VRU 2010 Flashcards
Magic angle effect is seen on what types of sequences/which sequences?
Short TE sequences such as T1, STIR, PD, T2*
Magic angle effect is seen most commonly in what 2 structures of the equine foot?
DDFT & in the collateral ligaments of the DIP joint at level of P2
Describe the magic angle effect
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
True or false, ultrasound has good specificity for diagnosis of proximal suspensory desmopathy in horses?
FALSE. POOR specificity only 66%.
Describe the ultrasound sensitivity & specificity for diagnosis of proximal suspensory desmopathy & accuracy of lesion localization.
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%)
Is anesthesia of the deep branch of the lateral plantar nerve specific for proximal suspensory desmopathy?
NO
Describe the changes seen on MRI following refrigeration of equine limbs
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
What 3 CT findings are seen in captive lions affected by HYPOvitaminosis A?
Calvarial hyperostosis syndrome characterized by foramen magnum NARROWing, thickening of the osseous tentorium cerebelli, & thickening of dorsal arch of atlas
Describe the appearance of the petrous temporal bone MRI pseudolesion
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
The transit time of Gastrografin through the GIT of Red-eared sliders is __________ compared to barium sulfate EXCEPT in the _________.
Gastrografin FASTER transit & emptying time (by at least 9 hrs) EXCEPT in gastric transit
What is a con of using Gastrografin to visualize the GIT in Red-eared sliders?
Gastrografin DILUTES as it passes through GIT causing progressive intestinal distension & decreased opacity in distal SmI and colon [barium maintains its opacity]
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
Highest confidence = B (dorsoventral view)
Highest sensitivity/specificity = D (no difference between views)
Embryogenesis of the CVC involves the anastamosis & regression of which 3 paired venous structures?
1) Posterior cardinal vein
2) Subcardinal vein
3) Supracardinal vein
The CVC is normally on the ________side of the aorta
Normally, the CVC is to the RIGHT of the aorta
If to the left it’s transposition of the CVC
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 = D
All the others may also be seen/have been reported in some cases
See online notes for portal circulation varices paper
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 = 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
True or False, in normal puppies the duodenal wall thickness is equal to or greater than the other parts of the GIT?
FALSE - duodenal wall is just greater (up to 3.8mmD) vs stomach & jejunum 2-3mm & colon ~1-1.5mm
T or F, in U/S of a normal puppy you will find a small volume of peritoneal effusion?
TRUE
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 = 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
True or False:, on CEUS of the liver using Sonazoid malignant tumors had different echogenicity than normal liver during arterial phase?
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%
Describe the characteristic findings of malignant hepatic nodules on CEUS using Sonazoid?
NO characteristic findings during portal phase
Which age of cats large LARGER pancreatic ducts?
OLDER cats = larger ducts
What drug administered IV will increase pancreatic duct diameter?
Secretin (stimulates bicarbonate secretion from exocrine pancreas)
What are 2 common locations for canine meningioangiomatosis?
Intramedullary spinal cord (usually thoracolumbar in humans) & brainstem
Describe the sensitivity and specificity for detecting full thickness cartilage erosions of the equine metacarpophalangeal joint using fat-suppressed gradient-recalled echo imaging?
HIGH specificity 92%, moderate sensitivity 56%
Accurate thickness measurements
When diagnosing PSS with MRI, what are the advantages and disadvantages of using contrast-enhancing MR angiography versus time of flight MR angiography?
= 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
Earliest CT changes of heartworm disease are seen in which lung lobe?
A) Right caudal
B) Left caudal
C) Right middle
D) Accessory
Answer = A
Right caudal lobe is a common predilection site for HW larvae deposition due to high volume blood flow in this area
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 = C
Progressive arterial changes occurred over time but remained mild
T or F, with experimental infection of a small burden of HW disease echocardiographic changes were seen as early as 125 days after infection?
FALSE, echocardiography was NORMAL at all time points
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 = 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
FBs on MRI are what intensity?
Commonly HYPOintense
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 = 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
Describe the characteristic radiographic appearance of a mature bone infarct.
Central radiolucent area with serpentine calcified margins & regional medullary sclerosis
A double line sign on T2W spin echo MRI sequences is nearly conclusive for what disease process?
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
How does a Type 1 Chiari malformation differ from a Type 2 Chiari malformation, which is also called an Arnold-Chiari malformation?
Type 2 Chiari malformation is caudal occipital malformation in conjunction with a meningomyelocele versus Type 1 is just caudal occipital malformation
What is the most common canine CNS tumor?
Meningioma
Acute hemorrhage on MRI has what signal characteristics?
T1 and T2 HYPOintense
