VRU 2005 Flashcards
Describe the DWI/ADC characteristics on MRI of acute infarction?
DWI hyperintense, ADC hypointense
What 2 dog breeds may be more predisposed to cerebellar cerebrovascular accidents?
Spaniels & CKCS
Are males or females MORE LIKELY to get cerebellar cerebrovascular accidents?
Males
Most cerebellar cerebrovascular accidents affect what vessel?
Rostral cerebellar artery
Describe the MRI appearance of a cerebrovascular accident
T2 hyperintense, T1 iso/hypointense, often WEDGE-SHAPED, predominantly affect GRAY matter of cerebellar hemispheres & vermis, minimal or no mass effect
What is the origin & insertion of the collateral DIP ligaments in a horse?
Collateral ligaments of the DIP originate at P2 and insert on P3 abaxial to the extensor process
Injury to the collateral ligaments of the DIP joint in a horse are best seen on which MRI sequences?
T2 & STIR transverse images
What is the only form of canine meningoencephalomyelitis that is often associated with normal CSF
Inflammatory distemper
MRI lesions seen in dogs with inflammatory CSF that have a 100%PPV are in what location?
Commonly MULTIFOCAL or DIFFUSE lesions that affect ALL AREAS of the brain
Multifocal or diffuse intracranial lesions that were T2 HYPERintense = moderate sensitivity (68%) and 100% PPV for inflammatory CSF
What % of MRIs in dogs with inflammatory CSF are normal?
24% interpreted as normal
What lesion on MRI has a low-to-intermediate T1 signal intensity, T2 high signal intensity with contrast-enhancing rim & hypointense center; with regional tissues that have similar T1/T2 signal intensity with a reticular/lacey pattern, +/- muscle enlargement?
Abscess (e.g. paraspinal)
A FB will be what signal intensity on MRI
HYPOintense on ALL sequences
On T2W images, they can be surrounded by a ring of increased intensity, contrast enhancement of surrounding abscess or granulation tissue
In dogs with reduced PV flow, what happens to hepatic arterial flow?
Hepatic arterial perfusion INCREASES
Which CT study provided the best vascular anatomical detail?
A) Dual phase (arterial & portal phases)
B) Single phase (venous phase) with timed dynamic CT angiography
C) 2 minute-delayed single phase timed dynamic CT angiography
D) None of the above
A
During dynamic CT of the feline pituitary gland, which portion enhances first?
Neurohypophysis ENHANCES FIRST (direct arterial supply)
Describe the enhancement patterns (2) of the feline pituitary gland.
initial dorsal & peripheral enhancement (4); initial central enhancement (4)
Homogeneous enhancement in ALL
T or F, there is minimal variation in acetabular angles with small differences in pelvic tilt and slice selection?
FALSE, significant variation!
- Maneuvers that result in a more horizontally positioned pelvis (e.g., hind limbs extended) should be avoided
Standardizing CT gantry angle to floor of sacral vertebral canal may be a reasonable landmark
The size and location of what nasal/paranasal aperture is age-dependent in horses?
Frontomaxillary aperture - connects frontal and caudal maxillary sinuses
- opens more caudally in older horses (110/210 vs 107/207
-also the largest aperture
Which equine nasal/paranasal sinus connects the ventral conchal sinus & rostral maxillary sinus?
Conchomaxillary opening
An intramural radiolucent & hypoattenuating band in the stomach of cats on radiographs & CT corresponds to what?
Normal fat within gastric submucosa
Seen in 35% of rads & 27% of CTs
In normal beagles, eyes with lens, vitreous body, hyaloid artery, and scleroretinal rim could be clearly identified from what day of pregnancy/gestation?
Day 37
FCE more common in what size dogs?
Medium & large breed > small
A large breed, non-chondrodystrophic dogs is presented with acute, non-painful asymmetric paresis of the left pelvic limbs. Describe what MRI findings you may see with the most likely ddx
Most likely DDx = FCE
Focal intramedullary T2 hyperintense lesion, +/- focal intramedullary cord enlargement in acute phase, usually NO or mild contrast enhancement
What is different about the anatomy of dog & cat duodenal papilla?
