Secret deck Flashcards
What dose of barium contrast medium is recommended in cats to achieve adequate filling of the stomach?
10 mL/kg Morgan VRU 1981
In regards to Upper GI studies in cats, how does the position of the stomach vary with respiration?
Deep inspiration caused stomach to shift caudally a distance of 1 vertebral body Morgan VRU 1981
What influences gastric emptying in the cat during upper GI studies?
Dependent on the volume of contrast medium If received over 10 mL/kg –> more complete emptying and minimal residual streaking at 30 min
Does laparoscopic assisted gastropexy alter GI transit times in the dog?
No Balsa JVIM 2017
GI transit times with Barium in the dog
- Gastric - 30 to 120 min
- Time to reach duodenum 15 min
- Time to reach jejunum - 30 min
- Time to reach ileum - 60 min
- Time to reach ICJ (aka SITT) - 90 to 120 min
- SI empty - 3-5 hours
GI transit times with Barium in the cat
- Gastric - 30 to 60 min (within 30 min if use 10ml/kg)
- SITT - 30-60 min
Dose of Barium in large dog (>20kg)? Small dog (<20kg)?
- 30% w/v (dilution of normal 60%-100% w/v)
- Large - 5-7 mL/kg
- Small - 8-12 mL/kg
What is this most consistent with?
Settling - irreversible process caused by barium coming out of suspension
What position is best for esophageal contrast studies?
Sternal position - faster transit time and increased stimulation of primary peristaltic waves for both liquid and kibble compared to lateral recumbency
Bonadio JVIM 2009
What are the 4 measured parameters of pharyngal function in the dog? How are these parameters affected in dogs with cricopharyngeal achalasia?
- Maximum caudal contraction of the pharynx
- Opening of the cranial esophageal sphincter
- Closure of the cranial esophageal sphincter
- Re-opening of the epiglottis
Opening and closing of the cranial esophageal sphincter was significantly delayed during both liquid and kibble swallows in dogs with cricopharyngeal achalasia.
Pollard VRU 2000
Which cranial nerves govern the oropharyngeal phase of swallowing?
- Trigeminal
- Facial
- Glossopharyngeal
- Vagus
- Hypoglossal
How is the pharyngeal constriction ratio calculated?
Area of pharynx at MAXIMAL constriction/area of pharynx at rest
Pollard VRU 2007
How does the pharyngeal constriction ratio differ between normal dogs and dogs with weak pharyngeal contraction?
Normal dogs have smaller PCR than dogs with weak pharyngeal contraction
Pollard VRU 2007
How does PCR change with diminished pharyngeal contractility?
As pharyngeal contractility diminishes, the PCR approaches 1
What are the most common imaging findings in cats undergoing video fluoroscopy?
- Hiatal hernia
- Esophageal stricutre
- Esophageal dysmotility
T/F: oropharyngeal and cricopharyngeal causes of dysphagia were not identified in the cat
True
Which view has the highest sensitivity for identifying pneumothorax?
Right lateral HB projection had the highest rate of detection and gradation of severity for pneumothorax
Which radiographic view is best for detection of pneumoperitoneum?
Left lateral view - gas accumulates dorsally near fluid-filled fundus
What type of stent is this? What are its indications?
Balloon-expanding metallic stent (BEMS) - premounted onto a balloon dilation catheter and balloon inflation deploys the stent at the target. The BEMSs are typically made of stainless steel and used in veterinary IR for palliation of nasopharyngeal stenosis or stenting of the right ventricular outflow tract
What type of stent is this? What are its indications?
Self-expanding metallic stent (SEMS)
Common indications for SEMSs in veterinary IR include tracheal, vena caval, and urethral stents
What are the types of self-expanding metallic stents (SEMS)?
