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484 Cards in this Set

  • Front
  • Back
Before assessing a radiograph for any abnormalities, what must you first apprise?
The radiographic quality
What lateral view(s) are taken routinely?
Right and Left lateral
Why is it important to obtain both lateral views?
During lateral recumbency the lung on the dependent side is partially collapsed and lacks aeration
Which frontal view is most comfortable foe the dog or cat?
Dorso-ventral (DV)
DV is also safest for animals in what condition?
Respiratory distress
In regards to the heart, why is a DV view preferred?
Heart lies in its natural position
What structure are better seen in the VD view?
Lung fields
When is the VD preferred over the DV?
When minor pulmonary changes are suspected
What is the main use of horizontal beam projections?
Evaluate a pneumothorax (and fluid distribution)
In general, the radiographic exposure should allow visualization of which structures?
The relatively lucent lung fields and the opaque heart
On the lateral view, pulmonary blood vessels should be seen where?
Out to the periphery of the lung
The DV/VD views should be sufficiently penetrated to see what major structures?
-main bronchi
-main caudal lobe pulmonary vessels
What type pf KvP is used when obtaining thoracic radiographs?
High kVp
What technique is used to view slightly over-exposed radiographs?
A bright light
If a patient is not completely cooperative for radiographic positioning what must you consider?
Chemical restraint
How should the forelimbs be positioned on the lateral radiograph?
Drawn forward
Chest rads are taken on full inspiration. On a lat view, the diaphragm should be see at what vertebral level?
How do you judge good inspiration on a DV/VD view?
Lowrs ribs are widely spaced and lung border bulges into the inner-costal spaces.
When would expiratory views be indicated?
To check for air trapping
How do you reduce the chances of blur from motion on a radiograph?
Use the shortest time (highest mA) available
A grid will improve radiographic quality and should be used on body parts greater than what thickness?
12-14 cm
Proper collimation on a chest radiograph would include what, caudally?
The cranial abdomen
What is the cornerstone to radiographic interpretation?
Routine systematic approach
Radiographically, at the thoracic inlet, the mediastinum blends with what other structures?
The soft tissue planes of the caudal neck
In what order should the thoracic structures be evaluated?
-thoracic boundaries
-mediastinal structures
How should the boney structures of the thorax be evaluated?
-ribs: examine individually
-examine sternabrae
-thoracic vertebrae should each be checked
On the right lateral, what is the position of the crus of the diagphragm?
The weigh of the cranial abd pushes the right crus forward with the vena cava.
On the left lateral, what is the position of the crus of the diaphragm?
The left crus is advanced by the weight of the gastric fundus, which can be seen immediately behind it.
What else should be evaluated in regards to the thoracic boundaries?
The contents of the cranial abdomen
What structures are contained in the cranial mediastinum?
-cranial vena cava
-brachycephalic trunk
-lymph nodes
In young animals, what structure might be seen in the DV/VD view as the sail sign?
Is the esophagus visible on the DV/VD view?
Yes, with a small amount of air in it.
Where is the trachea seen on the DV/VD view?
To the right of midline
What is the typical course of the trachea as seen on the lateral view?
Variable, tend to diverge from the vertebral column between the thoracic inlet to the carina (approx 5th ICS)
What are the only normally visible structures in the caudal mediastinum?
-cadual vena cava
On the DV/VD where is the aorta located?
Superimposed on the heart shadow, to the left of the midline
Grossly, the caudal vena cava should be no wider than what structure?
A thoracic vertebrae length
What oblique linear shadow can be seen in the left caudal thorax on the DV/VD view?
Caudal mediastinal fold
In cats, what structure separates the dorso-caudal lung lobes from the vertebral column?
Thick, sub-lumbar muscles
(don't confuse as free pleural fluid
What 2 structures comprise the heart shadow?
The heart and pericardium
The heart is widely variable in shape and size depending on the conformation of the thorax. What radiographic technique factor can make the heart appear larger?
Poor inspiration
On the lateral view, the cranial border of the heart represents which portion of the heart?
Right ventricle and right atrium
Most of the caudal border of the heart shadow, on the lat, represents which portion of the heart?
Left ventricle
Which heart structures are seen on the lat view and occupy the dorso-caudal segments?
Left atrium and pulmonary veins
On the DV?VD views, what are the clock-face positions of the
main pulmonary artery
left auricle
left ventricle
right ventricle and atrium
aorta- 12:00
main pulmonary artery- 1:00
left auricle1:30 -3:00
left ventricle 3:00-7:00
right ventricle and atrium 7:00- 12:00
What objective method has been developed to asses over heart size in dogs?
Vertebral Heart Score (VHS)
On which view is the VHS caculated?
Combined, the length of the heart length and width are compared to what?
The vertebral column starting at the cranial border of L4
As a guide, the VHS should be in what range?
8.5-10.5 vertebrae in length
What position does the feline heart lie on the lat view?
More horizontal
What shape is the feline heart on the DV/VD view?
oval to triangular
Is the VHS used in cats?
How many lobes does the left lung consist of?
Cranial (cr and cd segments)
Name the lobes of the right lung
Which lobe forms the shadow of the caudal mediastinal fold?
The accessory lobe of the right lung- lies partly on the left at and is near the caudal left lob
What appearance does the left cranial lobe tend to have?
Curls to the right side, taking the ventral portion of the cranial mediastinum with it
In most dogs and in some cats, how are some larger bronchi made radiologically visible?
Mineral deposits in the bronchi wall
Bronchial walls made be seen in cross-section when surrounded by what?
Soft tissue cuffs
What is the shape of the left and right main stem bronchi on the DV/VD view?
Inverted Y
The the cranial lung lobes, the lobar arteries lie where in position to the veins?
Dorsal (main lobar bronchi between them)
What structures are responsible for the complex background network of soft tissue densities throughout the lung fields?
Peripheral pulmonary vessels
Skin folds may mimic what condition on a DV/VD view?
when evaluating the chest wall, irregularities of the costal cartilages and sternabare ( past trauma) may resemble what pathology?
Active proliferative or destructive changes
Accumulation of fat in the ventral thorax and pericardium could be confused as what?
Free air or free fluid
Soft tissue nodules have to be what size to be considered significant?
close to 1 cm
In the chest, composite shadows of what structures should not be mistaken for localized lesions?
Ribs, vessels and mineralized bronchial walls
What are osteomas that may be seen in chest rads?
In older dogs, small deposits of bone on the pleura on in the lung parenchyma
Prolonged lateral recumbency may lead to what condition in the dependent lung?
Hypostatic collapse
What type of spaces are the pleural cavity and mediastinum?
Potential spaces
How are pathologic changes demonstrated in a radiograph?
By displacement of recognizable thoracic structures from their normal position
What imaging modality can help to visualize disorders of the pleural cavity that bring soft tissue or fluid lesion in contact with the thoracic wall?
Air in the pleural cavity usually affects which side?
Both, mediastinum is easily ruptured
On a lateral recumbent view, where does the free air go?
to the upper hemithorax, collapse of thje dependent lung reduces its volume
In the case of a pneumothorax, lateral view, what position does the heart assume?
Looses supports and slides towards the lowest point in the chest
Where is free air seen on a lat view?
Between the ventral border of the heart and ventral thoracic wall
On the DV view, where is free air found?
Forms a lid in the dorsal part of the thorax
What views give a more accurate assessment of free air?
Horizontal beam
On a lateral view, free fluid is found where?
Pooling in the dependent hemithorax obscuring the cardiac shadow
How is fluid visualized pooling in the lungs on a DV/VD view?
Fissure lines are seen more clearly
What are some of the causes of pneumothorax?
-lung rupture
-chest puncture
-esophageal/trachea rupture
-iatrogenic (following sx)
What are some causes of free fluid in the thorax?
-blood, chyle, pus
How might chronic inflammatory dz appear on a chest radiograph?
Pleural thickening with rounding of retracted lung borders
Radiographic evaluation of the chest wall includes assessing what areas sytematically?
-periperhal soft tissues
What types of conditions can cause disruption to the chest wall?
-subcutaneous emphysema
Occasionally, what might be found along the thoracic wall due to a rupture?
Abdominal contents
Lesions of which structures are easily missed?
Rib lesions can include what types of pathology?
-neoplastic lesion
Strenebral malformations and dislocations are generally without clinical significance. However, this area should be assessed for evidence of what?
Bone infection or neoplasia
All vertebrae should be inspected for potential evidence of what types of pathology?
Ribs and vertebrae are common sites for what pathology?
Intrathoracic masses arising from the chest wall will have what appearance?
Displacement of adjacent thoracic contents
Rupture of the diaphragm results in the cranial contents of the abdomen moving where?
Into the thorax
When does cranial displacement of the pylorus occur?
When part of the liver has migrated through a small right sided tear
How can you confirm a case of diaphragmatic rupture?
-contrast studies
How long after giving the barium orally should you wait before acquiring the images?
45 mins
What is the most common defect of the diaphragm?
Peritoneo-pericardial hernia
What type of clinical signs do animals with this condition show?
usually none
Radiographically, a Peritoneo-pericardial hernia appears how?
Abdominal contents in the pericardial sac increase the size of the heart silhouette
Hiatal hernias can be of what 2 types?
Permanent or sliding
How can a permanent hiatal hernia be diagnosed?
By the use of oral contrast
Demonstration of a sliding hiatal hernia may require the use of what imaging modality?
Sliding hiatal hernia is frequently associated with what condition?
Gasto-esophagitis in oriental cats
By what other means might the diaphragmatic musculature be altered?
Congenital malformations
What is the position of the affected side of the diaphragm in a case of unilateral diaphragmatic paralysis?
Displaced caudally
A pneumomediastinum can be caused by air entering from where?
-sub-pleaural rupture of lung
-intrathoracic tracheal or esophagus rupture
-via the thoracic inlet along fascial planes of the neck
What radiographic feature do you look for with a pneumomediastinum?
Visibility of the individual cranial mediastinal structures
What is a radiographic sign of free mediastinal air?
Reverse fissure shadows with wedge shaped soft tissue opacities extending peripherally from the hilus
Mediastinal masses are most often a result of what condition?
On a lateral view, what is a radiographic sign of a cranial mediastinal mass?
Elevation of the trachea, combined with soft tissue opacity in the cranio-ventral thorax, and caudal displacement of the carina
Fluid in the mediastinum is most commonly what type?
Pus or blood
What technique may help to visualize caudal displacement of the esophagus?
Contrast medium
What condition might mask the presence of mediastinal masses?
Pleural effusion, repeat radiographs after draining
The course of the trachea and the lumen diameter vary with what?
Position of the neck and respiratory phase
How does genuine displacement of the trachea appear radiographically?
Infers changes in adjacent mediastinal structures
Foreign bodies of the trachea that are easy to identify are of what density?
Tracheal rupture is more common in which species?
What is the appearance of the lumen after a tracheal collapse?
Appears increased
What appearance would tracheal hemorrhage have?
Localized luminal narrowing
What condition will cause the tracheal lumen to be narrowed throughout its length?
Congenital hypoplasia
Congenital hypoplasia is common in which species?
Brachycephalic dogs
Tracheal collapse is not easy to demonstrate of plain radiographs. At which respiratory phase should the exposure be made?
Expiration-intra-throracic narrowing occurs
Granulomas of the trachea can be caused by what parasite?
Filaroides oslerii
Tumors of the trachea are usually of what origin?
What is the preferred method to visualize the esophagus radiographically?
Barium swallow
What contrast agent type is used if you suspect a rupture of the esophagus?
Water soluble
What method is used to demonstrate the full extent of esophageal distension?
Mix barium with food
In the distal esophagus of the cat, what kind of muscle pattern would be seen with a barium study?
What is the most common esophageal f.b. in dogs, and where do they tend to be located?
Bones- between heart base and diaphragm
What other imaging technique can be used to evaluate the esophagus?
True or false. Megaesophagus is usually seen on plain films.
How would you demonstrate f.b. of soft materials?
What congential anomaly will cause a pouch to form in the cranial thoracic esophagus?
Vascular ring anomaly
What conditions can cause an acquired stricture of the esophagus?
-trauma (f.b.)
-reflux or corrosive esophagitis
Diverticula are usually located in which portion of the esophagus?
lower esophagus
What is the appearne of a gastro-esophageal intussusception?
Large rounded soft tissue mass in the distal esophagus
Neoplasia of the esophagus is rare except when this parasite is prevelent.
Spirocerca lupii
What wpould contrast studies of the esophgus demonstrate in a case of Spirocerca lupii?
Mural attachment
What do you consider when evaluating the lung fields in a radiograph?
-blood vessels
Lung patterns may be due to pathology but may also be caused by what?
-obese conformation
-faulty technique
Why are the terms "interstitial" and "alveolar" lung patterns confusin?
They refer to anatomic structures that can't be seen by the naked eye
What is the radiographic appearance of an airway or bronchial infiltrate lung pattern?
A distinct bad or layer of soft tissue opacity surrounding the bronchial lumen (look end on)
Vascular changes in the lungs are associated with what?
Alterations in pulmonary circulation
How is a "real" interstitial pattern described?
Background of the lung parenchyma is increased in opacity to the extent that peripheral vascular marking are partially obscured, but still just visible
In the alveolar pattern, it is implied that the alveolar air space has been replaced by what?
Material of soft tissue opacity: edema fluid, inflammatory tissue, blood or neoplastic cells
What is an air bronchogram?
When alveolar infiltration is extensive, the radiographic appearance is that of uniform homogenous opacification, through which air in the larger bronchi can be seen
A very small nodular pattern in the lung is refereed to as what?
Milliary opacities
Lung disease pattern as described in terms of distribution using what types of terms?
-patchy, cloudy, fluffy
Bronchitis will have what appearance on radiographs?
Increase in thickness of bronchial walls or surrounding lung tissue (peri-bronchial infiltration)
What is bronchiectasis?
Dilatation of bronchi, some of which contain exudate and my be increased in opacity
An increase in lung volume may be seen with bronchitis or bronchiectasis, what effect causes this increase in volume?
Check valve effect due to collapse of small bronchi during expiration
True or false. Any Mineralization of the bronchial wall and peri-bronchial infiltration is no tnormal.
False, most animals have some normally
Bronchiectatic lungs are pre-disposed to what condition?
Bacterial infections
What is the most common condition on which alveolar air trapping occurs?
Feline allergic bronchitis
What condition may be associated with feline allergic bronchitis?
Stress fx of the ribs
Bacterial pneumonias of systemic origin have what type of distribution in the lungs?
What type of lung pattern is seen with bacterial pneumonia?
Alveolar infiltration with air bronchograms
How do eosinophilic infiltrates present on a radiograph?
Fluffy irregular pattern, tendency to be a nodular configuration
Immune mediated infiltrates, such as those from FIP, produce what changes on a radiograph?
Homogenous opacification of the interstitial type
Inhalational pneumonia tend to affect which part of the lung lobes?
The dependent portions
An inhaled f.b. such as a grass seed tend to lodge where in the lungs?
Caudal lobes
Radiographic appearance of an inhaled f.b. may be what?
Interstitial type infiltration or well defined nodule formation
Granulomatous lesions tend to be located where in the lungs?
Pulmonary hemorrhage shows as which lung pattern?
What is the most common cause of pulmonary edema?
Congestive heart failure
Which lung lobe is often most severly affected with pulmonary edema from CHF?
Right caudal
When is pulmonary thrombo-embolism recognized radiographically?
In later stages, when infarction of the lung occurs
What appearance does pulmonary thrombo-embolism have?
That as an inflammatory lung disease
What happens to the lung lobe as a result of lung lobe torsion?
Becomes congested and filled with blood
What radiographic clue may indicate lung torsion?
Absence of fissures demarcating the affected lobe
Which lung lobes are usually affected by torsion?
Right middle and left cranial
After drainage what is the appearance of lung torsion?
A localized masss
What condition should be considered in any dog with severe and unremitting dyspnea and a normal chest radiograph?
Paraquat poisoning
Discrete solitary masses are usually easy to identify. Sometime, what additional views are needed for visualization?
Multiple projections- obliques
How large must a metastatic nodule be to be visible on a radiograph?
0.5- 0.75 cm in diameter
In some cases, when are small metastatic nodules best seen?
In portions of lungs superimposed on the heart or diaphragm where aerated tissue surrounding them is thin
What type of borders do metastases have?
Indistinct and fluffy
Milliary mets sometimes give the appearance of what texture?
Accumulation of free in in thin walled bullous structures of the lung are asscoiated with what 2 conditions?
-acute inflammatory dz
-recurring pneumothorax
What is the cause of a hematocyst?
Trauma- walled off collection of blood and free air that has escaped from damaged alveoli
What is the radiographic appearance of a hematocyst?
Clearly defined soft tissue opacity in the lung parenchyma, with a radiolucent center representing a gas bubble
How do you distinguish an abscess containing gas from a hemtocyst?
Margins are more irregular
What is the gas pattern seen in a cavitating neoplasm?
Irregular accumulation of gas
What is the main contribution of radiography to the management of cardiac disease?
Evaluation of pulmonary circulation
(preclinical recognition of hepatomegaly and ascites may also be heloful)
What does the cardiac silhouette on a radiograph represent?
The heart and pericardium
On a lat radiograph of the thorax of a dog, left artrial enlargement is seen as what?
Prominence of the caudo-dorsal prtion of the cardiac silhouette, the tenting effect
What structures become elevated as the left atrium increases in size?
Elevation of the carina and main stem bronchi
On the DV view, what is the clock face position of an enlarged left atrium?
As the left atrium continues to enlarge, it can be confused with what condition?
Right sided heart failure
What is the appearance of an enlarged left ventricle on a lateral view?
Straightening of the caudal cardiac border
Left ventricular enlargement is almost always accompanied by what condition?
Left atrial enlargement
Which chamber, when enlarged, is seen on the lat view as a bulging cranial heart shadow?
Right ventricle
What is the classic appearance of an enlarged right ventricle on a DV/VD view?
Reverse "D"
Why is an enlarged right atrium difficult to distinguish?
Lies mainly within the cranial mediastinum, changes merge with other structures
What is the most common cause of cardiomegaly in cats?
Hypertrophic cardiomyopathy
What is the most obvious radiographic finding in hypertrophic cardiomyopathy in a cat?
Bi-atrial enlargement
On the DV view, what is the appearance of the heart with hypertrophic cardiomyopathy?
Valentine shape
When does lobar vessel size become an issue?
From pulmonary volume overload
What pulmonary vasculature finding is charateristic in an infection with D. immiitis?
Wide, tortuous and truncated caudal lobe arteries
What is the most frequent reason for evaluating the pulmonary vasculature?
To check the effects of CHF and response to tx
When the heart shadow appears small and there is a reduction in the size of the peripheral vessels, what condition can you expect?
Shock or hypovolemia
When else might you see smaller than normal vessels?
Pulmonic stenosis and other congenital defects which lead to under-perfusion
Pericardial effusion appears how on a radiograph?
Globular heart shape
True or false. The globular heart appeatance is specific to pericardial effusion?
False, gross cardiac dliatation may have the same appearance
Which imaging modality is needed to distinguish pericardial effusion from gross cardiac dilatation?
What evidence of CHF might be seen radiographically before a change in the size or shape of the heart is seen?
Evidence of right sided CHF...wide caudal vena cava, enlarged liver
Which modality has revolutionized the dx of congenital heart defects?
What is the appearance of the heart in the case of a PDA?
Left atrial and ventricular enlargement, cardiac outline is elongated on both views, with marked ventricular rounding
In the DV projection, what is the appearance of the aortic and/or pulmonary segments in the case of PDA?
Maybe prominence
What are the classic radiographic signs of pulmonary stenosis?
Gross right ventricular enlargement and a prominent pulmonary knuckle
How do the lungs look in the case of pulmonary stenosis?
Under-perfused, pulmonary vasculature appears small and lungs hyperlucent
What finding might be seen in the case of subaortic stenosis?
May shpow as a prominence or bulge in the aortic arch, on both views
Dramatic signs of left or right sided cardiomegaly and CHF can be seen with what conditions?
Mitral or tricuspid valvular dysplasia
What is the most important view to visualize the pharlynx and larynx?
lateral view--low technique
In the conscious animal. where does the soft palate lie?
Ventral to the epiglottis
In the intubated dog, where does the epiglottis lie?
Ventral to the soft palate
Intraluminal lesions of the larynx and pharynx include what?
-foreign body
Cartilage disruption can be caused by what conditions?
Are hyoid fractures common or uncommon?
How many views does a radiopaque f.b. require for proper demonstration?
How can a soft tissue material type f.b. be delineated?
May be delineated by air
Laceration of the larynx/pharynx and resulting subcu emphysema is often a result of what type of trauma?
"run onto stick" injury
How might an abscess be seen radiographically?
May contain gas bubbles or streaks
Which type of tumor id distinctive, and relatively radiolucent?
What disease condition is seen as benign, well-circumscribed mineralized masses; the soft tissue of the neck is a predilection site.
Calcinosis cutis
What are the indications for radiography of the equine head?
-dental dz
-nasal discharge
-superficial swelling and/or discharging tracts
-signs of vestibular dz with facial paralysis
What are the technical requirments for radiography of the equine head?
-portable unit
-sedated, standing horse
-some form of cassette holder & stand
What is required to perform detailed dental radiography?
-deep sedation of horse & insertion of a gag
-possible gen anesthesia
Where do you center when taking a radiograph of the equine facial area?
On the distal facial crest
In the young adult hose, the sinus cavities are partially obscured by what structure?
Long reserve crowns of the cheek teeth
What view is used to see the maxillary arcade?
30 degree oblique
What view is used to visualize the mandible?
45 degree oblique
What is the purpose of intra-oral projections?
Demonstration of the rostral maxilla and mandible and incisor and canine teeth
Fractures of the skull are most common in what area?
Dorsal facial area
Penetrating fxs of the nasal bones and maxilla can lead to what condition?
-accumulation of blood in the paranasal sinuses
What is suture periostitis?
Damage to the fronto-nasal suture can lead to periosteal proliferation and associated soft tissue swelling
Hemorrhage of the gutteral pouch may be associated with what traumatic condition?
Fx of the skull base
Chip fx of the mandible and fxs involving teeth can become infected and lead to what condition?
Discharging tract with sequestra
Destruction of the nasal conchae is best seen on which view?
Is sinusitis in the horse related to dental dz?
Yes, can be primary or secondary to dental dz
What is the appearance of sinusitis?
