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Phase 1: Vascular Phase:
- This is the first phase of congestive heart failure.
- It represents pulmonary venous hypertension.
- Cephalization: Vessels in upper chest is more prominent as a manifestation of pulmonary venous hypertension.
- Note the blood vessels are more prominent in the upper lung fields compared to the lung base, just the opposite of normal.
- In supine film the vessels are same size in upper and lower lung fields.
- You see increased (>1) artery to bronchus ratio at hilar level.
Hilar Fullness With Haziness:
- Enlarged pulmonary veins with perivascular fluid collection leads to full hazy hilum and vessels.
Phase 2: Interstitial Phase:
- Kerley lines are 2-3 cm long horizontal lines in the base of lungs close to chest wall.
- They are the result of interstitial edema and increased lymphatic drainage.
- This is the second phase of congestive heart failure.
Phase 3: Alveolar Phase:
- This x-ray shows normal size heart with bilateral diffuse soft fluffy alveolar infiltrates coalescing with each other in a butterfly distribution typical of pulmonary edema.
- The heart can be normal and develop failure, as is in this case, due to acute MI.
- Pulmonary edema is the primary manifestation of heart failure when the left ventricle acutely fails.
- In chronic heart failure is where you see vascular, interstitial, alveolar phases and pleural effusions.
Pleural Effusions:
This x-ray shows:
- Cardiomegaly
- Basal congestion: This is gravity dependent accumulation of fluid in the lungs and alveoli are filled with fluid.
- Fuzzy full hilum: Represents enlarged pulmonary veins and fluid around them.
- Bilateral pleural effusions. Due to increased hydrostatic pressures.
How do you distinguish Pulmonary edema from ARDS in CXR?
- In ARDS the heart is normal in size and there are no pleural effusions.
- Clinical setting and the wedge pressure are necessary in some cases.
- ARDS is always preceded by a major event like trauma, surgery, bleeding etc. If there is no preceding major event do not consider ARDS.
