DR FATHIMATH ZAHRA,MDS SENIOR LECTURER ORAL MEDICINE & RADIOLOGY MALABAR DENTAL COLLEGE & RESEARCH CENTRE, MANOOR

1. Nuclear Medicine
Imaging in the
Dentomaxillofacial
Region
Dr Fathimath Zahra
senior lecturer
Oral Medicine & Radiology
Malabar dental college & research centre, Edappal

2. Nuclear Medicine :
– Nuclear medicine displays physiologic processes at the molecular
level.
– It is an imaging subspecialty that uses small amounts of
radioactive material to diagnose and treat disease.
– Radiopharmaceuticals administered are composed of a
radioactive component (radioactive atom) bound to a
physiologically active component.

3. Radionuclides :
– Properties of ideal radionuclide.
– Iodine (131I), gallium (67Ga), and selenium (74Se) are
used.
– The most commonly used is technetium 99m (99mTc).
– half-life of 6 hours
– emits primarily 140 keVphotons.
– when injected intravenously is concentrated by the salivary and
thyroid glands and gastric mucosa

4. –99mTc-MDP
–18F-NaF PET
–18F-FDG PET/CT

5. 99mTc-MDP
– To image bone, 99mTc is typically bound to methylene
diphosphonate (MDP).
– Dose of 20 to 30 mCi (740 to 1110 megabecquerels [MBq]) is
injected intravenously.
– UPTAKE MECHANISM: depends both on osteoblastic activity and on
blood flow

6. PROCEDURE:
Immediately after injection, the tracer distributes intravascularly.
Images made during this flow phase, the first 60 to 90 seconds,
are called radionuclide angiography
The second, or blood pool, phase, the tracer quickly moves into
the extracellular space.

7. The third, or bone scintigraphy, phase, is made 2 to 3 hours
after injection.
Images made 2 to 3 hours after injection show most of the
tracer activity in the skeleton, kidneys and bladder.

8. GAMMA CAMERA
– Anger cameras / scintillation cameras.
– These cameras capture photons and convert them to light and then
to a voltage signal.
– This signal is reconstructed to a planar image that shows the
distribution of the radionuclide in the patient.
– spatial resolution of 3 to 5 mm.

9. TH

10. SPECT:
– SPECT imaging is a method of acquiring tomographic slices through a
patient.
– Most gamma cameras have SPECT imaging capability.
– In this technique, either a single or a multiple gamma camera is
rotated 360 degrees around the patient.
– Image acquisition takes about 30 to 45 minutes.

11. chronic osteomyelitis of the mandible

12. 18F-FLUORIDE BONE SCAN:
– 18F-Fluoride is a highly sensitive bone-seeking PET tracer. 18F-fluoride is
produced in a cyclotron from 18O-water.
UPTAKE MECHANISM:
 The uptake mechanism is similar to 99mTc-MDP.
 Blood flow and bone remodeling.
 18F-ions pass from plasma through the extravascular fluid space into the crystal.
 The 18F-ions chemisorb to the hydroxyapatite.
 18F-NaF is an analogue for the hydroxyl ion, it exchanges quickly for the hydroxyl
ion on the surface of the hydroxyapatite matrix

13. – DOSE: 185 to 370 MBq (5–10 mCi) for adults.
– The half-life of 18F is 109 minutes.

14. ADVANTAGES OVER 99mTc-MDP
.
18F-fluoride
• first pass extraction is 70% to 100%
• Faster blood pool clearance (negligible protein binding)
• Faster blood pool clearance (10% remaining at 1 hour thus
short imaging duration
• 18F-NaF has higher accuracy than 99mTc-MDP planar and
SPECT bone scans

15. 18F-FLUORODEOXYGLUCOSE
PET
– Fluorine incorporated into a radiopharmaceutical such as glucose(FDG – glucose
analog) or amino acids by use of a medical cyclotron.
– After the radiopharmaceutical is injected into the patient, the isotope
distributes within the body tissue and emits a positron.
– This positron interacts with a free electron and mutual annihilation occurs,
resulting in the production of two 551-keV photons emitted at 180 degrees to
each other.
– The PET scanner consists of a ring of many detectors in a circle around the
patient

18. Advantage over CT & MRI
– shows abnormalities on the molecular level often before
CT and MRI can detect abnormalities based on
morphologic criteria.
– less limited by metallic artifacts.

19. PROCEDURE:
– Instructed to fast 4 to 6 hours.
– instructed to avoid strenuous exercise during the 24 hours
before the study.
– Blood glucose is checked before FDG injection where ideal
levels should be less than 150 to 200 mg/dL.
– A total of 10 mCi of FDG is injected and imaging starts 45 to 60
minutes following injection.
– FUSION OF PET/CT

20. PET/CT??
– CT imaging is fast (60–70 seconds), whereas the PET
component takes 30 to 45 minutes.
– CT resolution is 0.3 mm and PET resolution is 4 to 6 mm.
– The CT data are used for attenuation correction of the
PET data.

