What is the purpose of a chest radiograph?

A chest radiograph, commonly known as a chest X-ray, is primarily used to evaluate the lungs and heart. This imaging technique allows healthcare professionals to look for a variety of conditions related to these vital organs. By using radiation to capture an image, chest radiographs can help identify issues such as pneumonia, lung tumors, heart enlargement, fluid around the heart, and other abnormalities that may affect breathing or cardiovascular function.

The other choices focus on areas unrelated to the purpose of a chest radiograph: evaluating the digestive system pertains to different imaging types such as abdominal X-rays or ultrasounds; assessing bone density typically requires specialized tests called DEXA scans; and examining the brain involves imaging techniques like CT scans or MRIs, which are not related to chest radiographs. Thus, the correct response highlights the specific and important role of chest radiographs in diagnosing conditions related to the respiratory and cardiovascular systems.