In the ICU patient, the left lower lobe is subject to atelectasis most often. Atelectasis usually begins at the lung bases and is more common on the left in the ICU patient.

2. Which is more common in the ICU setting?
Atelectasis
Atelectasis is the more frequent abnormality detected in ICU chest films.

3. The diagnosis of atelectasis is favored over pneumonia by all of the following radioopaque signs except:
Hazy margins
Hazy margins can occur with other processes such as pneumonia or pulmonary edema.

4. Resolution of the chest film after aspiration of gastric contents can occur by the third day.
True
Aspiration pneumonitis often begins to resolve by day three.

5. Which of the following is not correct?
Most patients with a pulmonary embolism DO NOT have abnormalities on chest x-ray
Actually, most patients with pulmonary embolism WILL have an abnormality on chest x-ray. These abnormalities are usually nonspecific and commonly associated with atelectasis or effusions.