Unilateral pulmonary edema can develop through three main patterns: 1) Rapid thoracentesis can cause pulmonary edema on the side where a large pleural effusion was removed as fluid shifts into the exposed lung. 2) Dependency can lead to pulmonary edema localized to the dependent lung when a patient is lying on one side for a prolonged period. 3) Pulmonary contusions or embolisms can induce pulmonary edema on the side that is injured or blocked, with the edema sparing the bases initially in some cases.

1. 3 Unilateral Pulmonary Edema
Pattern

2. CLINICAL IMAGAGING
AN ATLAS OF DIFFERENTIAL DAIGNOSIS
EISENBERG
DR. Muhammad Bin Zulfiqar
PGR-FCPS III SIMS/SHL

3. • Fig C 3-1 Rapid thoracentesis. (A) Initial
radiograph of an elderly woman with metastatic
adenocarcinoma of the breast and a massive left
pleural effusion. (B) Repeat examination taken 2
hours after the rapid removal of 2500 mL of fluid
shows a left-sided pulmonary edema. The
segment of left lung not compressed by effusion
remains free of edema. Over the next 6 days, the
edema resolved spontaneously.13
c

4. • Fig C 3-2 Unilateral pulmonary edema due to
dependency. The diffuse alveolar pattern is
limited to the left lung.

5. • Fig C 3-3 Pulmonary contusion. (A) Admission
chest radiograph shows several right rib
fractures and an early right perihilar infiltrate.
(B) Repeat examination shows right-sided
post-traumatic pulmonary edema and
capillary hemorrhage that developed the next
day and persisted for a few weeks. An
organized extrapleural hematoma is present in
the right apex.13

6. • Fig C 3-4 Edema contralateral to pulmonary embolization. (A) Chest
radiograph in an acutely dyspneic older man shows moderate
cardiomegaly and early right-sided edema that spares the base. (B) An
angiogram obtained at the bedside shows nonopacification of all left
pulmonary branches and a few segmental right lower lobe branches. (C)
Radionuclide scan shows complete lack of perfusion in the left lung and
poor perfusion of the right lower lobe.13