Computed tomography (CT) is an advanced imaging modality that has become indispensable in a variety of clinical applications. However, the utility of CT has sometimes been limited by safety concerns related to the level of radiation exposure required for imaging. It is therefore critical that radiologic technologists understand the imaging parameters that can contribute to radiation dose, and the available techniques, as well as hardware and software, that can help mitigate radiation dose delivered to patients undergoing CT. After a brief review of the history of CT imaging, this article will discuss the advantages of CT imaging as compared to conventional X-ray, review CT imaging parameters that can contribute to radiation dose, and explain radiation dose units for reporting and measuring dose. In addition, the article will address new software and hardware options to reduce radiation dose during CT procedures, and recent updates to CT radiation dose regulations as the result of efforts by government and professional agencies. These discussions will be rounded out by a description of the role of the CT technologist in overseeing CT techniques and protocols for low-dose radiation techniques, as well as CT dose reduction strategies in clinical practice.
After reading this article, the participant should be able to:
- Explain the rise in prominence of CT diagnostic imaging over the past 3 decades.
- Describe effective radiation dose reduction techniques for patients undergoing CT imaging.
- Identify software tools used to achieve radiation dose reduction in CT.
- Understand legislative efforts to improve CT safety.