Obliteration of Costophrenic angle is seen in
A Small Amount of free fluid may be undetectable on an erect PA chest radiograph as it tends initially to collect under the lower lobes. As the amount of effusion increases, the posterior and then the lateral costophrenic angles become blunted, by which time a 200 to 500-mL effusion is present
Pneumothorax
Pleural effusion
Tuberculosis
Pneumonia
Respiratory Radiology