Thorax Radiography Flashcards
For VD and DV radiographs, which side of the image is the patients right side?
the left side of the image
in VD/DV radiographs, the caudal vena cava is on the left or right side?
right side of the patient (left side of image)
what condition would make it so every postion inside the thorax is switched
in situs inversus
in VD/DV radiographs, what side should the gastric fundus be?
left side
in VD/DV radiographs, what side should the splenic head be
left side
What is a cranioventral mediastinal reflection
an indicator of laterality in thoracic radiographs
present on the left side - thicker, probably from mediastinal fat
in VD/DV radiographs, what side is the cranioventral mediastinal reflection
left side of patient (right side of image)
in VD/DV radiographs, what side is the caudoventral mediastinal reflection?
left side of patient (right side of image)
what thoracic view shows the caudodorsal vessels better? *
DV
What radiographic view gives you three “bumps” from the diaphragm
VD
1) Diaphragm capula
2) Left hemidiaphragm
3) Right hemidiaphragm
What radiographic view gives you on large view of diaphragm
DV- cupula
what lateral view has the hemidiaphragms that are close and in line
right lateral
what lateral view has the hemidiaphragms separated?
left lateral
on lateral radiographs, the caudal vena cava merges with the
right hemidiaphragm (best seen on right lateral because the right hemidiaphragm is more cranial)
How do you tell appropriate positioning of a VD/DV thoracic radiograph
1) Roughly Equal thorax space each side of spine
2) Sternum is over the spine
3) Spinous-processes straight and have a tear drop shape
How should the sponous processes look in a correctly alighed VD/DV radiograph
tear drop shaped
How should the sternum be positioned in a VD/DV radiograph
over the spine
In a correctly positioned VD/DV radiograph the thoracic space should be ________ in relation to the spine
equal on each side of spine
You see on radiograph that a patient’s sternum is off to the patient’s left side (right side of image). How do you fix the positioning
Sternum needs to move a small distance to the patients right side
When taking lateral shots of the thorax, how do you know you have correct positioning
1) Rib heads superimposed
2) Rib curvature should match
3) Pull limbs out of image to minimize bone and soft tissue on the top of the lunb
When taking lateral thoracic shots, why do you need to pull the limbs out of the image
to minimize bone and soft tissue on the top of the lung that could be hiding a lesion
How many lobes of lung do the dog have
Left: 2- Cranial (cranial and caudal part) and Caudal
Right: 4 - cranial, middle, caudal, and accessory
How many lobes does the left canine lung have
2- Cranial (cranial and caudal part) and Caudal
How many lobes does the right canine lung have
1) Cranial
2) Middle
3) Caudal
4) Accessory
on a right lateral view, mostly the ________ lung is seen
left lung
What lung lobe typically shows up on both left and right lateral views
accessory lobe (right lung lobe) because it is close to midline
Veins are ________ and ________ to the bronchus
ventral and central
normal bornchial walls are invisible when
peripheral- becomes very small and invisible
Arteries and veins should be equal in size (or veins slightly larger) and they should be be no larger than the _______________ where they cross
9th rib (really subjective)
where do the pulmonary arteries and veins cross
at the level of the 9th rib
What might cause an animal to have both big pulmonary arteries and veins on radiograph
1) Left to Right Cardiac Shunt (PDA, VSD, ASD)
2) Iatrogenic fluid load
What conditions cause a left to right cardiac shunt and subsequent big arteries and veisn on radiography
1) Patent Ductus Arteriosus
2) Ventricular Septal Defect
3) Atrial Septal Defect
What are causes of small pulmonary arteries and veins on radiograph
1) Hypovolemia
2) Shock
Uncommon: addisons disease, severe pulmonic stenosis with hypoperfusion to lungs, right to left cardia shunt (tetraology fallot of reversal with high right heart pressure)
With tetralogy of fallot, what will the pulmonary arteries and veins look like
small
How might a left to right shunt reverse
due to high right sided heart pressure (Eisenmenger syndrome0
What might cause the pulmonary arteries to be big and the veins to be normal
1) Pulmonary hypertension
2) Heartworm Disease (huge and weird shaped)
3) Thromboembolism (rare)
