ICVA Veterinary Diagnostic Imaging 1 — Questions and Answers
Question 1: Which radiographic view is most commonly used to evaluate the thorax in a lateral recumbent patient?
- Ventrodorsal (VD)
- Dorsoventral (DV)
- Right lateral recumbent (Correct answer)
- Oblique lateral
Correct answer: Right lateral recumbent
The right lateral recumbent view is standard for thoracic radiography as it provides consistent cardiac silhouette positioning for comparison.
Question 2: On thoracic radiographs, a silhouette sign occurs when two structures of similar opacity are:
- Separated by air-filled lung
- In direct contact with each other (Correct answer)
- Overlapping but not touching
- Located on opposite sides of the mediastinum
Correct answer: In direct contact with each other
The silhouette sign occurs when two structures of similar opacity are in direct contact, causing their borders to become indistinct.
Question 3: What is the principle behind ultrasonographic imaging?
- X-ray attenuation through tissues
- Magnetic resonance of hydrogen nuclei
- Reflection of high-frequency sound waves from tissue interfaces (Correct answer)
- Detection of gamma rays emitted by radioactive tracers
Correct answer: Reflection of high-frequency sound waves from tissue interfaces
Ultrasound imaging uses the reflection (echoes) of high-frequency sound waves at tissue interfaces to create images.
Question 4: Which modality is BEST suited for evaluating soft tissue structures of the intervertebral disc in small animals?
- Survey radiography
- Fluoroscopy
- Magnetic resonance imaging (MRI) (Correct answer)
- Nuclear scintigraphy
Correct answer: Magnetic resonance imaging (MRI)
MRI provides superior soft tissue contrast, making it the gold standard for evaluating intervertebral disc material and spinal cord compression.
Question 5: On ultrasound, a structure described as 'anechoic' appears:
- Bright white
- Heterogeneous with mixed echoes
- Completely black with no internal echoes (Correct answer)
- Hyperechoic with acoustic shadowing
Correct answer: Completely black with no internal echoes
Anechoic structures produce no echoes and appear completely black on ultrasound, which is characteristic of fluid-filled structures.
Question 6: Which contrast medium is most appropriate for myelography in veterinary patients?
- Barium sulfate
- Iohexol (Correct answer)
- Iodinated oil-based contrast
- Air alone
Correct answer: Iohexol
Iohexol is a water-soluble, non-ionic iodinated contrast medium approved for intrathecal use in myelography due to its safety profile.
Question 7: The term 'opacity' in radiography refers to:
- How bright a structure appears on the image
- The degree to which a structure attenuates X-ray beam (Correct answer)
- The resolution of the radiographic image
- The amount of scatter radiation produced
Correct answer: The degree to which a structure attenuates X-ray beam
Opacity describes the degree to which a structure attenuates (absorbs) the X-ray beam, appearing white/light on the radiograph.
ICVA Veterinary Diagnostic Imaging 1
Which radiographic view is most commonly used to evaluate the thorax in a lateral recumbent patient?