Normal Hilar Anatomy

Question 1

The shape of the right hilum on frontal radiographs has been likened to as sideways V, with opening pointing rightward.

What vessels comprises the V?

Answer 1

The upper portion of the V is composed primarily of the truncus anterior and the posterior division of the right superior pulmonary vein.

The right interlobar artery forms the lower half of the V, as it descends lateral to the bronchus intermedia.

Question 2

The upper left hilar shadow is composed of what structure?

Answer 2

Composed centrally of the distal left main pulmonary artery and, more peripherally, of one or more branches of its LUL division and the posterior division of the left superior pulmonary vein

Question 3

What forms the lower portion of the left hilar shadow?

Answer 3

Left descending artery

Question 4

In more that 90% of normal individuals, the left hilar shadow is higher than the right.

Why?

Answer 4

Because the left pulmonary artery, which comprises the predominant portion of the left hilar shadow, ascends over he left main and upper lobe bronchus, where as the right pulmonary artery lies inferior to the RUL bronchus

Question 5

A right hilum that lies above the above the left suggest what disease process?

Answer 5

Volume loss of the RUL or LLL

Question 6

The avascular aspect of the composite hilar shadow, inferior to the shadow of the right pulmonary artery and veins and anterior to the descending left pulmonary artery and left superior vein is called what window?

Answer 6

Inferior hilar window

Question 7

This region is roughly triangular in shape, with its apex at the junction of the LUL and LLL bronchi and its based anteriorly and inferiorly.

Answer 7

Inferior hilar shadow