With pulmonary hypertension, what appearance will the pulmonary vessels have
Big Pulmonary Arteries
normal pulmonary veins
With heartworm disease, what appearance will the pulmonary vessels have
Big Pulmonary Arteries
normal pulmonary veins
What causes normal pulmonary arteries and big veins
Left sided heart congestion
a) Mitral valve degeneration
b) Cardiomyopathy (dilated, hypertrophic, etc)
rare: mitral valve dysplasia (congential) , left atrial obstruction (mass, thrombosis, cor triatriatum sinister)
In patients with left sided congestion heart failure, what radiographic appearance will you see
normal pulmonary arteries and big pulmonary veins
In patients with mitral valve degeneration, what radiographic appearance will you see
normal pulmonary arteries and big pulmonary veins
Are lung nodules or masses smaller
nodules
How does the appearance of lung nodules differ from lung masses
Nodules: soft tissue opaque, usually round
Masses: soft tissue opaque, round or irregularly shaped, can have ill-defined margins, can have air bronchograms
T/F: mineralized nodules are rare, often mixed with soft tissue opacity
True
What are your two differentials for multiple nodules/masses in the lung
1) Metastatic neoplasia: most common by far
2) Granulomas (fungal if geographical, feline asthma, certain inflammatory diseases)
3) Hematogenous pneumonia (rare)
What might cause multiple granuloma nodules/masses on the lungs
1) Fungal disease (if geographical)
2) Feline asthma
3) certain inflammatory diseases
What might cause a solitary nodule/mass in the lungs
1) Primary lung tumor (especially if one mass)
2) One small nodule (early metastatic neoplasia)
3) Granuloma (uncommon)
what are miliary nodules
nodules that are very tiny
may coexist with larger nodules
can occur in metastatic neoplasia
a pulmonary nodule/ mass that forms spontaneously or from trauma
cavity that contains gas
uncommon
Bulla
What is the smallest a nodule cab be visible on pulmonary radiographs
as small as 2mm, varies depending on patient size and regional superimposition
What might mimic pulmonary nodules on radiograph?
1) pulmonary osteomas
2) End-on vessels
3) Dermal structures: dermal nodules/masses and nipples
4) Costochondral junction remodeling
T/F: pulmonary osteomas is malignant
false- it is completely benign and unimportant
just when the lung decides to make bone
How can you tell pulmonary osteomas from pulmonary nodules
Pulmonary Osteomas have mineral opaque and often pointy shapes, but can be round
Pulmonary nodules are _____________ opaque while pulmonary osteomas are ________
Pulmonary nodules = soft tissue opaque (same as vessels)
Pulmonary Osteomas = mineral opaque (visible at smaller size)
Will Pulmonary osteomas or pulmonary nodules be more visible at a smaller size
Pulmonary Osteomas (mineral opaque)
Small pulmonary nodules are ________ shaped while pulmonary osteomas are _____ shaped
Small pulmonary nodules: round and smooth
Pulmonary osteomas: visible and weird shape
What are Pulmonary Osteomas
also called osseous metaplasia
very common
totally benign and unimportant
mineral opaque
often pointy shape, but can be round
often in lung periphery
may progress throughout the coarse of a dog’s life
End-on vessels will be (more/less) opaque than a same-sized soft tissue nodule
more opaque
Why are end-on vessels more opaque than a same size tissue nodule
because the opacity is based on the diameter
Nodules are sphere which gives it a soft tissue opacity
End-on vessels are cylinder which gives it a stack of soft tissue opacity = more opaque
How do end-on vessels differ from end-on airways
End-on vessels- very opaque, in the path of the vessel
End-on airways- lucent because they contain a stack of gas
What appearance do end-on airways have
lucent because they contain a stack of gas
What might cause cutaneous nodules that trick you in thinking pulmonary nodules
Nipples
where is costochondral junction
between the bone and cartilage within a rib
How can you locate the external location of a nipple when taking radiographs
coat the nipples with barium paste
What kind of dogs is costochondral junction remodeling common in
old dogs- small mineral nodules around these junctions
What does Costochondral junction remodeling look like
1) Mineral opaque
2) Location at the junction between the bone and cartilage
3) Usually irregular, can be smooth/round
How to you double check you are seeing nodules correctly
take other views
-DV to see caudodorsal lungs
-oblique views?