Inflammatory changes in the mucosa, build up of granulation tissue causes diffuse, patchy increase in opacity and air spaces, fluid levels may be seen
Rhinitos can cause mineralization of the nasal cavity which can have what kind of radiographic appearance?
Coral formation
Which sinus dz tend to fill the sinus cavity and produce a homogenous opacification, mineralization may be seen.
Sinus cyst
Which sinus dz is adjacent to the ethmoturbinate and may bleed into the sinus?
Ethmoidal hematoma
How common are other neoplasias of the sinus?
Incisors are best seen on what type of view?
intra-oral films
Which views best demonstrate the cheek teeth?
30 and 45 degree obliques
What are the main indications for radiography of the teeth?
-disorders of eruption
-trauma involving the teeth
-peri-apical infection
-dental cysts and tumors
-peri-odontal dz
What are some of the radiographic signs of peri-apical dz?
-peri-apical lucency
-loss or thickening of lamina dura
-distortion or roots (clubbing)
-isolated radiodense cement fragments (pearls)
-proliferation of alveolar bone
-cortical remodeling
-secondary sinusitis
What is an odontoma?
Dentigerous cyst- bone like structure grwoing from petrosal bone
Which views are the only feasible projections for the equine larynx/pharnyx?
Lateral only
What are the disorders of the larynx that may be demonstrated on a radiograph?
-epiglottic entrapment
-sub-epiglottic cysts
What are the disorders of the pharynx/soft palate that may be demonstrated on a radiograph?
-palatine displacement
What are the disorders of the guttural pouch that may be demonstrated on a radiograph?
-stylohyoid destruction
To minimize the amount of magnification on a chest radiograph of an equine, what FFD should you use?
At least 2 meters
How many radiographic fields are needed to cover the adult thorax?
What is the valur of chest rads in a horse?
Can show free pleural air and fluid
Hemorrhage, severe generalized infiltrates and localized lesions can be detected in the portions of lungs not obscured by the heart
Can the heart be evaluated on radiographs of the equine thorax?
Not accurately
When would VD views be useful in foals?
To localize pulmonary lesions such a Rhodoccous equi, pneumonia and pulmonary congestion from congenital defects
The cervical vertebral column of the horse is assessed with which view?
How do you indentify C6 on a radiograph?
has transverse processes
What normal changes are seen in the cranial thoracic spine of the horse?
Cartlaiges of prolongation mineralize irregularly
What are the indications to take radiographs of the equine vertebral column?
-congential malformation
-degenerative disorder
What radiographic signs of Wobbler's might you see?
-instability.stepping of C3-C4
-compression at C2-3
What is a radio-pharmaceutical?
A radioactive element attached to an appropriate organic molecule
RP's become attached to molecules in the body at what sites?
-blood cells
-liver cells
-alveolar air
The radioactivity concentrated at the target site is measured by what device?
Gamma camera
Areas of high concentration of radiopharmaceutical are called what?
In vet med, where is nuclear medicine most widely used?
Equine practice for bone lesions before visible radiographic changes have taken place
What is the RP used for bones?
Tc99m (technetium)
What nuc med studies can be performed on the lung?
What are some other vet med uses of nuc med?
-hyperthyroidism (cats)
-arthropathies/mets in bones
Why can radiation be used against tumors?
It kills cells
What is the goal of radiation tx?
Maximize tumor cell death, minimize normal cell death
Radiation tx is useful for tumors in what areas?
Near critical structures such as brain, spinal cord, large vessels, urethra
What is the limiting factor in the use of radiation tx?
Tolerance dose of the adjacent tissues
What is teletherapy?
Radiation delivered in the form of a beam
What is brachtherapy?
Implanted sealed radiation source
Orthovoltage x-ray tx is used to treat what type of lesions?
Superficial skin lesions
What type of radiation tx units treat deeper lesions?
Linear accelerators
Sealed radioactive sources are used to deliver doses and can be placed where?
What sources is used for brachytx?
Ccesiums137, iodine131, iridium192
Specific organ uptake tx is used to tx what condition?
Feline thyroid neoplasia-most common use in vet med
How does radiation tx for the thyroid work?
A dose of I 131 is given that selectively destroys iodine containing cells
What are the effects of radiation on DNA?
-direct molecular disruption
-indirect-via free radicals (most common)
What are the consequences of DNA damage?
-damage is repaired
-irreparable damage
(death of normal cells, carcinogenesis, heritable defects)
The sensitivity of a cell to radiation is dependent on what?
Its mitotic activity
Which tissues are sensitive to radiation?
-bone marrow
-germinal cells
Which tissues are resistant to radiation?
What cell type has high mitotic activity but low sensitivity to radiation?
Which type of cells are 3 times more resistant to radiation?
Hypoxic cells
What are the clinical signs of the effects of radiation tx on skin?
-hair loss
-moist desquamation
What are the clinical signs of the effects of radiation tx on the oral cavity?
What are the clinical signs of the effects of radiation tx on the GIO tract?
Late effects occurs in which tissues?
Those tissues whose cells divide infrequently:
skin (fibrous)
or not at all....muscle, lens, CNS
How is the does minimized in radiation tx?
Teletherapy- keep field small
Fractionation- divide the dose up
Brachyx- does restricted to a local area
Sound waves are a series of pulses made up of what?
Compressions and reflections
What is the range of frequency used in U/S?
2-15 MHz
Since there is an inverse relationship between frequency and velocity, what type of wavelength do high frequency transducers have?
Small wavelengths
Which frequencies travel deeper into tissue...higher or lower?
Lower frequency travels deeper
How are the ultrasound waves created?
Crystals mechanically vibrate when stimulated by electric current (piezo-electric effect), electrical energy converted to sound waves
Name some of the types of tranducers?
What % of time is the crystal the emitter? and the receiver?
emitter: 1%

receiver: 99%
The sound waves interact with tissues at different what?
