Respiratory System GW Flashcards
Lung scan indications
Diagnose PE
Evaluate PE
evaluate response to therapy
Perfusion RP and dose
99mTc MAA 1-4 mCi
10-90 um in diameter
Healthy adult patient should receive how many particles
200,000-700,000
Blocks less than 1% of aeterioles
What pathologies should get reduced particles and how many?
Pulmonary hypertension,
RIGHT to LEFT pulmonary shunting,
And children
100,000-200,000
Why do they need chest x ray
Needed for interpretation of lung image to rule out other pathology that might mimic PE symptoms or obscure its diagnosis
When should pt get chest X-ray
Within 24 hours of imaging
Or within 1 hour for patients whose signs and symptoms have changed
How should pt be positioned for perfusion
Supine
What view is cardiac impression seen
Anterior and left lateral
Purpose of ventilation imaging
Increase the specificity of perfusion study (tell the WHY)
- by differentiating perfusion defects that are from PE vs from obstructed lung disease
Ventilation RPs and dose
Xe133 - spirometry system
99mTc DTPA - nebulizer
25-35 mCi
Pt position for ventilation
Supine or upright - whatever is more comfortable
Standard view for Xe133
Posterior
99mTc DTPA dose and how much the patient will actually absorb
Dose is 25-35 mCi
Pt actually gets 0.5-1 mCi
How long does pt inhale 99mTc DTPA
5 minutes
Improper oxygen flow rate on nebulizer may affect
Aerosol particle size
-particles too large will lodge in the central airways instead of going to lungs
