How to look at a CXR Flashcards
What scans use ionising radiation?
X-ray
CT
Nucelar medicine scan
PET
Not MRI or US
When is CXR not helpful?
- non specific chest pain
- minor chest trauma
- pre-op
- no routine CXR
- unnecessary repeats
Lung lobes
Right = 3 Left = 2
Fissures on lungs
Right = horizontal above oblique Left = just oblique
What is the hilum
Medial part of lung where vasculature structures cross over
4 broad densities on x-ray
1 = air = black = no absorption 2 = fat =dark = little absorption 3 = water/soft tissue = mid grey = more absorbed 4 = bone/calcium = white
Standard position for CXR
Erect PA
Unless ill = AP
How to read a CXR?
Patient Name Male/Female Age Hospital Number Position on top right Check central trachea between clavicles Check exposure Heart size = CTR<0.5 (only PA) Aorta-pulmonary window (between aorta and pulmonary artery) Hilar (R. slightly lower) Diaphragm (R. higher) Densities of lungs in zones on both sides Clavicles in tact? Ribs count (7-10)
How to check exposure
Should be able to make out vertebral bodies and IVD through mediastinum
Pneumonia CXR
- consolidation
- air space changes (reduced, replaces with fluid/pus)
- increased density = whiteness
- silhouette sign = loss of normal outlines
- air bronchograms (residual air in larger airways surrounded by fluid/pus filled alveoli)
Collapse
- trachea shift towards affected side
- volume of lungs reduced
- compensatory hyperinflation of other lobes and lung
- rib crowding
TB
- patchy
- patchy, nodular between ribs
- fluffy
- calcified granuloma
- gohn focus (usually lower down)
- cavity (consolidated ring with air space in middle)
What causes cavitated consolidation?
INFECTION = pneumonia
- from TB
- Staph Aureus
- Klebsiella
- others = Wegners
Miliary TB
- haematogenous spread
- multiple nodular densities
- sometimes sarcoid can form this or metastases
Pleural effusion
- start of as blunting of costophrenic angle
- meniscus curved sign
Hiatus hernia
- double heart border
- horizontal air fluid level
- absence of stomach air bubble
Early sign of tension pneumothorax
Depressed hemidiaphragm
Congestive Heart Failure
- Kerley B lines near base
- enlarged heart
- increased backpressure on venous system
Pulmonary oedema
- haziness
- Kerley B lines
Lymphangitis
- lung cancer
- involved locking lymphatic channels
- lymph nodes affected
Interstitial Lung Disease
- pulmonary fibrosis
- mesh
- honeycombing
- shaggy heart
- reduced lung volume
Bronchiectasis
- lots of circular airspaces = bronchi
- tram track sign = double parallel signs
- need CT scan to characterise it as difficult to see
Pericardial effusion
- massive lobular heart = cardiomegaly
Metalwork
- sternotomy wires
- CABG = clips
- valves = mitral or aortic