How do you diffrentiate between PA and AP chest x- ray?

Answer 1

1) In AP view, the posterior chest is well demonstrated.

2) In AP view, the scapulae overlie the upper lung areas and the clavicles are projected more cranially over the apices.

3) In AP view, the disc spaces of lower cervical spines are more clearly seen.

4) In AP view, the heart is magnified.

Answer 2

Normally PA view is preferred. The clavicles won't project too high into the apices or thrown above the apices. The heart won't be magnified over the mediastinum. The ribs will not appear distorted or unnaturally horizontal like in lordotic chests. However pediatric chests normally employ AP recumbant or upright views because the infants or toddlers can take full inspirations and their body won't be so thick that anatomy will matter much in PA vs AP views.

Answer 3

The PA view is preferred for several reasons, already noted on this site. However, the relative exposure between the two has not been answered adequately. In theory, the thickness of a chest does not change between a PA or AP position, so the expousre technigue whould be unchanged. However, if the PA position causes compression of breast tissue it could slightly reduce overall exposure compared with the AP position.

But that isn't the whole story. Since breast tissue is particulary sensitive to radiation an AP view using the same technique will cause a significant increase in expousre to the breast tissue. This is because the PA position will cause much of the radiation to be absorbed prior to exiting at the level of breast tissue, while the AP position does not provide that body filtering to occur. Also, the inverse suare law means when breasts are close to the source the exposure will be higher. So an AP view will cause higher expousres to sensitive tissue even if the expousre technique is unchanged.

Answer 4

+ It reduces magnification of the heart therefore preventing the appearance of cardiomegaly; + It reduces the radiation dose to radiation-sensitive organs such as the thyroid, the eyes, the breasts; + The patient is stood erect, facing the image receptor. This facilitates a deeper inspiration and therefore visualises a maximum area of the lungs; + Easier positioning of the patients as they are required to roll their arms forward and either hold onto the back of the vertical x-ray unit or bend their elbows and place the backs of their hands on their hips. This moves the scapulae away from the lung fields; + Compression of the breast tissue against the image receptor/vertical x-ray unit reduces the density of tissue around the costo-phrenic bases therefore visualising them more clearly; + More stable positioning for the patient as they are leaning against the image recepto and can hold on the equipment if necessary. This reduces patient movement which in turn reduces movement unsharpness on the image therefore avoiding the need to repeat the examination and inceasing the radiation dose to the patient.

Answer 5

in pa view heart size is decreased,,,, scapulae are away from lung fields,,,, and lung apices are above claviclew

Answer 6

No the other way round