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ACVR Veterinary Radiology study materials
ACVR Veterinary Radiology study resources

ACVR Veterinary Radiology practice questions

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Question 1Radiology

On a thoracic radiograph, which structure normally forms the ventral border of the cardiac silhouette in a dog?

  1. The right ventricle Correct answer.
  2. The main pulmonary artery
  3. The left atrium
  4. The ascending aorta

Explanation

The cardiac silhouette is a composite shadow, but its ventral-most contour in the dog is formed by the right ventricle. The left atrium and pulmonary artery contribute to the dorsocaudal and cranial margins respectively.

Question 2Radiology

What is the normal radiographic appearance of the feline kidney on a ventrodorsal abdominal radiograph?

  1. The kidneys are normally not visible
  2. The left kidney is consistently larger than the right
  3. Both kidneys are typically silhouetted by small intestinal gas
  4. The right kidney lies more cranially than the left Correct answer.

Explanation

In the cat the right kidney sits further cranially than the left, which sits more caudally in the sublumbar region. This craniocaudal offset is a normal anatomic feature.

Question 3Radiology

Which radiographic sign is most consistent with a diagnosis of megaesophagus on a thoracic radiograph?

  1. A gas- or fluid-filled tubular structure dorsal to the trachea Correct answer.
  2. A generalized increase in pulmonary interstitial opacity
  3. Caudal displacement of the stomach
  4. Widening of the caudal mediastinum with a soft tissue mass

Explanation

A dilated esophagus appears as a tubular gas- or fluid-filled structure in the dorsal mediastinum, often displacing the trachea ventrally. This is the hallmark of megaesophagus.

Question 4Radiology

On a lateral thoracic radiograph, where does the trachea normally lie relative to the esophagus?

  1. Dorsal to the esophagus
  2. Caudal to the esophagus
  3. Lateral to the esophagus
  4. Ventral to the esophagus Correct answer.

Explanation

The air-filled trachea lies ventral to the esophagus in the cranial mediastinum. This relationship helps distinguish tracheal from esophageal structures on lateral views.

Question 5Radiology

Which of the following best describes the normal appearance of the canine urinary bladder on a survey abdominal radiograph?

  1. A soft tissue opacity structure in the caudal ventral abdomen Correct answer.
  2. A mineral-opaque structure in the mid-abdomen
  3. A gas-filled structure in the cranial abdomen
  4. A fat-opaque structure dorsal to the colon

Explanation

The fluid-filled bladder appears as a soft tissue opacity in the caudal ventral abdomen, often partly surrounded by falciform and pelvic fat. It is not mineral or gas opaque unless abnormal.

Question 6Radiology

What does the term 'silhouette sign' refer to in thoracic radiography?

  1. A ring of increased opacity around the heart
  2. Loss of a border between two structures of similar opacity that touch Correct answer.
  3. A double contour created by overlapping ribs
  4. Increased radiolucency of the lung periphery

Explanation

When two structures of similar radiographic opacity are in contact, their shared border disappears, producing the silhouette sign. This localizes lesions to specific anatomic regions.

Question 7Radiology

Which view is most appropriate for evaluating the canine hip joints for hip dysplasia?

  1. Lateral recumbency with the pelvis rotated
  2. Ventrodorsal extended pelvic view Correct answer.
  3. Dorsoventral thoracic view
  4. Standing lateral abdominal view

Explanation

The ventrodorsal extended pelvic view with the femurs parallel and patellae centered is standard for hip dysplasia screening. Proper positioning is essential for accurate assessment.

Question 8Radiology

On a radiograph, which tissue is normally the most radiolucent?

  1. Soft tissue
  2. Cortical bone
  3. Fat
  4. Gas Correct answer.

Explanation

Radiolucency increases as tissue density decreases; gas is the least dense and therefore most radiolucent structure. Bone is most radiopaque, with soft tissue and fat intermediate.

Question 9Radiology

A dog presents with acute vomiting, and survey abdominal radiographs show several focally dilated small intestinal loops with a 'stack of coins' appearance. What is the most likely diagnosis?

  1. Generalized ileus
  2. Mechanical small intestinal obstruction Correct answer.
  3. Peritoneal effusion
  4. Splenic torsion

Explanation

Focally dilated small bowel loops with a stacked appearance suggest mechanical obstruction. Generalized ileus usually produces diffuse, uniform dilation rather than focal loops.

