Nuclear medicine uses radiopharmaceuticals and imaging techniques like PET and SPECT scans to assess organ function and detect diseases. Some key applications include using F-18 FDG PET scans to identify cancer metastases based on increased glucose metabolism in malignant cells, Tc-99m sestamibi scans to detect myocardial ischemia, Tc-99m DMSA renal scans to assess kidney function, and somatostatin receptor imaging with radiolabeled octreotide to localize neuroendocrine tumors. PET provides superior detection of bone metastases compared to bone scans or whole-body MRI. Important considerations for nuclear medicine exams include selecting the appropriate radiotracer and ensuring normal blood glucose levels for oncology FDG PET scans

1. Nuclear medicine

2. nuclear medicine
• To assess function using radiopharmaceuticals
• Using
• Nuclear scan / isotope scan
• PET scan
• SPECT scan

3. Scintigraphy / radioisotopic studies Tc99
PET • F18
• 11C
• 13N
SPECT • Single photon emission tomography

4. Nuclear scan / isotope scan
• Using Tc99m (m
metastable)
• T1/26 hours
• Emits γ rays 
detected by γ camera
143 KeV

5. Gamma camera is used to
• Measuring the radioactivity
• It is also called as scintillation
camera or anger camera

6. Gamma camera is uded to detect
radioactivity

7. Tc99m bound to ligands for delivery to target
organ
Tc99m ligand
MDP Bone imaging
HIDA scan • a/c cholecystitis
• To exclude biliary atresia

8. Bone scan
• Mc investigation for bone metastasis
• IOC is PET scan
Osteoblastic activity Osteoclastic activity
• Increased uptake  hot uptake • Decreased uptake  cold uptake
• Osteoblastic 2*
• Pagets disease
• Osteroid osteoma
• Osteomyelitis
• Osteitis deformans
• OA (subchondral sclerosis )
• Enchondroma
• Osteochondroma
• Multiple myeloma
• Fibrous cortical defect
• Non ossifying fibroma
• Bone island
• Osteopoikilosis

10. Abnormal bone scan

11. Abnormal bone scane
Super scan • In diffuse metastatic ds of bone
• In diffuse metabolic ds of bone
• Renal failure
OM • Increased uptake in all 3 phases of bone scan
Mickey mouse sign • Pagets ds
Hot bone scan • Increased uptake in site where there is increased
uptake - neoplasm trauma infection avscular
necrosis
Cold scan • In multiple myeloma
• Histiocytosis
• Neuroblastoma
• RCC
• Thyroid carcinoma

12. Super scan
• Increased uptake in skeleton
• No background radiotracer activity
• But kidneys are not visualised
• In diffuse metastatic ds of bone
• In diffuse metabolic ds of bone
• Renal failure

13. Mickey mouse sign in pagets disease
• d/t increased uptake in
pedicles & spinous process

15. Big black beard / linoln sign
in pagets disease
• Increased condylar to condylar uptake in bone
scan

16. For infections of bone / osteomyelitis
• Gallium scan
• Indium labelled WBC scan (except in case of respiratory tract
infections )
• Increased uptake in all 3 phases

17. Nuclear medicine in heart

18. Nuclear medicine in heart
Myocardial perfusion studies • Thallium 201 (MC used)
• Tc99m tetrophosmin
• Tc99m sestamibi (MIBI scan)area of infarct
appears cold
Myocardial infarct imaging • Tc99 pyrophosphate (area of infarct appears hot)
MUGA scan • Tc99m labelled RBC are used

19. Myocardial perfusion scan
• SPECT scan is used To assess blood flow (perfusion )
• Using thallium 201 / Tc99 labelled tetrofosmin /Tc 99m labelled sestamibi
• Low perfused area appears cold (d/t decreased uptake of radioactive
material)

20. Stress thallium study
• Stress is given by physiologically / with dobutamine
• At peak of stress  inject thallium
• Uptake by normal myocardium with normal blood flow  hot areas
• Ischemic myocardium  cold areas
Reversible ischemia Ischemia on exercise but not on rest
Irreversible ischemia Ischemia both @ rest & execise

21. Myocardial infarct scintigraphy
• Using Tc pyrophosphate
• Uptake by infarcted myocardium
• Infarct  hot areas
• Blood flow is not assessed by this scan

22. • Gold standard for myocardial viability  PET scan
• Best investigation to differentiate b/w myocardial scar & hibernating
myocardium  PET
Cardiac PET uses
Myocardial metabolism FDG PET scan
Myocardial perfusion • radioactive ammonia (NH3)
• H20
• Rubidium 82
Rubidium 82  non cyclotron isotope used in PET scan

