Question

During CT x-ray exposure, the product of the selected mA setting and the scan time is called the:

-effective mAs
-peak mAs
-absorbed mAs
-constant mAs

Answer 1

The product of the mA setting and scan time in a CT scan is known as the effective mAs, which is crucial for determining the x-ray exposure and affecting image quality and patient safety.

Step-by-step explanation:

In the context of computed tomography (CT) scanning, the product of the milliamperage (mA) setting and the scan time (s) is known as the effective mAs. This parameter is a pivotal factor in determining the quantity of x-ray exposure the patient receives during the scan, as it combines both the intensity of the x-ray beam (milliamperage) and the duration of the exposure (time). For example, if the CT scan's exposure time is 0.250 seconds and a selected mA rating is used, the effective mAs is calculated by multiplying these two values. The effective mAs significantly affects the quality of the image produced and the dose of radiation absorbed by the patient's tissue. Understanding and carefully managing the effective mAs is crucial for optimizing image quality while minimizing radiation exposure to the patient, adhering to the principle of ALARA (As Low As Reasonably Achievable).