1. Dr. Mahesh Chaudhary
MD Radiology & Imaging, BSMMU
Phase-A Resident (March 2014 session)

2. PLEURAL EFFUSIONS
DEFINITION- A COLLECTION OF FLUID BETWEEN THE
PARIETAL PLEURA AND VISCERAL PLEURA.

3. The Right Lung
-Three lobes-the superior, middle and inferior, which are
separated by the horizontal fissure and the oblique
fissure.
-10 bronchopulmonary segments
The Left Lung
-Two lobes which are separated by the oblique fissure.
-10 bronchopulmonary segments
ANATOMY IN A HEALTHY LUNG

4. Bronchopulmonary segments

5. The main anatomy affected by pleural effusions are the layers in the
Lung
There are two layers-the parietal pleura and the visceral pleura.
• At the Hilum, the parietal pleura folds back on itself to become the visceral
pleura.
The pleural fluid contains –
-contains about 5-15ml of fluid at one time
-about 100-200ml of fluid circulates though the pleural space within a 24-hour
period
-has an alkaline pH of about 7.60 - 7.64
 Protein content less than 2% (1-2 g/dL)
 Glucose content similar to that of plasma
 Mesothelial cells
 Macrophages
 Lymphocytes (few)
 Sodium, potassium and calcium concentrations similar to that of interstitial fluid.
 Lactate Dehydrogenase concentration of less than 50% of that of plasma

6. ANATOMY
OF A
HEALTHY
LUNG
A pleural effusion is an accumulation of fluid
between the parietal pleura and the visceral pleura.
Chest X-ray frontal view: 100-200ml pleural fluid
ANATOMY OF A
LUNG WITH A
PLEURAL
EFFUSION

7. Recesses of Pleura

8. ANATOMY & PHYSIOLOGY OF A LUNG WITH A
PLEURAL EFFUSION
• The fluid accumulates due to the over production of pleural fluid by the
mesothelial cells and separates the visceral and parietal pleura.
• This fluid can not be drained by the lymphatic system, and so therefore continues
to accumulate, resulting in a pleural effusion.
• The accumulation of fluid may also be due to changes in hydrostatic pressure or
oncotic pressure.
The lung has the natural tendency to collapse towards the hilum and this is
opposed by forces of similar magnitude in the chest wall tending to expand
outward. Thus the parietal and visceral pleura are kept in close apposition. If
increase fluid or air collect in the pleural space ,the effect of outward forces on the
underlying lung is diminished, and the lung tend to retract toward its hilum.

9. Aetiology

10. There are 4 different fluids which can accumulate in the pleural space.
• Blood HAEMOTHORAX
• Pus EMPYEMA
• Chyle CHYLOTHORAX
• Serous fluid HYDROTHORAX
• They can further be classified into TRANSUDATES and EXUDATES
depending on
– Chemical composition
– Mechanism of fluid formation
Light’s criteria: Transudate vs. Exudate
•
Pleural fluid protein / serum protein > 0.5
Pleural fluid LDH / serum LDH > 0.6
Pleural fluid LDH > 2/3 ULN serum LDH

11. Pathophysiology
Hydrostatic Pressure
Oncotic pressure
Increased peritoneal fluid

12. Mechanisms for pleural fluid accumulation:
• Increased hydrostatic pressure (Eg. CCF)
• Reduced plasma oncotic pressure (Eg. Hypoproteinaemia)
• Increased capillary permeability (Eg.TB, Tumour )
• Reduced lymphatic drainage from pleural space
(Obstrustioin by tumour, TB, radiation)
• Transdiaphragmatic passage of fluid (Eg. Liver disease,
Acute pancreatitis) .

13. Transudates
• Clear, pale yellow, watery substance
• Increase hydrostatic pressure,
• Decrease oncotic pressure
• Common causes:
 Congestive heart failure
 Cirrhosis of the Liver
 Nephrotic syndrome
 Hypoproteinaemia
 Hypothyroidism
 Acute rheumatic fever

14. Exudates
• Pale yellow and cloudy substance, has a low pH
• Influenced by local factors where fluid absorption is
altered (inflammation, infection, cancer)
• Rich in white blood cells.
• Common causes:
 Pulmonary TB
 Pneumonia
 Bronchial carcinoma
 Pulmonary infarction
 Collagen disease (SLE, RA)
 Lymphoma
 Meig’s syndrome (Right pleural effusion, Ascites, Ovarian fibroma)

