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Flashcards in Lungs Deck (15):
1

Clinical significance

  • Diseases that involve the cardiovascular system and those that involve the pulmonary system have similar signs
  • Assessment of either system requires a good understanding of the anatomy and circulation dynamics of the pulmonary vasculature bed
  • Thoracic radiography is frequently performed to examine patients with expected neoplasia or clinical signs of coughing or dyspnea
  • Coughing or dyspnea may be due to disease of the heart, pleural space, trachea, lymph nodes, body wall, diaphragm, or lungs

2

Anatomy

  • 2 main pulmonary arteries originate from the main pulmonary trunk
  • Left PA is more dorsal than the right
  • One main pulmonary vein courses back from ea. lung to empty into the left atrium
  • Similarly a bronchus supplies each lung
  • The bronchus is always accompanied by an artery and vein--triad (bronchus is in the middle)

3

Radiographic anatomy

  • When you look at the pulmonary blood vessels you should see that they branch and taper toward the periphery
    • Should see these vessels clearly extend to the lung borders
  • "Veins are venral and central"
  • Caudal lobe pulmonary blood vessels are better seen in DV view
  • Arteries and veins of the non-dependent (up) lung are easier to see
  • In the L lateral view the right cranial lobar artery and vein should be the same size

4

Radiographic anatomy: lung lesions

  • In small animals, lung lesions generally are detected best in the non-dependent lung because the 'up' lung is better aerated and therefore provides better contrast of lesions
    • Ex: the DV view is better for evaluating the caudal lung lobes; LLAT is better for evaluating right lung lobes
  • Other lesions (i.e. not lung) generally are best seen on the 'down' side because they are not distorted by magnification
  • In large animals lung lesions are best detected in the lung closest to the cassette because lesions in the "far" lung are distorted due to magnification

5

What are the 4 lung patterns?

  1. Bronchial
  2. Interstitial
  3. Alveolar 
  4. Mixed

6

Bronchial pattern

  • Normally only main stem bronchi seen
  • Smaller bronchi become visible with:
    • Mineralization
    • Cellular or fluid infiltration
  • Increased conspicuity of the bronchial tree
  • Ring shadows (donuts)
  • Tram lines

7

Interstitial pattern

  • Often diffuse
  • Structured pattern
    • Nodular pattern < 2cm
    • Mass lesions very distinct
    • Metastasis #1 DDx
  • Unstructured pattern
    • Most difficult one to diagnose
    • Generalized haziness
    • Pulmonary lymphoma

8

Alveolar pattern

  • Alveoli no longer filled with air
  • Air (radiolucent) replaced by soft tissue (increased) opacity
  • Consolidation--air replaced by fluid or cells
    • Edema, blood, pus, neoplasia
  • Atelectasis--air is squashed out of lung
    • Total atelectasis = lung collapse
    • Often assoc. w/ pleural disease

9

Alveolar pattern: 4 types

  • Air bronchograms
    • Air only in bronchioles--can see nothing else
  • Border effacement
    • Only caused by alveolar pattern 
  • Lobar distribution
    • Fissure separating normal from abnormal lung lobe
  • Labile
  • Major pitfall: confusing an air bronchogram with a normal gas filled bronchus (w/ its pulmonary vein and artery on either side)

10

Atelectasis vs. consolidation

  • Atelectasis
    • Inc. soft tissue opacity
    • Dec. size of lung lobe
    • Shift of heart towards rib
  • Consolidation
    • Inc. soft tissue opacity
    • Normal to inc. sized lung lobe
    • Heart remains in normal position

11

Mediastinal shift

  • Best seen on VD/DV radiograph
  • Usually not apparent on the lateral
  • Atelectasis may appear on lateral as lesion of inc. soft tissue opacity
  • Lung atelectasis--mediastinum moves to side of decreased lung size
  • If thoracic mass or fluid--mediastinum moves to opposite side and lung compensates

12

Airway vs. non-airway

  • Alrternative way of classification
  • Helpful to determine further diagnostic approaches
  • Airway: alveolar or bronchial pattern
    • Transtracheal aspiration or bronchoalveolar lavage
  • Nonairway: interstitial pattern
    • Rather percutaneous or open aspiration/biopsy needed

13

Interpretation: focal vs. non-focal

  • Focal
    • Abscess
    • Granuloma
    • Neoplasia
  • Multifocal
    • Neoplasia
    • Abscess
    • Fungal granuloma
    • Parasitic 

14

Mineralization

  • Bronchial pattern
  • Lesions
    • Histoplasmas granulomas in dogs
    • Aspirated barium contrast material
    • Neoplasia (dystrophic)
  • Incidental
    • Pulmonary osseous metaplasia

15

Blood vessels vs. nodules

  • Blood vessels
    • Soft tissue (end on, inc. length, inc. opacity)
    • Well-marginated
    • Smaller to periphery
    • Associated with blood vessels
    • Tail sign
  • Nodules
    • Any size
    • Same opacity (round)
    • Not as well marginated
    • Not assoc. w/ blood vessels