American Registry of Radiologic Technologists (ARRT) Practice Exam

An increase in the Source to Image Distance (SID) directly improves recorded detail in radiography due to a reduction in geometric blur. When the SID is increased, the X-ray beam diverges less by the time it reaches the imaging receptor, resulting in sharper images. This reduction in blur is important for enhancing the resolution of the images produced, which is crucial for accurate diagnoses. The increase in distance allows for a more precise representation of the structures being imaged, thereby increasing the detail captured on the film or digital imaging sensor.

In addition, increasing the SID can also decrease the amount of scatter radiation that reaches the image receptor, further contributing to improved image quality and clarity. Although factors like patient safety may be indirectly improved by ensuring better images for diagnosis, and exposure time might change based on intensity calculations, the most direct effect of increasing SID is on the recorded detail of the radiographic image.