What is acoustic impedence?
Resistance to the transmission of sound
How does the US unit calculate an image?
The distance traveled of the reflected sound
The transmission of sound through air results in a reflection of what % of the sound waves?
Bone reflects how much of the sound waves?
The ability to see a fluid filled structure is passed on what principle?
Not all tissues attenuate equally (weakening of beam)
To ensure maximal reflection of sound back to the transducer, the transducer must be held in what position?
Perpendicular to the tissue of interest
Do higher or lower frequency transducer have better image quality?
Higher ... but don't penetrate as much
What is lateral resolution?
The ability to discern 2 objects close together in a lateral plane
What type of beam pulse gives better lateral resolution...thicker or thinner?
Two dimensional, general US work is done with which mode?
B mode
When is the M mode used?
The eyes are scnned using which mode?
A-amplitude mode
When is Doppler used?
Blood flow, specialized cardiac
B mode stands for what
Brightness...real time
What is meant by the term echogenic?
Echoes are visible
What is echongenicity?
Ability of a tissue to generate echos

if it cant is its echolucent or anechoic
What is an object that is hypoechoic?
Shades of grey
Bright or white
Abdominal radiography requires a minimal of which view(s)
Recumbent lateral and VD
How is a true lateral view obtained?
Pads placed under the sternum and between the stifles to avoid pelvic tilt
What view is taken to demonstrate free air in the abdomen?
Left lateral decubitus view
Which U/S transducer is used for a dog's abdomen?
3.5 - 7.5 Mhz
The presence of what, in the abdomen, increases radiographic contrast on plain films?
Intra-abdominal fat
What is the radiograhic appearance of the abdomen when it is fluid filled?
-lack of contrast
-homogenous soft tissue opacity
-poor serosal definition of the intestines
-inability to define the margins of the liver, spleen, bladder
-intestinal gas shadows lie in center of abdomen
-pendulous abd wall margins
-small volumes of fluid give an indistinct appearance to the center of the abd
For peritoneal fluid, what is the imaging modality of choice?
When might peritonitis form?
-secondary to trauma of abd wall or rupture of abd organ
-secondary to pancreatitis or pancreatic neoplasm
-seen with bile or urine in the abd
Peritonitis or abdominal fluid may have what appearance on U/S?
Swirling-snowy appearance
What findings might be seen in a case of retroperitoneal fluid--hemorrhage or urine?
-poor retroperitoneal detail
-ill defined renal shadows
-displaced renal silhouette
-displaced colon
Intra abdominal free gas may show what radiographic signs?
-separation of diaphragm from liver
-gas shadows surrounding and ehancing renal silhouettes
-unusual gas patterns- bubbles/streaks not associated with the GI tract
What is the standard method for imaging the GI tract?
Radiographs, plain and with contrast
Which lateral view is taken for a basic abdominal exam?
Right ( and VD)
What abnormalities might you find on an abdominal series?
-gastric distension/volvulus
-displacement or abnormal position
On a lateral view of the stomach, where is the long axis located?
Parallel to the 10th ICS
On the left lateral view, gas is seen in which portion of the stomach?
Pyloric region
The empty pylorus can sometimes be mistaken for what?
A f.b.
On the VD view, how does the stomach lie in a dog?
Long axis at right angle to the vertebral column
What is the shape and location of the cat stomach on a VD view?
On the left side of the abdomen, in a C-shape
Which drug can cause marked gastric dilatation?
What are some of the causes of gastric outflow obstruction?
-pyloric fb
-obstruction due to pyloric stenosis or neoplasia
-secondary extrinsic obstruction dues to pancreatitis or panc neoplasia
What radiographic sign might be seen in the case of a partial gastric torsion?
A soft tissue stripe seen crossing the area of the stomach compartmentilzation- food may be seen in 1 compartment
What other signs of torsion might be seen?
-small intestines in dorso-cranial abd
-air throughout the intestine
What additional technique might be need for confirmation?
Barium study
Which intestinal abnormalities requires radiologic investigation?
What is the normal diameter of the small intestine?
2 rib widths
What is the indication for a barium swallow?
-radiolucent f.b.
-infiltratitve bowel dz
Prior to using barium to examine the bowel, what 2 conditions should be met?
-stomach and bladder emptied
What is the GI transit time, and when should the tract be emptied post barium administration?
30-120 mins
should be empty in 3-5 hours
The normal colon in the dog has what shape to it?
Question mark-shaped
What are the outpouchings seen along the antimesenteric border of the duodenum on a barium study on a dog?
Peyers patches or "pseudoulcers"
collection of lymphoid material
What appearance does the duodenum of the cat often have?
String of pearls
True or false, a fimbriated appearance of the small intestine, with barium, is abnormal?
false, normal brush border appearance
As a rule of thumb, what should the size of the intestinal wall be?
1/8 to 1/4 the diameter of lumen
With which transducer can you image the layers of the stomach and intestine?
High frequency
What is meant by the term ileus?
Distension of a segment or segments of small intestine, may be localized or generalized
Where is the ileo-cecal joint located on a DV radiograph of a cat?
It isn't...it's the ileo-colic joint
What are some causes of local distension of bowel loops?
-neoplastic infiltrate
-local ahesions
The gravel sign is an indication of what?
Chronic obstruction
Generalized ileus is often associated with what conditions?
-chronic obstruction in the distal sm intestine
What would you suspect if you see barium outlining an irregular mucosal border?
Infiltration of the bowel wall from inflammatory dz or neoplasia
What is a redundant colon?
when the descending colon lies to the right of midline
What are some causes of colon distension?
-pelvic obstruction
-rectal diverticulum
-perineal hernia
Normally, where does the liver lie?
Within the costal arch
On a lateral view how does the liver appear?
