ICVA Veterinary Diagnostic Imaging 2 — Questions and Answers
Question 1: In computed tomography (CT), Hounsfield units (HU) are used to measure:
- Signal intensity of hydrogen protons
- Electron density relative to water (Correct answer)
- Sound wave attenuation coefficient
- Radiotracer uptake in tissues
Correct answer: Electron density relative to water
Hounsfield units quantify the electron density of tissues relative to water (0 HU), with air at -1000 HU and bone at +1000 HU or higher.
Question 2: Which of the following best describes the appearance of acute hemorrhage on T1-weighted MRI?
- Hypointense (dark) (Correct answer)
- Hyperintense (bright)
- Isointense to muscle
- Variable depending on field strength only
Correct answer: Hypointense (dark)
Acute hemorrhage (oxyhemoglobin stage, <24 hours) appears hypointense on T1-weighted images due to the paramagnetic properties of intact red blood cells.
Question 3: Nuclear scintigraphy (bone scan) in veterinary patients primarily detects:
- Structural bone fractures
- Areas of increased osteoblastic activity (Correct answer)
- Cortical bone density loss
- Soft tissue mineralization
Correct answer: Areas of increased osteoblastic activity
Bone scintigraphy using technetium-99m phosphonate complexes detects areas of increased osteoblastic activity and bone remodeling, highlighting active lesions.
Question 4: A dog presents with a caudal abdominal mass. Ultrasound shows a large structure with multiple anechoic compartments separated by hyperechoic septa. This finding is MOST consistent with:
- Solid hepatic neoplasia
- Simple renal cyst
- Multiloculated cystic structure (Correct answer)
- Mineralized adrenal mass
Correct answer: Multiloculated cystic structure
Multiple anechoic compartments separated by hyperechoic septa describe a multiloculated cystic structure, consistent with cystadenoma or multilocular cyst.
Question 5: Which radiographic finding is most consistent with a left-sided congestive heart failure in a dog?
- Pulmonary hyperinflation
- Pulmonary venous distension and perihilar interstitial to alveolar pattern (Correct answer)
- Pleural effusion only
- Hepatomegaly with ascites
Correct answer: Pulmonary venous distension and perihilar interstitial to alveolar pattern
Left-sided CHF causes pulmonary venous hypertension leading to pulmonary edema, seen radiographically as distended pulmonary veins and a perihilar interstitial to alveolar pattern.
Question 6: Fluoroscopy is most useful in veterinary medicine for evaluating:
- Bone density and mineralization
- Dynamic real-time motion studies such as swallowing (Correct answer)
- Fetal viability in pregnant animals
- Soft tissue masses within the thorax
Correct answer: Dynamic real-time motion studies such as swallowing
Fluoroscopy provides real-time continuous X-ray imaging, making it ideal for dynamic studies such as esophageal motility, swallowing function, and joint motion.
Question 7: When performing abdominal radiography to detect free peritoneal gas (pneumoperitoneum), the MOST sensitive patient positioning is:
- Ventrodorsal (VD) with horizontal beam
- Left lateral recumbent with horizontal beam (Correct answer)
- Dorsoventral (DV) standing
- Right lateral recumbent standard view
Correct answer: Left lateral recumbent with horizontal beam
Left lateral recumbency with a horizontal beam allows free gas to accumulate along the right lateral body wall between the liver and diaphragm, optimizing detection.
ICVA Veterinary Diagnostic Imaging 2
In computed tomography (CT), Hounsfield units (HU) are used to measure: