Congress:
EuroSafe Imaging 2019
Keywords:
Quality assurance, Dosimetric comparison, Diagnostic procedure, CT, Thorax, Abdomen, Radioprotection / Radiation dose, Action 6 - Clinical audit tool for imaging, Action 3 - Image quality assessment based on clinical indications, Action 2 - Clinical diagnostic reference levels (DRLs)
Authors:
H. Brat, F. Zanca, D. Fournier, B. Rizk, J. Helal, N. Correia, J. Favre, P. Bosson, M. Eric
DOI:
10.26044/esi2019/ESI-0042
Background/introduction
"Diagnostic reference level" (DRL):
- introduced in 1996 by the International Commission on Radiological Protection (ICRP) (1),
- updated in 2017 with recommendations on DRLs in medical imaging and clarification issues related to definitions of the terms (2).
According to ICRP publication 135 (2):
- National DRLs (NDRLs) are representative of an entire country,
- Local DRLs (LDRLs) are representative of a few healthcare facilities in a local area.
They consider faster local optimization processes than NDRLs and remain anatomy-based.
NDRLs and LDRLs are calculated as the third quartile of the median dose values of each CT modality.
- Clinical DRLs (CDRLs) define more specific dose levels according to the a specific clinical indication (example: a CT of the abdomen to exclude renal calculi will require a lower patient exposition than to characterize a kidney tumor).
- Local Clinical DRLs (LCDRLs) are representative of a few healthcare facilities in a local area for specific clinical indications.
LCDRLs are calculated as the third quartile of the median dose values of each CT scanner involved in the study.
The purpose of this multicenter prospective study was to estimate institutional dose levels based on clinical indication (LCDRLs) and compare it to the new Swiss NDRLs (3,4),
while considering CT technology and protocol harmonization across scanners.
SWISS NDRL |
CTDIvol P50 (mGy) |
CTDIvol P75 (mGy) |
DLP P50 (mGy.cm) |
DLP P75 (mGy.cm) |
CHEST |
6 |
7 |
210 |
250 |
ABDOMEN |
10 |
11 |
470 |
540 |