X-Ray, How To Read Chest X-Ray

[Sahrish Dar 516]

Chest X-ray is one of the commonest OPD investigation we frequently encounter. All of us must know how to read it and interpret.  Reading a chest x-ray, though looks simpler, often overlooked by us. Here is a simpler way to remember and read a chest x-ray easily.

The popular mnemonics to remember is DRSABCD. This is quite simple to understand and interpret accordingly.

D – Details  about the patient and the x-ray. Why it’s important? Well, a what’s can go wrong if we interpret another patient’s x-ray for some one else. We describe details under the following sub heading.

•          Patient name, age / DOB, ***

•          Type of film – PA or AP, erect or supine, correct L/R marker, inspiratory/expiratory series

•           Date and time of study

R- Ripe it’s for assessing the technical  quality of the image. 

• Rotation – medial clavicle ends equidistant from spinous process

• Inspiration – 5-6 anterior ribs in MCL or 8-10 posterior ribs above diaphragm, poor inspiration?, hyperexpanded?

• Picture – straight vs oblique, entire lung fields, scapulae outside lung fields, angulation (ie ’tilt’ in vertical plane)

• Exposure (Penetration) – IV disc spaces, spinous processes to ~T4, L) hemidiaphragm visible through cardiac shadow.

S – Soft tissues and Bones –

• Ribs, sternum, spine, clavicles – symmetry, fractures, dislocations, lytic lesions, density

• Soft tissues – looking for symmetry, swelling, loss of tissue planes, subcutaneous air, masses

• Breast shadows

• Calcification – great vessels, carotids

A- Airway and Mediastinum

• Trachea – central or slightly to right lung as crosses aortic arch

• Paratracheal/mediastinal masses or adenopathy

• Carina & RMB/LMB

• Mediastinal width <8cm on PA film

• Aortic knob

• Hilum – T6-7 IV disc level, left hilum is usually higher (2cm) and squarer than the V-shaped right hilum.

• Check vessels, calcification.

B – Breathing

Lung fields

• Vascularity – to ~2cm of pleural surface (~3cm in apices), vessels in bases > apices

• Pneumothorax – don’t forget apices

• Lung field outlines – abnormal opacity/lucency, atelectasis, collapse, consolidation, bullae

• Horizontal fissure on Right Lung

• Pulmonary infiltrates – interstitial vs alveolar pattern

• Coin lesions 

• Cavitary lesions

Pleura

• Pleural reflections

• Pleural thickening

C – Circulation

• Heart position –⅔ to left, ⅓ to right

• Heart size – measure cardiothoracic ratio on PA film (normal <0.5)

• Heart borders – R) border is R) atrium, L) border is L) ventricle & atrium

• Heart shape

• Aortic stripe

D- Diaphragm

• Hemidiaphragm levels – Right Lung higher than Left Lung (~2.5cm / 1 intercostal space)

• Diaphragm shape/contour

• Cardiophrenic and costophrenic angles – clear and sharp

• Gastric bubble / colonic air

• Subdiaphragmatic air (pneumoperitoneum)

E – Extras

• ETT, CVP line, NG tube, PA catheters, ECG electrodes, PICC line, chest tube

• PPM, AIDC, metalwork