What is the purpose of the 72-inch SID used for chest radiography?

Question

Quizplus · Accepted Answer

The purpose of the 72-inch SID (source-to-image distance) is to minimize magnification of the heart shadow, making it appear more true-to-size on the radiograph. The longer distance also reduces patient dose. The choice A is not correct because the longer SID can actually make positioning more challenging due to the increased distance between the X-ray tube and detector. The choice D is also not correct because the scapula (shoulder blade) is not typically demonstrated in the lungs on a chest radiograph.

What Is the Purpose of the 72-Inch SID Used for Chest