- Woven SEMS:
- Stainless steel or nitinol
- Forshorten (compressed stent longer than deployed stent)
- Reconstrainable for correction of improper positioning if less than 60-70% of the stent has been deployed
- Laser-cut SEMS:
- Nitinol
- Do not forshorten
- Are not reconstrainable
What is the difference between these 2 stents (can come in both BEMS and SEMS)?
D - Covered form or stent graft; help to constrain tissue proliferation and luminal restenosis, but may act as a nidus for infection
E - Bare-metal form
B - cutting balloon dilator
C - conventional balloon dilator
What are the phases of excretory urography?
- Arteriogram
- Nephrogram
- Pyelogram
- Cystogram
What are contraindications for IVP?
- Dehydration
- Previous contrast reaction
- Oliguria/anuria
- Multiple myeloma
What phases of IVP are these kidneys in?
A - before
B - nephrogram
C - pyelogram
T/F: 4 mL/kg sufficiently distends bladder to eliminate wall thickening due to incomplete filling, but does not eliminate mucosal irregularity due to cystitis
True
Wall should not be >2mm in thickness at this degree of distention
Describe normal appearance of equine myelogram in neutral, flexed, and extended positions
NEUTRAL
- Dorsal column is wider and more uniform than ventral column
- Dorsal column widens at the caudal aspect of each foramina
- Ventral column usually narrows and is slightly elevated at intervertebral disc spaces
FLEXION:
- Dorsal contrast column remains the same
- Ventral column becomes even narrower at the disc spaces
EXTENSION:
- Dorsal column remains the same
- Ventral column becomes slightly wider C5
Sensitivity and specificity of myelography for identifying CVM in horses
Sensitivity of myelogram is low and specificity is moderate no matter the criteria used
Sensitivity and specificity appear higher for C6-7 than mid-cervical sites
What are described measurements for myelography in CVM horses? What is the accuracy of each?
- 50% reduction of the dorsal contrast column at the intervertebral disc space
- Recently been shown to have false positive results
- 70% reduction of the dorsal column necessary to avoid false positives
- >20% reduction in dural diameter
- more accurate in neutral views
- 2 mm reduction in the dorsal contrast column signify significant compression
- Not recommended
At C6-7, what percent reduction in dorsal contrast column height and dural diameter have a high sensitivity and specificity?
At C6-7, reduction of the dorsal contrast column height by 70% or reduction in dural diameter by 25% have a high sensitivity and specificity
What are the most common sites of compression in CVM horses?
- C3-4 > C6-7 > C5-6 > C4-5
- Rarely detected at the other sites in the cervical spine
- 29% of compressive horses had it in multiple sites
Papageorges 1987
Which stent is recommended by Weisse for urethral stenting due to obstruction by tumor? Due to recurrent stricture?
Obstruction - Self-expanding metallic stent (SEMS), laser cut, uncovered
Stricture - SEMS, laser cut, covered
Calculate the tracheal stent size needed given that your raw radiographic measurement (not corrected for magnification) measures 13mm in the cervical trachea and 10mm in the intrathoracic trachea. The marker measures 11mm in length. The length of the trachea requiring stenting is ~85mm.
Choose a 14mm diameter stent (to be 2-3mm greater in diameter than the maximal measure)
A 14 x 58 mm stent expanding between 9mm and 12mm (calculated from radiograph) will be approximately 85mm in length once expanded
What fatal complications is automatic tru-cut biopsy of the liver associated with in cats?
Fatal hypotension and bradycardia within 15 minutes of biopsy
How do different anesthetic protocols affect uptake of 2-deoxy-2-[18F]fluoro-D-glucose (FDG) by the brain in PET/CT imaging?
- Standard uptake value (SUV) for the frontal and occipital lobes was significantly higher than in the brainstem in all dogs regardless of protocol
- Dogs receiving medetomidine/tiletamine-zolazepam also had significantly higher whole brain SUVs than the propofol/isoflurane group
What is the radiopharmaceutical uptake caused by?
