Intro to Thorax

Question 1

Radiographic technique for the thorax

Answer 1

High kVp and low mA to provide a long scale of contrast in a region with inherently short contrast because of the air in the lungs; short time; take film on inspiration (few exceptions); minimum of 2 orthogonal views (RL and VD)

Question 2

Normally, for positioning animal on VD/DV views, forelimbs are drawn cranially. What is the exception?

Answer 2

Pull forelimbs down to the side if questionable lesion in cranial lung lobes.

Question 3

Lateral view: inspiration vs expiration - Diaphragm

Answer 3

Inspiration - flat

Expiration - round

Question 4

Lateral view: inspiration vs expiration - caudal vena cava

Answer 4

Inspiration - horizontal

Expiration - Ascends caudally

Question 5

Lateral view: inspiration vs expiration - heart/diaphragm contact

Answer 5

Inspiration - minimum/none

Expiration - overlap

Question 6

Lateral view: inspiration vs expiration - heart/sternum contact

Answer 6

Inspiration - less

Expiration - More

Question 7

Lateral and DV view: inspiration vs expiration - pulmonary radiolucency

Answer 7

Inspiration - increased

Expiration - decreased

Question 8

DV view: inspiration vs expiration - costo-diaphragm angle

Answer 8

Inspiration - increase

Expiration - decrease

Question 9

RL vs LL view of thorax

Answer 9

RL - Minimal contact of heart with diaphragm, caudal vena cava enters R crus, gas in fundus of stomach, trachea and CVC in alignment

Question 10

In a right lateral view of the thorax, it is normal to see the trachea and CVC in alignment. What would push the trachea and CVC apart?

Answer 10

Left atrial enlargement

Question 11

In a right lateral view, which crus is further forward?

Answer 11

Right crus - can see CVC entering

Question 12

In a left lateral view, which crus and further foward?

Answer 12

Left crus - fundus of the stomach is caudal to the left crus

Question 13

VD vs DV

Answer 13

VD - 3 humps seen (right crus, left crus, cupula); heart is elongated
DV - one hump; heart is rounder

Question 14

Air surrounding nodule - better seen on VD or DV view to distinguish between a sillhoute with collapsed lung?

Answer 14

DV view

Question 15

3 differentials for obscured diaphragmatic margin

Answer 15

1. Diaphragmatic Hernia;
2. Pleural Effusion;
3. Pulmonary infiltration (primary lung caudal lung tumor)

Question 16

Radiographic signs of a diaphragmatic hernia:

Answer 16

1. Diaphragm silhouettes with the heart
2. Empty abdomen
3. Cranial displacement of abdominal structures
4. Pleural effusion if liver in thorax
5. Loss of diaphragmatic outline
6. Abdominal structures in the thorax
7. Mediastinal shift

Question 17

Congenital Diaphragmatic Hernia

Answer 17

Hiatal, Peritoneal pericardial (may have gas filled intestines/stomach in pericardial sac; Pleuroperitoneal; absent