-retake the same view to see if it moves relative to the lung
-external structures coated with barium paste or tape on BBs
-humanoid projection
-recheck in 1-2 months
What is a humanoid projection
a VD where the thoracic limbs are pulled caudall.
move scapulae and soft tissues away from the cranial lung lobes
can help distinguish if you worried about pulmonary nodules
gas filled round structure with a very thin soft tissue opaque rim
bulla
what causes bulla
unknown cause or from trauma
what could rarely occur with bullas
could rarely rupture causing a pneumothorax - be careful with the degree of lung inflation under anesthesia
show up in typical locations between lobes
when normal, can see thin margins of visceral pleura that surrounds the lung lobes
pleural fissure lines
What appearance does pleural effusion have?
it widens the pleural fissure lines, especially wider peripherally (triangle-shaped)
What are the radiographic signs of pleural effusion
1) Widened pleural fissure lines
2) Larger volumes- thorax more opaque and soft tissue opacity around the lungs (border effacement of cardiac silhouette and diaphragm)
3) Lungs retracted and rounded
VD/DV: apparent widening of the cranial mediastinum (border effaced)
On VD/DV, what does pleural effusion look like?
apparent widening of. the cranial mediastinum (border effaced)
When you see widened pleural fissure lines, what do you think?
pleural effusion
Lungs may have interstitial pattern with pleural effusion due to
1) Underexpansion
2) Superimposed soft tissue opaque
may have an alveolar pattern if atelectasis
Lungs may have an alveolar pattern with pleural effusion due to
atelectasis
On a DV radiograph, where is pleural effusion pulled
gravity pulls fluid into the ventral thorax
-ventral thorax is narrower
-fluid stacks higher
-more opaque
heart is ventral and more border effaced by fluid on this view
On a VD radiograph, where is pleural effusion pulled
fluid goes into the dorsal thorax
-wider and able to spread out
more easily see pleural fissure lines
Are pleural fissure lines better seen on DV or VD
VD
With pleural effusion, is the heart more easily border effaced on a DV or VD view
DV
How will pleural effusion change the cranial mediastiium
it will make it look wider
free gas around retracted lung margins
-lack of vessels in gas-filled pleural space
atelectasis
pneumothroax
what does pneumothorax look like on lateral view
1) heart is dorsally displaced due to gas between the heart and sternum
2) Diaphragm is flattened
what does pneumothorax look like
1) free gas around retracted lung margins
-lack of vessels in gas-filled pleural space
2) atelectasis
Lateral:
1) heart is dorsally displaced due to gas between the heart and sternum
2) Diaphragm is flattened
what are the three pulmonary pattern types
-Bronchial
-Alveolar
-Interstitial
the region where blood vessels and other structures (like bronchi) enter an organ
Hilus
What does a bronchial pattern look like
End-on: thick rings, lucent in center (onion rings)
Long-axis: Paired thick lines, seen more peripherally, thinner than vessels
What is the mechanism of developing a bronchial pattern
*Thickening of airways
1) usually chronic inflammation (hypertrophy and fibrosis)
2) sometimes acute( edema)
3) Rarely neoplasitc
What diseases cause a bronchial pattern?
a) Feline asthma
b) Eosinophilic bronchopneumopathy
c) Chronic/previous inflammation (older patients, previous disease, inhaled irritants)
d) infection (usually other patterns are present)
What is your first differential for a purely bornchial pattern in cats
Feline asthma
what is the radiographic appearance of alveolar pattern
-Soft tissue opaque lung region
-At least one of the following:
1) Air bronchogram
AND/OR
2) Lobar signs
AND/OR
3) Border effacement with soft tissues
An alveolar pattern is soft tissue opaque with one of what three criteria?