Peroneal nerve block
This occurs in approximately 50% of blocked limbs and can mimic a tibial lesion on the lateral view in approximately 20% of blocked limbs. Associated with higher dose of anesthetic.
How does acepromazine influence count density in horse limbs?
- Intravenous administration of acepromazine increases peripheral blood flow causing an earlier onset of the vascular phase during the three-phase bone scan; increased count density of vascular phase
- Acepromazine did not increase the count density of the bone phase scintigrams
In regards to trans-splenic portoscintigraphy, are there any distinguishing features differentiating between single intrahepatic and single extrahepatic shunts?
No distinguishing features
What is the morphology of this shunt?
Portoazygous - Tc bolus traveled dorsally, running parallel to the spine and entering the heart craniodorsally
What is the morphology of this shunt?
Splenocaval - bolus ran from the area of the portal vein/splenic vein junction in a linear fashion toward the caudal vena cava entering the heart caudally
What are the 3 identified shunt morphologies with trans-splenic portography?
- Porto-azygous
- Spleno-caval
- Internal thoracic
What is the most common distribution of feline thyroid disease?
Bilateral asymmetric
T/F: multifocal thyroid disease will develop in a few cats that have ectopic thyroid disease or thyroid carcinoma
True. Ectopic thyroid disease and thyroid carcinoma are relatively uncommon in hyperthyroid cats
Which thyroid scintigraphy measurement has the highest sensitivity for diagnosis of hyperthyroidism in cats?
T/S ratio had the accurary
Which thyroid scintigraphic parameter is the best parameter to predict the functional volume and metabolic activity of the feline adenomatous thyroid gland?
Percent thyroidal uptake of Tc (TcTU)
List differentials for generalized osteosclerosis in the cat?
- Osteopetrosis
- FeLV
- Lymphoblastic leukemia, lymphoma
- C-cell tumor
- Myeloproliferative disorders
- Chronic renal failure
Does head and neck position have an effect on nasopharyngeal size in horses? If so, which results in the smallest diameter?
- Significant influence of head and neck position on pharyngeal diameter, with head position having the major effect; neck position was less important, but still significant
- Smallest pharyngeal diameter was found at the dorsal, flexed position
What head and neck position in the horse results in the largest nasopharyngeal diameter?
Largest pharyngeal diameter was found at the extended midway position
Are intra- and intervertebral ratios good for differentiating normal from CVM in Dobermans? How do the ratios change with location along the cervical spine (general)?
- No difference in either the intervertebral or intravertebral ratio between normal vs. affected dogs
- In all dogs (normal and CVM), ratios decreased progressively along the cervical spine, being smallest at C6–C7 and C7
What signalment parameters are associated with small intra- and intervertebral ratios in Dobermans?
- Increasing age
- Males
Left cranial vena cava
- Pathophysiology
- Clinical significance
Most commonly encountered anatomic variant, but not clinically significant
- Failure of left anterior cardinal vein regression
- Can occur alone or with a normal right cranial vena cava
- Left cranial vena cava enters the right atrium caudally (see image)
- Has no detrimental effect but assumes importance during surgery as catheterization of left jugular can cause catheter to take unexpected path
- Transpositional venous anomalies often seen in patients with transpositional arterial anomalies (i.e., left cranial vena cava and persistent right aortic arch)
What are the standard views for evaluation of the foot in cows?
- Dorsal 65 proximal-palmarodistal and a lateral 30 dorsal-mediodistal oblique
- Allow the pedal bone and distal sesamoid bone, as well as the distal interphalangeal joint, to be displayed and evaluated in 2 different planes
DOI: https://doi.org/10.1016/j.cvfa.2013.11.003
Where was the injection made? Label the anatomy.
Right atrium
Left image
- Right auricle
- Right ventricle
- Pulmonary sinus of Valsalva
- MPA
- LPA
- RPA
Right image
a. Pulmonary v.
b. Left atrium
c. Left ventricle
d. Sinus of Valsalva
e. Ascending aorta
f. Brachicephalic trunk
g. Left subclavian a.
