Well Omar... it is a good question
I think that both cases have some similarity in x-ray shadowing but the main thing to differentaite between them is the
shifting of mediasinum or lung fissures...
I mean in cases of Atelectasis you can uasually notice shifting of mediasinal contents (hilum of lung, trachea...etc) or lung fissure toward the collapesd lobe or segment...
While in Consolidation usually there is no such shifting or at least not significant shifting of lung fissure...
This is what I think