J. Geleijns et al., PATIENT DOSE AND IMAGE QUALITY FOR COMPUTED-TOMOGRAPHY IN SEVERAL DUTCH HOSPITALS, Radiation protection dosimetry, 57(1-4), 1995, pp. 129-133
Citations number
NO
Categorie Soggetti
Radiology,Nuclear Medicine & Medical Imaging","Nuclear Sciences & Tecnology
In several Dutch hospitals a survey of computed tomography (CT) techni
ques was performed at 14 CT scanners. In this survey the computed tomo
graphy dose index (CTDI) was measured free-in-air with a pencil type i
onisation chamber. These measurements yield dose values related to a s
ingle CT scan of one slice whilst radiation exposure of patients due t
o a complete CT examination should preferably be expressed in terms of
organ and tissue doses or effective dose. Organ and effective doses w
ere derived by application of published organ dose conversion factors.
Effective doses varied from 0.7 mSv to 2.2 mSv for head scans, from 6
.0 mSv to 13 mSv for chest scans and from 7.1 mSv to 21 mSv for standa
rd abdomen scans. The survey also included the assessment of parameter
s related to image quality, i.e. high contrast resolution and noise (s
tandard deviation, sigma, of Hounsfield units) associated with the CT
scanners and protocols at the different locations. Image quality in te
rms of noise or resolution and effective dose did not reveal a signifi
cant correlation for the different CT scanners.