Nuclear Medicine

Question 1

Describe a bone scan protocol in nuclear medicine.

Answer 1

IV injection with 600MBq Tc-99m HDP.
Image 2-3 hours later.
Scan duration 30 minutes.
Whole body - supine, head out.
Higher activities are used for SPECT.
Patient prep: void prior to imaging, and drink plenty after imaging.
LEHR collimators.
Energy window: 140 keV, 20% total window (+/-10%)
Matrix: 1024 x 256
Scan speed: 10 cm/min

If a SPECT-CT, use low dose CT after.

Question 2

What does a symmetric uptake in nuclear medicine bone scan suggest?

Answer 2

Not abnormal: Arthritis?

Question 3

What does an asymmetric uptake in nuclear medicine bone scan suggest?

Answer 3

Abnormal: mets? broken bones?

Question 4

Describe a lung VQ protocol in nuclear medicine.

Answer 4

Ventilation = 40 MBq Technegas/DTPA inhaled
Perfusion = 200 MBq Tc-99m MAA IV injection
Acquire ventilation SPECT then inject Tc-99m MAA to swamp out ventilation tracer. Acquire perfusion SPECT
Perfusion swamps ventilation – ratio of 4:1.

Patient prep: chest xray within 24 hours prior
LEGP collimators
Patient position: supine on couch, or sitting/standing
140keV energy window with 20% width
256 matrix for planar
128 matrix for SPECT
Ventilation end point: 200k counts planar, 12 min SPECT
Perfusion end point: 400k counts planar, 10 min SPECT

Question 5

Describe a DMSA protocol in nuclear medicine.

Answer 5

Used to assess: kidney scarring, “horseshoe” kidney, solitary or ectopic kidney, relative renal function in children with hypertension pre/post medication, a transplanted/donor kidney function.

Tc-99m DMSA - 80MBq IV injection.
Image 2-3 hours post IV
3 static images taken
Motion correct
Relative function: L(bgd corr)/ [L(bgd corr) + R(bgd corr)]

Question 6

Describe a DATScan protocol in nuclear medicine.

Answer 6

Used to asses: Atypical tremor, response to anti-Parkinson’s medication, diagnosis of Parkinson’s disease from essential tremor, diagnosis of Alzheimer’s disease from dementia with Lewy bodies, Parkinson’s disease.

Inject 185 MBq Iodine-123 FPCIT
Image at 3-6 hrs
Iodine blockade
SPECT
Specific uptake ratio (0 = no uptake, >1.3 = normal): (target - background)/ background

Question 7

Describe a gastric emptying protocol in nuclear medicine.

Answer 7

Used to assess: delayed emptying.
Rate of emptying depends on content of meal.
Planar imaging.
Static images up to 2 hours + review (0, 15, 30, 60, 120 mins).  
At 2 hours (SNM guidelines): 
- Abnormal – no 4hr image
- Below 10% - no 4hr image
- Otherwise do 4hr image
Plot results on graph.

Question 8

Describe a renogram protocol in nuclear medicine.

Answer 8

Used to assess: ureteric obstruction

IV injection - 100 MBq Tc-99m MAG3
40 mins dynamic imaging
Plot uptake curves
Calculate relative renal function
Diuretic at 20 mins
If after diuretic, kidney drains = baggy renal pelvis

Question 9

Describe a MUGA protocol in nuclear medicine.

Answer 9

Used to assess: cardiac function.

IV injection with tin colloid
600 MBq Pertechnetate
ECG gated images
10 mins

Calculate ejection fraction:
EF = End Systole / (End Systole + End Diastole)
^ all background corrected.

Question 10

Describe a Parathyroid SPECT-CT protocol in nuclear medicine.

Answer 10

Used to: localise adenoma in patients with primary hyperparathyroidism prior to surgery.

Inject with 800MBq Tc-99m MIBI
Static image at 10 mins and 2 hours
SPECT at 2 hours
Low dose CT
LEHR collimators
End point: 300 seconds for statics, or 15 minutes for SPECT.
Matrix: 256 x256