 1. The most recent and highest quality study suggests that the conversion factor for adult chest CT is 0.014 mSv $ mGy1 $ cm, but for CT examinations confined to the cardiac region, the estimated conversion factors are greater, with an average value of 0.026 mSv $ mGy1 $ cm1 1.

From the Research

Radiation Dose of X-ray mGy

• The mean entrance surface air kerma (ESAK) values for common X-ray examinations were reported as follows:
  • Chest PA: 0.12 mGy 2
  • Chest LAT: 0.66 mGy 2
  • Cranium AP: 1.01 mGy 2
  • Cranium LAT: 0.69 mGy 2
  • Cervical spine AP: 0.72 mGy 2
  • Cervical spine LAT: 0.63 mGy 2
  • Lumbar spine AP: 4.12 mGy 2
  • Lumbar spine LAT: 5.74 mGy 2
  • Pelvis AP: 2.57 mGy 2
  • Abdomen AP: 1.94 mGy 2
  • Kidneys and urinary bladder (KUB) AP: 2.47 mGy 2
• The 75th percentiles of ESAK values for these examinations were also reported, with values ranging from 0.14 mGy for chest PA to 7.24 mGy for lumbar spine LAT 2
• A study compared the mean exposure values of X-ray examinations to diagnostic reference levels (DRL) and found that the mean values were above DRL, except for lateral lumbar spine and lateral thoracic X-ray 3
• The study also reported that optimizing X-ray examinations, such as increasing tube voltage, can reduce the dose area product (DAP) while maintaining image quality 3