How does decreased collimation affect patient effective dose with fixed technique?

Decreased collimation refers to a larger x-ray beam area than what is necessary for the specific imaging procedure. When collimation is reduced, more tissue is exposed to radiation than intended. This increased exposure can lead to a higher dose of radiation received by the patient. As a result, the effective dose, which accounts for the biological effects of radiation on tissue, also increases when collimation is not properly applied.

In fixed techniques where the exposure settings (kilovoltage, milliamperage, and time) remain constant regardless of the degree of collimation, allowing for wider beam exposure inadvertently raises the amount of radiation that the patient absorbs. This can lead to higher risks of radiation-induced effects, emphasizing the importance of appropriate collimation in managing patient safety and minimizing exposure.

Though other options touch on aspects related to radiation exposure or image quality, they do not accurately reflect the implications of decreased collimation regarding patient dose, making the understanding of how it increases patient effective dose critical.