Soft tissue signs of bony injury are commonly demonstrated on skull and facial bone images. This page identifies common soft tissue signs and their significance.

If you are using a digital imaging system (DR or CR) good algorithms and appropriate post-processing are your best friends. Soft tissue signs are of no utility if you cant see them. Consider the two lateral facial bones images shown below. Both images are taken using the same DR machine.

This image looks like a radiograph despite that fact that it was taken using a DR machine. There is no soft tissue information and the nasal bones are difficult to see.	This image was taken on the same DR machine.machine and using the same algorithm. The radiographer has post-processed the image using the DR software to display soft tissue and bone in the one image. Note that the nasal bones and anterior nasal spine are clearly demonstrated.

This image is taken using a DR system This is a PA 20/25 projection of the facial bones. There is evidence of orbital emphysema (black arrows). There is a fluid levelopacification inof the left maxillary sinus (white arrow) I don't favour this processing algorithm for facial bones. A facial bone image taken on a DR system should demonstrate all bony structures as well as all soft tissues. This looks like a radiograph rather than a DR image! CT scanning will often reveal where the subcutaneous air has tracked from. The maxillary sinus or the ethmoid sinus are usually involved. It is not uncommon for patients to be unaware of facial bone fractures until they develop orbital emphysema. This can be revealed when patients sneeze or strain on the toilet.

This is the same image which has been post-processed in Photoshop rather than using the DR software- the result is not as good as would have been achieved with the DR software. Despite this limitation, there is now evidence of further subcutaneous emphysema (grey arrow). There is no justification for creating an image that is contrasty (pretty) at the expense of it's diagnostic value. This may appear self-evident, but I suspect that this "goal-displacement" is more common than we might be prepared to admit.

	The OM view tends to obscure the orbital emphysema. A fracture of the left lower orbital margin is demonstrated (grey arrow). There is soft tissue opacification of the left maxillary sinus associated with the fracture suggesting propulsion of orbital soft tissues into the maxillary sinus. (not arrowed) The fluid level (blood) is again demonstrated in the left maxillary sinus (black arrow)

This is a slit basal view of the zygomatic arches. The patient's head has been "tipped" from a true slit basal position to favour demonstration of the affected side (a "teacup view" would arguable have been a better view). The slit basal image does not demonstrate a fracture of the zygomatic arch. Subcutaneous emphysema is again demonstrated. Note that the bony anatomy and soft tissues are demonstrated in the same image (once you've used DR it's hard to use anything else!)

	Soft tissue swelling is noted (grey arrow). This soft tissue swelling is projected over the right orbit but is actually overlying the maxillary sinus. There is evidence of a fracture of the right lower orbital margin (white arrow) There is a fluid level in the right maxillary sinus (black arrow)

	The OM30 view similarly demonstrates soft tissue swelling over the right maxillary sinus (white arrow). Compare this soft tissue line with that on the left (black arrow)