22. ROLE OF NUCLEAR MEDICINE IN
DENTOMAXILLOFACIAL REGION

23. ROLE OF NUCLEAR MEDICINE IN
DENTOMAXILLOFACIAL REGION
– INFECTION
– INFLAMMATORY DISEASE
– SJOGREN’S SYNDROME
– SAPHO SYNDROME
– TMD
– CONDYLAR HYPERPLASIA
– PAGET DISEASE
– MALIGNANT NEOPLASM
– EVALUATION OF BONE GRAFTS
– MEDICATION RELATED OSTEONECROSIS OF THE JAW
– ASSESSMENT OF SEQUELE OF THERAPY FOR H & N CARCINOMA

24. INFECTION:
– CT and MRI are sensitive in evaluating : abscess formation,
osteomyelitis, airway narrowing and vascular compromise.
– Triple-phase 99mTc bone scanning superior to CT in diagnosis of
osteomyelitis.
– 18F-FDG PET is superior to MDP bone scan for distinguishing soft
tissue and bone infections and diagnosing osteomyelitis
complicated by fracture or surgery.

25. Garre ´ sclerosing osteomyelitis

26. Inflammatory disease

27. Incidentally detected periodontal disease in a 60-year-old woman who had restaging FDG PET/CT for colon cancer. Focal
hypermetabolism on FDG PET (A) and fused PET/CT (B) and widening of the periodontal ligament spaces in the second right
molar on CT (C) are consistent with periodontal disease.

28. Sjo¨gren syndrome.
Left greater than right
enlargement of the parotid
glands is seen on axial CT (A)
and bilateral parotid
hypermetabolism on axial
fused PET/CT (B).
Similarly, left greater than
right lacrimal gland
enlargement is seen on axial
CT (C) with bilateral
hypermetabolism on fused
PET/CT (D) in a patient with
active Sjo ¨gren syndrome

29. – 99Tc pertechnetate salivary gland scintigraphy can
differentiate between chronic obstructive parotitis and SS
– In the former, uptake is normal and excretion is
decreased, and in SS uptake and excretion are diminished

30. TMDs:
– 18F-PET bone uptake ratio had higher sensitivity and accuracy
compared with 9mTc-MDP bone ratio in diagnosing
temporomandibular disease with osteoarthritis and
differentiating it from TMD with anterior disk displacement

31. Temporomandibulardisease
99mTcMDP bonescan (topimags)
18F-NaFPET,PET/CT, and CT (bottom
images)
all demonstrate a deformed,
sclerotic, hyperactive degenerated
right temporomandibular joint
(arrow).

32. Condylar hyperplasia

33. Squamous cell carcinoma
• Help in staging
• Accurate evaluation of respose to treatment
• Restaging
• Help to distinguish benign & malignant
especially when surgical intervention greatly
altered anatomy
• Studies on nuclear therapy able to
differentiate cancer which respond & not
respond to radiotherapy under progress

34. Staging tongue cancer by FDG PET/CT

35. Help to distinguish benign & malignant especially when surgical intervention greatly altered anatomy

36. Accurate radiation planning

37. Metastatic rectal cancer

38. Zoledronic acid–related osteonecrosis of the mandible.

39. Osteoradionecrosis of the mandible
18F-NaF PET is superior to 18F- FDG PET in osteoblastic bone tumors, whereas the latter is
superior in osteolytic bone tumors.

40. To conclude:
 Nuclear medicine studies evaluate the physiology on a molecular level providing earlier detection of
lesions before morphologic change is evident.
 99mTc-MDP and 18F-NaF PET bone scans aid in the detection of osseous tumor, infection, condylar
hyperplasia, temporomandibular disorder and osteoradionecrosis and can assess bone graft viability.
 99mTc-MDP and 18F-NaF PET bone scans detect osteomyelitis earlier than CT and 18F-FDG PET/CT can
assess osteomyelitis complicated by fracture or surgery.
 18F-NaF PET/CT bone scan is more sensitive and specific than 99mTc-MDP for evaluation of osseous
lesions.
 18F-FDG PET/CT provides more accurate staging, restaging, response to treatment, and prognostic data
for malignant disease than CT alone resulting in more precise patient management and improved
outcomes.

41. References:
– Nuclear Medicine Imaging in the Dentomaxillofacial Region Heidi R. Wassef, Patrick M. Colletti
. Dent Clin N Am. 2018; 491–509.
– Infante JR, Garcı´a L, Rayo JI, et al. Diagnostic contribution of quantitative analysis of salivary scintigraphy in
patients with suspected Sjo¨gren’s syndrome. Rev Esp Med Nucl Imagen Mol 2016;35(3):145–51.
– Chen J, Zhao X, Liu H, et al. A point-scoring system for the clinical diagnosis of sjo¨gren’s syndrome based
on quantified SPECT imaging of salivary gland. PLoS One 2016;11(5):e0155666.
– White & pharaoh .7th ed.
– Burket’s 12th ed.

42. Thank you …