Radiography Respiratory Flashcards
Causes of mediastinal shift? Or apparent mediastinal shift?
- unilaterla pleural effusion/pnumothorax
-diaphragmatic hernia - collapsed lung lobes
- chronic pleural disease with adhesions
- sternalvertebral abnormalities
> NB: oblique projection may give impression of shift
What may a rounded lung lobe with pleural effusion indicate?
More proteinaceous effusion (not for definite)
What structure lie in the mediastinum? * those that can be seen on rads?
- trachea*
- oesophegous
- heart*
- caudal VC *
- cranial VC
- aorta and major branches (brachiocephalic trunk)
- thoracic duct
- LNs
- Nerves
What result of injection in the neck may present with thoracic changes? How would this be seen on rads and what may occour 2* to this?
- pnuemomediastinum
- ^ visability of BVs, oesophagous and tracheal wall
> 2* gas lucency in neck fascial planes, thoracic wall and pneumoperitoneum
> CAN lead to to pneumothorax (But not the other way round)
Width of normal mediastinum?
< 2x thoracic vertebra width
* exception: bulldogs, may be fatter normally
Causes of widened mediastinum?
- bulldogs
- obesity
- thymic sail in young animals
- hameorrhage
- mediastinal/ascess
- oedema
- chylomediastinum
- mediastinal masses
WHat mediastinal masses may be present?
- thymus in young animals
- neoplasia
- oesephageal dilation
- sternal lymphadenopathy
- abscess/granuloma
- haematoma
- cyst
What are the most common positions of mediastinal masses? What are the likely causes at each position?
- cranial to heart under trachea
- thymoma, lymphoma, haemangiosarcoma, could be abscess/cyst) - tracheobronchial lympho nodes dorsal to trachea and at bifurcation
- caudo ventral thorax
- diaphragmatic hernia - dorsocaudal thorax
- hiatal hernia or gastraoesophageal hiatal hernia
Which side should trachea lie to?
right hand side
What may cause diaphragmatic diplacement?
> caudal - inspiration - pnuemothorax - emphysema > cranial - ascite - hepatomegaly - abdominal neoplasia - obesity - gastric distension
Potential radiographic signs fof diaphragmatic hernia?
- incomplete visualisation of diaphragm
- enlarged cardiac silhouette (PPDH)
- caudal mediastinal mass (PMDH)
- extrapleural mass
- cranial displacement/malposition of abdominal viscera
- pleural effusion
What are the most radiodense structures in the lung?
Pulmonary arteries and veins
- branch and taper in the periphery
What further problems shold be suspected if pneumothorax seen?
- trauma eg. rib fx
- urinary bladder visable?
What should be suspected if pleural fluid seen?
- tracheal/lobar dispalcement suggestive of mass?
- cranial displaceent of abdo viscera?
What should be looked for if cardiac enlargement suspected?
- cardiac failure signs eg. ukonary oedema, hepatomegaly, ascites
What hsould be suspected if ventral lung is consolidated?
- oesophageal dilation
What should be suspected if minimal pulmonary lesions are found in a coughing animal?
Laryngeal or tracheal lesions
What appearances may be seen on rads of URT? 5
- normal nasal passages (eg. acute rhinitis)
- areas of ^ soft tissue opacity on NORMAL conchal pattern (eg. chornic rhinitis, nasal FB)
- areas ^ soft tissue opacity superimposed on areas of CONCHAL DESTRUCTION
- ares v opacity due to conchal destruction
- mixed
Which lesions OCCUPY the upper airway?
- FB
- mucosal nodules due to oslerus osleri
- neoplasia
Which lesions cause NARROWING of the upper airway?
- tracheal hypoplasia
- collapsing trachea
- thickened tracheal membrane (severe tracheitis)
- submucosal haemorrhage (coumarin toxicity)
- neoplasia
Which lesions may cause NARROWING and DISPLACEMENT of the upper airway?
- retropharyngeal lymphadenopathy
- mediastinal mass
POtneital pulmonary patterns visable on radiograph? Defining features?
- bronchial (affects bronchi only)
- vascular (affects vessels only)
- interstital (patchy and rough looking, CAN STILL SEE VESSELS)
- alveolar (fluffy and cloud like, NO VESSELS VISABLE)
Stages of bronchial pattern visable?
- none
- normal
- thickened (donuts and tramlines)
- bronchiectasis (end stage of all pumonary inflammatory disorders)
What may cause bronchial patterns?
- bronchial mineralisation (normal ageing process)
- allergic bronchitis
- chronic bronchitis
- peri bronchial cuffing (oedema, bronchopneumonia)
hat causes interstitial patterns?
- pneumonia
- oedema
- haemorrhage (any cause)
- neoplasia
What vascular patterns are possible and what causes them?
- enlarged arteries: pulmonary hypertension (R-L shunt PDA, dirofilariasis)
- enlarged veins: congestion (mitral insufficiency)
- aa and vv. enlarged: overcirculation (L-R shunt, overhydration)
- SMALL aa. and vv. : hypovolaemia, tetrology of fallot
Causes of alveolar pattern?
Lack of air in the alvioli -> NO visibility of vessels > localised - bronchopneumonia - oedema - hmeorrhage - neoplasia - lung collapse/atelactasis - dirofilaria - pulmonary infarct > diffuse - severe bronchopneumonia - severe oedema - hamoerrhage * near drowning * smoke inhalation
Causes of lung hyperlucency?
> diffuse - overexposure - weight loss - hypovolaemia - overinflation - air trapping - emphysema > focal - bulla - lobar emphysea - pulmonary embolism
Causes of calcifed lung lesions?
> focal/multifocal - bronchial calcification (not pathological) - PHBF - granuloma - osteosarcoma mets - 1* lung neoplasia - aspirated barium sulfate > diffuse - HAC - HPTH - chronic uraemia - idiopathic
What is contained within the mediastinum?
(formed by reflection of parietal pleura)
- trachea
- heart
- oesophagus
- aorta and major braches
- thoracic duct
- LNs
- nerves
What should you be able to see within the mediastinum on a normal radiograph?
- caudal vena cava, aorta, cardiac silhouette
Causes of mediastinal shift?
> pressure difference in left and right pleural cavities
- unilateral lung collapse
- diaphragmatic hernia
- collapsed lung lobes
- chronic pleural space disease with adhesions
- sternal and vertebral abnormalities
- NB. Oblique positioning may give impression of mediastinal shift
What may be seen with pneumoomediastinum?
- increased visability of oesophagus, tracheal wall and blood vessels (cranial vena cava, brachiocephalic trunk)
What may occour 2* to pneumomediastinum?
- gas lucency in fascial planes of neck
- pneumoperitoneum
- pneumothorax (but not vice versa)
WHat width should the normal mediastinum be?
- =/<2x thoracic vertebra width
- exception: bulldogs wider mediastinum
causes of widened mediastinum?
- bulldog
- obesity
- thymic sail in young animals
- haemorrhage
- mediastinitis/abscess
- oedema
- chylomediastinum
- mediastinal mass
What masses may be present in the mediastinum?
- thymus (young)
- neoplasia
- oesophageal dilation
- sternal lymphadenopathy
- abscess/granuloma
- haematoma
- cyst
