Imaging Flashcards
What makes CTPA poor
Cardiac failure
Poor contrast timing
Poor breath holding
When do not use V/Q scan
Over 35
Use of chest US
Confirm effusion
Guide aspirate
Radiation risk from CT vs x ray
Chest CT equivalent to 3.6 background years of radiation
CXR equivalent to 3 days of background radiation
How assess CXR quality
Is everything included in film
Well rotated?- are spinal processes halfway between medial ends of clavicle
Inspiration- 6 anterior ribs/10 posterior ribs
Penetration-
What are most CXRs and problem with other
PA
AP makes heart appear too big
What defines overinflation and what seen in
Over 7 anterior ribs
COPD and ventilated patients
Chest x ray presentation
Details- radiography
PRIP- projection, rotation, inspiration, penetration
Comment on lines and tubes
ABCDE
Airway
B- every lung field
Cardiac
Diaphragm and gas
E- bones, subcut emphysema, hilar lymphadenopathy
How assess NG tube positioning
Descent in midline
Tip below diaphragm
How assess endotracheal tube positioning
5cm above carina- normally around T2 as carina at T4/5
What does endotracheal tube misplacement lead to
Lung collapse if in wrong bronchus
Desaturation if in oesophagus
How spot oesophageal placement of ET tube
Excess gas in stomach and mediastinal gas
What is correct positioning of central line
Inserted via IJV to reach Junction of SVC and right atrium
Do CXR to confirm correct positioning and check for pneumothorax
Causes of cavity in lung
Malignancy- squamous most common= thicker wall
TB
Aspergilloma
Vasculitis
Staph aureus
Klebsiella
How differentiate mass from consolidation
Presence of air bronchograms in consolidation
Causes of lung collapse
Obstructions in airway- mass, foregin object, mucous plug
Compression from external source
Poor inspiration- pain post op
Causes of cannonball mets
RCC
Choriocarcinoma
Endometrial
Prostate
Adrenal
Patchy infection on lung causes
Viral- CMV, COVID, RSV
TB- mycobacterium avium
Mycoplasma
PJP
Air behind heart causes
Hiatus hernia
Pneumoperitoneum vs chailaditis sign
Pneumoperitoneum- crisp line
Chailaditis is a benign bowel loop seen just under diaphragm
Caecal volvulus on AXR
Direction of mass is up to left shoulder
See large loos of small bowel with valvulae conniventes
Ischaemic stroke on CT head
Hyperdense artery
Loss of white grey matter differentiation
Hypodense area