23. MUGA scan
• method for assessment of LV functionmeasure ejection fraction
• ECHO can also be used
• most accurate is MRI
• 99mTc-labelled albumin or red cells that are uniformly distributed
throughout the blood volume /

24. Tc 99m labelled RBC is used for
• Haemangioma
• GI bleeding
• Splenic disease
• Cardiac ventriculography

25. Nuclear medicine in GIT
Tc99m labelled RBC • Minimal lower GI Bleeding
• Sensitive test (0.1ml/min)
Tc99m pertechnate • Pertechnate is taken up by gastric mucosa  to
detect ectopic gastric mucosa
Tc99m sulphur colloid • Taken by RE cell
• To detect Focal nodular hyperaplasia (FNH) also
used in accessory spleen & abscess
• IOC for upper GI bleed  endoscopy
• IOC in lower GI bleed  mesenteric angiography
/ Tc99 RBC

26. Lower GI bleed
Mesenteric angiography Tc 99 RBC
Can detect 0.5 ml/min blood loss Can detect 0.1 ml/min blood loss

27. Uses of Tc99m labelled pertechnate
• Thyroid scintigraphy
• Salivary gland scintigraphy
• Meckels diverticulum

28. Renal radionuclide imaging
• Dynamic renal scintigraphy  functional imaging Static renal scintigraphy
Tc99 DTPA GFR estimation Tc99m DMSA
• To assess cortical function / corticomedullary
differentiation/ functional mass / scarring of VUR
Tc99 MAG 3  best for dynamic renal scintigraphy
I123 –OIH  effective renal plasma flow

29. Dynamic renal scintigraphy
Tc99m DTPA GFR estimation Tc99m MAG3
• DTPA  neither reabsorbed / secreted
• Used to measure GFR
• Demonstration of VUR
• Differentiate obstruction from stasis by diuretic
DTPA scan
• To assess transplanted kidney
• MAG3 is secreted as well as filtered
• Best study for renal function
• Glomerular + tubular function
Captopril DTPA is used for detecting reno vascular HTN

30. Ventilation perfusion scan
Ventilation Using inert gases like krypton or xenon
Perfusion Tc99m microaggreagtes of albumin
Tc99m labelled RBC
• V/Q scan to detect Pulmonary thromboembolism in
pregnancy & In iodine allergy contrast cant be used
• IOC in PTE MDCT with contrast

31. To localise parathyroid adenoma in primary
hyperparathyroidism
• 99_Tc sestamibi scan.
• After one hour of injection, uptake is done by both thyroid and parathyroid
gland.
• After 3 hrs uptake evidence is there only in parathyroid. So by computer
subtraction adenoma is located.
• Tc – thallium substraction scan can also be used

32. Radioactive iodine
T1/2 Uses
I131 8 days • Systemic therapy of thyroid metastasis
• Emits both β&γ rays
• β rays killing thyroid cells
I 125 60 days • Radioimmunoassay
• Brachytherapy of prostate
I124 4 days • Used in PET scanning
I 123 13 hrs • Functional thyroid scintigraphy
• Not available in india  done by Tc99
pertechnetiate
• Radioactive iodine uptake
Stable isotope of iodine I 127

33. • In case of neuroendocrine tumours  carcinoid , glucaganoma ,
VIPoma
• Somatostatin receptor scintigraphy
• Octreotide scintigraphy
• insulinoma
• IOC  EUS
• As somatostatin receptor is negative

34. HIDA scan
• Hepatic Iminodiacetic acid scan (HIDA Scan)is a biliary scintigraphic
scan.
• Applications & indications include:
• 1. Acute cholecystitis (investigation of choice)
• 2. Congenital biliary atresia
• 3. Biliary leak evaluation
• 4. Biliary – enteric fistula
• 5. Chronic GB dysfunction

35. Thyroid Scan
Hot nodule Cold thyroid nodule
Adenoma & thyroid Carcinoma
(extremely rare)
Inflammatory mass, Benign tumor &
Malignant tumor

36. SPECT scan
• Single positron emission computed tomography
• 360 * revolving γ scanner
• Also uses Tc99m

37. HMPAO SPECT • Lipophilic compound
• cross BBB
• For cerebral perfusion
• Alzheimers d/s  decrease perfusion in
temporoparietal
• Picks ds  decrease perfusion in
frontotemporal
Ictal SPECT with
HMPAO
• Hypermetabolic foci  localise
epileptogenic foci
• For lesions not localised
Interictal SPECT with
FDG
• Hypometabolic seizure