Sharp triangular opacity peeking our beyond the last rib
Changes in the size or position of the liver are seen as changes to what?
The position of outline of the stomach or diaphragm
At which respiratory phase should a radiograph of the liver be made?
Expiration- inspiration may cause the lover to lie caudal to the costal arch
What are some radiographic signs of an enlarged liver?
-rounding of the caudal margin projecting beyond the costal arch
-projection beyond the costal arch
-cadual displacement of the gastric axis
-caudal displacement of abd organs
What causes a mirror artifact in U/S
Imaging a structure located next to a curved surface
What are some causes of reduced liver size?
-diaphragmatic hernia
How do you determine reduced liver size on radiographs?
-inability to identify ventro-caudal liver margin
-gastric axis displaced cranially
What contrast technique might be used to diagnose PSS?
Portal venography- cannual into the jejunal mesenteric vein
What is seen on a normal portal venogram?
Contrast fills the portal vein and its branches
What would you expect to see on a venogram with a PSS?
Contrast is shunted directly to the caudal vena cava or azygous vein
Which U/S technique can assist with a dx of PSS?
What is the gold standard to diagnosing a PSS?
Nuclear med
Where is the radioactive isotope administered to dx a PSS?
in the rectum
What is the echogenicity of choleliths?
Is the spleen visualized on radiographs?
Yes- the splenic head can be seen in the left cranial abd, lateral to the stomach on the VD view
In which lateral view is the spleen seen as a soft triangle on the mid-ventral abd, caudo-ventral to the pylorus and caudal to the stomach?
The right lateral...not consistently seen on the left lateral
What is the U/S appearance of the spleen?
Hyperechoic compared to the lover and kidneys, only a few vessels identified
What is the appearance of splenomegaly?
Soft tissue mass, mid ventral abd
What large circular finding in the mid ventral abd should not be mistaken for an enlarged bladder?
Hemangiosarcoma of the spleen
Spelenic rupture can have what radiographic appearance?
Poor serosal definition locally due to hemorrhage or metastatic seeding
What are the U/S findings of splenic rupture?
-echogenic fluid oscillating in the abd
-fibrn tags on serosal surface
-disruption of normal splenic outline
Splenic trosion may be seen as what sign by U/S?
Starry sky
How do ventral hernias appear on a radiograph?
Abdominal structures lying outside the abd cavity under the skin
what technique can help dx a perineal hernia?
contrast cystography
How does peritoneal fluid present on a radiograph?
-poor abdominal contrast
-serosal detail is indistinct
-may be local or general
Which modality is the method of choice for imaging fluid in the abdomen?
What is the U/S appearance of peritoneal fluid?
-anechoic areas outlined the serosal surfaces of abd structures
-swirling-snowy appearance
-fibrin tags
What are some causes of peritoneal hemorrhage?
-ruptured spleen
-ruptured liver
-avulsed blood vessel
-erosion of vital structure by neoplasm
-neoplasia ,carcinomatosis, melanoma
-peritoneal seeding-splenic neoplasia
Peritonitis may be seen with what types of fluid in the abd cavity?
What are the radiographic signs of peritonitis?
-poor serosal detail
-with intestinal perforation or pancreatitis it is usually localized
-free-intra-abdominal air
What is the appearance of the fluid in peritonitis on U/S?
Highly echogenic
What imaging procedure is used to evaluate the urinary tract?
Intravenous urogram (IVP)
A low volume of contrast is given rapidly...how can you improve the viscosity of the contrast before injecting it?
Warm to body temp
Post injection, images are taken at what time intervals?
0,1,5,10,15,20 minutes
What additional procedure can help visualize the bladder?
Pnuemocystography, bladder inflated with 50-200 ml air
In which situations should you NOT perform pneumocystography?
For U/S exam of the bladder should the bladder be full or air of urine?
Urine or saline
Which U/S scan plane is best to see the ureters?
Ectopic ureters are best seen with which procedure?
True or False. Cystitis is not usually diagnosed by radiography.
Uroperitonuem can be caused by what conditions?
-rupture of bladder
-rupture of ureters in peritoneal cavity
-rupture of urethra
-bladder rupture
What radiographic technique is useful on male dogs to evaluate the integrity and patency of the urethra?
Retrograde urethrography
An U/S evaluation of the kidneys includes what?
-number of kidneys
-focal or diffuse parenchymal lesions
-renal pelvis and collecting system
What 3 planes do you scan in for an U/S exam of the kidneys?
What types of kidney lesions can be seen with U/S?
What is the U/S appearance of a renal cyst?
Anechoic and well marginated
What type of renal lesion can have a mixed echogenicity and a disrupted architecture?
A renal neoplasm requires what procdure fro a definitive dx?
What conditions will appear diffusely in the kidney?
-ethylene glycol posioning
A hypoechoic area of the kideny cortex can be do to what dz?
A hyperechoic cortex could indicate what dz conditions?
-ethylene glycol poitoning
Poor corticomedullary definition can indicate what condition?
End stage renal dz
A distended renal pelvis and ureter can indicate what condition?
What are the U/S signs of chronic renal failure?
-small kidneys
-irregular margins
-diffuse hyperechoic kidneys
A large anechoic area surrounding the kidney can indicate what condition?
Perinephric cyst
Unilateral hydroneophrosis can be caused by what?
-ectopic ureter
-localized neoplasia in the bladder
-urethral calculus
What are some of the causes of bilateral hydronephrosis?
-neoplasia in bladder trigone
-severe or chronic cystitis
-ectopic ureter
what is the appearance of the renal pelvis and ureter in the case of hydronephrosis?
-distended pelvis
-tortuous ureter
What does a hydroureter look like on U/S
Anechoic tubular structure originating in renal pelvis, often tortuous
A hyperechoic foci in the renal pelvis is consistent with what finding?
renal calculi
What would a ruptured kidney look like on a IVP?
