The purpose of this study was to make an inventory of the radiation do
se from CT in the Netherlands and to relate the dose to the way the ex
amination was performed. Details were obtained from approximately 3000
CT examinations carried out in 18 hospitals (22 CT scanners). Effecti
ve dose was calculated for each examination using CTDI-to-effective do
se conversion factors. For most scanners, the conversion factors were
available from the literature, for some they had to be derived with a
computer model using a Monte Carlo algorithm. The data on effective do
se, examination parameters and patient population are presented on a p
er hospital basis. Mean effective doses from brain CT were 0.8-5 mSv,
from lumbar spine CT 2-12 mSv, from chest CT 6-18 mSv and from abdomin
al CT 6-24 mSv. The general indications for the various CT examination
s were as follows: for the brain ischaemia and malignancy, for the lum
bar spine disc herniation and for the chest and abdomen a known malign
ancy. This explains the relatively advanced age of the patients. In ma
ny hospitals intravenous contrast is used less than is recommended in
current literature.