21 - Imaging of the Head and Neck Flashcards
What colour are denser objects on X-rays and CT?
Why would a CT scan be used over an x-ray to image the head and neck?
- Can see soft tissue better and can create bone, soft tissue and lung windows
What mode of imaging would you use if a patient presented to A and E with a severe head injury?
- CT as MRI is more expensive, takes up to 30 minutes and need to fill in check list to make sure compatible e.g metallic foreign bodies
- MRI used in setting of finding pathology on CT and wanting to explore further or suspect spinal cord injury
When would you use the following to image the head and neck regions:
- Ultrasound
- CT
- MRI
- X-Ray
- US: thyroid, superficial infection, carotid doppler, neck lumps
- CT: trauma, malignancy, infection, angiogram, intracranial haemorraghes, orbital fracture
- MRI: tumour evaluation, cervical spinal cord traumatic injury, head and neck tumours
- XR: facial bone fracture
What is being shown on this facial x-ray?
- Tripod fracture
Fractre of: zygomatic arch; lateral orbital wall; inferior orbital wall
What is being shown on this facial x-ray?
- Black eyebrow sign
- Air in the superior orbit, mostly due to orbital fracture
Where on this x-ray should you look for fractures?
Most common areas along the lines of fracture
What is the abnormality on this orthopantomogram?
If you see one break almost certainly will have another, like a polo
What is the abnormality on this facial x ray?
Fractured right orbit with blood in the paranasal sinus
What is being shown on this sagittal x-ray of the skull and what is it a sign of?
Fluid in the sphenoid sinus just below the sella turcica, sign of base skull fracture. If you see any fluid in air spaces suspect infection or fracture
Why may you do a cervical spine x ray?
Label the following x-ray of the saggital spine.
When looking at a saggital view of the cervical spine on x-ray, what is considered normal?
- Spinous process in straight line and equal distance between
- 4 straight lines but if not may be spinal cord injury
- 3mm atlantodens angle, anymore could be dislocation of atlas on axis so spinal cord injury
- Soft tissue thickening could be retropharyngeal axis
What are the possible diagnoses for this open mouth x ray?
- Dislocation of axis on atlas
- Jefferson fracture
The line between C2 and C1 should be straight like this image
How can you tell if a spinal column fracture is stable or unstable?
Stable: only one column affected
Unstable: more than one column affected
What is this CT scan showing?
- Extradural haemorraghe, can see fracture on bone window image
What is being shown on the following CT?
- Chronic subdural haemorraghe as dark not white
- Correct anticoagulation and manage conservatively if small as slow venous bleed
What is being shown on the following CT?
- Subarachnoid haemorraghe from trauma or ruptured aneurysm
How can you test the function of the optic nerve?
- Visual acuity
- Pupillary light reflex
- Not fundoscopy as this is looking at the anatomy
What two structures protect the larynx from aspiration?
- Vocal cords by adducting and closing glottis
- Epiglottis by closing over laryngeal inlet
Middle ear, not geniculate ganglion as this is where the greater petrosal nerve comes off
- Webers would lateralise to the right affected side as conductive hearing loss so nothing to mask the sound of the bone conduction
- Rinne’s the bone conduction would be louder than air conduction
What nerves are involved in the cough reflex?
What cartilages arise from each pharyngeal arch?
