Diagnostic imaging of the respiratory tract Flashcards
Describe thoracic radiographs.
Almost always indicated
▪ Do not take radiographs of dyspneic pets!
▪ Take both lateral and a vd-view
▪ Abnormally increased lung opacity over a wide area?
Predominant radiographic lung pattern?
▪ Bronchial
▪ Interstitial
▪ Vascular
▪ Alveolar
Main 4 radiographic lung patterns?
▪ Bronchial
▪ Interstitial
▪ Vascular
▪ Alveolar
what do you see in the left?
and the right?
Characteristics of a bronchial lung pattern?
tram tracks and donuts
Describe a bronchial lung pattern.
The tram tracks and donuts are caused by Thickening of the airway walls, accumulation of cell infiltrates around or
inside the bronchi.
Possible causes of a bronchial lung pattern: (9)
Age-related bronchial mineralization,
chronic bronchitis,
eosinophilic
bronchopneumopathy (dogs),
asthma (cats),
bacterial tracheobronchitis,
bronchopneumonia,
aspiration pneumonia,
edema,
bronchiectasis.
what do you see in the left?
and the right?
Characteristics of an interstitial lung pattern?
Mild-moderate increase in lung
opacity, lung appears hazy.
Describe an interstitial lung pattern.
The lung opacity or haziness is caused by Increased interstitial tissue, fluid or cell infiltrates in the interstitium of the lungs.
Possible causes of an interstitial lung pattern: (7)
Artefacts,
exudates,
edema,
hemorrhage,
pulmonary fibrosis,
metastatic neoplasia,
primary neoplasia uncommon.
alveolar lung pattern
Characteristics of an alveolar lung pattern? (4)
Uniform soft tissue opacification,
border obliteration with adjacent
soft tissues,
aerobronchograms,
lobar sign
Caused by Alveoli filled with fluid
or cells or collapsed.
Possible causes of an alveolar lung pattern: (5)
Bronchopneumonia,
aspiration pneumonia,
atelectasis,
pulmonary contusion,
edema
alveolar pattern
broncho-alveolar pattern
likely bronchopneumonia, cardiac edema, asthma yms.
vascular pattern
Vascular patterns are due to
An Increase in pulmonary vascularity.
Pulmonary arterial branches and/or
veins distended.
o End-on vessels = round opaque shadow
o Side-on vessels = thick bands
E.g. caused by Early left heart failure, left-to-right shunts, heart worm disease.
A Decrease in pulmonary vascularity may be caused by Hypovolemia, right-to-left shunts, dirofilaria.
Topographic description of lung fields
Unilateral or bilateral
perihilar, cranioventral, dorsocaudal, caudoventral
PAthologies typical to Cranioventral lung fields (4)
▪ Bronchopneumonia,
aspiration pneumonia,
hemorrhage,
neoplasia
Pathologies typical to Caudodorsal lung fields (4)
Pulmonary edema,
fibrosis,
hemorrhage,
neoplasia
A diffuse lung pattern such as pictured can be typical to… (4)
Bronchitis,
eosinophilic bronchopneumopathy,
fibrosis,
extension of caudodorsal disease
cardiac hemangiosarcoma with metastatic disease
unilateral Pneumothorax
Displacement of the heart dorsally away
from the sternum in lateral view.
Retraction of the lung lobes away from
the thoracic wall.
Lack of vascular and bronchial markings
beyond the border of collapsed lung lobes.
Increased opacity to the lung lobes
secondary to atelectasis.
Flattening of the diaphragm.
tumor in pulmonary artery in this image, causing In Pleural effusion. A Large amount of fluid that Obscures the cardiac shadow and diaphragm.
◦ Retraction of lung margins from
sternum, lungs appear to be floating in the fluid
◦ Dorsal displacement of trachea and
pulmonary hilus
Describe Ultrasound of the thorax.
Air-filled lungs obscure deeper pulmonary
lesions.
Useful for evaluation of pleural effusion or
peripheral lung lesions.
Can help in identifying pulmonary edema,
other pulmonary pathology or
pneumothorax.
Ultrasound-guided fine needle aspirates and thoracocentesis.
What is VetBlue?
Stands for Veterinary Bedside Lung Ultrasound Exam, its a U/S protocol for small animals.
its a regional, pattern-based approach that has its views named caudodorsal, perihilar, middle, and cranial lung regions plus the Diaphragmatico-Hepatic (DH) view.
This approach is analogous to how we are taught to interpret lung on radiography.
”Wet” vs. ”dry” lung
- A-lines (normal) and B-lines (abnormal)
What do the Shred Sign, Tissue Sign, Wedge Sign, and Nodule Sign have in common?
For signs of consolidation, the vetblue U/S protocol has defined several signs including the Shred Sign, Tissue Sign, Wedge Sign, and Nodule Sign.
Describe Imaging of nasal cavity
- Radiography the least sensitive
CT, MRI preferred - Several projections needed
for radiographs
Frontal projection
Open mouth ventrodorsal
Dorsoventral projection
Lateral projection
The 4 projections needed for nasal cavity radiographs.
Frontal projection
Open mouth ventrodorsal
Dorsoventral projection
Lateral projection
frontal projection for nasal cavity radiography
Open mouth ventrodorsal for nasal cavity radiography.
Dorsoventral projection for nasal cavity radiography
Lateral projection for nasal cavity radiography
Heart sizing of dogs off thoracic radiographs. (2 options)
LATERAL VIEW
Dogs
* Vertebral heart score (VHS)
8.5-10.5 (breed variation!)
or
* 2.5- 3.5 intercostal spaces
Heart sizing of cats off thoracic radiographs.
LATERAL VIEW
Cats
* Vertebral heart score 7.2-7.8
or
* 2- 2.5 intercostal spaces
Assessment of heart shape
Enlargement of left atrium
* Normal shape of left atrium (red line)
* Enlarged left atrium is forming
a bulging convex shape (blue line)
Left: right side of heart enlarged
Right: atrial enlargement and cardiogenic pulmonary edema
