The utilization of CT imaging has increased dramatically over the past two decades. Even
though the benefits from CT examinations for various clinical diagnoses are considerable,
there are potential adverse risks from exposure to ionizing radiation. There are three (3)
categories of patients, which are particularly sensitive to the risks of radiation exposure:
pregnant patients, small children and the breast of young women. Hence, it is desirable
to minimize the radiation doses to patient if it can be accomplished without any
significant impact upon the diagnostic accuracy of the examinations.
Often CT scan parameters are selected in a rather arbitrary manner. Neuroradiologists
tend to favor relatively high dose techniques with the goal of improving image quality
without establishing realistic criteria. To simplify operational protocols, the same scan
parameters are frequently utilized for all patient sizes. This presentation will relate the
image noise to the scan parameters and the patient size. For pediatric and smaller
patients, it will be demonstrated that the patient radiation doses can be reduced by factor
of more than four without a significant impact upon the image quality. The discussion
will encompass appropriate mAs reduction and selection of kVp for the scans.