38. PET scan

40. PET
• This technique has been used in the
• evaluation of solitary pulmonary nodules and as
• aid to staging lung cancer,
• identification of mediastinal lymph node involvement by malignancy.
• Radiation induced necrosis

41. Uses gamma rays

42. Based on principle of annhilation

44. Annhilation

45. Annihilation
• Positron emitted from photon
emitting radionucleitide 
combine with electron to form
gamma rays of energy 511 KeV
• Gamma rays Are detected by
PET scanners coupled to
photomultiplier tubes

46. • Gamma photon are
detected by PET Scanner
composed of scintillation
crystals made up of
• Bismuth germinate
• Cerium doped lutetium
oxysilicate
• Cerium doped gadolinium
silicate

48. • PET
• It is increasingly being used to identify malignant lesions in the lung based
on their increased uptake and metabolism of glucose.
• The technique involves injection of a radiolabeled glucose analogue, 18f-
fluoro-2-deoxyglucose (fdg), which is taken up by metabolically active
malignant cells. However, fdg is trapped within the cell following
phosphorylation, and the unstable fluorine 18 decays by emission of
positrons, which can be detected by a specialized pet camera or by a
gamma camera that has been adapted for imaging of positron-emitting
radionuclides.

49. Cyclotron
• Used to produce artificial
isotopes
• F18 is produced in a cyclotron
by bombarding O18 enriched
water with high energy
photons in a cyclotron
• Other positron emitting C11
N13 & O15 can also be
produced
• 18FDG is most commonly
used
T1/2
Oxygen 2 minutes
Nitrogen 10 minutes
Carbon 20 minutes
Flourine 110 minutes

50. Role of 18 FDG in PET Scan
• In oncology
• Warburg effect in malignant cells
• Aerobic glycolysis
• Even in presence of O2 no TCA cycle
• Malignant cells have increased glucose utilisation d/t upregulation of
hexokinase activity
• Increased glucose uptake  increased 18 FDG uptake

51. Warburg effect in tumour cells

52. 18 FDG enters glycolysis  undergoes
phosphorylation but donot undergo
further metabolism

53. Uses of 18 FDG PET
• Staging of various tumours
• Identifying metastasis
• Rx response & follow up
• Used to detect tumour recurrence
• Differentiate post surgical scarring / post RTx fibrosis from tumour
recurrence

54. 18 FDG PET
False positive (even in absence of malignancy) False negative
• c/c infections (TB)
• Brown adipose tissue
• Bronchoalveolar carcinoma (low mitotic &
metabolic activity)
• Carcionid (low mitotic & metabolic activity)
• Brain metastasis
• In fasting & DM (increased uptake by all cells)
Blood glucose should be normal
before PET scanning

55. 18 FDG PET in brain
• Greater uptake in brain & liver
• Not useful to detect brain metastasis
• 11C methinonine PET is better than 18 FDG PET to detect brain
metastasis
• Investigation of choice for brain metastasis is
MRI
• Investigation of choice for recurrent brain
tumour  PET scan (recurrence is seen against
post surgical or post RTx scarring)

56. IOC for solitary pulmonary nodule on CT scan
 PET scan

57. Bone metastasis
• IOC is PET
• PET scan >>> whole body MRI >>>bone scan
• Na + F- PET scan is better than 18 FDG
• 18 FDG cannot detect brain & liver metastasis

58. PET scanning in heart
• 2 types can be used
• N13 ammonia PET
• 18 FDG PET scan
N 13 ammonia PET to
detect myocardial perfusion
18 FDG PET  to detect
myocardial viability
/metabolism
Scar tissue -ve -ve
Hibernating myocardium -ve +ve (ischemic heart
preferentially uses glycolysis
rather than fatty acids)
• To differentiate hibernating myocardium
form scar tissue
• Only in hibernating myocardium stenting can
be done & it is useless in case of scar tissue

59. IOC in pheochromocytoma
Test
Adrenal pheochromocytoma Light bulb appearance in MRI
Extra adrenal pheochromocytoma 18F DOPA PET

60. Light bulb appearance on MRI of adrenal
pheochromocytoma

61. PET scan in carcinoid syndrome
• Carcinoid syndrome  low mitotic & low metabolic activity 18 FDG
will be negative
• Carcinoid syndrome  octreotide PET & DOTATOC PET are used