1) Air bronchogram
AND/OR
2) Lobar signs
AND/OR
3) Border effacement with soft tissues
What is an air bronchogram seen with the alveolar pattern
lucent airways with surrounding soft tissue opacity
all regional vessels are border effaced (because they are also soft tissue opaque)
What is the lobar sign seen with alveolar pattern
distinct smooth soft tissue opaque margin at the edge of a lobe, adjacent to normal lung
What is border effacement with nearby soft tissues seen in alveolar pattern
lose visibility of margins of cardiac silhouette, diaphragm, etc
What causes alveolar pattern
1) Edema (noncardiogenic or cardiogenic pulmonary edema)
2) Blood (trauma or coagulopathy)
3) Pus (Pneumonia- aspiration) or inflammatory (eosinophilic bronchopneumopathy)
4) Neoplasia (primary or metastatic)
*stuff in alveoli or atelectasis
What are the radiographic features of an interstitial pattern
1) Increased background opacity of the lung: opacified interstitial space is usually textured appearance between the gas-filled alveoli
2) Large pulmonary vessels visible but fuzzy (small peripheral vessels are not visible)
*Not as severe as alveolar- not meeting any of the 3 criteria
T/F: intersitial is not as severe as alveolar
true
What causes an interstitial pattern
1) Edema (noncardiogenic or cardiogenic pulmonary edema)
2) Blood (trauma or coagulopathy or LEPTOSPIROSIS)
3) Pus (Pneumonia- aspiration) or inflammatory (eosinophilic bronchopneumopathy)
4) Neoplasia (primary or metastatic LYMPHOMA)
5) Fibrosis *
6) Underexpansion (lack of air in alveoli)
Underexpansion (lack of air in alveoli) would lead to what pattern
Interstitial
Leptospirosis causes what pattern
Interstitial
Fibrosis causes what pattern
Interstitial
Lymphoma causes what pattern
Interstitial
Feline asthma causes what pattern
Bronchial
Eosinophilic bronchopathy causes what pattern
Bronchial
What pattern is seen with decreased lung volume
Interstitial or Alveolar
-can be one lobe, one region, or entirety of lungs
What causes atelectasis on radiography
1) Image taken at expiratory phase of breathing (not at peak inspiration)
2) Hypo inflated- dog not taking deep breathes (body shape, mass, disease preventing lung expansion)
3) Sedation
4) Anesthesia - pure O2 increases atelectasis
5) Prolonged recumbency in one position
6) Pleural space contents: Pneumothorax- gas; Pleural effusion- fluid
7) Bronchial obstruction: mucus plug, mass, foreign body
How could anesthesia cause atelectasis
1) Pure O2
2) Prolonged recumbency in one position
3) Sedation
What pleural contents could cause atelectasis
1) Gas- pneumothorax
2) Pleural effusion- fluid
What pattern is seen with atelectasis
Interstitial or alveolar from decreased lung volume
It is best to take thoracic radiographs at
peak inspiration
Taking radiographs at expiratory phase could result in
marked caudodorsal interstitial pattern
-should go away with inspiratory phase
What radiographic finding tells you the dgeree of lung inflation
the size of the triangle between the cardiac silhouette, caudal vena cava, and diaphragm
-indicates the degree of lung inflation
What lung shows lesions better
the up lung
Right lateral shows left lung better
DV shows dorsal lung better than VD
Is the down or up lung more likely to have atelectasis
down lung
-soft tissue opaque lesions will be invisible or less visible
Mineral lesions might still show up
*some important lesions might still show up (can miss lesions or fail to localize without both laterals)
What is the horizontal beam VD
a view to demonstrate atelctasis
Dog laying on left side (like left lateral view)
X-ray tube moved to make radiograph parallel with the tube
Partial atelectasis of the down lung happens with all lateral thoracic views
Partial atelectasis of the down lung happens with all
lateral thoracic views
Why is a right and left lateral recommended in al thoracic study
because Partial atelectasis of the down lung happens with all lateral thoracic views
DV shows ________ lung better than VD
dorsal lung
What should be included in a thoracic study
right AND left lateral is recommended
Typically VD or DV (can do both)
When do we use DV views
1) Dyspneic animals
2) Better view of dorsal lungs and pulmonary vessels
3) Cardiac studies (depends on familiarity)
When do we use VD views
1) Usually better patient compliance
2) Spread out pleural fluid
Is DV or VD better for dorsal lungs and pulmonary vessels
DV
Is DV or VD better for dyspneic animals
DV
What radiograph view spread out pleural fluid
VD
Can you rule out minimal pleural effusion if you see thin pleural fissure lines?
