L9 Pulmonary Imaging

• Air: Black
• Fat: Near Black
• Soft Tissue: Shades of Gray
• Bone: White
• Metal: White
• Calcium: White

Air --> Fat --> Soft Tissue --> bone

-density determines how much of the xray beam is absorbed or attenuated

-as the density of an object increases, fewer xrays pass through it

-heart positioned against the screen (to avoid magnifying the heart)

• -Anterior-Posterior
• -Lateral

-radiograph is a summation of a complex 3D object in a single plane

• 1. Tubes/lines
• 2. Lung
• 3. Mediastinum
• 4. Abdomen
• 5. Soft Tissue
• 6. Bones

A,B,Cs

Non-specific, can be many things

• -Water
• -Blood
• -Cells
• -Pus
• -Inflammation (rarely)

• DDx:
• 1. Atelectasis of entire lung (Shifting towards)
• 2. Large Pleural Effusion (Shifting away)
• 3. Pneumonia of entire lung (No Shift)
• 4. Post-pneumonectomy (Shfiting towards)

• Shifting includes mobile structures:
• -trachea
• -heart
• -hemidiaphragm

• -when two abutting objects are of similar density it is difficult to identify their boundaries
• -an interface between isodense materials in contact is non-resolvable radiographically
• 

• Left Lower Lobe
• -can see R hemidiaphragm
• -heart border is clear

• -dyspnea on exertion
• -orthopnea
• -paroxysmal nocturnal respiratory distress
• -weight gain
• -lower extremity edema
• -cough
• -hemoptysis

• 1. Cardiogenic
• 2. Neurogenic
• 3. Increased Permeability
•      -Toxin inhalation
•      -High altitude sickness
•      -Aspiration
•      -Contusion
•      -Fat embolism
•      -Amniotic Fluid embolism

• -patchy inflitrates
• -Kerley B lines
• -Interlobar fissure thickening
• -pleural fluid
• -redistribution (increased size of vessels to upper lobes)
• -Parahilar zone bronchial cuffing
• -Parahilar vessels less distinct

• Pulmonary Edema
• -blunting of costophrenic angle
• -haziness throughout
• -enlarged heart

Kerley B lines

Pulmonary Edema

Pulmonary edema

• Decreased lung volume
• -should see 9-10 ribs with deep inspiration

• NOT pulmonary edema
• -aspiration of water from near drowning
• -distinguish based on history

• 1. Traumatic
• 2. Iatrogenic
•      -thoracoscopy
•      -thoracentesis
•      -placement of central venous lines
•      -artificial ventilation
•      -post thoracic surgery
•      -transthoracic and bronchial bx
• 3. Spontaneous
•      -rupture of bleb/bullae
•      -secondary to pulm disease
•      -secondary to pneumomediastinum

• -visceral pleura is visible when air gets in
• -thin white line
• -absence of lung markings NOT sufficient for dx

NOT pneumothorax

the line is due to air trapped within a skin fold

-air gets trapped in pleural space and leads to displaced mediastinal structures

• 
• -horizontal line

Pneumothorax

Deep sulcus Sign: in patients that lay supine the air accumulates posteriorly and anteriorly

• Bilateral pneumothorax
• -air has moved into the subcutaneous tissue leading to subcutaneous lucency

• Inspiration:
• 

• Expiration:
•