Question 10Radiology

A lateral thoracic radiograph of a cat shows a small cardiac silhouette with increased lung radiolucency and flattening of the diaphragm. Which condition is most likely?

  1. Pneumothorax Correct answer.
  2. Pleural effusion
  3. Cardiomyopathy
  4. Pericardial effusion

Explanation

Pneumothorax creates increased pleural radiolucency, retracts the lung lobes, and can make the heart appear small while flattening the diaphragm. Pleural effusion would increase opacity instead.

Question 11Radiology

Which radiographic finding is most characteristic of hypertrophic osteopathy (Marie's disease) in a dog with a thoracic mass?

  1. Periosteal new bone formation along the diaphyses of distal limb bones Correct answer.
  2. Focal cortical destruction at the metaphyses
  3. Lytic lesions in the diaphyses of long bones
  4. Joint space widening with subchondral cysts

Explanation

Hypertrophic osteopathy produces palisading periosteal new bone along the diaphyses of the distal extremities, often secondary to an intrathoracic mass. It spares the metaphyses and joint spaces.

Question 12Radiology

A dog with a history of trauma has a lateral thoracic radiograph showing a focal area of increased opacity in the right middle lung lobe with air bronchograms. What does the air bronchogram indicate?

  1. Bronchial cartilage mineralization
  2. Alveolar filling with fluid or cells Correct answer.
  3. Pulmonary fibrosis
  4. Pleural thickening

Explanation

Air bronchograms occur when alveoli are filled with fluid or cells while the airways remain air-filled, outlining the bronchi. This is a sign of alveolar disease such as pneumonia or hemorrhage.

Question 13Radiology

Which structure forms the cranial margin of the cardiac silhouette on a lateral thoracic radiograph of a dog?

  1. The right atrium and right auricle Correct answer.
  2. The left atrium
  3. The left ventricle
  4. The main pulmonary artery

Explanation

The cranial cardiac contour in the dog is formed largely by the right atrium and auricle. The left ventricle contributes to the caudal margin.

Question 14Radiology

On an abdominal radiograph, a dog has a large soft tissue mass in the mid-abdomen causing medial displacement of the small intestine and lateral displacement of the colon. Which organ is most likely involved?

  1. Liver
  2. Stomach
  3. Urinary bladder
  4. Spleen Correct answer.

Explanation

A splenic mass typically displaces the small intestine medially and the colon laterally or caudally. Hepatic masses displace the stomach caudally and lie cranially.

Question 15Radiology

Which of the following is the primary advantage of computed tomography over survey radiography for evaluating the nasal cavity?

  1. Lower radiation dose to the patient
  2. Faster acquisition in unsedated patients
  3. Ability to assess joint spaces
  4. Superior contrast resolution and cross-sectional anatomy Correct answer.

Explanation

CT provides cross-sectional images with superior contrast resolution, allowing detailed evaluation of the nasal cavity and surrounding bone. Radiographs superimpose structures and have lower contrast resolution.

Question 16Radiology

A radiograph of a dog's elbow shows a small mineral opacity separated from the medial coronoid process. What is the most likely diagnosis?

  1. Fragmented medial coronoid process Correct answer.
  2. Ununited anconeal process
  3. Osteochondritis dissecans of the humeral head
  4. Panosteitis

Explanation

A mineral fragment near the medial coronoid process is consistent with fragmented medial coronoid process, a component of elbow dysplasia. Ununited anconeal process involves the anconeal process at the olecranon.

Question 17Radiology

A cat with a history of chronic renal disease has small, irregular kidneys with increased opacity on abdominal radiographs. What is the most likely explanation?

  1. Hydronephrosis
  2. Renal lymphoma
  3. Chronic interstitial nephritis with fibrosis Correct answer.
  4. Acute nephritis

Explanation

Chronic interstitial nephritis leads to fibrotic contraction and mineralization, producing small, irregular, opaque kidneys. Acute disease typically causes renomegaly without mineralization.

Question 18Radiology

On a thoracic radiograph, a dog has a widened caudal mediastinum with dorsal displacement of the trachea and a soft tissue opacity cranial to the diaphragm. Which structure is most likely enlarged?

  1. Right atrium
  2. Main pulmonary artery
  3. Cranial mediastinal lymph nodes
  4. Caudal mediastinal (tracheobronchial) lymph nodes Correct answer.

Explanation

Enlarged caudal mediastinal (tracheobronchial) lymph nodes create a soft tissue opacity in the caudal mediastinum and can displace the trachea dorsally. Cranial mediastinal nodes lie more cranially.

