Clinical and technical challenges associated with CT dose optimization in practice

Abstract

Radiation burden represents a particular issue in realizing the greater benefits of computed tomography (CT), conceptual dose levels, real-time and offline dose monitoring software being among major efforts towards optimizing the benefit. Here we share technical and clinical challenges faced on a regional scale in implementing such tools in clinical practice. Conceptual dose baselines, although not limited to the diagnostic reference level (DRL), have for CT been based on anatomical body parts such as the head, chest, abdomen etc. The methodology and calculations used in establishing DRLs have nevertheless resulted in wide variability across CT dose indices. Example, DLP based head trauma DRLs have been reported as 556 mGy cm, 753 mGy cm, and 1820 mGy cm. The suggestion is of a need to establish DRLs based on examinations sharing similar objectives, in particular focusing on clinical indications, seeking to reduce the wide dose variations associated with anatomical based DRLs. Implementing this clinically is a challenge, particularly since CT scan acquisition series are not directly linked nor labeled according to clinical indications. Alternatively, clinical indications are more applicable when linked with CT protocols which are saved on the CT console and easily retrieved. Dose variation is also seen with use of the same protocol, scan coverage and number of scan acquisition series being contributing factors. DRLs based on scan acquisition series for every protocol allows better control and elimination of confounding factors.