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

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

Normal PA

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

Normal AP

Views

Lateral Localises, shows posterior to heart Side of interest placed against film

Decubitus PA on side Small pleural effusions

Norm lateral

vertebrae

Heart

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

Breast shadows

Surgical emphysema

surgical emphysema

Pacemaker

Heart valve

ICD

ECG

ETT

Bony Structures Ribs Scapulae Clavicles Vertebrae

#Clavicle

#ribs

Trachea Deviated Carina Artificial airway

ETT

#RibsICD

Mediastinum Deviated Hilar shadows Aortic arch

Mediastinum - Heart

Size No larger than half width of chestPosition Two thirds on the leftBorders 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

normal

Right upper lobe collapse

Right Lower lobe collapse

Pneumothorax

Pneumothorax

Consolidation

Pleural effusion

Pleural effusion

Right pneumonia

Air bronchogram

Emphysema

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