Mediastinum

Question 1

The mediastinum consists of

2 layers of mediastinal ________

and the space between them

Answer 1

pleura

Question 2

T/F:

Unilateral disease is common in the mediastinum

Answer 2

FALSE!

it is uncommon

Question 3

The mediastinum communicates with the

neck __________ and the

retroperitoneal space ___________

Answer 3

cranially

caudally

Question 4

Name the 3 Mediastinal reflections

Answer 4

Cranioventral

Caudoventral

Plica Vena Cava

Question 5

What structures can be seen in radiography of the mediastinum?

Answer 5

Heart

CAUDAL vena cava

Thymus (young animals)

Esophagus (occasionally in LEFT lateral)

(TECH)

Question 6

Which structures are normally NOT visible in

mediastinal radiography?

Answer 6

CRANIAL vena cava

Lymph nodes

Azygous veins

Nerves

(CLAN)

Question 7

The width of the mediastinum depends on

Answer 7

fat accumulation

Question 8

The width of the mediastinum in the dog should be less than

______X the width of the thoracic vertebral bodies

Answer 8

2X

Question 9

The width of the mediastinum in the cat should be less than

______X the width of the thoracic vertebral bodies

Answer 9

1x

Question 10

T/F:

Width of the mediastinum decreases in obese patients

Answer 10

FALSE

it INCREASES

Question 11

The ________ mediastinal reflection occurs on the LEFT

because the accessory lobe extends to the left.

It is only seen in VD/DV views

Answer 11

caudoventral

Question 12

A “sail sign” in a VD or DV view is indicative of this

structure, often seen in young animals in the cranial mediastinum

Answer 12

THYMUS

Question 13

If you seen a round structure silhouetting with the heart

in the cranial mediastinum,

but your patient is very young, should you be concerned?

What is it?

Answer 13

NO! It is the Thymus!

Question 14

Which view is more useful for assessing mass location

in the mediastinum?

Answer 14

DV or VD

Question 15

Cranial masses of the mediastinum result in

displacement of the

heart and lungs __________

deviation of the

trachea ______

and compression of the trachea

Answer 15

heart and lungs caudally

tracheal dorsally

Question 16

Which lymph nodes can be found in the mediastinum?

Answer 16

Sternal LN

Cranial Mediastinal LN

Tracheobronchial LN

Question 17

If you see a “bow-legged cowboy” sign on a DV view of the

mediastinum, what does this indicate?

Answer 17

A dorsal mediastinal disease:

Tracheobronchial LN enlargement

Question 18

Tracheobronchial LN enlargement

results in displacement of the principle bronchii ______

and

a curved appearance

Answer 18

laterally

Question 19

Tracheobronchial LN enlargement can be mistaken for

Left _______ enlargement

on a radiograph

Answer 19

atrial

Question 20

This condition can hide mediastinal masses

Answer 20

Pleural effusion

Question 21

Free gas in the mediastinum is known as

Answer 21

Pneumomediastinum

Question 22

Pneumomediastinum can progress to _________

Answer 22

pneumothorax

(but not vice versa)

Question 23

T/F:

Pneumomediastinum can result in dyspnea

(difficult or labored breathing)

Answer 23

FALSE!

Question 24

Usually, you cannot see the cranial vena cava, brachiocephalic

trunk, left subclavian, esophagus, or trachea in a normal radiograph.

If you CAN see these things, what disease is indicated?

Answer 24

Pneumomediastinum