Question 19Radiology

Which radiographic projection is best for detecting a small volume of free abdominal gas in a dog?

  1. Dorsoventral view
  2. Ventrodorsal view
  3. Left lateral recumbency Correct answer.
  4. Right lateral recumbency

Explanation

Left lateral recumbency places the pylorus nondependent, allowing free gas to accumulate and be detected more readily. This positioning improves sensitivity for small pneumoperitoneum.

Question 20Radiology

A dog has a lytic lesion in the distal radius with a zone of transition that is wide and indistinct. Which feature most suggests an aggressive bone lesion?

  1. Sclerotic margin with periosteal thickening
  2. Well-defined geographic lucency
  3. Wide zone of transition with cortical destruction Correct answer.
  4. Sharp, narrow zone of transition

Explanation

A wide, indistinct zone of transition and cortical destruction indicate an aggressive process such as neoplasia or osteomyelitis. Benign lesions typically have narrow zones of transition and sclerotic margins.

Question 21Radiology

A dog presents with a cough, and thoracic radiographs show a soft tissue opacity in the left cranial lung lobe with a 'sail sign' appearance of the collapsed lobe. Which lobe is most likely affected?

  1. Left caudal lung lobe
  2. Right caudal lung lobe
  3. Left cranial lung lobe Correct answer.
  4. Right middle lung lobe

Explanation

Collapse of the left cranial lung lobe can produce a triangular soft tissue opacity resembling a sail near the heart base. Lobar collapse creates volume loss and increased opacity of the affected lobe.

Question 22Radiology

A dog with a perineal mass has a radiograph showing a soft tissue opacity in the caudal abdomen with medial displacement of the descending colon. Which structure is most likely enlarged?

  1. Spleen
  2. Urinary bladder
  3. Prostate
  4. Sublumbar lymph nodes Correct answer.

Explanation

Enlarged sublumbar (medial iliac) lymph nodes displace the descending colon ventrally or laterally and appear as a soft tissue opacity in the caudal dorsal abdomen. Prostatic enlargement is more caudal and central.

Question 23Radiology

A cat with a heart murmur has a lateral thoracic radiograph showing a 'valentine heart' shape and a bulge at the heart base. Which condition is most likely?

  1. Dilated cardiomyopathy
  2. Pericardial effusion
  3. Aortic thromboembolism
  4. Hypertrophic cardiomyopathy Correct answer.

Explanation

A valentine-shaped cardiac silhouette in a cat often reflects biatrial and bi-ventricular enlargement typical of hypertrophic cardiomyopathy. Pericardial effusion produces a globoid silhouette rather than a valentine shape.

Question 24Radiology

A dog has a mineral opacity within the urinary bladder on a lateral radiograph. Which additional finding would most suggest a struvite urolith rather than a calcium oxalate urolith?

  1. Radiolucent stones
  2. A single large stone with a smooth surface
  3. Multiple small stones with irregular surfaces
  4. Stones associated with a urinary tract infection Correct answer.

Explanation

Struvite uroliths are commonly associated with urease-producing urinary tract infections, which alkalinize urine and promote stone formation. Calcium oxalate stones are typically radiopaque and not infection-associated.

Question 25Radiology

On a thoracic radiograph, a dog has a large soft tissue opacity in the cranial mediastinum causing dorsal displacement of the trachea. Which of the following is the most likely differential?

  1. Thymoma Correct answer.
  2. Pulmonary edema
  3. Diaphragmatic hernia
  4. Pleural effusion

Explanation

A cranial mediastinal mass such as a thymoma produces a soft tissue opacity that can displace the trachea dorsally. Pulmonary edema causes diffuse increased lung opacity, not a focal mediastinal mass.

Question 26Radiology

Which radiographic opacity describes gas within the stomach or lungs?

  1. Metal opacity
  2. Mineral opacity Correct answer.
  3. Fat opacity
  4. Soft tissue opacity

Explanation

The five radiographic opacities in increasing order are gas, fat, soft tissue/fluid, mineral, and metal. Gas is the most radiolucent and appears black. It is not mineral, fat, or metal in character.

Question 27Radiology

Which radiographic sign indicates a true lateral thoracic projection in a dog?

  1. Superimposition of the left and right hemidiaphragm
  2. Complete superimposition of the ribs
  3. Superimposition of the left and right ventricles Correct answer.
  4. Superimposition of the thoracic vertebrae

Explanation

On a well-positioned lateral view, the left and right ventricles and the left and right hemidiaphragm should superimpose. Ribs are never completely superimposed because they course caudoventrally. This symmetry confirms no rotation.

