Soft Tissue & Gland Imaging Flashcards
What are the three pairs of major salivary glands in head and neck ?
Parotid.
Submandibular.
Sublingual.
What are patient diagnoses which might indicate imaging of salivary glands ?
Obstruction.
Dry mouth.
Swelling.
What are the three most common obstructive salivary gland diseases ?
Neoplasia.
Mucous plugs.
Salivary stones (sialoliths).
Why is ultrasound good for imaging salivary glands ?
Superficially positioned.
Can assess parenchymal patter, vascularity, ductal dilation or neoplastic masses.
Can give sialogogue to aid saliva flow for visualisation of ductal dilation.
Briefly describe ultrasound imaging.
No ionising radiation.
High frequency sound waves interact with tissues of different densities, bounce back to transducer - varying lengths of time it takes for sound waves to reach back, creates an image.
What is the reason for using coupling agent ?
Allows movement of sound waves into tissues e.g. Ultrasound gel.
What is the imaging protocol for salivary gland obstruction ?
- Ultrasound.
- Plain film (mandibular true occlusal).
- Sialography.
What are the symptoms of obstructive salivary gland disease ?
Prandial swelling and pain (i.e. at mealtimes).
Rush of saliva into mouth.
Bad taste.
Thick saliva.
Dry mouth (with no other signs of Sjogren’s).
What gland is most commonly affected by sialoliths ?
Submandibular (80%).
What % of salivary stones are radiopaque ?
80%
Briefly describe what sialography is.
Injection of iodinated radiographic contrast into salivary duct to look for obstruction (1-1.5ml through catheter).
What are the indications for sialography ?
Obstruction or stricture of salivary duct.
Planning for interventional procedures i.e. basket retrieval.
What are the risks of sialography ?
Pain.
Swelling.
Infection.
Allergy to contrast.
Where is the parotid gland orifice ?
Buccal mucosa adjacent to upper 6 and 7.
Where is the sublingual orifice ?
Lingual papilla in floor of the mouth at midline.
How is normal findings of parotid gland described in sialography ?
Tree in winter.
How is normal findings of submandibular gland described in sialography ?
Bush in winter.
How will acing changes present on sialography radiograph ?
Snow storm appearance - usually seen in Sjogren’s.
‘Globular sialectasia’.
What two radiographs are most commonly taken with sialography ?
OPT and lateral oblique - contrast phase and emptying phase.
Why is a radiograph taken in emptying phase ?
Allows gland to work and produce saliva to excrete contrast - shows how well gland is functioning.
What is the four parts of selection criteria for stone retrieval procedure ?
Must be mobile.
Should be patent and widen to pass stone through.
Located in lumen on main duct distal to posterior border of mylohyoid (submandibular).
Should be distal to hilum or at anterior border of gland (parotid).
What are the two interventional procedures which can be carried out ?
Balloon dilation.
Basket retrieval.
What is the gold standard diagnosis technique for Sjogren’s ?
Labial gland bx.
What are the ultrasound characteristics of Sjogren’s ?
Atrophy.
Heterogeneous parenchymal pattern (leopard print).
Hypoechoic areas - indicates focal glandular destruction.
Fatty infiltration.
What is the biggest malignancy risk from Sjogren’s ?
MALT lymphoma.
Therefore, ultrasound is always indicated in these patients as part of screening for MALT lymphoma.
What is the ultrasound appearance of MALT lymphoma ?
Large hypoechoic area.
Irregular margin.
Describe briefly what scintiscan is ?
Injection of radioactive technetium 99m to assess how well glands are working. There will be uptake into gland if it is working optimally.
Describe characteristics of benign salivary gland tumour.
Well defined.
Encapsulated.
Peripheral vascularity.
No lymphadenopathy.
Give two examples of benign salivary gland disease.
Pleomorphic adenoma.
Warthins tumour.
Describe characteristics of malignant salivary gland disease.
Irregular margins.
Poorly defined.
Increased internal vascularity.
Lymphadenopathy.
Give an examples of malignant salivary gland disease.
Acinic cell carcinoma.
Adenoid cystic carcinoma.
What are the two types of bx which can be used for neoplastic salivary gland lesions ?
Fine needle aspiration - for cytopathology.
Core biopsy - for histopathology.
When might an MRI be indicated ?
Pre-surgical assessment and deep margins of lesions that cannot be visualised on US.
Allergy to iodine.