Where was the injection made? Label the anatomy.
Injection made in vena cava
Left image:
- Right atrium
- Right ventricle
- Pulmonary sinus of Valsalva
- MPA
- Right auricle
Right image:
a. Left atrium
b. Left ventricle
c. Left auricle
d. Aorta
e. Brachiocephalic trunk
f. Left subclavian
Where was the injection made? Label the anatomy.
Injection made in vena cava
- Vena cava
- Right atrium
- Right auricle
- MPA
- Right ventricle
- MPA
Label the anatomy
- Left atrium
- Left ventricle
- Ascending aorta
- Descending aorta
- Brachiocephalic trunk
Label the anatomy
What are the two commonly used balloon-dilator catheters for pulmonic stenosis as described in Weisse?
- TYSHAK
- Thin, minimally compliant
- Relatively low maximal burst pressure
- Low profile
- Most sizes can accomodated a 0.035” guide wire
- Commonly selected for BPV in dogs
- Z-MED
- Thicker –> require larger introducer size
- Greater maximal burst pressure
What are the 3 types of esophageal stents?
- Biodegradable (BDS) made of PDS suture
- SEMS
- Self-expanding plastic stents (SEPS)
They are either uncovered, partially covered, or fully-covered. The advantages of a covered stent is a lower rate of re-obstruction, especially with strictures, but a higher rate of migration, due to the failure of tissue in-growth. Esophageal stents have a dumb-bell shape at each end, to aid in preventing migration, and the covered stents, since they are intended for short-term use, have a string around each end so that they can be removed endoscopically with a grasping instrument.
What stent is recommended for tracheal stenting?
Mesh, self-expanding metallic stents are most commonly used for tracheal stenting procedures,as balloon-expandable and laser-cut stents have been ssociated with unacceptable risks of migration and fracture, respectively
Label the anatomy of the digital flexor tendon sheath.
Which tendon of the shoulder is this?
Supraspinatous
Infraspinatous
Biceps tendon
Features of insulinoma on different modalities (CEUS, CT, and MRI)
- CEUS
- Variable enhancement patterns, but generally increases conspicuity of the nodule
- CT (variable reports)
- Hyperattenuating to normal pancreas in arterial phase
- Variable in venous and delayed phases
- MRI
- T2w fat-saturation hyperintense
- Post-gad T1w fat-saturation isointense
Which equine intercarpal ligaments were visible with CT arthrogram
- Medial and lateral palmar intercarpal ligaments
- Radiocarpal ligament
- Transverse intercarpal ligaments
- Palmar carpal ligament
In dogs, mean ratio of kidney length to the second lumbar vertebra length is dependent on what?
Skull type - brachycephalic dogs had the highest median LK/L2 ratio and dolichocephalic dogs the lowest. Mesaticephalic dogs were in the middle
Using the right lateral view, what is the mean ratio of kidney length to the second lumbar vertebra length for different skull types?
- Brachycephalic dogs - LK/L2 ratio of 3.1
- Dolichocephalic dogs - 2.8
- Mesaticephalic dogs 2.97
T/F: A mean ratio kidney to L2 length of >3.5 was found only in mesaticephalic dogs on the ventrodorsal view
True
How did the mean ratio of kidney length to L2 length correlate with body weight?
- Small dog = larger ratio
In the Latimer et al. paper regarding lung lobe torsions in juvenile dogs (<12 mo), which lung lobes were affected most commonly and in what order?
- Left cranial lung lobe
- Right middle lung lobe
- Right cranial lung lobe
This paper consisted of mostly pugs, which are predisposed to L Cr LLT. The two non-pugs in this paper did not have torsions of L Cr.
In D’Anjou et al., was there a predilection for site of lung lobe torsion and weight?
Yes.
- Large dogs - Right middle lung lobe
- Small dogs - Left cranial lung lobe
- Cats (n=2) - right cranial and right middle
What is the most-likely diagnosis?
