Chest Radiography Flashcards
Posterioranterior (PA)
Less magnification of the heart
This requires pts. to be able to stand
Left Lateral
- Determines location
- Confirms presence of disease
- Demonstrates disease not visible on the frontal image
Lateral decubitus
Assess pleural effusions
Look for layering of fluid
Penetration
- On a PA film, thoracic spine structures should be visible through the heart
- You should be able to see bronchovascular structures through the heart
- On lateral film, the spines appears to darken as you move caudally
Overpenetration
makes the picture too dark and may look like emphysema or a pneumo
Rotation
Medial heads of clavicles should be centered on either side of the thoracic spine
Air
Absorbs least amount of xray
“Blackest” on images
Fat
Gray – darker than soft tissue
Fluid or soft tissue
Light gray
Calcium (bones)
White
Metal/Contrast
whiter than bone
Pneumonia
- More opaque than surrounding lung
- Margins may be fluffy, except where they abut a pleural surface
- Homogeneous in density
- Air bronchograms
- Atelectasis in affected portion of segmental pneumonias
Lobar Pneumonia
- Silhouette sign
- airbronchograms centrally
- typical cause is S. pneumoniae
Segmental Pneumonia
- Tends to be multifocal, does not have air bronchograms, and can be associated with volume loss because the bronchi are also filled with inflammatory exudate
- Most common cause is Staphylococcus aureus
- Margins tend to be fluffy and indistinct
Interstitial Pneumonia
- Most common cause is viral pneumonia, mycoplasma pneumoniae, pneumocystis pneumonia in pts w/ AIDs
- Tend to take on a fine, reticular pattern early on
- May mimic pulmonary edema
Cavitary
- lucent cavities produced by lung necrosis as its hallmark
- Affects the apical or posterior segments of the upper lobes or the superior segments of the lower lobes.
- Bilateral upper lobe disease is very common.
Aspiration Pneumonia
- Aspiration almost always occurs in the most dependent portion of the lung
- When a person is recumbent, aspiration usually occurs into the superior segments of the lower lobes or the posterior segments of the upper lobes.
- The right side is more often affected than the left because of the straighter and wider nature of the right main bronchus.
Different types of atelectasis
- subsegmental
- compressive/passive
- obstructive
Pleural effusion fluid collection
-75cc blunts costophrenic angle on lateral xray
250-300cc blunts angle on frontal view
2L will opacify entire hemithorax
Pleural Effusion-how to recognize
Shift of mobile structures away from side of effusion with a large effusion
Effusions act as a mass pushing structures away
Effusions will flow freely with position change (lateral decub view)
