Thread by @MoreXGrok

What's the most likely diagnosis?

53 year-old with mild shortness of breath

Hiatal hernia

Pneumothorax

Pneumonia

Pulmonary infarct

Left lower lobe atelectasis

Single axial CT scan of the chest on a different patient with same disease

Answer:

5. Left lower lobe atelectasis

Left Lower Lobe Atelectasis

All types of atelectasis involve loss of volume in some or all of a lung with resultant increased density of the involved lung

👉 here is that caused by bronchial obstru, usually a tumor (i.e. a bronchogenic carcinoma), a foreign body or mucus plug

Left lower lobe collapse

👉has distinctive features, and can be readily identified on frontal chest radiographs, provided attention is paid to the normal cardiomediastinal contours

However, the shadow cast by the heart does make it more difficult to see than the right lower lobe collapse.

Some of the findings of right lower lobe collapse can be grouped together as they are almost identical on both sides.

Differential diagnosis

The characteristic shape associated with volume loss usually does not allow for any significant differential diagnosis.

As always one should consider:

left lower lobe consolidation (of the medial basal segment)

pulmonary or posterior mediastinal mass

Reference:

Radiopedia

by Craig Hacking

♦️

learningradiology.com/archives2007/C…