Lung lobe torsion
- Vesicular gas pattern
- Abrupt tapering of bronchus
- Mild pleural effusion
In Lang et al. (1986), which radiographic view was most sensitive for detecting pulmonary metastasis?
- R lateral > Left lateral > VD
- Recommend two-viewers review all met checks or, if only one reviewer, a 3-view study should be used
What side do these cranial lobar vessels belong to in this left lateral radiograph?
Right pulmonary vessels - The pulmonary vessels in the right cranial lung lobe are more conspicuous in a left lateral than in a right lateral radiograph. This is caused mainly by the dorsal displacement of the right cranial lobe that occurs when the patient is in right lateral recumbency resulting in the right cranial lobar vessels being superimposed on the left cranial lobar vessels.
Thrall 6 ed.
Which is left and right?
T/F: An enlarged left atrium causes bronchial collapse resulting in coughing
FALSE. No association between moderate‐to‐severe left atrial enlargement and left bronchial collapse (Singh and Johnson, JVIM)
How does 40mcg/kg dexmedetomidine IM influence the size of the cardiac silhouette on different views in cats?
Dexmedetomidine was associated with a small but significant increase in cardiac silhouette size:
- Right lateral (vertebral heart score)
- VD/DV (percentage width)
Enlargement may be persistent at a minimum of two hours postdexmedetomidine reversal
Radiographic appearance of non-cardiogenic pulmonary edema
- Mixed
- Symmetric
- Peripheral
- Multifocal
- Bilateral
- Dorsal lung
Can be asymmetric and unilateral
A Bulldog presents for dyspnea after a collapse episode and you suspect NCPE. On radiographs, you see asymmetric, unilateral, and dorsal pulmonary interstitial to alveolar pattern. What is the most likely cause of this distribution of NCPE?
Post-obstructive pulmonary edema
When the distribution was unilateral, pulmonary infiltration involved mainly the right lung lobes
What criteria can be used to assess the pulmonary veins in dogs with MMVD (Oui et al., 2015)?
Normal dogs:
- Pulmonary arteries and veins are similar in size
- Cranial lobar vessel diameter smaller than 4th rib (lateral)
- Right caudal PV <1.22x width of 9th rib (VD)
Right caudal pulmonary vein can be enlarged without distention of cranial pulmonary vein
What is the most likely diagnosis?
Laryngeal paralysis –> air-filled laryngeal ventricles (Stadler VRU 2011, Figure 3)
Magic angle
- 55 degrees relative to B0
- Short TE (PD, STIR, T1w)
- Occurs in neutral and angled limbs
- Increasing the TE to >40ms in spin echo sequences and >80ms in TSE sequences, eliminates the magic angle effect in tendons
- Other paper says that magic angle is reversed at TE 140ms, but 120 ms had the best balance bt image quality and magic angle artifact
Werpy
T/F: Due to the configuration of the fibers, ligaments more susceptible to magic angle effect than tendons
True - ligament fibers have a more complex organization than tendons
MRI features of coccidioides granulomas
- Difficult to determine location (intra- vs. extra-axial location)
- Variable MR features, many of which overlap with neoplasia
- Variably enhancing, may be marked
- Often poorly defined borders –> this will differentiate between meningiomas, which have sharp margins
Bentley VRU
Newer paper out of AZ (Spoor VRU 2019) describes a different appearance - bilateral, symmetric T2w hyperintensities, faint/wispy enhancement in the caudate nucleus, frontal lobe, and rostral internal capsule. Impressive brain atrophy once the infection resolved.