In dogs, accessory pancreatic duct terminates in minor papilla. In 92% of dogs, the common bile duct and a tiny pancreatic duct terminate together in the major papilla. (In dogs, the accessory PD is the main secretory duct)
In cats, the CBD and pancreatic duct terminate together in the major papilla
A young dog presents with metaphyseal bone irregularities of distal radius & ulna - what breed of dog is this? And describe the changes associated with this condition?
Newfoundland, usually MALES & ASYMPTOMATIC
METAPHYSEAL bone irregularities of distal radius & ulna characterized by islands of reduced opacity outlined by thickened, radiopaque osseous trabeculae, which were aligned with the axis of stress; sporadic evidence of flattening of the distal metaphysis of the ulna by 4 months, metaphyseal flaring; no periosteal rxn
What is the mean VHS?
A) < 12 +- 0.2
B) <10.2 +- 0.5
C) 9.7 +- 0.5
D) 9.2 +- 0.2
Answer = C
Mean VHS = 9.7±0.5
VHS was ≤10.5 suggested as a clinically useful upper limit for normal heart size in most breeds.
What is the ONLY tumor that occurs predominantly in the UB of young/new born dogs? Describe its appearance
Rhabdomyosarcoma; botryoid
T or F, in the diagnosis of intra-thoracic lesions, especially neoplasia, FNA samples are nondiagnostic less often than biopsy samples?
FALSE, FNA non-diagnostic MORE OFTEN
In radiography of the feline tympanic bullae, what projection is SUBJECTIVELY more accurate and easier to perform than a rostrocaudal open mouth view?
rostro 10° ventro-caudodorsal oblique (R10°V-CdDO)
What are the 2 most constant radiographic signs of elbow incongruence in dogs?
Widening of the humero-ulnar joint space & step defect between radial head & ulnar LATERAL coronoid process
Radiography is a sensitive and specific test to detect what if the elbow is flexed at a 90° angle regardless of the radiographic beam position?
MODERATE to SEVERE radio-ulnar incongruence (2mm and over)
Best specificity & 100% sensitivity for each evaluator obtained with 90° elbow flexion & with 3mm of incongruence
Ischemic myelopathy in dogs affects which areas (gray or white matter) of the spinal cord?
GRAY matter > white matter
-higher metabolic demand in gray matter
In cat echocardiography, an increase E:A ratio at the mitral valve indicates what?
Restrictive mitral flow
What is the most common location for a distal sesamoid fracture in horses?
A) medial parasagittal, HL > FL
B) lateral parasagittal, HL > FL
C) medial parasagittal, FL > HL
D) lateral parasagittal, FL > HL
Answer = D
Lateral parasagittal, FL > HL
T or F, there is a significant linear correlation between pancreatic duct diameter and age in cats?
True
Describe the MRI appearance of bone marrow edema on T1 and T2 fat saturated images?
T1 hypointense, T2 fat sat hyperintense
Describe the comparison between FLAIR and T2 weighted MRI images in dogs/cats with suspected brain disease
Very similar, FLAIR only identified lesions not seen in T2W images in 5% of cases
Endoscopic retrograde cholangio-pancreatography CANNOT be performed in what size dogs?
Dogs < 10kg
What are the 3 CT features of diffuse alveolar injury?
1) Patchy or diffuse ground glass opacification = hazy increase in lung attenuation, with preservation of bronchial and vascular margins
2) Consolidation = homogeneous increase in lung attenuation, but bronchovascular margins are obscured. Air bronchograms may be present
3) Diffuse reticular pattern = innumerable, interlacing lines that may be fine, intermediate, or coarse
Ground glass opacification in ALI/ARDS is thought to reflect an active inflammatory process involving both the lung interstitium or alveolar wall and incomplete filling of the air space with inflammatory cells, cellular debris and edema.
Consolidation occurs when the lung is completely or near completely airless, because of filling of air spaces or atelectasis or a combination of both.
Reticular pattern may be acute because of edema or interstitial inflammation or chronic because of fibrosis
T or F, a septic process originally involving the navicular bursa can extend into the DIP joint or the digital tendon sheath?
True, can lead to septic arthritis & septic navicular bursitis
Describe the radiographic findings of an abdominal chondrolipoma?
