Imaging of the Salivary Glands

Question 1

What are the 3 pairs of salivary glands

Answer 1

parotid
submandibular
sublingual

Question 1

where are minor salivary glands

Answer 1

hard palate
soft palate
retromolar pad
fom

Question 2

why do we image salivary glands

Answer 2

obstruction (mucous plugs, salivary stones, neoplasia)
dry mouth
swelling

Question 3

what imaging modalities can we use for salivary glands

Answer 3

plain radiographic techniques
ultrasound
sialography
CT
MRI
nuclear medicine

Question 4

imaging protocol for salivary gland obstruction

Answer 4

Question 5

plain film radiographs for imaging salivary glands

Answer 5

lower true occlusal
OPT
lateral oblique

Question 6

other calcifications that could be mistaken for sialoliths

Answer 6

tonsilliliths
phleboliths
calcified plaques in carotid artery
normal anatomy (hyoid bone)

Question 7

what is ultrasound

Answer 7

no ionising radiation
high frequency sound waves
transducer emits and detects sound waves

Question 8

what does hypoechoic present on ultrasound

Answer 8

dark

Question 9

what does hyperechoic present on ultrasound

Answer 9

bright

Question 10

what does homogenous mean for ultrasound

Answer 10

uniform density

Question 11

what does heterogenous mean for ultrasoun

Answer 11

mixed density

Question 12

why is ultrasound good for imaging salivary glands

Answer 12

glands are superficially positioned
can assess parenchymal pattern, vascularity, ductal dilation or neoplastic masses
can give a sialogogue ie. citric acid to aid salivary flow

Question 13

what is obstructive disease

Answer 13

‘meal time symptoms’
prandial swelling of pain
‘rush of saliva into the mouth’
bad taste
thick saliva
dry mouth

Question 14

aetiology of obstructive disease

Answer 14

sialolith or mucous plug

Question 15

what is sialography

Answer 15

injection of iodinated radiograpahic contrast into salivary duct to look for obstruction

Question 16

indications for sialography

Answer 16

-looking for obstruction or stricture (narrowing) of salivary duct could be leading to meal time symptoms
-planning for access for interventional procedures (basket retrieval of stones or balloon dilation of ductal strictures)

Question 17

risks of sialography

Answer 17

discomfort
swelling
infection
any stone could move
allergy to contrast

Question 18

what is fluroscopic sialography

Answer 18

can watch the contrast entering the ductal system in real time
increased radiaiton dose to patient
staff must wear lead aprons due to increased dose

Question 19

what are the phases of sialography

Answer 19

pre-contrast
contrast/ filling
emptying

Question 20

normal appearance of parotid gland

Answer 20

‘tree in winter’

Question 21

normal appearance of submandibular gland

Answer 21

‘bush in winter’

Question 22

if there is acinar changes what appearance is on radiograph

Answer 22

snow storm appearance

Question 23

how many images should you take

Answer 23

at least 2 images
- contrast phase with cannula in place
- emptying phase with time delay

Question 24

what do use if patient has a iodine allergy

Answer 24

MRI sialogrpahy

Question 25

what is interventional for removal of salivary stone

Answer 25

dilate strictures (narrowing of the duct)

Question 26

selection criteria for stone removal

Answer 26

1. stone must be mobile 2. stone must be located within lumen on main duct distal to posterior border of mylohyoid 3. stone should be distal to hilum or anterior border ofo the gland 4. duct should be patent and wide to allow passage of the stone

Question 27

what is balloon dilatation

Answer 27

Contrast will be used to locate the blockage. The duct will then be dilated using a balloon which can then be deflated and removed.

Question 28

what disease do patients with dry mouth sometimes have

Answer 28

sjogren's disease

Question 29

other investigations used for sjogrens

Answer 29

blood tests schimer test sialometry labial gland biopsy

Question 30

what are you looking for on ultrasound for sjogrens

Answer 30

atrophy heterogenous paraenchymal pattern hypoechoic (darker) fatty infiltration

Question 31

what do patient with sjogrens have a higher change of developing

Answer 31

MALT lymphoma

Question 32

stages of sjogrens syndrome

Answer 32

stage I - punctate stage II - globular stage III - cavitation stage IV - destructive

Question 33

what is scrintigraphy

Answer 33

intravenous injection of radiactive technetium 99m pertechnetate assess how well the glands are working

Question 34

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

Answer 34

ultrasound

Question 35

if neoplasia swelling presnt what is required

Answer 35

biopsy

Question 36

what technique is needed for cytopathological diagnosis

Answer 36

fine needle aspiration

Question 37

what is needed for tissue histopathological diagnosis

Answer 37

core biopsy

Question 38

example of benign salivary gland tumours

Answer 38

pleomorphic adenoma warthins tumours

Question 39

signs of a benign salivary gland tumour

Answer 39

well defined encapsulated peripheral vascularity no lymphadenopathy

Question 40

examples of malignant salivary gland tumours

Answer 40

mucoepidermoid carcinoma acinic cell carcinoma adenoid cell carcinoma

Question 41

examples of malignant salivary gland tumours

Answer 41

irregular margins poorly defined irregular/ torturous internal vascularity lymphadenopathy

Question 42

when is an MRI useful

Answer 42

pres-surgical assessment and deep margins of lesions that may not be seen on ultrasound also try to do before biopsy

Question 43

when do you need to image minor salivary glands

Answer 43

only need to image if enlarged or pathological usually ultrasound if superficial MRI beneficial if deep or possibly bony involvement

Question 44

do minor or major salivary glands have a higher chance of malignancy

Answer 44

minor salivary glands