Pleural effusion, in standing position gravitates n the region of
i.e. (Costodiaphragmatic recess: (1658-66 - H17th) (306-8-CMDT-l1)* Most dependent recess of the pleura is the posterior costophrenic angle**. So in pleural effusion this recess would be filled earliest. But at least 100-200 ml of fluid. Would be required to fill this recess before it can be defected on a PA view* The lung is less dense than water and floates on pleural fluid that accumulates in dependent regions* Sub pulmonary fluid may appear as lateral displacement of the apex of the diaphragm with an abrupt slop to the costophrenic sulcus or a greater than 2 cm seperation between the gastric air bubble and the lung.* On a standard upright chest radiograph approximately 75-100 ml of pleural fluid must accumulate in the posterior costophrenic sulcus to the visible on the lateral view and 175-200 ml must be present in the lateral costophrenic sulcus to be visible on he frontal view (307-CMDT-l 1)* Best method to defect minimal pleural effusion decubitus view with a horizontal beam*** Most common cause of pleural effusion is LVF* Most common cause of an exudative pleural effusion developing countries TuberculosisCriteria of Exudative pleural effusion1. Pleural fluid protein / serum protein > 0.52. Pleural fluid LDH / serum LDH >0.63. Pleural fluid more than two thirds normal upper limit for serumCauses of Transudative Pleural Effusion 1. CHF (>90% of cases)2. Cirrhosis with ascitis3. Pulmonary embolization4. Nephrotic syndrome5. Peritoneal dialysis6. SVC obstruction7. Myxedema8. Urinothorax9. Constrictive pericarditis10. Atelectasis (Acute)Chest CT scan may identify as little as 10 ml of fluid
Oblique fissure
Costomediastinum recess
Costodiaphragmatic recess
Cardiac knoch
Respiratory