VRU 2010

Question 1

Magic angle effect is seen on what types of sequences/which sequences?

Answer 1

Short TE sequences such as T1, STIR, PD, T2*

Question 2

Magic angle effect is seen most commonly in what 2 structures of the equine foot?

Answer 2

DDFT & in the collateral ligaments of the DIP joint at level of P2

Question 3

Describe the magic angle effect

Answer 3

Asymmetric signal pattern within ligaments/tendons in LOW & HIGH field MRI when these structures are oriented at 55±10°, or any interval of this to the main magnetic field. Seen in neutral or angle limb positions as well as when the limb is parallel to the central magnetic axis

Question 4

True or false, ultrasound has good specificity for diagnosis of proximal suspensory desmopathy in horses?

Answer 4

FALSE. POOR specificity only 66%.

Question 5

Describe the ultrasound sensitivity & specificity for diagnosis of proximal suspensory desmopathy & accuracy of lesion localization.

Answer 5

POOR Specificity for both diagnosis & accuracy compared to MRI.

Fair sensitivity of U/S for diagnosis of proximal suspensory disease (77%, but less than MRI 84%)

Question 6

Is anesthesia of the deep branch of the lateral plantar nerve specific for proximal suspensory desmopathy?

Answer 6

NO

Question 7

Describe the changes seen on MRI following refrigeration of equine limbs

Answer 7

Bone marrow becomes slightly STIR hyperintense & T2 hypointense after 24 hrs of refrigeration. Associated with changes in SNR; this effect is reversible on T2W images with warming.
- NO change in DDFT SNR

Question 8

What 3 CT findings are seen in captive lions affected by HYPOvitaminosis A?

Answer 8

Calvarial hyperostosis syndrome characterized by foramen magnum NARROWing, thickening of the osseous tentorium cerebelli, & thickening of dorsal arch of atlas

Question 9

Describe the appearance of the petrous temporal bone MRI pseudolesion

Answer 9

Focal symmetric or asymmetric hyperintensities in the region of the hippocampus or ventral to it on T1, T2, and FLAIR images.

STIR images will cause PARTIAL suppression of this artifact.

Use fat suppression techniques to differentiate between artifact & pathology

Question 10

The transit time of Gastrografin through the GIT of Red-eared sliders is __________ compared to barium sulfate EXCEPT in the _________.

Answer 10

Gastrografin FASTER transit & emptying time (by at least 9 hrs) EXCEPT in gastric transit

Question 11

What is a con of using Gastrografin to visualize the GIT in Red-eared sliders?

Answer 11

Gastrografin DILUTES as it passes through GIT causing progressive intestinal distension & decreased opacity in distal SmI and colon [barium maintains its opacity]

Question 12

With regards to radiography of tympanic bullae in rabbits, which view has the highest observer confidence & which has highest Sensitivity/specificity?
A) Rostro 40° ventral-caudodorsal
B) Dorsoventral
C) left & right latero 40° vntral-laterodorsal
D) No significant difference between any view

Answer 12

Highest confidence = B (dorsoventral view)

Highest sensitivity/specificity = D (no difference between views)

Question 13

Embryogenesis of the CVC involves the anastamosis & regression of which 3 paired venous structures?

Answer 13

1) Posterior cardinal vein
2) Subcardinal vein
3) Supracardinal vein

Question 14

The CVC is normally on the ________side of the aorta

Answer 14

Normally, the CVC is to the RIGHT of the aorta

If to the left it’s transposition of the CVC

Question 15

What is the most common survey radiographic finding in dogs/cats with intestinal diverticular malformation?

A) Generalized lack of abdominal detail
B) Corrugated gas-distended intestinal loops & paralytic ileus
C) Abdominal mass effect
D) Small intestinal mechanical obstruction pattern

Answer 15

Answer = D

All the others may also be seen/have been reported in some cases

Question 16

See online notes for portal circulation varices paper

Question 17

Which of the following sonographic changes is NOT indicative of parvoviral enteritis?

A) Duodenal/jejunal mucosal layer thinning
B) Duodenaljejunal hyperechoic mucosal speckling
C) Enlarged jejunal lymph nodes
D) Fluid-filled, atonic small & large intestine

Answer 17

Answer = C

Jejunal lymph nodes are NORMAL sized

8 changes seen with parvo enteritis =
1) Fluid filled GIT
2) Atony and/or functional ileus
3) REDUCED duodenal/jejunal mucosal thickness
4) Hyperechoic mucosal speckles of duodenum & jejunum
5) Irregular luminal mucosal surface of jejunum > duodenum
6) Indistinct wall layering
7) Corrugation of duodenum > jejunum
8) Peritoneal effusion

Question 18

True or False, in normal puppies the duodenal wall thickness is equal to or greater than the other parts of the GIT?

Answer 18

FALSE - duodenal wall is just greater (up to 3.8mmD) vs stomach & jejunum 2-3mm & colon ~1-1.5mm

Question 19

T or F, in U/S of a normal puppy you will find a small volume of peritoneal effusion?

Answer 19

TRUE

Question 20

Which of the following best describes the appearance of malignant hepatic nodules on CEUS using Sonazoid?

