Thoracic Imaging

Chest Radiography and other techniques

X-ray projection Department or mobile unit Projection – PA of AP according to

direction in which X-ray beams travel through patient

Heart magnified in AP projection X-ray taken during full inspiration Arms abducted

X-ray projection

X-ray projection Lateral x-ray – patient turned 90º,

effected side against film cassette

Arms extended forward

X-ray projection

X-ray projection Lateral decubitus – small pleural

effusions Patient lies horizontally, effected

side placed downwards Film cassette at the back of

patient, X-ray beam from front

X-ray projection

Lordotic film – middle lobe collapse

AP projection – patient arches back so that shoulders are touching the cassette

Other techniques Fluoroscopy – “real time” visuals of

patient on television monitor

Other techniques Ultrasonography – high-frequency

sound waves Limited use in chest, but used for cardiac imaging

Other techniques Computer tomography – X-ray tube

and detectors rotate around patient

Other techniques Magnetic resonance imaging –

patient lies in middle of large magnet

Combination of intense magnetic field and series of radiofrequency waves

Other techniques - MRI

Other techniques Radionuclide imaging – ventilation-

perfusion scanning of the lung Suspected pulmonary embolus

Interventional procedures Needle biopsy

Interventional procedures Arteriography – glide catheter from

femoral vein or vein in elbow, through right side of heart to pulmonary artery

Contrast injected

Normal chest x-ray Outline of mediastinum and heart The hila Pulmonary vessels and main

bronchi Diaphragm Soft tissue and bones of the

thoracic cage

Normal chest

Mediastinum and heart Mediastinum – trachea, aortic arch,

superior vena cava and oesophagus Heart – one-third to right of the

spine and two-thirds to the left Transverse diameter less than

transverse diameter of hemi-thorax

Hila and diaphragm Hila – pulmonary arteries and veins Diaphragm – highest point of right

hemidiaphragm is between anterior ends of 5th and 7th ribs

Left 2cm lower in erect position Costophrenic angle Lateral view – heart to viewer’s left

Lateral X-ray

Interpreting a X-ray Name of patient, time and date Left and right side markers PA or AP Supine vs erect Patient rotation – distance between

medial ends of clavicle and spinous processes

State of inspiration

Interpreting a X-ray Should be able to see vertebral

bodies through heart shadow Thoracic cage Heart and mediastinum Diaphragm and costophrenic angle Lungs

Consolidation Air-filled spaces replaced by products of

disease – water, pus or blood Localized areas - infection Radiological signs – air bronchogram and

silhouette sign Air bronchogram – black branching

structures Silhouette sign – border of structure

gone

Consolidation

Collapse (atelectasis)

Loss of aeration and collapse of lobe or lung

Tumour, foreign object or mucus plug

Collapse - signs ↑ density of collapsed lobe Shift of fissures Silhouette sign Hilar and mediastinal shift Crowding of vessels, airways and ribs Elevation of hemidiaphragm

Right upper lobe collapse

Right middle lobe collapse

Right lower lobe collapse

Left upper lobe collapse

Left lower lobe collapse

Pneumothorax

Pleural effusion

Pulmonary nodules and metastasis

Lung abcess

Paediatrics