Respiratory System GW

Question 1

Lung scan indications

Answer 1

Diagnose PE
Evaluate PE
evaluate response to therapy

Question 2

Perfusion RP and dose

Answer 2

99mTc MAA 1-4 mCi

10-90 um in diameter

Question 3

Healthy adult patient should receive how many particles

Answer 3

200,000-700,000

Blocks less than 1% of aeterioles

Question 4

What pathologies should get reduced particles and how many?

Answer 4

Pulmonary hypertension,
RIGHT to LEFT pulmonary shunting,
And children

100,000-200,000

Question 5

Why do they need chest x ray

Answer 5

Needed for interpretation of lung image to rule out other pathology that might mimic PE symptoms or obscure its diagnosis

Question 6

When should pt get chest X-ray

Answer 6

Within 24 hours of imaging

Or within 1 hour for patients whose signs and symptoms have changed

Question 7

How should pt be positioned for perfusion

Answer 7

Supine

Question 8

What view is cardiac impression seen

Answer 8

Anterior and left lateral

Question 9

Purpose of ventilation imaging

Answer 9

Increase the specificity of perfusion study (tell the WHY)
- by differentiating perfusion defects that are from PE vs from obstructed lung disease

Question 10

Ventilation RPs and dose

Answer 10

Xe133 - spirometry system

99mTc DTPA - nebulizer
25-35 mCi

Question 11

Pt position for ventilation

Answer 11

Supine or upright - whatever is more comfortable

Question 12

Standard view for Xe133

Answer 12

Posterior

Question 13

99mTc DTPA dose and how much the patient will actually absorb

Answer 13

Dose is 25-35 mCi

Pt actually gets 0.5-1 mCi

Question 14

How long does pt inhale 99mTc DTPA

Answer 14

5 minutes

Question 15

Improper oxygen flow rate on nebulizer may affect

Answer 15

Aerosol particle size
-particles too large will lodge in the central airways instead of going to lungs

Question 16

Should ventilation or perfusion go first

Answer 16

Ventilation, no matter which RP

Question 17

Perfusion study count rate should be ___ times greater than ventilation study

Answer 17

4 x

Question 18

Of perfusion is performed before Xe ventilation, what should be done

Answer 18

Take a 99mTc background image in the Xe photopeak window

Question 19

Venography RP and dose

Answer 19

99mTc MAA 6mCi

99mTc RBCs. 20-30 mCi

Question 20

Venography is used for what

Answer 20

To image acute DVT in lower extremities

Question 21

What can cause DVT

Answer 21

Immobility
Surgery
Certain meds
Obesity
Cancer
CHF
Recent MI

Question 22

What is d dimer

Answer 22

By product of blood clot degradation

Question 23

Pt prep for Venography

Answer 23

None

Question 24

Injection to image time for Venography

Answer 24

10 minutes
60-90 minutes

Question 25

Venography image views

Answer 25

ANT and POST
pelvis, thighs, knees, and calves