This document provides a systematic method for reading chest x-rays consisting of 1-2-3 ABCDE. It begins by outlining indications for chest x-rays and common x-ray views. It then details a step-by-step method involving checking patient identification and film quality, identifying external hardware, and examining the airway, bones, soft tissues, cardiac shadow, diaphragm and pleura, and lung parenchyma. It concludes by listing common findings expected on chest x-rays of TB patients such as infiltrates, cavitary lesions, and hilar lymphadenopathy.

1. Systematic method for
Reading chest x-rays.
By Ngabo Moses, KEMU, MBchB

2. INDICATIONS
• Any patient wit sever or persistent shortness of breath, cough, chest
pain, chest trauma, evidence of tuberculosis or a malignancy by
history and pulmonary findings on physical examination.

3. TYPES OF CHEST XRAYS
• Posterior-anterior(PA) – best for most patients.
• Anterior-posterior(AP) – for patients who cant get out of bed(as in the
ICU)
• Lateral – useful when combined with PA film to determine 3
dimensional positions of pathology
• Lateral decubitus – an PA film performed wit patient lying on side;
useful in determining size and flow of pleural effusions.

4. SYSTEMATIC METHOD FOR READING AN XRAY
• NOTE; always follow the same method so that you don’t miss out on
anything.
• METHOD; 1 2 3 ABCDE
1. Identify the patient; make sure that this is the correct patient and correct
date.
2. Quality of the film; films look very different depending on the quality.
• Rotation: identify the medial ends of the clavicles and select one of the
vertebral spinous process that falls between them. The medial ends of the
clavicles should be equal distances from the spinous process
• penetration: look at the vertebral bodies visible through the heart
shadows(too white=under penetration, too dark=over penetration)

5. • Inspiration: should be able to see 7 anterior ribs, if >7 consider
hyperinflation, if < consider poor inspiratory effort for film.
3. External hardware: look for central lines, chest tubes, NG
tube(should be in the stomach and below diaphragm),or endotracheal
tubes( should be 2-4 cm above the carina)

6. Airway: identify the position of the trachea and carina and whether it is
shifted to one side or another.
Bones and soft tissues: Evaluate external structures first that might get
overlooked.
• bones-look for fractures, lytic bone lesions(cancer),dislocations.
• Soft tissues- look for subcutaneous emphysema

7. Cardiac shadow
• Mediastinum-assess the size(if wide, aortic dissection),rule out
pneumomediastinum(thin line of air around the heart)
• Heart-assess the size(cardiomegaly-heart should be > half of the total chest
width, two thirds of the heart should be on the left side)
• Heart borders- Right border is right atrium, left border is the left ventricle.
At the level of the left hilum it is the left appendage. Above this is the
pulmonary artery and aorta.
• Hila-main pulmonary arteries and bronchi compose
hilum(lymphadenopathy, tumors, large PA can cause hilum to look bulky).
note that the left hilum is approximately 2.5 cm higher than the right.

8. Diaphragm and pleura; look at the borders before the lungs
• Diaphragms-shaped like domes, flat suggests emphysema, right
should be higher than the left(elevated left could mean phrenic nerve
paralysis),air below diaphragm suggests pneumoperitoneum.
• Costophrenic angles- should be clear and sharp(if blunted think of
pleural effusion)
• Pleura- thickened pleura(suggests prior TB)

9. Everything else; finally look at the lung parenchyma
• Parenchyma- evaluate for alveolar process vs interstitial process(air
bronchograms present in alveolar filling),lobar infiltrate(bacterial),vs
diffuse infiltrate(viral, pneumocystis' carine pneumonia)
• PTX-if no lung markings, consider Pneumothorax(tension
pneumothorax will have mediastinal shift)
• Nodules-consider cavitary lesions, tumors
• Vasculature-large vessels suggest vascular congestion.

10. What to expect on an x-ray of a TB patient.
• Infiltrates
• Cavitary lesions
• Hilar lymphadenopathy
• Pleural effusion
• Air bronchograms in the interstitial lung
• Nodule with poorly defined margins seen on CT scan.(tree in bud
sign)