Question 28Radiology

What is the normal appearance of the feline small intestine on a survey abdominal radiograph?

  1. Homogeneous soft tissue opacity with no visible loops
  2. Beaded, segmented appearance Correct answer.
  3. Plicated appearance with visible circular folds
  4. Uniformly gas-filled loops

Explanation

The normal feline small intestine has a characteristic beaded or segmented appearance due to its muscular tone. Dogs typically show homogeneous soft tissue opacity without this pattern. Loss of this appearance can indicate disease.

Question 29Radiology

Which structure forms the cranial border of the cardiac silhouette on a lateral thoracic radiograph of a dog?

  1. Aortic arch Correct answer.
  2. Right atrium
  3. Left atrium
  4. Main pulmonary artery

Explanation

The cranial border of the cardiac silhouette is formed by the ascending aorta and aortic arch. The right atrium forms the cranial-ventral bulge, and the left atrium forms the caudal border. The main pulmonary artery is located more centrally.

Question 30Radiology

Which radiographic view best demonstrates the trachea and mainstem bronchi in a dog?

  1. Left lateral thoracic view
  2. Dorsoventral thoracic view
  3. Right lateral thoracic view
  4. Ventrodorsal thoracic view Correct answer.

Explanation

The ventrodorsal view allows the trachea and mainstem bronchi to be seen without the cardiac silhouette obscuring them as on lateral views. The dorsoventral view also shows the bronchi but with more magnification of the heart.

Question 31Radiology

What does a positive contrast study using barium sulfate primarily demonstrate?

  1. Luminal outline of the gastrointestinal tract Correct answer.
  2. Gas within the gastrointestinal tract
  3. Bone mineralization
  4. Soft tissue masses in the abdomen

Explanation

Positive contrast agents such as barium outline the lumen of the gastrointestinal tract, revealing mucosal irregularities, strictures, and obstructions. It does not primarily demonstrate gas, soft tissue, or bone.

Question 32Radiology

Which finding on a thoracic radiograph suggests left-sided congestive heart failure?

  1. Enlarged left atrium and pulmonary edema Correct answer.
  2. Pleural effusion and pneumothorax
  3. Enlarged right atrium and ascites
  4. Widened caudal vena cava and hepatomegaly

Explanation

Left-sided heart failure causes left atrial enlargement and pulmonary edema, often with a perihilar distribution. Right-sided failure typically causes pleural effusion, ascites, and caudal vena cava enlargement.

Question 33Radiology

Which radiographic feature is most consistent with a benign bone lesion?

  1. Wide zone of transition with cortical destruction
  2. Moth-eaten lysis with indistinct margins
  3. Narrow zone of transition with smooth margins Correct answer.
  4. Extensive periosteal reaction with soft tissue mass

Explanation

A narrow zone of transition and smooth margins indicate a slow-growing, non-aggressive process typical of benign lesions. Wide zones of transition, cortical destruction, and aggressive periosteal reactions suggest malignancy.

Question 34Radiology

A dog with a suspected diaphragmatic hernia is examined radiographically. Which view is most helpful for confirming the presence of abdominal organs in the thorax?

  1. Dorsoventral thoracic view
  2. Both lateral and ventrodorsal thoracic views Correct answer.
  3. Lateral thoracic view
  4. Ventrodorsal thoracic view

Explanation

Diaphragmatic hernias are best confirmed when both lateral and ventrodorsal views are evaluated together because the displaced organs may only be visible on one projection. The combination provides a three-dimensional assessment of the defect.

Question 35Radiology

A dog presents with a swollen, painful limb, and a radiograph shows a soft tissue swelling with no bone abnormality. Which additional imaging modality best evaluates for early osteomyelitis?

  1. Radiography with a repeat in 10 days
  2. Computed tomography without contrast
  3. Nuclear scintigraphy
  4. Magnetic resonance imaging Correct answer.

Explanation

MRI is sensitive for early osteomyelitis, detecting marrow edema before radiographs show bone changes. Radiographs may be normal for up to 10 to 14 days. Scintigraphy is sensitive but nonspecific, and CT without contrast is less sensitive for marrow changes.

Question 36Radiology

A cat with a history of trauma has a lateral thoracic radiograph showing a focal area of increased opacity in the right caudal lung lobe. Which additional finding would most suggest pulmonary contusion?

