Mastoid cells which are a little opaque or blurred can be found in the condition called secretory otitis media where the Eustachian Tube and the middle ear is filled with thick, tenacious fluid which may produce the symptoms you has described. I don't think it signifies any infective pathology in the middle ear and mastoid air cell system. This condition can be treated medically and surgically. This choice and options can be given to you by an ENT surgeon only.