Other Imaging Modalities Flashcards
Why might we want to image the salivary glands?
- Obstruction
- Dry mouth
- Swellings
What type of obstructions can occur in salivary glands?
- mucous plugs
- salivary stones
- neoplasia
Label the glands shown on this image from top to bottom:
- Parotid
- Submandibular
- Sublingual
What is a good option for imaging the salivary glands?
Ultrasound
Why is ultrasound a good option for imaging salivary glands?
- Glands are superficially positioned
- Can give a sialogogue to aid saliva flow to allow better visualisation of ducts
What can we assess about salivary glands with ultrasound?
- parenchymal pattern
- vascularity
- ductal dilatation
- neoplastic masses
What is ultrasound?
High frequency sound waves (cannot be heard audibly)
- no radiation
What is the imaging protocol order for salivary gland obstruction?
- ultrasound
- plain film (mandibular true occlusal)
- sialography
What might be indicative that a patient is suffering from obstructive disease of salivary gland?
- swelling and pain during meals
- bad taste
- thick saliva
- dry mouth
What is usually the cause/aetiology of obstructive salivary gland disease?
Sialolith or mucous plug
What is a sialolith?
Sialolithiasis is a crystallopathy where a calcified mass or ‘sialolith’ forms within a salivary gland, usually in the duct of the submandibular gland
- these are radiopaque
What is sialography?
Injection of iodinated radiographic contrast into salivary duct to look for obstruction
- 1.0 - 1.5ml of liquid injected
When is sialography indicated?
- looking for obstruction or stricture of salivary duct which could be leading meal time symptoms
- planning for access for interventional procedures (eg retrieval of stones)
What risks are associated with Sialography?
- discomfort
- swelling
- infection
- allergy to iodine contrast injection
How could the normal finding of an imaged parotid gland be described?
‘tree in winter’
How could the normal finding of an imaged submandibular gland be described?
‘bush in winter’
What would this salivary gland imaging suggest?
Gland obstructions
- ‘snow storm appearance’
Why should you always take at least 2 images when performing Sialography?
So you can image:
- contrast phase with cannula in place
- emptying phase with time delay
Allows gland to work and produce saliva to excrete contrast
What is the selection criteria for salivary stone removal?
- Stone must be mobile
- Stone should be located within lumen on main duct distal to posterior border of mylohyoid
- Stone should be distal to hilus or at anterior border of gland
- Duct should be patent & wide to allow passage of stone
What should be used alongside Sialometry to diagnose Sjogrens Syndrome?
- blood test (anti-Ro anti-La)
- Schirmer test
- labial gland biopsy
When investigating for Sjogrens syndrome with ultrasound imaging of glands, what are you looking for?
- Atrophy
- Heterogeneous parenchymal pattern (leopard print)
- Hypoechoic (darker)
- Fatty infiltration
What is a Scintiscan?
Injection of radioactive Technetium 99m into glands to assess how they work
- uptake into glands if working well
If neoplasia is suspected after ultrasound imaging of salivary glands, what should be done?
Biopsy
- fine needle aspiration for cytopathological diagnosis
- core biopsy for tissue histopathological diagnosis
What are the features of a benign tumour?
- well defined margins
- encapsulated
- peripheral vascularity (not internal)
- no lymphadenopathy