A) Hypoechoic to normal parenchyma on parenchymal phase
B) Hypo or hyperechoic to normal parenchyma on parenchymal phase
C) Isoechoic to normal liver on arterial phase
D) No characteristic findings on arterial phase

Answer 20

Answer = A

• Malignant nodules HYPOECHOIC to normal liver in PARENCHYMAL phase – Accuracy 96%, Sn 94%, Sp 100%, PPV 100%, NPV 86%
• benign lesions were isoechoic to the surrounding normal liver during the parenchymal phase​

Question 21

True or False:, on CEUS of the liver using Sonazoid malignant tumors had different echogenicity than normal liver during arterial phase?

Answer 21

TRUE - malignant tumors were either hyperechoic (e.g. hepatocellular carcinoma) or hypoechoic (e.g. hemangiosarcoma). Accuracy 91%, Sn 93%, Sp 83%, PPV 93%, NPV 83%

Question 22

Describe the characteristic findings of malignant hepatic nodules on CEUS using Sonazoid?

Answer 22

NO characteristic findings during portal phase

Question 23

Which age of cats large LARGER pancreatic ducts?

Answer 23

OLDER cats = larger ducts

Question 24

What drug administered IV will increase pancreatic duct diameter?

Answer 24

Secretin (stimulates bicarbonate secretion from exocrine pancreas)

Question 25

What are 2 common locations for canine meningioangiomatosis?

Answer 25

Intramedullary spinal cord (usually thoracolumbar in humans) & brainstem

Question 26

Describe the sensitivity and specificity for detecting full thickness cartilage erosions of the equine metacarpophalangeal joint using fat-suppressed gradient-recalled echo imaging?

Answer 26

HIGH specificity 92%, moderate sensitivity 56%
Accurate thickness measurements

Question 27

When diagnosing PSS with MRI, what are the advantages and disadvantages of using contrast-enhancing MR angiography versus time of flight MR angiography?

Answer 27

= CE-MRA requires LESS time (< 10 min) vs TOF-MRA
= CE -MRA is NON-SELECTIVE vs TOF-MRA which can be used for selective abdominal venograms & to detect caudocranial (presumed venous) and craniocaudal (presumed arterial) flow
= Both can used for intra AND extrahepatic PSS

Question 28

Earliest CT changes of heartworm disease are seen in which lung lobe?

A) Right caudal
B) Left caudal
C) Right middle
D) Accessory

Answer 28

Answer = A

Right caudal lobe is a common predilection site for HW larvae deposition due to high volume blood flow in this area

Question 29

What are the initial CT changes identified during the prepatent period of HW infection?

A) Caudal pulmonary arterial filling defects
B) Right ventricular and MPA enlargement
C) Peripheral caudal lobar pulmonary arterial enlargement & periarterial interstitial infiltrates
D) Diffuse arterial enlargement and a nodular interstitial to alveolar pattern

Answer 29

Answer = C

Progressive arterial changes occurred over time but remained mild

Question 30

T or F, with experimental infection of a small burden of HW disease echocardiographic changes were seen as early as 125 days after infection?

Answer 30

FALSE, echocardiography was NORMAL at all time points

Question 31

Which of the following affects proventriculus:keel ratio measurement?

A) Anesthesia
B) Rotation/obliquity
C) Feeding versus fasting
D) Repeat imaging within a short time frame (e.g. < 8 hrs)

Answer 31

Answer = B

Use well-positioned lateral anesthetized films for evaluation.

Ratios differed when quantified 3 wks apart - Fluctuations in the proventriculus:keel ratio within the normal range appear to be normal and are NOT indicative of proventricular disease

Question 32

FBs on MRI are what intensity?

Answer 32

Commonly HYPOintense

Question 33

Which of the following is NOT seen with the inherited lysosomal storage disease ceroid lipofuscinosis?

A) Cerebral infarcts
B) Bilaterally symmetric periventricular T2 hyperintensities
C) Cerebral atrophy
D) Ventriculomegaly

Answer 33

Answer = A

Can see cerebral atrophy, dilated sulci, ventriculomegaly, bilaterally symmetric periventricular white matter T2 hyperintensities​

Case report of subdural hematoma formation & meningeal enhancement hypothesized to be due to rapid brain atrophy contributing to the subdural hematoma formation & secondary meningitis

Question 34

Describe the characteristic radiographic appearance of a mature bone infarct.

Answer 34

Central radiolucent area with serpentine calcified margins & regional medullary sclerosis

Question 35

A double line sign on T2W spin echo MRI sequences is nearly conclusive for what disease process?

Answer 35

Bone infarction

Double line/rim sign seen in all sequences.

On T2W images, the hypointense outer rim corresponds to sclerotic bone & inner hyperintense rim is vascularized granulation tissue or chondroid metaplasia.

Mature infarcts are T1 and T2 HYPOintense due to medullary fibrosis & calcification

Question 36

How does a Type 1 Chiari malformation differ from a Type 2 Chiari malformation, which is also called an Arnold-Chiari malformation?

Answer 36

Type 2 Chiari malformation is caudal occipital malformation in conjunction with a meningomyelocele versus Type 1 is just caudal occipital malformation

Question 37

What is the most common canine CNS tumor?

Answer 37

Meningioma

Question 38

Acute hemorrhage on MRI has what signal characteristics?

Answer 38

T1 and T2 HYPOintense