NO
show up in typical locations between lobes
pleural fissure lines
What widens pleural fissure lines
pleural effusion
What are the radiographic findings of pleural effusion
1) Widened pleural fissure lines
2) Larger volumes
-Thorax is more opaque than usually (soft tissue opacity around lungs)
-Border effacement of cardiac silhouette and diaphragm
-Lungs retracted and rounded
-VD/DV: apparent widening of cranial mediastinum (border effaced)
With pleural effusion, how are the lungs shaped *
retracted and rounded
what sign of VD/DV will you see with pleural effusion
apparent widening of the cranial mediastinum (Border effaced)
Lungs may have _______ pattern with pleural effusions by may have ___________ if atelectasis
Pleural effusion: interstitial
Atelectasis: Alveolar
Why do lungs have intersitital pattern with pleural effusion
-Underexpansion
-Superimposed soft tissue opaque fluid
On DV, where does pleural effusion go
gravity pulls fluid to the ventral thorax
-Fluid stacks higher
-More opaque
Heart is ventral (more likely border effaced by fluid on this view
With pleural effusion, what view is most likely to result in the heart being border effaced
DV- heart is ventral
Does pleural fluid stack higher on DV or VD
DV- fluid stacks higher and more opaque
On VD, where does pleural effusion go
dorsal thorax- wider and more spread out
more easily see pleural fissure lines
Is pleural effusion lines more likely to be seen on DV or VD
VD- fluid is in dorsal thorax and more widely spread out
free gas around retracted lung margins
pneumothorax
-lack of vessels in gas-filled pleural space *
What are the radiographic appearances of pneumothorax
1) Free gas around retracted lung margins
2) Lack of vessels in gas filled pleural space
3) Atelectasis
4) Heart is dorsally displaced (gas between heart and sternum)
5) Flattened diaphragm
What might you be suspicious of if you see the heart being dorsally displaced from the sternum on lateral view
Pneumothorax
all the “middle” tissues between the lungs (including the heart)
mediastinum
what does the normal thymus look like
“sail sign”
-triangular soft tissue opacity in cranial mediastinum
-visible in left cranial thorax
Where is the normal thymus visible
left cranial thorax
When should the thymus be gone by
1 year of age
(often a small amount of remnant)
What is a mediastinal shift
rightward or leftward displacement of the mediastinum (including cardiac silhouette) on DV/VD
What might cause a mediastinal shift
volume loss of increase
What might cause a leftward mediastinal shift
1) Volume increase on right due to lung mass
2) Volume decrease due to left cranial lung lobectomy or atelectasis
3) Obliquity
left cranial lung lobectomy would result in a
leftward mediastinal shift
right lung mass would result in
leftward mediastinal shift
in an anesthetized dog you see a left sided mediastinal shift due to volume decrease from atelectasis, what would bring it back to normal
positive pressure ventilation
What is the normal cranial mediastinum size on VD view *
Dog: <2x the width of the thoracic vertebrae
Cat: Same size as thoracic vertebrae
What are causes of cranial mediastinum widening on VD view
1) Fat (especially brachycephalic breeds) *
2) Masses *
3) Pleural or mediastinal fluid
4) Esophageal dilation (esp w fluid)
What breed is likely to have cranial mediastinal widening due to fat
brachycephalic breeds
What are your differentials for a cranioventral mediastinal mass
1) Lymph node enlargement
-Neoplasia- lymphoma, histiocytic sarcoma, metastatic neoplasia)
-Fungal disease
-Reactive lymphoid hyperplasia (node draining inflamed region)
2) Thymoma- or normal thymus in a very young patient
3) Brachial / Mediastinal cyst (benign) -especially in cats, can be large
4) Ectopic thyroid tumor (rare)
What might cause mediastinal masses (not in the cranioventral area)
-Enlarged esophagus (dilation, foreign body, tumor, abscess)
-Abscesses, mediastinitis (rare)
-Hiatial hernia
What are the radiographic signs of cranioventral mediastinal masses
VD/VD: usually midline mass- widened cranial mediastinum and rounded margin
All views (sometimes)
-Trachea displaced/compressed
-Heart displaced
-Less cranial lung inflation
T/F: Pneumomediastinum can lead to pneumothorax
true
T/F: Pneumothorax can lead to pneumomediastinum
false
What are the radiographic findings of Pneumomediastinum
1) Small volume (bubbles)
2) Large volume = increased visibility of mediastinal structures
-Trachea (inner and outer margins)
-Esophagus
-Major vessels
3) +/- Gas in neck or retroperitoneal space
-Areas connected with mediastinum
4) Normal lung expansion unless also pneumothorax
With Pneumomediastinum large volume of gas there is an increased visibility of mediastinal structures. Which structures?