CT and MRI features of carotid body paragangliomas (Mai VRU 2015)
- Centered on carotid body
- CT
- hypoattenuating to adjacent muscles
- strong, heterogeneous enhancement
- MRI
- hyperintense to muscles in T1- and T2-weighted MRI
- strong, heterogeneous enhancement
- Invasion of adjacent structures - most common was basilar portion of skull; others included regional vessels, tympanic bulla, cranial cavity
Carotid body paragangliomas
- Common presenting complaint
- Signalment
- Most common reason for imaging was a palpable cervical mass or respiratory signs (i.e., dyspnea or increased respiratory noises
- Most commonly affected breed was Boston terrier (n = 5)
- Predominately male castrated
- Median age was 9 years [range 3–14.5].
7‐year‐old male neutered domestic short‐haired cat had depression for 5 months and acute blindness
Pituitary apoplexy
A dog presents for hindend weaknes. On MRI you see heterogeneous STIR hyperintensity in the hindlimb muscle and the majority of the STIR‐hyperintense region does not enhance indicating poor perfusion. What is the most likely diagnosis?
Ischemic myopathy
Which MRI sequence is best for evaluating facial neuropathy?
VIBE (sensitivity 86-96% and the specificity 87-92%)
Conventional T1-weighted images yielded a sensitivity of only 39-65% and a specificity of 94-96%
T/F: MRI was not a sensitive detector of vestibulocochlear nerve abnormalities
True
A pelvic width reaching ____ was observed in several dogs and cats with clinically normal renal function that were not receiving IV fluids
3 mm (D’Anjou VRU 2011)
Mean pelvic width increased in polyuric animals or animals receiving IV fluids; increased further with pyelonephritis
What width of the renal pelvis has been suggested as a cut-off for predicting animals with urinary outflow obstruction?
13mm
What measurements are considered normal, indicative of hyperplasia, or indicative of neoplasia regarding parathyroid US per Wisner VRU 2005?
- >4mm = adenoma or carcinoma
- 2-4mm = hyperplastic
- <2mm = normal
The strength of a sound wave depends on:
- Amplitude
- Intensity
Amplitude
- Maximum variation along the y-axis
- In diagnostic US, positive compression amplitude exceeds the negative rarefaction amplitude (asymmetric, non-sinusoidal waveform)
Intensity
- Concentration of energy (power) per unit of area (W/cm2)
- Inversely related to wave width
- Intensity of the beam is greatest where the beam is narrowest (i.e., focal point)
- Higher intensity beam = increased risk of adverse biological effects
Wavelength (λ)
- Distance between 2 areas of compression (rarefaction)
- Determines penetration power and image resolution along the beam
- large λ = low frequency
- small λ = high frequency
Frequency (f)
- Number of cycles per unit of time (Hz)
- Inversely related to wavelength
How do image resolution and penetration vary with changing frequency?
- Low frequency (large wavelength) = high penetration, but low resolution
- High frequency (small wavelength) = low penetration, but high resolution
_____ and _____ are dependent on the propagation medium, but ____ is not dependent on the propagation medium
Wavelength and speed are both depended on the propagation medium, but frequency is not dependent on the propagation medium
Acoustic velocity depends on:
- Density - increased density —> slower speed
- Stiffness - increased stiffness –> faster speed
- More important than density
- Compressibility - increased compressibility = slower speed
- Inverse of stiffness
Rank soft tissues, air, and bone in order of acoustic velocity (propagation speed) from fastest to slowest
Bone (4,080 m/sec) > soft tissue (1,540 m/sec) > air (331 m/sec)
Focusing the beam improves _____ resolution
- Lateral (narrower beam)
- Elevational (less important)
Advantages of harmonic imaging
- Increased lateral resolution
- Increased signal to noise ratio
- Decreased artifacts:
- Reverberation
- Refraction
- Scatter
- Noise
- Side lobes
As the angle (insonation angle) between the transmitter and interface approached ____ degrees, the accuracy of the estimation of velocity decreases
90 degrees. Only the sound waves parallel to the beam contributes to Doppler effect. In general, use an insonation angle <60 degrees to give accurate estimate of velocity. May have increased artifact if the angle is less than 30 degrees
Strain elastography
- Aka compressive elastography
- Stress is applied by repeated manual compression of the transducer and the amount of lesion deformation relative to the surrounding normal tissue is measured and displayed in color
- Largely dependent on the examiner’s experience, and significant interobserver variability has been found
Shear-wave elastrography
- Uses an acoustic radiation force impulse created by a focused ultrasound beam, which allows measurement of the propagation speed of shear waves within the tissue to locally quantify its stiffness
- Kilopascals or meters per second
- Highly reproducible
- Potential for an increase in artifacts caused by reflection and refraction
The Doppler frequency shift is defined as:
- A. The difference between the Doppler frequency and the imaging frequency
- B. The difference between the transmitted and received frequencies
- C. The time between the transmitted and received pulses
- D. The rate at which the transducer emits pulses
B. The difference between the transmitted and received frequencies.
The Doppler effect causes the transmitted Doppler frequency to be altered when it encounters a moving reflector. The frequency is increased if the reflector is moving toward the beam and decreased if the reflector is moving away from the beam. The difference that occurs between the transmitted frequency and the altered frequency that is reflected back is known as the frequency shift.
While performing a Doppler study, the measurement of the Doppler angle of incidence was underestimated. What error will result from this mistake?
- A. The frequency shift will be underestimated.
- B. No Doppler frequency shift will be detected.
- C. Mirror imaging of the Doppler spectrum will occur.
- D. The velocity estimation will be inaccurate.
- E. Aliasing of the Doppler spectrum will occur
D. The velocity estimation will be inaccurate.
Power Doppler
- Uses the amplitude of Doppler signal to detect moving matter
- Independent of velocity and direction of flow, so there is no possibility of signal aliasing
- Independent of angle, allowing detection of smaller velocities than color Doppler
- Higher sensitivity than color Doppler, which makes a trade-off with flash artefacts
In the cat, normal measurements of:
- Esophageal wall
- Cardia wall
- Pyloric wall
- Pyloric muscularis layer
- Length of duodenal submucosal thickening
- Esoph - 4.9 mm
- Cardia - 5 mm
- Pyloric wall - 4.4 mm
- Pyloric mucosal layer - 2.5 mm
- Length of duodenal SM thickening - 4.7 mm
In Zwingenberger JVIM 2011, muscularis thickening on ultrasound correlated with cellular infiltration of what layers? Lymphadenopathy was associated with infiltration of what layers?
- Muscularis thickening - mucosal and submucosal
- Lymphadenopathy - mucosal and submucosal OR mucosal, submucosal and muscularis
T/F: In cats with infiltrative bowel disease, disease confined to the mucosa and lamina propria was not associated with ultrasonographic changes
True
What is this artifact and why does it occur?
- Twinkle
- Occurs behind a strongly reflective interface, such as those produced by urinary tract stones or parenchymal calcifications, and appears as a quickly fluctuating mixture of Doppler signals with an associated characteristic spectrum of noise
- Narrow-band signal error generated by highly echogenic interfaces seems to be the primary cause
- Enhanced with rough surfaces
In vivo, which factors influence the appearance of Twinkling artifact
- Gain
- Surface roughness
- Stone size
Ultrasonographic appearance of lipiduria in cats
- Suspended +/- gravity independent echoes
- No artifact
Clumping of suspended echoes in lipiduric cats is associated with ________
- Type of lipid - diacylglycerol (DAG)
Label the anatomy in this Gelding
- Arrows - ureters
- Arrowheads - deferent ducts
Label the anatomy in this mare
- Arrows - ureters
- Arrowheads - vagina
Label the anatomy in this Stallion
- Arrows - ureters
- Arrowheads - ampullae
In horses, what is the normal ureteral wall thickness and diameter of ureter (contracted vs. expanded)?
