Chapter 28 - Thoracic wall

Question 1

How many sternebra are normal?

Answer 1

8

Question 2

When can mineralization of the costal cartilages be seen?

Answer 2

young and old dogs

Question 3

What pedunculated soft tissue opacities can be seen on the thoracic wall?

Answer 3

nipple, papilloma, engorged ticks

Question 4

Ventral displacement of the sternum is called?

Answer 4

pectus carinatum

Question 5

Dorsal displacement of the sternum is called?

Answer 5

pectus excavatum

Question 6

Radiographic changes that can occur secondary to thoracic wall trauma?

Answer 6

rib fractures
soft tissue swelling
subcutaneous emphysema

Question 7

What is a flail chest?

Answer 7

segmental rib fractures involving the dorsal and ventral aspect of at least 2 adjacent ribs

Question 8

What occurs with a flail chest during inspiration and expiration?

Answer 8

Paradoxical movement
Ribs move inwards during inspiration
Ribs move outwards during expiration
(should be opposite)

Question 9

What can cause non-traumatic rib fractures in cats?

Answer 9

diseases that result in prolonged espiratory effort or coughing, metabolic diseases, certain neoplasia

Question 10

What is an extrapleural sign?

Answer 10

a radiographic change that is seen due to a thoracic wall mass

Question 11

What does an extrapleural sign look like radiographically vs a pulmonary mass?

Answer 11

Extrapleural: if a mass origiantes from thoracic wall and extends into thoracic cavity - junction of mass and wall forms an angle greater than 90 degrees. Usually very broad-based

Pulmonary mass: if a lung originates in the pulmonary parenchyma and approaches the thoracic wall - the junction between the mass and the thoracic wall will be less than 90 degrees

Question 12

Most common thoracic wall masses?

Answer 12

Originating from the ribs (mesenchymal origin: chondrosarc, osteosarc, fibrosarc) connective tissue, nerves, vessels, muscles

abscess from foreign body

Question 13

What do rib infections most commonly occur due to?

other differentials?

Answer 13

penetrating wound

extension of pyothorax, mycotic infection

Question 14

Radiographic difference between an infectious process in a rib and a neoplasia?

Answer 14

unable to determine - both may be lytic, lytic and productive, or productive only.

Question 15

Etiologies for rib masses?

Answer 15

Primary tumors (mesenchyma in origin: chondrosarc, fibrosarc, osteosarc)

Metastatic lesions

Question 16

Most common sternebral tumors?

Answer 16

mesenchymal in origin: osteosarc, fibrosarc, osteosarc