Author Question: In the standard posteroanterior chest film, the heart shadow should be less than what proportion of ... (Read 78 times)

SO00 · **on:** Jul 16, 2018

In the standard posteroanterior chest film, the heart shadow should be less than what proportion of the chest width?

a. 33
b. 40
c. 50
d. 65

Question 2

What problem exists when interpreting an overexposed chest film?

a. There is difficulty in seeing the peripheral blood vessels.
b. The ribs appear wider than normal.
c. The heart shadow is blurred.
d. The lymph nodes in the mediastinum can-not be seen.

AISCAMPING · **Reply #1 on:** Jul 16, 2018

Answer to Question 1

ANS: C
In the posteroanterior projection, the diameter of the heart shadow should not exceed one-half the diameter of the chest.

Answer to Question 2

ANS: A
An overpenetrated x-ray overexposes the film, leaving the lung parenchyma black and no ability to visualize the peripheral blood vessels. This overpenetration will make evaluation of the lung parenchyma far more difficult.