Plain film consists of a single shot image using x rays.

What are the different densities in x rays?

1. • Black – gas

2. • White – calcified structures

3. • Grey – soft tissues

4. • Darker grey – fat

5. • Intense white – metallic objects

What are the basics that must not be missed?

Always check:

1. • Name of patient, date of birth and date – this may give information about patient's age and gender, which could elucidate the underlying pathology.

2. • Adequacy of imaging: does the x ray cover the entire area of interest?

3. • Orientation of film: right vs. left – ‘R’ label on corner of film.

4. • Position of patient. For example, a pneumothorax will look different on supine chest x ray vs. erect film; air under the diaphragm will not be seen in a chest x ray of a patient lying flat.

5. • Cervical spine: multiple standardised views (see Chapter 49, Cervical spine x ray).

6. • Distal limbs: minimum of two views. If only one view is shown, ask for a second view.

What are the rules of 2?

1. • 2 sides: in paired structures (e.g. limbs) always compare the affected structure with the contralateral one, which may be normal.

2. • 2 views: obtain two views of the same structure, e.g. anteroposterior and lateral.

3. • 2 times: view images of the same structure at two different points in time: compare current images with previous ones.

4. • 2 joints (in orthopaedics): view the joint above and the joint below the one of interest.

5. • 2 readers: get a second opinion.

What is fluoroscopy?

1. • An imaging modality that uses continuous x ray exposure to get dynamic imaging

2. • Has the capacity to save representative images

3. • Contrast material used to help differentiate pathology.