Dutch term (edited): met groot luchtvochtniveaubeeld basaal

'beeld' can just mean this is what you see (so leave out) or this is what it looks like, in this case you could add 'with evidence of' or something

However, since this is a large one I suppose it is just what they see:

a large air-fluid level in the basal region (of the lungs)

Hydropneumothorax is defined as the presence of both air and fluid within the pleural space surrounding the lung. An upright chest x-ray will show air fluid levels. The horizontal fluid level is usually well defined and extends across the whole length of hemithorax.

http://en.wikipedia.org/wiki/Hydropneumothorax