  1. Pneumothorax with a widened mediastinum
  2. Flattened diaphragm with increased radiolucency
  3. Rib fractures adjacent to the opacity Correct answer.
  4. Air bronchograms within the opacity

Explanation

Pulmonary contusion is a common cause of focal pulmonary opacity after trauma, and adjacent rib fractures support this diagnosis. Air bronchograms are nonspecific and can be seen with many alveolar processes. Pneumothorax and a flattened diaphragm suggest other injury patterns.

Question 37Radiology

A dog has a mineral opacity in the region of the kidneys on a lateral radiograph. Which additional feature would most suggest nephrolithiasis rather than a renal mass?

  1. A gas-filled structure within the kidney
  2. The opacity is located within the renal pelvis Correct answer.
  3. A soft tissue mass displacing the kidney
  4. A large kidney with irregular margins

Explanation

Nephroliths are mineral opacities located within the renal pelvis and collecting system. Renal masses are soft tissue opacities that distort the renal outline. The location within the renal pelvis distinguishes a stone from a mass.

Question 38Radiology

A dog with a history of chronic otitis externa has a radiograph showing narrowing of the external ear canal and sclerosis of the bulla. Which diagnosis is most likely?

  1. Aural hematoma
  2. Nasopharyngeal polyp
  3. Ear canal neoplasia
  4. Otitis media with bulla involvement Correct answer.

Explanation

Sclerosis and narrowing of the external ear canal with bulla involvement are typical of chronic otitis media. Aural hematoma affects the pinna, and nasopharyngeal polyps are soft tissue masses in the pharynx. Neoplasia typically produces a soft tissue mass rather than sclerosis.

Question 39Radiology

Which radiographic finding most suggests a retained surgical sponge (gossypiboma) in a dog?

  1. A homogeneous soft tissue opacity with no distinct margins
  2. A well-defined mineral opacity in the abdomen
  3. A gas-filled structure with air-fluid levels
  4. A radiolucent serpiginous structure with a thin mineral rim Correct answer.

Explanation

Gossypibomas often appear as a radiolucent sponge-like structure with a thin mineral or soft tissue rim, and may contain gas. The radiolucent serpiginous appearance is characteristic. Mineral opacity alone or homogeneous soft tissue opacity is less specific.

Question 40Radiology

A dog with a history of vomiting has a radiograph showing a gas-filled stomach with an air-fluid level. Which additional finding would most suggest gastric outlet obstruction?

  1. A large volume of gas in the small intestine
  2. A gas-filled colon with a normal diameter
  3. A distended stomach with a small amount of gas in the duodenum Correct answer.
  4. A small stomach with no gas

Explanation

Gastric outlet obstruction causes gastric distension with little gas passing into the duodenum. A distended stomach with minimal duodenal gas supports this diagnosis. Increased small intestinal gas suggests ileus rather than obstruction.

Question 41Radiology

Which radiographic view is most useful for evaluating the lumbosacral junction in a dog with cauda equina syndrome?

  1. Lateral lumbosacral view Correct answer.
  2. Ventrodorsal pelvic view
  3. Craniocaudal stifle view
  4. Dorsoventral pelvic view

Explanation

The lateral lumbosacral view best demonstrates the lumbosacral junction and is useful for assessing cauda equina syndrome. The ventrodorsal and dorsoventral pelvic views are less helpful for this junction. A stifle view is unrelated.

Question 42Radiology

A cat with a history of dyspnea has a radiograph showing a large volume of pleural fluid. Which additional finding would most suggest a chylothorax?

  1. A large heart with a valentine shape
  2. A gas-filled esophagus with a widened mediastinum
  3. A small heart with a widened caudal vena cava
  4. A soft tissue opacity in the cranial mediastinum Correct answer.

Explanation

Chylothorax in cats is often associated with cranial mediastinal masses, which appear as soft tissue opacities. A valentine-shaped heart suggests a different condition. A small heart with a wide vena cava suggests right heart failure.

Question 43Radiology

A dog with a history of trauma has a radiograph showing a fracture of the femoral diaphysis. Which feature best distinguishes a pathologic fracture from a traumatic fracture?

  1. A transverse fracture line with sharp margins
  2. A fracture with adjacent soft tissue swelling
  3. A comminuted fracture with multiple fragments
  4. An underlying lytic bone lesion at the fracture site Correct answer.

