RTBC Image Evaluation and Quality Control (122) Practice Exam

Spatial resolution in radiographic images is primarily influenced by the distance between the X-ray source and the image receptor, known as source-to-image distance (SID), and the distance between the object being imaged and the image receptor, referred to as object-to-image distance (OID).

When SID is increased, the geometric unsharpness decreases, which leads to enhanced spatial resolution, meaning that finer details can be visualized in the image. Conversely, if OID is increased, it can result in greater magnification and blur due to the increased distance from the object to the imaging receptor, which negatively impacts spatial resolution. Therefore, understanding the relationships between SID, OID, and their effects on image clarity and detail is essential for optimizing image quality in radiography.

The other options do contain factors that can influence image quality in various ways, but they do not directly correlate to spatial resolution as effectively as SID and OID. For instance, film speed and density primarily relate to the exposure and contrast characteristics of the film rather than resolution; patient size can affect dose and perhaps scatter but isn’t a direct determinant of spatial resolution; and while the type of detector and its calibration are important for overall image quality, they are not specific to spatial resolution in the