-Trachea (inner and outer margins)
-Esophagus
-Major vessels
With pneumomediastinum there is normal lung expansion unless there is
pneumothorax
What are the causes of pneumomediastinum
1) Tracheal tear/ rupture
-HBC
-Bite wound
-overinflation of endotracheal tube (in cats often days after anesthetic event)
2) Esophageal perforation
Overinflation of the endotracheal tube can lead to
pneumomediastinum
overinflation of endotracheal tube (in cats often days after anesthetic event)
What are the 3 different intrathoracic lymph nodes
Sternal
Cranial Mediastinal
Tracheobronchial
Where are the sternal lymph nodes
just dorsal to the 1st to 3rd sternebrae on midline
usually seen on lateral view (if very large, cranial mediastinum widened on VD/DV)
What view can you see sternal lymph nodes
usually seen on lateral view
(if very large, cranial mediastinum widened on VD/DV)
If there is very large sternal lymphadenopathy, where might you see the sternal lymph nodes
(if very large, cranial mediastinum widened on VD/DV)
Where are the cranial mediastinal lymph nodes
dorsal to the region of the sternal lymph nodes
cranial to cardiac silhouette, ventral to trachea
just dorsal to the 1st to 3rd sternebrae on midline
sternal lymph nodes
How many tracheobronchial lymph nodes are there
3
Right
Left
MIddle
Any may be enlarged
What are the radiographic signs of tracheobronchial lymphadenopathy
VD/DV: enlarged middle node = mass between the mainstem bronchi
(mainstem bronchi pushed laterally)
Lateral view: carina may be angled ventrally
On lateral view, what sign will show you there is tracheobronchial lymphadenoapthy
carina may be angled ventrally
On VD/DV, what sign shows you there is tracheobronchial lymphadenopathy
enlarged middle node = mass between the mainstem bronchi
(mainstem bronchi pushed laterally)
What are your differentials for tracheobronchial lymphadenopathy
-Histiocytic sarcoma or lymphoma
-Fungal disease
-Sometimes inflammatory lung diseases (e.g eosinophiic bronchopneumopathy0
How do you tell tracheobronchial lymph node vs left atrial enlargement
Both will have a perihilar mass that spreads the mainstem bronchi on VD image
HOWEVER
tracheobronchial LN enlargement is separated from the cardiac silhouette, sometimes ventral angle of carina
LA enlargement merges with the cardiac silhouette
-No ventral angle of carina
Does tracheobronchial LN enlargement or LA enlargement more likely to have ventral angle of carina
Tracheobronchial LN enlargement
What are reasons to image the trachea
-“honking cough”
-dyspnea
-cough elicited easily on tracheal palpation
What might cause narrowing of the trachea
tracheal collapse due to chondromalacia (common)
tracheal collapse due to chondromalacia is common in what breeds
small/toy breed dogs
What is dynamic tracheal collapse
narrowing of the trachea that is sometimes seen different between views in a radiographic study
What is static tracheal collapse
narrowing of the trachea that is consistent throughout respiratory cycle
What is a fakeout for tracheal collapse
soft tissue is often superimposed with the dorsal trachea
-called redundant dorsal tracheal membrane or esophageal draping
interpretation should be informed by dog breed (some small breeds and most larger dog breeds shouldnt get chondromalacia)
redundant dorsal tracheal membrane
also called esophageal drapping
soft tissue is often superimposed with the dorsal trachea
interpretation should be informed by dog breed (some small breeds and most larger dog breeds shouldnt get chondromalacia)
What are the radiographic findings of traumatic diaphragmatic hernia
1) Cant see part of the diaphragm
2) Abdominal organs in the thorax
-Soft tissue opaque and/or gas containing
-Abdominal organs absent from abdomen
3) Mediastinal shift due to herniated structures
4) Pleural effusion
What diaphragmatic hernia is typically congenital
Peritoneo-pericardial diaphragmatic hernia (PPDH)
usually doesnt cause problems
T/F: Peritoneo-pericardial diaphragmatic hernia (PPDH) usually doesnt cause a problem
true
What are the two different types of hiatal hernias
1) Sliding hiatal hernia (common)
-Brachycephalics
-Stomach slides cranial through hiatus
2) Paraesophageal hernia (uncommon)
-Fundus herniates to side of esophagus
What is the most common hiatal hernias