- Ureteral wall thickness 1.0 - 2.4mm
- Ureteral diameter contracted - up to ~9.5mm
- Ureteral diameter distended - up to 19mm
Normal urinary bladder thickness in horses
1 to 5 mm
Differences in enhancement pattern of the spleen between non-sedated dogs, dogs sedated with butorphanol, and dogs sedated with dexmedetomidine?
- Normal and butorphanol dogs were the same
- Initial phase - rapid, intense enhancement of small arteries
- Venous phase - heterogeneous enhancement of splenic parenchyma gradually becoming more homogeneous
- Wash-out phase - gradual, homogeneous decrease in intensity
- Dexmedetomidine
- Slower distribution of contrast medium
- Whole organ was diffusely hypoechoic during the first 30s
- Enhancement was weak and homogeneous throughout
T/F: Butorphanol does not cause subjective or objective effects during normal contrast-enhanced ultrasound of the spleen
True
Increased GB volume and reduction in GB ejection fraction were seen in which of the following groups:
- Normal
- Mobile sludge
- Immobile sludge
- Mucocele
Seen in all dogs with sludge or mucocele, but the mucocele group was most severely affected
T/F: Biliary stasis occurs not only in dogs with gallbladder mucocele but also in dogs with biliary sludge
True
CEUS adrenal gland enhancement patterns in normal dogs versus dogs with PDH
Normal:
- Initial enhancement of an artery within the medulla parallel to the long-axis of the gland
- Centrifugal enhancement of small arteries branching off the central artery
- Diffuse, homogeneous, intense enhancement
- Gradual washout - homogeneous loss of intensity
PDH
- rapid, chaotic, and simultaneous perfusion of US contrast agent into both the adrenal medulla and cortex
- Three enhancement patterns
- In all PDH dogs, regardless of these vascular patterns, there was a uniform distribution of the contrast agent during the late washin phase and the entire gland became iso-enhanced, followed by slow and progressive washout, similar to that of the remaining adrenal parenchyma
What are the 3 early wash-in enhancement patterns in the adrenal glands of dogs with PDH?
- Type 1
- only the central longitudinal artery of the medulla was seen, but it was barely visible
- dogs with <24ug/dl on ACTH
- Type 2
- perfusion of the adrenal gland by the contrast agent was so fast and disordered that the central longitudinal artery was not detectable, even in the initial washin stages
- ACTH-stimulated cortisol levels > 24ug/dl
- Type 3
- nodular pattern - presence of abnormal vessels forming nodular lesions together with homogeneous, but chaotic enhancement of the contrast agent within the whole adrenal parenchyma
Normal CEUS pattern of small intestine in healthy cats
- Initial rapid enhancement of serosal and submucosal layers
- Followed by a more gradual enhancement of the entire wall
- At peak enhancement, there was a lack of demarcation between wall layers
- Late phase, there was a gradual wash out of signal from the intestinal wall. The wash out of the submucosal layer occurred last
T/F: kVp, but not mAs influences the energy (quality) or the x-ray beam
True. kVp is the only factor to control quality (aka energy) of the x-ray beam
T/F: Both kVp and mAs control quantity of the x-ray beam
True.
What are heat units? How is this calculated?
Heat units describe maximum load (function of heat energy) that can be safely applied to an x-ray tube; heat energy determined by exposure factors
- Simple generator: HU = kVp * mA * exposure time (sec)
- For 3-phase generators - multiple by 1.35
- For constant potential generators - multiple by 1.4
Calculate the heat units for a simple generator with settings of 70 kVp, 100 mA, and 0.1 sec exposure time
70 * 100 * 0.1 = 700 HU
Calculate the heat units for a constant potential generator with settings of 70 kVp, 100 mA, and 0.1 sec exposure time
70 * 100 * 0.1 * 1.4 = 980 HU
What is the relationship between radiographic contrast and kVp?
- Inversely related
- Low kVp = high contrast
- Increased energy (kVp) photons are more likely to undergo scatter than photoelectric effect –> compton decreases image contrast (makes it gray)