What is the Film-Focused Distance (FFD) for the AP/PA sacrum projection?

The Film-Focused Distance (FFD), also known as the Source-to-Image Distance (SID), is an important parameter in radiographic imaging that influences the quality of the image produced. For the Anteroposterior (AP) and Posteroanterior (PA) projections of the sacrum, the appropriate FFD is 37 inches.

This distance is established to optimize the image sharpness and minimize distortion. A shorter or longer FFD can affect magnification and ultimately impact the diagnostic quality of the radiograph. In the case of the sacrum projection, using a FFD of 37 inches ensures that the image remains clear and anatomically accurate, providing a reliable representation of the sacral region for diagnostic purposes.

Understanding the correct FFD is vital for radiologic technologists, as it ensures the integrity of the imaging process, leading to more accurate evaluations of patient conditions.