The Normal Chest X-Ray. Introduction Most of the chest x-rays you will see will be normal In order to recognise abnormality, you need to know what a normal.

The Normal Chest X-Ray

Introduction

• Most of the chest x-rays you will see will be normal

• In order to recognise abnormality, you need to know what a normal CXR looks like

The CXR on the next slide is normal. How would you interpret it?

General Principles

• Have a systematic approach• Interpret the CXR in conjunction

with the clinical findings• Always compare with previous CXR

if available to assess for change• Ask yourself “does my

interpretation make sense?”

•Name/marker/rotation/ penetration

•Lines/metal work

•Heart

•Mediastinum

•Lungs•Zones (upper/middle/lower)

•Bones

•Diaphragm

•Soft Tissues

Systematic Approach

•Name/marker/rotation/ penetration

Systematic Approach

clavicles equidistant from

spinous processes of thoracic spine

can just see lower thoracic spine

•Lines/metal work

Systematic Approach

Look for:

•Sternal wires (implies previous thoracic surgery)•Tip of endotracheal tube (2cm above carina)

•Lines/metal work

Systematic Approach

Tip of central venous lines at

origin of superior vena cava. See tubes and lines presentation.

•Heart

Systematic Approach

•Occupies up to 50% of the maximum internal thoracic diameter on a standard PA erect view•Cannot comment on heart size on AP view because of magnification of heart

•Mediastinum

Systematic Approach

•Hilar vascular structures should be crisply defined•No widening of mediastinum•Trachea should be central

•Lungs

Systematic Approach

upper zone

lower zone

middle zone

•Compare upper, mid and lower zones•Look between ribs for lung detail•Remember to look “behind” the heart

•Bones

Systematic Approach

•Look at each rib in turn•Clavicles•Scapulae and humeri if visible•Lower cervical and thoracic spine

•Diaphragm

Systematic Approach

•Both diaphragms should form a sharp margin with the lateral chest wall•Both diaphragm contours should be clearly visible medially to the spine

Position of stomach gas bubble (not present on this CXR)

•Soft Tissues

Systematic Approach

•Supraclavicular fossae (enlarged nodes)•Lateral chest wall (surgical emphysema)•Under diaphragm (pneumoperitoneum)

How would you summarise this?

“This is an erect chest X-Ray of an adult male. The heart is not enlarged, the mediastinal

contours are normal and the lungs are clear”

Take Home Points

• Be systematic• Review with history and physical

examination in mind