Is the image diagnostic? (10 point plan)

6. Optimum definition

The mobile chest radiograph needs to demonstrate the relevant anatomy / pathology and any tubes / lines used for the management of the patient

The mobile chest radiograph is assessed to determine if it is a visually sharp reproduction of the anatomy with limited / no distortion of:

  • Lungs
    • Lateral margins, apex and diaphragm
    • Trachea and proximal bronchi
    • Vascular pattern in the whole lung particularly the peripheral vessels
    • Costophrenic angles
    • Retrocardiac lung
  • Heart, mediastinum and aorta
    • Borders of the heart, mediastinum and aorta
  • Bone margins and cortex/trabecular patterns

The image is also assessed to determine if the following ae clearly demonstrated:

EndoTracheal Tube (ETT)

The position of tip of the ETT should be 5 cm above the carina in the neutral position of neck. When the carina is not visible, the tip of the ET tube should lie between the level of the medial clavicles and aortic arch. The location can vary approximately 2 cm in the caudal or cephalic directions with neck flexion and extension, respectively on chest radiograph emphasising the need to obtain with the head in neural wherever possible. Projection of anterior portion of the mandible over the lower cervical spine indicates neck flexion whereas a non-obscured cervical spine denotes that the neck is in extension

Central venous line

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Central venous catheters are inserted through major veins such as the subclavian vein to reach the superior vena cava (SVC). The tip of the line should be distal to last venous valve, which is located at the junction of internal jugular and subclavian veins. The preferred position of the catheter tip is in the distal third of the SVC. On the mobile chest radiograph, the first anterior intercostal space corresponds to the approximate site of the junction of the brachiocephalic veins to form the SVC and the cavoatrial junction corresponds to the lower border of bronchus intermedius. The position of valve corresponds to the inner aspect of the first rib. There are also Extracorporeal Membrane Oxygenation (ECMO) catheters which have different positions depending on the method being used which should be visible.

Nasogastric tubes

This is available within e-LfH 

Chest radiographs are rarely first line test for determining position of a naso-gastric tube. Gasrtic aspirate should be obtained, with a pH <5 confirming location within the stomach and that it is safe for use. NGT aspirate with an equivocal aspiration should have NGT tip position confirmed by chest radiograph.

A correctly positioned nasogastric tube passes vertically in the midline, or just to the left of the midline, bisects the carina and passes 10 cm beyond the gastro-oesophageal junction.

Chest drains/ intercostal drainage tubes (ICD)


Chest drains are usually inserted through the chest wall in the mid-axillary line to reduce a pneumothorax. They are also used to drain a pleural effusion. The ICD tube has a terminal hole as well as side holes. These side holes can be identified on Chest radiograph by the interruption in the radiopaque outline of the tube. No side holes should lie outside the thoracic cavity and the integrity of the images portion of the tube should be examined (e.g. kinked)  and the tube should not float above the effusion.

Note: Lines and tubes which are incorrectly placed may result in complications which may be life threatening and should be treated as ‘red flag’ and the clinical team notified immediately