Diagnostic imaging of the respiratory tract 1 Flashcards
Describe normal lung radiograph
majority of lung radiolucent. most radiodense structures are pulmonary arteries and veins, arteries and veins branch and taper in the periphery. the pulmonary veins are ventral to the principal bronchus on the lateral view and medial to it on the VD and DV views (veins are ventral, veins are central).
What should you consider if there are signs of a pneumothorax?
Other signs of trauma - rib fractures (count ALL ribs), ruptured diaphragm, urinary bladder visible?
What should you consider if there are signs of pleural fluid?
- Tracheal or lobar displacement to suggest a mass?
- Cranial displacement of abdominal viscera?
What should you consider if there are signs of possible cardiac enlargement?
Any signs of cardiac failure? (left sided - pulmonary oedema versus right sided - hepatomegaly and ascites)
What should you consider if there are signs of dialted oesophagus?
signs of aspiration pneumonia
What should you consider if there are signs of ventral lung consolidation?
Look for oesophageal dilatation
What should you consider if there are signs of minimal pulmonary lesions in coughing animal?
look carefully for laryngeal and tracheal lesions
What should you consider if there are signs of an unexpected or puzzling lesion?
examine entire film again
Probable origin - cough that is exercise-induced - 3
larynx, trachea, cardiac disease
Probable origin - cough that is low-grade and persistent
bronchi, pulmonary lesion impinging on bronchi
Probable origin - noisy dyspnoea
Upper airway obstruction (laryngeal mass, tracheal stenosis, mass impinging on trachea)
Probable origin - quiet dyspnoea
SOL in thorax (pneumothorax, pleural fluid, mass, ruptured diaphragm)
Probable origin - cyanosis
Airway obstruction OR right-to-left shunt (ToF)
Probable origin - panting
Probably normal. Possibly cushings.
List the 5 different patterns visible when radiographing the nasal cavities.
- ) Normal
- ) Areas of increased soft tissue opacity superimposed over normal conchal pattern
- ) Areas of increased soft tissue opacity superimposed over areas of conchal destruction
- ) Areas of decreased opacity due to conchal destruction
- ) Mixed pattern
Possible cause - normal nasal passage appearance on radiography
Normal animal OR acute rhinitis
Possible cause - areas of increased soft tissue opacity superimposed over normal conchal pattern - 2
Chronic rhinitis
Nasal FBs
Possible cause - areas of increased soft tissue opacity superimposed over areas of conchal destruction - 2
Conchal destruction indicates aggressiveness - one of two options - aspergillosis (areas of increased and decreased opacity within the same side of the nose)OR neoplasia (more uniform destruction across nose, e.g. adenocarcinoma)
Possible causes - decreased opacity areas due to conchal destruction - 2
Aspergellosis OR neoplasia
Possible causes - mixed pattern (of increased and decreased opacity)
Aspergellosis OR neoplasia
What are the 3 broad manifestations of lesions affecting the upper airway?
- Occupy the airway
- Cause narrowing
- Cause narrowing and displacement
What might occupy the URT? 3
FB
Mucosal nodules due to Oslerus osleri
Neoplasm
What might cause narrowing of the URT? 5
- Tracheal hypoplasia
- Collapsing trachea
- Thickened tracheal membrane (severe tracheitis)
- Submucosal haemorrhage (coumarin toxicity)
- Neoplasm
What might cause narrowing and displacement of the URT?
Retropharyngeal lymphadenopathy mediastinal mass
What age-related changes might be seen in the lung? 3
Pleural lines, mineralised bronchial walls and mild hazy lung appearance.
Why is the non-dependent lung more informative on radiography?
The non-dependent part of the lung is better aerated (so provides a better background).
Do lung changes reflect specific aetiologies?
No - the lung responds to various aetiological factors in very few ways. Furthermore changes seen change over time and indicate disease progression or regression.
List the 5 different lung patterns
bronchial, interstitial, alveolar and vascular
(this is the order of disease progression too, reverse this order for regression either with treatment or spontaneously).
Mixed = where there is alveolar and interstitial patterns identified together.
Define bronchiectasis
a clinical sign, not a disease in itself. all untreated lung diseases end like this. the bronchi diameter are enlarged (i.e. they don’t taper towards the periphery)
How can you distinguish an interstitial from an alveolar lung pattern?
Interstitial - blood vessels are present
Alveolar - blood vessels are absent
Define bronchial pattern
mineralisation of the bronchial walls with age. Also thickening of the bronchial walls and/or increased diameter of the bronchi.
Causes - bronchial pattern - 5
- Bronchial mineralisation (age)
- Allergic bronchitis
- Chronic bronchitis
- Peribronchial cuffing (oedema)
- Bronchopneumonia
Causes - interstitial pattern
- pneumonia
- oedema
- haemorrhage of any cause
- neoplasia
Define interstitium
elements of the lung that do not contain air - alveolar and interlobular septa, microscopic BVs.
How is interstitial pattern characterised?
Localised or diffuse
Nodular or unstructured (hazy)
What is the sensitivity of radiology for pulmonary metastasis?
65-90% - right and left lateral view of the thorax are required.
Differentials - pulmonary nodules
- metastatic neoplasia*
- haematomas
- granulomas
- fluid-filled bronchi
- abscesses
How are primary pulmonary masses different?
larger than nodules and may cause displacement of the mediastinal structures to the contralateral hemithorax.