-absent or abnormal kidney shadow
-contrast leakage into adjacent area
On U/S a ruptured kidney will have what appearance?
-abnormal outline or disruption of the renal cortex or medulla
-retroperitoneal mass
True or False. U/S is the best method to image a ruptured ureter?
False- radiography
When is the genital tract of the non-pregnant female visualized on plain radiographs?
Only when the uterus or ovaries are enlarged- otherwise not seen
In the pregnant animal when does the uterus become visible on rads?
About the 5th week of pregnancy
When do fetal bones ossify?
Day 45
Via U/S, when can pregnancy be detected in the dog? The cat?
dog- 23-25 days
cat- 15th day
When can fetal movement be detected?
35 days
In the case of fetal death, what is Spalding's sign?
Overlapping bones of the cranium
What are the U/S sounds of fetal death?
-lack of fetal heartbeat and movement
-ags echoes within the fetus
How is pyometra seen radiographically?
As an enlarged uterus in the caudal abd that displaces the intestines cranially and dorsally
What is the appearance of a closed pyometra on U/S?
-a series of large, circular, thin-walled structures in the caudal abd- distended uterine loops are seen adjacent to each other
When is the prostate gland seen on radiographs?
-on the lateral view, just cranial to the pubic brim when the bladder is distended with urine
What are the causes of prostatomegaly?
-cyst formation
In which direction does prostatitis displace the bladder?
cranially and ventrally
What technique would help differentiate the bladder from the prostate?
Neoplasia of the prostate can metastasize to what areas?
-long bones
What is the overall appearance of the benign hyperplastic prosate on U/S?
The gland retains its shape, symmetry and smooth margins
What signs of prostatic neoplasia can be seen on U/S?
-irregular shaped gland
-multiple coelescing hyperechoic foci
-areas of hemorrhage and necrosis may be seen
Focal mineralization and cavitation can be U/S findings for what condition?
Can a specific type of testicular neoplasia be dx on U/S?
No, not specific type
What is the normal width of the cardiac shadow of the cat?
2 intercostal spaces
How is pericardial effusion identified on U/S?
An anechoic area surrounding the heart separating it from the pericardium
What happens to the appearance of the right atrial appendage in a tamponade condition?
The right appendage flails, right atrial wall collapses
What are some neoplastic masses that occur in the heart?
-heart base tumor
What is most common acquired cardiac disease in middle aged and older dogs?
Mitral insuffciency
What are some causes of mitral insufficiency?
endocardiosis, ventricular dilaiton, ruptured chordar tendinae, cardiomyopathy, endocaridits, congenital mitral valve dysplasia
What is a primary radiographic finding of mitral insufficiency?
Enlarged left atrium
On U/S what congenital defects might be seen in mitral insufficiency?
-valve leaflets may be shortened or club shaped
What condition, in addition to those that cause mitral insufficiency, can cause tricuspid insufficiency?
In which species is hypertrophic cardiomyopathy more common?
What condition is associated with hypertrophic cardiomyopathy?
In which species is dilated cardiomyopathy more common?
Which ventricle is enlarged in dilated cardiomyopathy?
The left vent
What is the U/S appearance of the left ventricle in hypertrophic cardiomyopathy?
Lumen appears reduced in size
-thickening of the septum and wall
-atrium us usually enlarged
What are the clinical signs of hypertrophic cardiomyopathy?
-sudeen onset of dyspnea
-weight loss
-hindlimg ataxia or paresis from thrombus of the terminal branches of the aorta
In what type of dogs are rupture of the chordae tendinae seen?
Athletic dogs or chronic cardiac dz
What is the radiographic presentation of the heart with pulmonic stenosis?
-rounding of right heart border
-increased sternal contact
-elevation of trachea
right vent rounded
True or False, with an US view the pulmonary artery should be the same width throughout its length?
What is the radiographic appearance of aortic stenosis?
-absence of cranial cardiac waist caused by post stenotic dilatation
-straightened caudal cardiac border
-aortic arch prominent between 12-1:00 on DV
Which way does blood shunt in a PDA?
Left to right-pulmonary overload
What 3 radiographic signs of a PDA form a knuckle on the DV view between 1-3:00?
-enlarged pulmonary artery
-enlarged aortic arch
-dilatation of left atrium
Which US mode helps to dx the PDA via blood flow?
Ventricular septal defect is more common in which species?
On US where is the ventricular septal defect often seen?
High in the ventricular septum just below the aortic valve
What imaging technique can be used to view the defect?
Contrast echocardiogram or Doppler
How common is an atrial septal defect?
Uncommon usually doesn't occur alone
Atrial septal defect should not be confused with what normal condition?
Septal dropout- a very thin membrane replaces the normal spetum
How do you distinguish a septal dropout from a septal defect?
Contrast echo (bubble study) or doppler
What are the terms for a low or high location for an atrial defect?
Low = primum
High = secundum
Heart base tumors arise in what area?
Around the heart base and the great vessels
Pericardial fluid is common in a heart base tumor. What other radiographic signs are seen?
-elevation of terminal trachea and/or esophagus
-trachea may be displaced to the right
-cardiomegaly caused by pericardial effusion
What is the US M mode and when it is used?
Motion mode- for cadiology- accurate chamber measurement
What is the duplex mode?
A scanner that displays 2 D and M mode at the same time
What can Doppler help determine?
-blood flow direction
-flow velocity
-uniformity of flow
In Doppler, what does the red color coding mean? Blue?
Red= towards the transducer
Blue= away from the transducer
In Doppler, what is meant by an array of bright colors?
What is measured by using pulsed wave Doppler?
Pressure within vessels
What type of transducer is needed to image the thoracic wall?
High frequency
Which imaging modality is preferred for diagnosing a pneumothorax?