Table 4.

Effective dose and organ radiation doses for abdominal/pelvic CT examinations estimated at our institution

Routine Abdomen-PelvisSuspected Aneurysm or DissectionRoutine Upper Abdomen
Effective dose (mSv)a14.817.26.2
Organs or tissuesOrgan Dose (mGy or mSv)b
    gonads31.335.90.8
    bone marrow (red)12.414.33.8
    colon23.226.90.7
    lung7.48.77.5
    stomach24.829.421.6
    bladder32.438.90.2
    breast1.41.61.3
    liver22.727.320.5
    esophagus (thymus)1.11.31.1
    thyroid0.10.10.1
    skin8.810.23.3
    bone surface16.419.16.9
    remainder12.114.03.8
  • aEffective doses and organ doses are reported for a single scan.

  • bThe radiation dose, a measure of ionizing energy absorbed per unit of mass, is expressed in grays (Gy) or milligrays (mGy); 1 Gy = 1 joule per kilogram. The radiation dose is often expressed as an equivalent dose in Sieverts (Sv) or millisieverts (mSv). For x-ray radiation, which is the type used in CT scanners, 1 mSv = 1 mGy.