Nuclear Medicine: Myocardial perfusion scanning

Question 1

Briefly describe what is meant by ishaemic heart disease

Answer 1

Also known as coronary artery disease
Affects blood supply to the heart
Blood vessels narrowed / blocked
Reduces supply of oxygen to heart
Can result in area of myocardium being deprived of blood
Which can lead to a heart attack

Question 2

Compare cardiac PET and SPECT:

1. What is the maximum resolution capability of each?
2. How much time must be allocated for each scan (stress & rest)?
3. What is the radiation dose (mSv) for each modality?
4. Which modality has the greater running cost per patient?
5. Which modality has the greater equipment cost?

Answer 2

(Answers are always PET vs SPECT)

1. 5mm vs 8mm
2. 30 min for stress/rest vs 60 min stress & 30 min stress
3. 1.4-1.9 mSv vs up to 8 mSv
4. PET has greater running costs
5. PET has greater equipment costs

Question 3

Pick the correct answer:

Cardiac PET has a lower sensitivity BUT greater specificity than cardiac SPECT
(87% vs 91% and 89% vs 73% respectively)

Cardiac PET has a lower sensitivity AND lower specificity than cardiac SPECT
(87% vs 91% and 73% vs 89% respectively)

Cardiac PET has a greater sensitivity AND greater specificity than cardiac SPECT
(91% vs 87% and 89% vs 73% respectively)

Cardiac PET has a greater sensitivity BUT lower specificity than cardiac SPECT
(91% vs 87% and 73% vs 89% respectively)

Answer 3

Cardiac PET has a greater sensitivity AND greater specificity than cardiac SPECT

(91% vs 87% and 89% vs 73% respectively)

Question 4

Solid state, CZT based technologies are becoming more widely available.

1. What does CZT stand for?

Comparing against traditional SPECT camereas:

2. Which as better spatial resolution?
3. Which is more sensitive?

Answer 4

1. Cadium - Zinc - Telluride
2. CZT camera
3. CZT camera

Question 5

Pick all answers that are applicable. With increased sensitivity on the CZT camera you can:

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Throw away your dual headed cameras

Must be careful of overexposing the crystal

Reduce scan time to increase patient throughput

Decrease administered dose

Answer 5

Reduce scan time to increase patient throughput

Decrease administered dose

Question 6

Briefly outline the steps to gating an image.

Answer 6

Link patient up to an ECG machine
Map the patients R-R interval
R-R interval is between diastole phases
Split the SPECT data into bins
Commonly 8 or 16 bins
Use the data to simulate and visualise the motion of the left ventricle

Question 7

Name 3 basic functional parameters we can get from our gated data:

Answer 7

End Diastolic Volume
End Systolic Volume
Left Ventricular Ejection Fraction

Question 8

Describe a common problem with gated cardiac images and explain how this happens?

Answer 8

The bins are set to a specific time
If beat is shorter than the prescribed bin time we’ll see a loss of counts in the final bin
If beat is longer than the prescribed bin time we’ll get noisey images all out of sync