Lung

Question 1

explain aeresol study

Answer 1

-uses TcDTPA to assess bronchopulmonary distribution
-assess ventilation
-the total dose given to patient is 25-35 mCi (30 at Froedtert)
-a tightfitting mask or mouthpiece is used to deliver dose
-approx 10% of total dose or particles actually reach lung
-pt should breathe for approx 3 min or enough for 1 mCi of Tc DTPA to show (100 k counts)
-image for 8 images (300 k counts each)
-give upright if possible to allow particles to settle to bottom of lungs
-advantage, obtained SPECT

Question 2

How would a perfusion study be done?

Answer 2

-eval pulmonary arterial blood flow distribution
-use Tc MAA (macro aggregated albumin)
-injected via IV over 10-15 seconds
-counts should be at least 3x’s that of aerosol so image for 500k counts the 8 images
-total dose is 4 mCi injected
-inject while pt is supine
-if pregnant, sign consent, perfusion first and only 1-1.5 mCi
-if pleural effusion, upright views
-never straight stick, never draw blood off, albumin likes to clump
-particles are 10-90 microns
-pt coughs or takes few deep breaths before this

Question 3

explain how ventilation w xenon works

Answer 3

-used either or for Tc DTPA
-10-20 mCi is dose
3 phases
-first breath/breath hold
-breathing
-washout phase
-pt will have tightfitting mask and Xe-133 will be used to spray into mask
-gas form
-pt takes a deep breath and before exhaling then inject mask with gas, breathe in and hold for 20 seconds if possible
-then breathe in circuit closed with oxygen for 3 minutes
-washout phase only takes 90 seconds but is done by breathing in room air or pure oxygen and breathing out into Xe trap. this will be 6 images for a minute each
-poorly ventilated areas recieve activity via collateralk drift now
-during first breath, poorly ventillated ares will not have alot of activity
-air trapping indicates copd or asthma
-if kid or preggo not happening
-sensitive test
-dry rite=O2
-soda lime=CO2
-charcoal filters Xe-133
-Xenon trap, traps Xe in system

Question 4

resp volumes

Answer 4

inspiration- 500 mL
expiration- 500 mL
tidal volume-quiet breath in and out
inspiratory reserve volume-3000 mL
expiratory reserve volume- 1100 mL
resiudal volume=1200 mL

Question 5

treating pe

Answer 5

thrombolutic theraoy
-tpa stroke
embolectomy
vena cava interuption
treat underlying disorder
anticoagulant therapy