A subpulmonic effusion is excess fluid that collects at the base of the lung, in the space between the

pleura The pulmonary pleurae (''sing.'' pleura) are the two opposing layers of serous membrane overlying the lungs and the inside of the surrounding chest walls. The inner pleura, called the visceral pleura, covers the surface of each lung and dips ...

and diaphragm. It is a type of

pleural effusion A pleural effusion is accumulation of excessive fluid in the pleural space, the potential space that surrounds each lung. Under normal conditions, pleural fluid is secreted by the parietal pleural capillaries at a rate of 0.6 millilitre per ...

in which the fluid collects in this particular space but can be "layered out" with decubitus chest radiographs. There is minimal nature of costophrenic angle blunting usually found with larger pleural effusions. The occult nature of the effusion can be suspected indirectly on

radiograph Radiography is an imaging technique using X-rays, gamma rays, or similar ionizing radiation and non-ionizing radiation to view the internal form of an object. Applications of radiography include medical radiography ("diagnostic" and "therapeuti ...

by elevation of the right

diaphragm Diaphragm may refer to: Anatomy * Thoracic diaphragm, a thin sheet of muscle between the thorax and the abdomen * Pelvic diaphragm or pelvic floor, a pelvic structure * Urogenital diaphragm or triangular ligament, a pelvic structure Other * Diap ...

atic border with a lateral peak and medial flattening. The presence of the gastric bubble on the left with an abnormalagm of more than 2 cm can also suggest the

diagnosis Diagnosis is the identification of the nature and cause of a certain phenomenon. Diagnosis is used in many different disciplines, with variations in the use of logic, analytics, and experience, to determine " cause and effect". In systems engin ...

. Lateral decubitus views, with the patient lying on their side, can confirm the effusion as it will layer along the lateral chest wall. Subpulmonic space refers to the space below the lungs in which the subpulmonic fluid fills. Subpulmonic fluid is common particularly in trauma cases where the apparent

hemidiaphragm The thoracic diaphragm, or simply the diaphragm ( grc, διάφραγμα, diáphragma, partition), is a sheet of internal skeletal muscle in humans and other mammals that extends across the bottom of the thoracic cavity. The diaphragm is the ...

appears defeated and the apex is displaced laterally.

References

{{reflist Anatomy Lung disorders