Which of the following is a characteristic of a PA chest X-ray?

The correct option is:
2) X-ray beam passes from back to front

Explanation:

• In a Posteroanterior (PA) chest X-ray, the patient stands with their chest against the X-ray detector while the X-ray beam enters from the back (posterior) and exits from the front (anterior).
• This positioning provides a clearer view of the lungs and heart, reducing the magnification of heart structures compared to an AP (Anteroposterior) view.

Additional Information:

• Option 1 (Incorrect): In a PA view, the patient faces the detector, not the X-ray tube.
• Option 3 (Incorrect): This describes an AP (Anteroposterior) X-ray, where the beam enters from the front and exits through the back.
• Option 4 (Incorrect): A supine position is commonly used for AP chest X-rays, especially for bedridden patients.

Hence, the correct answer is X-ray beam passes from back to front (Option 2).