What are the differences between PA view and AP view of chest x-rays?
Posterior-Anterior (PA) is the standard projection. PA x-rays are taken from the posterior to the anterior of the patient – hence Posterior-Anterior (PA) projection. This means the x-rays pass from behind the patient. PA projection is not always possible because the patient cannot sit upright if they are too unwell, that is when AP films are taken, with the x-rays passing from the front of the patient instead. Both PA and AP views are viewed as if looking at the patient from the front. PA views are of higher quality and more accurately assess heart size compared with AP images which can make the heart look bigger than it actually is.