Adequacy/Quality

When determining the adequacy or quality of a film a number of questions need to be considered:

Is the whole of the chest included on the x-ray, especially in resus films?

The x-ray is missing bases.

Click on the x-ray to enlarge.

Is there rotation evident?

Turning of the patient’s body to right or left will cause asymmetry in the appearance of the lung markings in particular. To assess rotation look at the medial ends of the clavicles; they should be equidistant from the spinous processes of the thoracic vertebrae between them.

Click on the x-ray to enlarge.

Is the film adequately penetrated?

Overexposure will produce a dark film that may miss lesions; underexposure causes a hazy white film which lacks detail. In an adequately exposed film the lower thoracic vertebrae should be just visible through the heart but their bony details should not be clearly seen.

This is an overpenetrated x-ray clearly displaying vertebral disc spaces (see arrows).

Click on the x-ray to enlarge.

Has the patient inspired adequately?

Inadequate inspiration will make lung markings too dense and prominent. For adequate expansion the posterior 9th rib should meet the right hemi diaphragm.

Learning bite

A number of patient and technical issues can affect the chest x-ray appearance but awareness of these, and a systematic approach, can allow accurate interpretation of many ED films.