Congress:
EuroSafe Imaging 2019
Keywords:
Action 2 - Clinical diagnostic reference levels (DRLs), Action 4 - Dose management systems, Thorax, Radiation physics, Radioprotection / Radiation dose, CT, Physics, Radiation safety, Statistics, Dosimetric comparison
Authors:
N. Saltybaeva, H. Alkadhi
DOI:
10.26044/esi2019/ESI-0061
Conclusion and recommendations
Analysis included 1280 CT procedures (PE=290; LC=595; LNFU=360; CCTA=95).
The clinical DRLs for the investigated indications are shown in Table 1.
The clinical DRLs for PE and LC were similar to the recently revised NDRLs (CTDIvol=7mGy; DLP=300 mGy*cm) for the chest.
The clinical DRLs defined for CCTA were higher than NDRLs,
while the values for LDFU were significantly lower.
Within the same type of the procedure,
a strong correlation between CTDIvol and patient size was observed for LE and LNFU (r-values 0.77 and 0.79,
respectively); whereas the correlation between LC and CCTA and patient size was moderate (r-values 0.68 and 0.55 respectively).
Table 1.
CT DRLs,
based on clinical indications,
defined as 75th percentile of the CTDIvol and DLP distributions
Clinical indication
|
CTDIvol,
mGy
|
DLP,
mGy*cm
|
Pulmonary embolism
|
7.1
|
242.4
|
Lung Cancer
|
7.5
|
278.5
|
Lung nodules follow-up
|
0.4
|
15.9
|
Coronary CT angiography
|
15.5
|
215.1
|
Clinical indications have strong influence on CT acquisition parameters and applied radiations within the same body region.
Clinical-based DRLs allow for a more objective radiation dose analysis and benchmarking and should be therefore used as a tool for further dose optimization.