Tissue fullness definitely means that the tissues are swelling and when the swelling is focal in nature, it means that there is a specific cause at a particular position which is causing the swelling. While for all the types of troubles, the basic reason can be infection of the tissues or the local nerves, which can also result into tinnitus
. I would suggest you to follow the Radiologist's advice and perform further visualization investigations. You must also see your ENT physician for a further opinion.