Congress:
EuroSafe Imaging 2019
Keywords:
Action 2 - Clinical diagnostic reference levels (DRLs), Action 4 - Dose management systems, Radioprotection / Radiation dose, CT, Dosimetry, Dosimetric comparison
Authors:
E. Balázs, Z. Dankó, P. Bágyi, E. Lilla, L. Balkay, L. Urbán
DOI:
10.26044/esi2019/ESI-0086
Description of activity and work performed
Diagnostic reference levels were established from dosimetric data collected throughout 12 months.
In this poster we present the most common CT protocols used at our institution and their frequency.
( Fig. 1 ,
Fig. 2 )
During the study duration (between June of 2017 and June of 2018) CT scans were performed on 12434 and 6903 patients with a GE BrightSpeed S 16 slice (Scanner1) scanner and a Siemens SOMATOM Definition AS 64 slice (Scanner2) scanner,
respectively.
Our own dose management software automatically collects dosage information from the scanners and estimates the effective dose.
The effective dose values were calculated based on the DLP,
and on the examined body part and the patient’s weight.
The DLPs were measured in mGy*cm for each CT series and device. These data were collected from the last CT report of a patient’s study along with the associated parameters (protocol name; patient name,
ID and weight).
[3][4]
Each dose report DICOM file was automatically sent to a dedicated PACS server and an appropriate algorithm calculated the effective dose data after receiving the DICOM file.
All data were stored in a MS SQL server.
Any additional data evaluation and analysis was performed by MS Access and Excel applications connected to the SQL server.
The diagnostic reference level for each protocol and separately for the two scanners was defined as the 75th percentile DLP and effective dose.
The achievable doses for the examination protocols was defined as the 25th percentile DLP and effective dose. Fig. 3
We investigated the DRL value overruns for all examinations each month and compared it with the number of all exams.
Fig. 4
The monthly changes of these DRLs of two different scanners in the examined period are presented on Fig. 5 and Fig. 6