Other Imaging Modalities

Question 1

Describe how Sialography works

Answer 1

Injection of ionised radiographic contrast into salivary ducts to look for obstruction
No LA required

Question 2

Indications for Sialography

Answer 2

Obstruction or stricture of salivary duct

Question 3

Risks of Sialography

Answer 3

Discomfort
Swelling
Infection
Allergy to contrast (MRI = alternative)

Question 4

Normal radiographic findings expected from sialography (3)

Answer 4

Snow storm appearance (destruction of acini)
Tree in winter
Bush in winter

Question 5

List the criteria for removal of stone (3)

Answer 5

• Duct wide enough to allow passage
• Mobile
• Stone distal to hilum

Question 6

Radiographic imaging indicated for salivary gland swellings

Answer 6

Ultrasound - rules out obstruction or neoplasia (need biopsy)

Question 7

Compare features of benign lesions to malignant lesions

Answer 7

BENIGN
- Well defined
- Regular margins
- Encapsulated
- Peripheral vascularity
- No lymphadenopathy

MALIGNANT
- Poorly defined
- Irregular margins
- Increased internal vascularity
- Lymphadenopathy

Question 8

Compare CBCT to CT

Answer 8

CBCT
- Cone shaped beam
- Low dose
- Poor soft tissue contrast
- Patient upright

CT
- Fan shaped beam
- High dose
- Good soft tissue contrast
- Patient horizontal

Question 9

TMJ imaging indications (3)

Answer 9

Myofascial pain - none
Internal derangement - MRI
Degenerative - CBCT

Question 10

Compare CT to MRI

Answer 10

CT
- Radiation involved
- Quicker

MRI
- No radiation
- Slower
- More contraindications (pacemaker, cochlear implants, claustrophobia)
- Better for assessing:

Perineurial spread

Bone invasion via bone marrow

Soft tissue characteristics of lesion