On chest PA, air-fluid level in the left thorax is seen. On the left scapular lateral view, however, the air-fluid cavity (arrow) is extended outside the rib cage and beneath the left scapula, it is not hydropneumothorax, but complicated fluid in the left chest wall.
Just inferior aspect of the air-fluid level, mottled air densities are noted (arrowheads) as well, suggesting dirty fluid collection or abscess.
On the T2 fat saturated axial MRI, similar findings are noted such as air-fluid level, mottled air density within the fluid, as well as increased signal intensity at the surrounding fat tissue. The air-fluid cavity is located beneath the scapular (S) and just outside the rib, suggesting infraserratus bursa.
