Q. Define Radiological anatomy?

The borders of the mediastinum on the CXR are defined by the contrast produced by adjacent air filled lung.

Postero-Anterior View

It indicate the structures that form the mediastinal contours. The right ventricle is the only chamber that does not contribute to the cardiac silhouette on the PA view.

Lateral View

The lateral view is always used in combination with the PA view. In addition to defining specific chamber enlargement, it is particularly useful in the following situations:

i) Demonstrates lesions in the retrosternal and costophrenic regions.

ii) Localizes lung pathology to its lobe and assesses lobar volume loss.

iii) Defines interlobar or small pleural effusions.

iv) Separates diaphragmatic variants from adjacent lung or subdiaphragmatic pathology.

It illustrates the structures that are border forming on the lateral view. The right ventricle and pulmonary trunk form the anterior margins of the cardiac contour. The posterior border is formed by the left atrium and the left ventricle. There is a small contribution from the inferior vena cava (IVC)