salivary gland and soft tissue imaging

Question 1

What is sialography?

Answer 1

Injection of iodinated radiographic contrast into salivary duct to look for obstruction
Done either with panoramic, skull views or fluoroscopic approach
Very small volume of contrast injected (1-1.5ml)

Question 2

What are the indications for sialography?

Answer 2

Looking for an obstruction or stricture of salivary duct which could be leading to meal time symptoms
Planning for access for interventional procedures (retrieval of stones or endoscopy)

Question 3

What are the risks of sialography?

Answer 3

Discomfort
Swelling
Infection
Allergy to contrast - very rare, MRI used as alt here

Question 4

What are the normal sialography findings?

Answer 4

Parotid gland looks like a tree in winter
Submandibular gland looks like a bush in winter

Question 5

What do acinar changes look like in sialography?

Answer 5

A snow storm appearance

Question 6

What images should be taken in sialography?

Answer 6

2 images
Contrast phase with a cannula in place
Emptying phase with a time delay
This allows the gland to work and produce saliva to excrete contrast

Question 7

What is interventional sialography?

Answer 7

Not routinely done in Scotland
Rather than surgical removal of stone, can attempt to dilate structures of the duct

Question 8

What are the selection criteria for stone removal?

Answer 8

Stone must be mobile
Stone should be located within lumen on main duct distal to posterior border of mylohyoid (submandibular gland)
Stone should be distal to hilum or at anterior border of the gland (parotid)
Duct should be patent and wide to allow passage of the stone

Question 9

What is the success rate of balloon dilation?

Answer 9

87% technical success
56% complete resolution of symptoms on follow up

Question 10

Why is an ultrasound important in Sjögren’s?

Answer 10

Higher chance for MALT lymphoma to develop in Sjögren’s syndrome

Question 11

What should be assessed in an ultrasound for Sjogren’s?

Answer 11

Gland atrophy
Heterogenous parenchymal matters (leopard print)
Hypochromic (darker)
Fatty infiltration

Question 12

What is a scintiscan?

Answer 12

Injection of radioactive Technetium 99m
Assesses how well the glands are working
Uptake into the glands if they are working well

Question 13

What is the first line imaging technique to rule out obstruction or neoplasia?

Answer 13

Ultrasound

Question 14

Describe benign salivary gland tumours

Answer 14

Well defined
Encapsulated
Peripheral vascularity
No lymphadenopathy
Eg - pleomorphic adenoma

Question 15

Describe malignant salivary gland tumours

Answer 15

Irregular margins
Poorly defined
Increased vascularity
Lymphadenopathy
Eg - acinic cell carcinoma

Question 16

When should minor salivary glands be imaged?

Answer 16

Only if enlarged or pathological
Usually use ultrasound

Question 17

What is used for soft tissue imaging?

Answer 17

Ultrasound is first line imaging - possible biopsy if required
MRI should be considered for further investigation - vascular lesions or if too large to be seen on ultrasound in completeness

Question 18

What are the chances of malignancy in lesions between major and minor salivary glands?

Answer 18

Minor salivary glands have a higher chance of malignancy if pathological than a lesion in the major salivary glands