Radiography: skull (basic)

• Radiography of the skull requires general anesthesia or heavy sedation. This is the only way to obtain accurate projections.
• Endotracheal tubes can interfere with the interpretation of the images.
• A grid is not necessary.
• The objective is to produce well-positioned radiographs which are correctly exposed and developed, free from movement blur and free from artifact.
• The anatomical marker, the patient's identification, the date, and the name of the hospital or practice should be clearly shown.

Print off the Owner Factsheet on Xray and Ultrasound to give to your clients.

Uses

• To identify Radiology: skull and dentition:
• • Dental disease Teeth: dental disease - overview .
  • Fracture Limb fracture .
  • Osteomyelitis Osteomyelitis: commonly associated with dental disease.
  • Rhinitis Rhinitis/sinusitis: radiography is not particularly effective to detect purulent discharge from the nasal cavity. CT scan or MRI are superior to visualise changes in the nasal cavity, and even endoscopy can be used in particular cases.
  • Abscesses Abscess: commonly associated with dental disease .
  • Bulla disease Otitis media/interna: radiography is not particularly effective to detect changes in the bulla, and CT or MRI are significantly superior .
  • Temporomandibular joint disease.
  • Ocular disease . However, radiography is not particularly effective to detect ocular changes, as many cases of exophthalmus are caused by retrobulbar abscesses, and CT or MRI provide a significantly superior image in these cases . Skull radiograph is indicated in cases of dacryocystitis or excessive lacrimation, as these cases are usually related to dental disease.
  • Soft tissue neoplasia Cutaneous neoplasia.
  • Bony neoplasia.
  • Foreign bodies: occasionally, needles and other foreign objects have been found inside the mouth of rabbits.

Advantages

• Non-invasive (although it requires GA or sedation).

Alternative techniques

• Computed tomography (CT) Computed tomography and magnetic resonance imaging (MRI) Magnetic resonance imaging are the modalities of choice for most brain imaging, where these are available, but also for suspected otitis, retrobulbar disease, rhinitis and even complex dental disease.

Time required

Preparation

• Dependent upon the method of chemical restraint (GA Anesthesia: general or sedation Sedation).

Procedure

• 10-15 min, or longer, dependent upon skill of radiographer.

Decision taking

Criteria for choosing test

• Is the examination appropriate?
• Can you make the diagnosis without it?
• Can it tell you what you need to know?
• Will your management be affected by the radiological findings?

Choosing the right projection

• Lateral:
• • Standard projection  and open mouth .
  • May show gross fractures, depending on their position.
  • May show skull vault shape abnormalities.
  • Will give some information about the nasal chambers and frontal sinus, notwithstanding the fact that the two sides are overlying each other.
  • May show neoplasms involving the bone.
  • Allow partial assessment of dental arcades
• Dorsoventral:
• • May give information on skull vault shape .
  • May show gross fractures, depending on their position.
  • Good for fractures of the zygomatic arches.
  • Good for some mandibular fractures and dislocation of the temporomandibular joints.
  • Of some use for tympanic bullae and rhinitis.
  • A ventrodorsal view is many times equivalent.
• Lesion orientated obliques:
• • For suspected depressed fractures and for lumps on the skull the best projection is often an oblique, positioned so that the beam passes tangentially across the lesion or area of interest.
  • Particularly useful to assess dental roots .