Explanation

Pathologic fractures occur through bone weakened by an underlying lesion, so a lytic lesion at the fracture site suggests this diagnosis. Transverse fractures with sharp margins and comminution are typical of trauma. Soft tissue swelling is nonspecific.

Question 44Radiology

Which radiographic finding is most consistent with a retained testicle (cryptorchidism) in a dog?

  1. A gas-filled structure in the abdomen
  2. A soft tissue opacity in the perineum
  3. A soft tissue opacity in the inguinal region Correct answer.
  4. A mineral opacity in the scrotum

Explanation

A retained testicle appears as a soft tissue opacity along the path of descent, often in the inguinal region or abdomen. Mineral opacity in the scrotum would suggest a normal scrotal testicle. Gas-filled structures and perineal opacities are unrelated.

Question 45Radiology

A dog with a history of weight loss has a radiograph showing a large soft tissue mass in the mid-abdomen causing medial displacement of the small intestine. Which additional finding would most suggest a mesenteric mass rather than an intestinal mass?

  1. The mass contains gas and an air-fluid level
  2. The mass causes a mechanical obstruction pattern
  3. The mass is inseparable from the intestine
  4. The mass displaces the intestine but is separate from it Correct answer.

Explanation

A mesenteric mass displaces the intestine but is separable from it, whereas an intestinal mass is inseparable from the bowel. Gas with an air-fluid level suggests an intraluminal lesion. Mechanical obstruction suggests an intraluminal or mural lesion.

Question 46Radiology

A dog with a history of chronic renal disease has small, irregular kidneys with increased opacity on abdominal radiographs. Which additional finding would most suggest renal osteodystrophy?

  1. Soft tissue mineralization in the liver
  2. Periosteal reaction along the diaphyses
  3. Focal lytic lesions in the long bones
  4. Generalized osteopenia with a rubber jaw Correct answer.

Explanation

Renal osteodystrophy causes generalized osteopenia and a rubber jaw due to secondary hyperparathyroidism. Focal lytic lesions suggest neoplasia. Periosteal reactions suggest hypertrophic osteopathy, and hepatic mineralization is unrelated.

Question 47Radiology

Which radiographic feature most strongly suggests an aggressive bone lesion in a dog?

  1. A narrow zone of transition with smooth margins
  2. A well-defined mineral opacity within the medullary cavity
  3. A uniform periosteal reaction along the diaphysis
  4. A wide zone of transition with cortical destruction Correct answer.

Explanation

A wide zone of transition with cortical destruction indicates an aggressive, rapidly growing lesion. Narrow zones of transition and smooth margins suggest benign processes. A well-defined medullary opacity may represent an infarct or benign lesion.

Question 48Radiology

A cat with a heart murmur has a lateral thoracic radiograph showing a valentine heart shape and a bulge at the heart base. Which diagnosis is most likely?

  1. Pericardial effusion
  2. Dilated cardiomyopathy
  3. Hypertrophic cardiomyopathy Correct answer.
  4. Tricuspid valve dysplasia

Explanation

A valentine-shaped heart with a bulge at the heart base in a cat suggests hypertrophic cardiomyopathy with left atrial enlargement. Pericardial effusion produces a globoid heart. Dilated cardiomyopathy causes generalized cardiomegaly. Tricuspid dysplasia causes right-sided enlargement.

Question 49Radiology

A dog with a history of a perineal mass has a radiograph showing a soft tissue opacity in the caudal abdomen with medial displacement of the colon. Which additional finding would most suggest a perineal hernia?

  1. A gas-filled structure within the perineal region Correct answer.
  2. A soft tissue opacity in the perineal region with a normal colon
  3. A mineral opacity in the perineal region
  4. A widened caudal vena cava

Explanation

A perineal hernia often contains gas-filled intestine or bladder within the perineal region. Mineral opacity suggests a urolith or other mineralization. A normal colon does not support displacement, and a widened vena cava suggests right heart failure.

Question 50Radiology

A dog with a lytic lesion in the distal radius has a wide, indistinct zone of transition. Which feature most strongly suggests malignancy rather than infection?

  1. A narrow zone of transition
  2. Cortical destruction with a soft tissue mass Correct answer.
  3. Sclerosis surrounding the lesion
  4. Presence of a periosteal reaction

Explanation

Cortical destruction with an associated soft tissue mass strongly suggests malignancy. Periosteal reactions and sclerosis can occur with both infection and neoplasia. A narrow zone of transition suggests a benign process.