15. Blood stained fluid
Tends to loculate early
CT scan shows higher density measurement
Common causes:
-Chest injury
-Bronchial carcinoma
-Pulmonary infarction
-Lymphoma
Haemothorax

16. Chylothorax
• Milky fluid due to lymph and fats
• Chyle leaks from the thoracic duct due to
-damage to the lymphatic vessels.
-lymphatic obstruction (tumor) or trauma
• High triglyceride levels found in fluid analysis
• Common causes:
• Traumatic (thoracic surgery), trauma to thoracic duct
• Neoplastic ( Bronchial carcinoma, metastasis)
• Infective (TB)
• Lymphoma (involving thoracic duct)

17. Empyema
• Pus in pleural space
• Yellow, cloudy, and foul odor
• Has a pH > 7.2
• Common causes:
 Pneumonia
 Rupture of lung abscess,
 Rupture of sub-phrenic abscess
 Tuberculosis
 Infected chest wounds
 Secondary infection during aspiration of pleural fluid

18. Diagnosis of Pleural Effusions
• Medical history
• Physical examination
• Plain film chest x-ray – first line imaging
• CT
• Ultrasound imaging
Diagnosing Pleural Effusions
through Imaging

19. Characteristics on a supine
chest radiograph
• Fluid accumulates posteriorly
• Affected hemi-thorax appears whiter or
paler grey
• Apparent thickening of the pleura
• Approx 200 mls of fluid present before
abnormal pale grey appearance is
produced

20. First line imaging – Chest x-ray
Clear right side
hemi-diaphragm
and sharp
costophrenic
angle
Area of
homogenous
Whiteness, with
loss of hemi-
diaphragm
Meniscus shaped
upper border
Features on a PA or AP erect radiograph

21. A large right side pleural effusion
The heart
has been
pushed towards
the left side by the
fluid
Entire white-out
of right
hemi-thorax

22. Lateral decubitus chest radiograph
Free layering pleural effusion
At least 100ml
pleural fluid is
necessary

23. Laminar Pleural effusion

24. Subpulmonic effusion

26. Loculated fluid

28. Loculated effusion
(elliptical, pointed margins)
in left major fissure
CT Scan

29. Pleural Effusion Diagnosis through
CT Imaging

30. Aorta
Left Lung
Heart
Right Lung
Ribs
Crescent-
shaped
pleural
effusion

31. Aorta
Mass, right
upper lobe
Irregular
soft-tissue
thickening
Pleural
effusion

32. Right Lung
Pleural
effusion
SpleenDiaphragm
Liver

33. CT signs:
Pleural effusion vs ascites.

34. 4 signs
1.Displaced crus sign:
Pleural fluid may collect posterior to the diaphragmatic crux and therefore
displace the crus anteriorly, whereas ascites collects anterior to the crus and
may cause posterior displacement.
2.Diaphragm sign:
As an extension of the displaced crus sign,
Any fluid that is on the exterior of the dome of the diaphragms in the pleura,
whereas any that is within the dome is ascites
3.Interface sign:
The interface between the liver or spleen & pleural fluid is said to be less sharp
than that between the liver or spleen and ascites
4.Bare area sign:
The peritoneal coronary ligament prevents ascitic fluid from extending over the
entire posterior surface of the liver, whereas in a free pleural space, pleural
fluid may extend or over the entire posterior costophrenic recess behind the
liver

35. Ultrasound
• No radiation,
• Small effusions missed on CXR
• Even 20-25 ml of fluid can be detected
• Transudate-Anechoic, Exudative- Reflectative +/-
• Identify pleural thickening and masses
• Used to guide thoracocentisis

36. Patient position
• Patient seated, arms folded, leaning
forward
• Unwell patient imaged semi-supine

37. MRI
• Not used to image pleural effusion
• Incidental finding

38. Treatment
• Needed if patient becomes breathless
• Small effusions are left and ‘observed’
• Usually directed at underlying cause
(antibiotics for pneumonia)
• Underlying cause treated effusion will go
away for good
• If not it will return within few weeks

39. Thoracocentisis
• Invasive procedure
• Removes fluid from pleural space
• Allows lung to expand, making breathing easier
• Guided using ultrasound

40. Pleurodesis
• Chemical inserted into pleural space
• Parietal and visceral layers become irritated
• Closes space
• Painful
Pleuroperitoneal Shunt
• Internal shunt
• Fluid drains from chest into abdominal cavity
Pleurectomy
• Operation to remove the pleura
• Most severe cases

42. Have a nice day