Sliding hiatal hernia (common)
-Brachycephalics
-Stomach slides cranial through hiatus
a hernia where the stomach slides cranial through the hiatus
Sliding hiatal hernia
Sliding hiatal hernia is commonly seen in what breeds
Brachycephalics
a hernia where the fundus herniates to the side of the esophagus
paraesophageal hernia
where a portion of stomach herniates into thorax in expected region of esophagus
with or without gas
often intermittent/dynamic
hiatal hernia
How many ribs are there normally
13 paired ribs
evenly spaced
Rib tumors
may be expansile, lytic, and/or osteoproductive (produce bone)
-Primary bone tumor most common
-Metastasis also common
Look for rib lysis if there is an extrapleural mass
Can be complete lysis of rib
Rib tumors may be:
1)
2)
3)
Expansile
Lytic- extrapleural
Osteoproductive
Are rib tumors likely to be
primary bone tumor
How do you distinguish extrapleural vs pulmonary masses
Extrapleural: obtuse angle of surrounding lung
broad margin in the chest wall
Pulmonary: acute angle of surrounding lung, narrow interface with chest wall (if any)
only works if you are tangential to the interface
What does an acute rib fracture look like
displaced sharp margins
may have soft tissue swelling or emphysema (trapped gas)
What does a chronic rib fracture look like
smooth oval of bony callus when healed
some may never heal, resorption causes smooth edges
T/F: with rib fractures, often multiple ribs are affected in a row and at similar level
true
T/F: degenerative changes in the sternum are common and unimportant
True unless there is ill-defined lysis, irregular periosteal proliferation (neoplasia or osteomyelitis)
When might sternal abnormalities be important
ill-defined lysis, irregular periosteal proliferation (neoplasia or osteomyelitis)
What are the general regions of lung distribution on lateral radiographs
Cranioventral
Caudodorsal
Ventral
Perihilar
Peripheral
Cardiogenic pulmonary edema in dogs is from
left sided congestive heart failure
What lung pattern is typically seen with cardiogenic pulmonary edema
interstitial and/or alveolar pattern
-generally caudodorsal region or perihilar
T/F: Perihilar intersitital and/or alveolar pattern is less common but more specific for cardiogenic pulmonary edema
True
Where is the interstitial and/or alveolar pattern typically seen with cardiogenic pulmonary edema
perihilar or caudodorsal region
What are the radiographic findings of cardiogenic pulmonary edema in dogs
1) Intersitial and/or alveolar pattern (generally caudodorsal or perihilar)
2) Left Atrial enlergement +/- left ventricle enlargement (tall silhouette), may be obscured by the alveolar pattern
3) +/- visible pulmonary vein dilation (very specific)
asymmetric or symmetry
What are radiographic signs of cardiogenic pulmonary edema in cats
1) Cardiomegaly (less than dogs)
2) No typical pattern of cardiogenic edema in cats
-sometimes similar to dogs
-often more random patchy, multifocal
3) Can have pleural effusion with L sided congested heart failure
Cats can have what with L sided congested heart failure
pleural effusion
Does Cardiogenic or Noncardiogenic pulmonary edema have:
left atrial enlargement
Cardiogenic
Does Cardiogenic or Noncardiogenic pulmonary edema have:
Perihilar pattern
Cardiogenic
Does Cardiogenic or Noncardiogenic pulmonary edema have:
Peripheral pattern
Noncardiogenic
Does Cardiogenic or Noncardiogenic pulmonary edema have:
normal pulmonary vessels
Noncardiogenic
Does Cardiogenic or Noncardiogenic pulmonary edema typically occur in older animals
cardiogenic - except in congenital heart disease
Does Cardiogenic or Noncardiogenic pulmonary edema have systemic problems
noncardiogenic
What are the clinical signs of non-cardiogenic pulmonary edema
1) Intersitial and/or alveolar pattern (mainly caudodorsal) but peripheral distribution is more specific for non-cardiogenic
2) Heart often normal (unless coincidence)
asymmetric or symmetric
What should you do if you are unsure there is cardiogenic or noncardiogenic pulmonary edema
Echocardiogram or try furosemide to see if pattern improves in 24 hours
Peripheral distribution is more specific in pulmonary edema that is
non-cardiogenic
What are the important causes of non-caridogenic pulmonary edema
1) Seizures (if severe)