Results from cartilaginous metaplasia & leads to amorphous mineralization of regional fat/abdominal tissues - although no discrete organ involvement was identified
What are the 2 most commonly reported INTRADURAL forms of spinal neoplasia in dogs?
Meningioma & nerve sheath tumors
What are the most common EXTRADURAL spinal tumors?
Primary bone tumors
What are the most frequently reported spinal tumors of young animals? And what is the predominant location in the spinal cord (extra, intra) ?
Nephroblastomas, primarily intradural extramedullary
What are the 3 locations of meningiomas?
Intracranial - 82%
Intraspinal - 15%
INTRAorbital - 3%
__________ should be considered as a DDX for multifocal, compressive spinal cord lesions with intradural extramedullary lumbar subarachnoid filling defects with some having classic “golf tee” sign & evidence of cord swelling
Papillary meningioma
What is the sensitivity, specificity, accuracy, PPV, and NPV of color Doppler ultrasonography in predicting the reducibility of the intestinal intussusception?
100% Sn, 50% Sp, 80% accuracy, 75% PPV, 100% NPV
Color Doppler ultrasonography is a useful method for predicting the reducibility of intussusception in dogs
From where does the supinator originate?
lateral humeral epicondyle
Name the components of the calcaneal tendon in DOGS?
Biceps femoris
SemiTENDINosus
Gracilis
Gastrocnemius
SDF
What dog breed is predisposed to calcaneal tendon injury?
Dobermans
True or False:, cardiac anatomic M mode measurements are associated with greater accuracy and less variability than conventional M mode?
True
AMM increased correlation level of LV dimensions & LA diameter
AMM increased level of agreement with 2D measurements
CMM greatly UNDERestimated LA diameter versus AMM which overestimated
Both CMM & AMM overestimated AO diameter
Describe the most common MRI appearance of cervical spine meningiomas?
Intradural extramedullary lesions, enhancing dural tail, T2 hyperintense to the spinal cord, T1 iso- to hypointense, moderate well-defined enhancement; gradual expansion of the subarachnoid space cranial and caudal to the mass (similar to myelographic “golf tee” sign)
Glossopharyngeal (CrN 9), vagus (CrN 10), and accessory (CrN 11) are very close to each other; emergence was seen lateral to the myelencephalon through what structure?
Tympano-occipital fissure
All the cranial nerves are what signal intensity on MRI?
T1/T2 isointense to GRAY matter
Mandibular branch of trigeminal nerve exits through the _________?
Oval foramen
Maxillary branch of the trigeminal nerve exits through the _____?
Round foramen
Opthalmic branch of trigeminal nerve exits through the _____?
Orbital fissure
What 4 structures travel through the orbital fissure?
Opthalmic branch of trigeminal nerve, oculomotor nerve (CrN 3), trochlear nerve (CrN 4), & abducens nerve (CrN 6)
What are 7 MRI signs that may be used to help intracranial brain neoplasia from non-neoplastic etiologies?
1) Dural tail (82%)
2) Dural contact
3) Adjacent bone lesions (42%, PPV 93%)
4) SINGLE lesion (85%)
5) contrast enhancement (94%, PPV 74%)
6) mass effect (82%)
7) regular shape (ovoid/spherical -58%)
T or F, the location of the celiac/cranial mesenteric arteries are useful for localization of spinal lesions on MRI?
FALSE. Location of celiac/cranial mesenteric arteries varied considerably & NO useful relationship to breed, gender, age, or body weight.
71% of celiac arteries originated ventral to L1
97% of cranial mesenteric arteries originated ventral to L1 or L2
Describe the location of the cisterna chyli?
ventral to the first four lumbar vertebrae
Most common route of infection for discospondylitis?
Hematogenous spread ( genitourinary system, oral cavity, heart valves, or skin & in cats bite wound abscesses at tail base)
Most common bacterial etiologic agents in diskospondylitis in dogs are?
Staph, Strep, Brucella, & E coli
T or F, there is a significant difference in resistive index (RI) and PI between benign and malignant nodes?
True, LOWER RI & PI in NORMAL nodes - cut offs 0.68 RI, 1.49 PI
What is the ultrasonographic difference in superficial lymph node Short:long axis ratio between normal and malignant nodes?
lymphoma nodes more round S/L axis > 0.7 vs normal/reactive nodes more oval S/L axis < 0.6
What is the ultrasonographic difference in superficial lymph node blood flow between normal and malignant nodes?
