Purpose of this study is to compare typical doses for 10 CT clinical indications in three Croatian university hospitals with EU indication based diagnostic reference levels (hereinafter: clinical DRLs), as given in Radiation protection 195 publication (hereinafter: RP 195).

Although recent recommendations suggest use of clinical DRLs instead of DRLs based on anatomical region [1,2], the previous practice in Croatia involved comparison of typical doses with the national DRLs (hereinafter: nDRL) which are based on the anatomical regions since Croatian legislation still does not recognize clinical DRLs [3]. In order to investigate to which level practice in Croatia is in line with the recent recommendations, comparison of typical values of CT dosimetric quantities for clinical indications was performed. Three university hospitals with six CT...

The results of the analysis show that for the same clinical indication, imaging is performed differently in different hospitals and in some cases differently when more CT units are used at the same hospital, starting with the use of different numbers of phases (precontrast and postcontrast) (Figure 1). In some cases where examination is performed using different number of phases for the same indication using the same CT unit, data for insufficient number of patients was provided for specific phase hence for that phase typical...

For the same indication choice of used imaging protocol in same cases significantly varies from hospital to hospital, even from CT unit to CT unit within the same hospital indicating that imaging protocols are not standardised but left to radiologist to choose. Results of this study emphasise the importance of the use of clinical DRLs (instead of anatomical) and shows the need for thorough analysis of used CT protocols and continuation of cooperation of all involved professions towards further optimisation.

[1] Paulo G, Damilakis J, Tsapaki V, Schegerer A A, Repussard J, Jaschke W, Frija G, Hierath M, Clark J and Radiology E S of 2020 Diagnostic Reference Levels based on clinical indications in computed tomography: a literature review Insights Imaging 11 96 [2] European Commission 2021 European Study on Clinical Diagnostic Reference Levels for X-ray Medical Imaging Radiat. Prot. Publ. 195 [3] Ordinance on the conditions for use of ionising radiation sources for medical and non-medical pruposes Off. Gaz. 42/18, 8/2 [4] ICRP 2017...

I. Kralik: Nothing to disclose B. Brkljačić: Nothing to disclose D. Cvetko: Nothing to disclose I. Hulina: Nothing to disclose M. Justić: Nothing to disclose J. Popić: Nothing to disclose I. Bjelobrk: Nothing to disclose T. Turk: Nothing to disclose D. Faj: Nothing to disclose