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Thoracic Imaging. Thoracic Imaging. Chest x-ray Computerised tomography Ultrasound Magnetic resonance imaging New advances. Background Chest X-ray. Most common radiological investigation – 40% of all investigations Standard component of a pulmonary examination
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Thoracic Imaging • Chest x-ray • Computerised tomography • Ultrasound • Magnetic resonance imaging • New advances
Background Chest X-ray • Most common radiological investigation – 40% of all investigations • Standard component of a pulmonary examination • Systematic review is vital in interpretation of chest x-rays
Limitations of a chest x-ray • 2 dimensional image of a 3 dimensional structure • X-ray findings may lag behind other clinical features • Normal x-ray does not rule out pathology • Dependent on good quality image
Chest x-ray views/types • Posteroanterior - PA • Anteroposterior - AP • Lateral • Decubitus
Views PA • Standard, radiology dept • X-rays posterior to anterior • Standing position
Lung Anatomy (1) aortic arch (2) pulmonary trunk (3) left atrial appendage (4) left ventricle (5) right atrium (6) superior vena cava (7 & 8) diaphragm (9) transverse fissure
Views AP • Cassette placed behind patient • X-rays anterior to posterior • Sitting in chair, semi-erect in bed, supine • AP marked on film • Heart enlarged, poorer inspiration
Views Lateral • Localises, shows posterior to heart • Side of interest placed against film Decubitus • PA on side • Small pleural effusions
vertebrae Heart Norm lateral
Lung Anatomy (1) oblique fissure (2) transverse fissure (3) retrocardiac space (4) retrosternal space
BASICS Air shows as black solid structures white • Too white • Too black • Too large • In the wrong place (Corral et al 1997)
Chest x-ray viewing guide Correct CXR • Name • Date of birth • Date • Left and right, marker/stomach
Normal PA Stomach
Patient Position • PA, AP, lateral or decubitus view • Rotation – Sternal end clavicles equal from vertebral body • If AP what position
Exposure • How dark or light a film is • Should see vertebral bodies through heart
Soft Tissues • Breast shadows • Piercing • Air in tissues • Tissue folds in obese • Medical equipment
Heart valve Pacemaker
ECG ICD ETT
Bony Structures • Ribs • Scapulae • Clavicles • Vertebrae
Trachea • Deviated • Carina • Artificial airway
ETT #Ribs ICD
Mediastinum • Deviated • Hilar shadows • Aortic arch
Mediastinum - Heart Size • No larger than half width of chest Position • Two thirds on the left Borders • Clear
Diaphragm • Shape • Height: right –6rib ant, left – 7 ant • Cardiophrenic angle • Costophrenic angle
Lung Fields • Black with lung markings • Other opacity indicated pathology • Fissures • Zones • Air bronchograms • Consolidation
Other imaging Computerised tomography • Transverse images, cross section • Localises masses • High radiation dose
Other imaging cont Ultrasound • Useful for pleural effusions • Good images of heart and valves
Other imaging cont MRI • Malignancy • Vascular • Congenital abnormalities • Tuberculosis
New advances Patient archive communication system • Film free radiology • Computer use • Image enhancement