Normal nodes = hilar flow
Malignant nodes = peripheral flow
What are the 3 most important parameters to distinguish between normal & malignant superficial lymph nodes on U/S?
Lymph node size, the distribution of vascular flow within the lymph nodes, and the pulsatility index (1.49 PI cutoff, lower = normal/benign)
Which mode was superior for depicting angioarchitecture and demonstrating the presence of malignant vascular patterns within lymphomatous nodes in dogs?
A) Power Doppler
B) Tissue harmonic mode
B) Tissue harmonic mode - with the exception of resolution of pericapsular vasculature
What are the 2 most prevalent abdominal lymphomatous malignant node characteristics?
1) loss of central hyperechoic band
2) Diffusely hypoechoic
Describe the characteristic U/S appearance of a migrating grass awn FB?
linear double/triple spindle-shaped echogenic interface within soft tissue +/- RARE acoustic shadowing; regional steatitis and/or abscess creating anechoic halo
Describe the characteristic brain MRI lesions with PSS?
Widened sulci, T1 hyperintensities of lentiform nuclei +/- nucleus accumbens WITHOUT contrast enhancement (due to manganese deposition), GRAY matter atrophy from rostral frontal lobe to caudal parietal lobe
The characteristic brain lesion on MRI with PSS is due to what?
T1 hyperintensities of lentiform nuclei +/- nucleus accumbens WITHOUT contrast enhancement due to manganese deposition
What interthalamic adhesion thickness is a critical point to define brain atrophy?
5mm or less
What are the common MRI features associated with brain atrophy?
Ventricular dilation, widened/well-demarcated sulci (subarachnoid space enlargement), diffuse scattered T2 HYPERintensity of periventricular WHITE matter (e.g. lateral ventricles)
Intraspinal but extramedullary hemorrhage can be subarachnoid, subdural, or epidural and is termed what?
Hematorrhachis
Acute hemorrhage is ______?
a) Methemoglobin
b) Oxyhemoglobin
C) Deoxyhemoglobin
D) Hemosiderin
C - deoxyhemoglobin which appears HYPOintense on T2 & GRE sequences
What CT finding during arterial phase in all dogs indicates arterioportal fistulae?
Dilated and aneurysmal portal vessels filled with hyperattenuating blood
- In arterioportal fistulae, the pattern of portal filling is earlier, of higher attenuation and shaped like a peak
Describe the relationship between dog size and lung lobe torsion
Large breed dogs = Right middle lobe
Small breed dogs = Left cranial lobe
T or F, females are more likely to have a lung lobe torsion versus males?
FALSE, males more common
Describe the thoracic radiographic findings of lung lobe torsion
increased lobar opacity and pleural effusion (100%)
Vesicular emphysema (87%)
Decreased lobar bronchial visualization, Lobar bronchial only visualized in 54%
Bronchi irregular, focally narrowed or blunted bronchi (75%)
Displaced bronchi (63%)
Mediastinal shift (60%)
Curved and dorsally displaced trachea (47%)
Axial rotation of carina (47%)
Which embryologic structures form the kidney & the ureters?
Metanephros forms the kidney
Metanephric ducts form the ureters
T or F, inverted contrast medium of the bladder on CT is an artifact?
False. Potential causes may include excessive urinary bladder sediment, lipiduria (RARE in dogs), sperm or possibly a combination of conditions (e.g. lubricant contamination)
T or F, pre-treatment T-4 assessment was useful in determining which cats may have potentially relevant echocardiographic abnormalities?
FALSE, pre-treatment T4 assessment was NOT useful & < 10% of the pre- or post tx abnormalities would be considered clinically relevant.
PNSTs looked very similar to vessels in longitudinal plane in U/S, appearing as tubular, hypoechoic structures but what is a differentiating feature?
Lack hyperechoic vessel walls & blood flow
What can result following surgical ligation of a PDA on repeat echocardiography?
Aneurysmal ductal dilation
- post-operative ductus arteriosus aneurysm is usually a false aneurysm consisting of an organized hematoma arising from a ruptured ligated duct or due to increased radial forces following PDA closure
