Other Bony Imaging

Question 1

Describe the CBCT pattern of MRONJ.

Answer 1

Irregular central radiopacities in areas of radiolucency i.e. moth eaten bony radiolucency, no corticated margins.

Question 2

For TMD with suspicion of internal derangement, what is the gold standard imaging technique ?

Answer 2

• MRI.
• Shows soft tissue i.e. articular disc within joint space.
• Parasagittal view - short axis of condyle.
• Paracoronal view - long axis of condyle.

Question 3

For TMD with suspicion of degenerative change or trauma or recent change in occlusion, what is the gold standard imaging technique ?

Answer 3

CBCT.

RA or osteoarthritis.

Question 4

Where suspicion of condylar hyperplasia, what is the gold standard imaging technique ?

Answer 4

SPECT (single photon emission CT - radionuclide imaging) - checks for areas of activity and active growth.

Question 5

What is the problems with SPECT ?

Answer 5

High sensitivity but low specificity - could be inflammation or metastasis i.e. osteochondroma.
Therefore, can only be used as screening method of condylar hyperplasia.

Question 6

Where you wish to ascertain metastatic spread of cancer to lymph nodes, what is the gold standard imaging technique ?

Answer 6

US guided biopsy.

Question 7

Describe PET/CT.

Answer 7

Nuclear medicine imaging technique - positron emission tomography.
Radioactive fluorine labelled glucose (18-FDG) injected which metabolically active tissues uptake.
Overlaid over CT to give anatomical detail.

Question 8

What is the benefits of MRI vs. CT ?

Answer 8

MRI -
- No radiation dose.
- More contraindications i.e. pacemakers, cochlear implants, claustrophobia.
- MRI better for assessing perineurial spread, bone invasion and soft tissue characteristics.
- Less streak effect.

CT - quicker, less contraindications.

Question 9

What are the indications for PET scans ?

Answer 9

Looking for unknown primary tumours and follow up/recurrence.