NAVLE Diagnostic Imaging Interpretation 5

Question 1

On a lateral thoracic radiograph of a dog, which structure should be used to assess left atrial enlargement?

Accepted Answer

Dorsal elevation of the left mainstem bronchus

Answer

Left atrial enlargement causes dorsal elevation and splaying of the left mainstem bronchus (carina angle >60°) on lateral radiographs.

Question 2

Which ultrasonographic finding is MOST consistent with gastric dilatation-volvulus (GDV) versus simple dilatation in a dog?

Accepted Answer

Compartmentalization of the stomach into two gas-filled regions on the right lateral view

Answer

GDV causes the stomach to rotate, creating a compartmentalized 'double bubble' appearance, whereas simple dilatation shows uniform distension.

Question 3

Acoustic shadowing on ultrasound is caused by:

Accepted Answer

Complete absorption or reflection of the sound beam by a highly attenuating structure

Answer

Dense structures such as calculi or bone absorb or reflect nearly all the ultrasound energy, preventing transmission and creating a shadow distal to the structure.

Question 4

In equine foot radiography, which landmark is used to assess the position of the navicular bone relative to the distal phalanx?

Accepted Answer

Palmar angle of the distal phalanx relative to the ground surface

Answer

The palmar angle of P3 on lateral foot radiographs is used to assess navicular bone position and the degree of podotrochlear pathology.

Question 5

On CT myelography of a dog, an 'intramedullary' lesion is characterized by:

Accepted Answer

Fusiform swelling of the spinal cord with thinning of the contrast column on all sides

Answer

Intramedullary lesions expand the cord itself, producing symmetric fusiform cord enlargement that thins the contrast column circumferentially.

NAVLE - North American Veterinary Licensing Examination Practice Test

NAVLE - North American Veterinary Licensing Examination Practice Test

NAVLE Diagnostic Imaging Interpretation 5