A decrease in SID will create what effect?

A decrease in Source to Image Distance (SID) will indeed create size distortion. This phenomenon occurs because as the distance from the radiation source to the image receptor decreases, the projected size of the object being imaged will increase. This is a crucial concept in radiography: when the SID is reduced, the geometric distance from the source to the object becomes less, leading to a larger image of the object on the receptor.

In practice, this means that structures being imaged can appear larger than their actual size due to the angle and distance from which the x-rays are emitted. Understanding SID and its effects is vital for radiologic technologists, as it impacts the accuracy of diagnoses based on images obtained during procedures.

Furthermore, while image blurring and decreased resolution can occur due to other factors such as motion or improper focus, they are not directly related to a decrease in SID. Increased contrast is typically influenced by factors like exposure settings and imaging techniques rather than the distance from the source to the image receptor.