Chest x-ray



PA film

  • Left hilum "never" lower than right
  • Left hilum usually more prominent
  • CTR = max heart vs max internal (rib to rib) chest diam
  • Both domes and heart borders clear?
    • RHB indistinct = RML
    • LHB indistinct = LUL
    • Rt diaphragm indistinct = RLL
    • Lt diaphragm (medially) = LLL

CXR Lateral

Lat CXR

  • Lower T spine darker than upper
  • Whole right diaphragm visible
  • Left visible from cardiac shadow to costophrenic recess

Upper mediastinum: 1st rib to betw angle of Loius & T4

  • Upper reaches of all in lower mediastimum

Lower mediastimun divided into 3:

Ant ⅓: Body sternum to pericardium:

  • Thymus
  • Nodes
  • Internal thoracic vessels

Mid ⅓: Pericardium:

  • Heart/Pericardial sac
  • Origins great vessesl
  • Tracheal bifurcation

Post ⅓ Pericardium to vertebrae:

  • Descending aorta/branches
  • Azygos /hemiazygos venous veins
  • Thoracic duct ∓ cisterna chyli
  • Oesophagus
  • Vagus & splanchnic nerves

CXR lateral

Lateral CXR

Ant mediastinal mass (4Ts)

  • Thymoma (Ca++, 15% have myaesthenia gravis)
  • Teratoma
  • Thyroid
  • Terrible Lymphoma

Pulmonary oedema

CXR signs

  • Upper lobe diversion (distended cf normal)
  • Kerley B line (1cm long lat subpleural, interstitial fluid)
  • Cardiomegaly
  • Batwing (peripheral sparing) oedema
  • Peribronchial cuffing (airway oedema)
  • Pleural effusions

Pulm. Oedema DDx

  • ARDS
  • Pulm. haemorrhage
  • Atypical pneumonia e.g. fungal, PCP

Fibrosis

Lower lobe fibrosis

SCAR

Systemic sclerosis

Cryptogenic fibrosing alveolitis

Asbestosis

Rheumatoid arthritis

Upper lobe fibrosis

BREASTS+C

Beryllium

Radiation

Extrinsic allergic alveolitis

Ankylosing spondylitis

Sarcoidosis

TB

Scoliosis

Coal workers pneumoconiosis



Content by Dr Íomhar O' Sullivan. Last review Dr ÍOS 4/04/23.