Concept #3
• Diffuse Distribution is ALMOST ALWAYS a
reflection of a Systemic Disease Process
– ARDS, Goodpastures, Cystic Fibrosis
• Focal Distribution is often a reflection of a
Local Disease Process
– Bacterial pneumonia, Contusion
Bonus: Atelectasis Does NOT Cause Fever
• Chest: Volume 107 (1), Jan 1995 81-84.
• Prospective evaluation of 100 post cardiac
patients over first three days.
• Demonstrated an Inverse relationship with
post-operative fever and atelectasis!
• Atelectasis: 43%  79% over 3 days.
• Fever (>38.0): 37%  17% over 3 days.
Atelectasis: Not A Cause of Fever Mavros, et
al “Atelectasis as a cause of postoperative fever. Where is the
clinical evidence? Chest; April 2011
Concept #4
The “Wide Mediastinum” is common and on its
own, not concerning
• Mediastinal Width: Volume status, Rotation and
Body Size
• Mediastinal Density: Blood or lymph nodes
• Mediastinal Contour: Tortuous aorta, ascending
aorta dilatation, lymph nodes, mass
Pre and Post Dialysis
Pre and Post Line Placement
Trauma
Concerning or not?
Concerning or not?
Questions?
Concepts
1) Density differences form the image
2) Pattern and distribution are key
3) Diffuse versus focal reflects systemic versus local
4) Wide mediastinum
Objective #1
• Remember your search pattern and use it!
– Alphabet method (Airspaces, bones, cardiac, etc.)
– BIO (Between, inside, outside the lungs)
– Top down
– Other
• My approach: Abnormalities, right lung, left lung,
compare the two lungs, trachea, mediastinum, heart,
outside the lungs (including abdomen) and bones
Objective #2
•
Learn appropriate positioning of ET tubes and central
lines
– ET tube 3-4 cm above the carina, at T4 or T5 vertebral body
– Subclavian artery and vein: artery may arch above the clavicle
on a frontal CXR, vein does not
– SVC: begins at approximately the 1st anterior rib space
– Cavoatrial junction: ~2 vertebral bodies below the carina, or
about 2 cm below the initial SVC-right atrium bump,
Objective #3
• List the six commonly encountered
radiographic patterns on CXR
– Consolidation
– Ground Glass
– Lines (interstitial or septal thickening)
– Nodules
• Tree-in-Bud opacities
– Peripheral Lace-like opacities
– Cysts
Objective #3
• Of the six, focus on consolidation and GGO
– Acute? Think infection, water, blood for either
– Don’t forget about atelectasis
• But don’t worry about it either, it’s hard to learn
‘Education is the Progression from
a Cocky Ignorance to a Miserable
Uncertainty.’
Mark Twain