2) Electric shock (chewing on chord)
3) Hypoxemia
4) Near drowning
5) Choking or other upper respiratory obstruction
6) Acute Respiratory Distress Syndrome (ARDS)
you should suspect aspiration pneumona is what is in the history
vomiting, regurgitation, or anesthesia
-especially if severe vomiting or dysfunction of larynx (ie laryngeal paralysis)
What are the different kinds of pneumonia
1) Aspiration: vomiting, regurg, anesthesia, laryngeal dysfunction
2) Infectious (Bronchopneumonia)
Bacteria, viruses, some parasites
Fungal infection (Histo, Blasto, Valley fvr)
3) Hematogenous
What pattern is typically seen with aspiration pneumonia
alveolar pattern
+/- interstitial and/or bronchial
almost always ventral distribution (especially craniovental)
one or multiple lung lobes
Aspiration pneumonia is almost always what distribution
almost always ventral distribution (especially craniovental)
one or multiple lung lobes
What does aspiration pneumonia look like on radiographs
1) Alveolar patterns (+/- interstitial and/or bronchial) - often hide the cardiac silhouette
2) Ventral distribution (esp cranioventral), one or multiple lung lobes
Bacterial/Parasitic pneumonia may be identical to aspiration pneumonia or
random patchy bronchial/interstitial/alveolar pattern
What does viral pneumonia look like
diffuse or regional interstitial pattern
if secondary bacterial infection: ventral alveolar pattern
What can fungal pneumonia look like
any pulmonary pattern or combination
can have miliary pattern, nodules, or masses
often thoracic lymph node enlargement
Systemic illness and travel hx is very important
What is often enlarged in fungal pneumonia
thoracic lymph nodes
what does metastatic pulmonary neoplasia look like
multiple nodules/masses
miliary pattern (numerous tiny nodules)
solitary site of metastatic neoplasia is less common
What does primary pulmonary neoplasia look like
usually one mass
can have lung metastasis late in dises (one buig mass and multiple smaller nodules - size disparity)
can be cavitary (esp in cats)
rarely have regional bronchial thickening from infiltration
What does lymphoma look like of radiographs
Diffuse interstitial pattern or nodules
+/- thoracic LN enlargement
rarely bronchial thickening
What does histocytic sarcoma look like on radiographs
one or multiple pulmonary masses
+/- thoracic lymph node enlargement
Predisposed to peripheral locations
What are other differentials for neoplastic processes in the thorax
fungal disease (geographic)
abscess (single mass, rare)
granulomas (feline asthma)
In cats, primary pulmonary masses can
spread to the digits
can be one digit or multiple digits on multiple limbs
In lung-digit syndrome, what phalanx is most commonly affected by lysis
distal 3rd phalanx
T/F: in lung digit syndrome in cats, lameness is often detected before the pulmonary mass
true
What should you do if you see lysis of the digits upon radiography
take thoracic radiographs
Lower airway diseases, commonly caused by allergic, infectious/inflammatory etiologies is what pattern
Bronchial pattern * +/- other patterns
What are the radiographic consequences of bronchial disease
1) Lung lobe collapse
-Bronchial obstruction from mucus plugs
-Cranial and middle lung lobes most common
-Marked volume loss, alveolar pattern
2) Pulmonary hypertension
-Lucent expanded lungs
-Flattened diaphragm
-Tenting of diaphragm
3) Spontaneous rib fractures from respiratory effort- especially caudal ribs
4) Bronchiectasis
With bronchial disease, what causes lung lobe collapse
bronchial obstruction from mucus plugs
With bronchial disease, what lobes are most commonly affected
cranial and middle lung lobes
weakened bronchial wall due to chronic inflammation, seen in lower airway disease
Bronchiectasis
What are the radiographic features of Bronchiectasis
1) persistently increased bronchial diameter
2) Bronchus doesn’t taper well peripherally
3) Thickened bronchial wall if bronchitis
What does pulmonary hyperinflation seen with lower airway disease look like
1) lucent expanded lungs
2) flattened diaphragm
3) Tenting of diaphragm
What does a pulmonary contusion look like on radiograph
patchy interstitial to alveolar pattern, can be anywhere
often asymmetric
history of trauma
can have other findings of trauma and shock
