There are many practices in radiography that have an unclear status and an unclear acceptance. This page considers practices and conventions in radiography . If you have never heard of them, you might consider them idiosyncrasy rather than good practice. Others you may consider to have had their day and dismiss them as anachronisms. If you would like to add your comments on these conventions, customs etc, please start a "thread"at the bottom of this page.

This is not an attempt at humour. The word "X-ray" can be spelt with a lower case "x" or an upper case "X". Originally, the “X” in "X-ray" simply stood for unknown. But is that the case today? A distinction can be made between "X-ray" and terms like "e-mail" where the "e" is an abbreviation and terms like "S-bend" where the "S" describes a shape. For what it's worth, "X-ray" appears to have greater acceptance and greater usage. Lower case "x-ray" spelling is, I believe, an acceptable spelling, and "xray" is simply wrong.

The Anatomical Position

There are a few practices (and exceptions to practices) that relate to viewing X-ray images. The first amongst these is the convention of viewing X-ray images as if you were looking at the patient standing in the anatomical position as shown below.

http://nursingassistants.net/2008/02/04/spot-light-medicalnursing-jargon/

http://nursingassistants.net/2008/02/04/spot-light-medicalnursing-jargon/

The anatomical position and the descriptions are helpful in as much as they allow medical staff to speak to each other and view images without having to continuously clarify meanings. Radiographers come to appreciate the value of universal terminology when surgeons ask them to move the image intensifier "up"- that could mean "up" literally (towards the sky) or, more commonly, they mean up the patient (superiorly).

Hand and Feet X-ray Images

As with all good rules, there are some well accepted exceptions. Hands and feet images are a good example.

I googled "hand X-ray"and these are the first four results. Whilst this might be a coincidence, I suspect that this is a well accepted exception to the "anatomical position rule". If the hands images were viewed in the true anatomical position they would be flipped vertically. The google results were similar for foot X-ray- toes at the top, calcaneum at the bottom.

Lateral Chest X-ray

I thought there were universally accepted conventions for viewing lateral chest X-ray images.... but after doing a google images search, I'm not so sure.

The principle followed here is that lateral images should be viewed from the perspective of the X-ray source. I would always view a left lateral chest X-ray as shown to the left. The only time I would present the image in reverse is when it was a right lateral. The google images evidence suggest that there is possibly a slight bias towards viewing a left lateral chest X-ray image as shown below. Some radiologists view all lateral chests as shown below and are not likely to change.

Lateral Placement

Side-markers should be placed where they are least likely to obscure anatomy ( a do-no-harm philosophy). Some radiographers position side markers laterally with respect to the anatomy rather than medially. Once again, google images ( and K.C. Clarke) have lowered my confidence in this custom.

The first six AP ankle images from a google search followed the lateral side-marker placement custom and the following three didn't.

A further consideration with film/screen radiography is that the side-marker should be placed near the information/name window. This allows the radiologist to read all of the relevant information in the same location on the image.

The Decubitus Side-marker Convention

This is the convention that is advocated in Merrill's and K.C. Clarke	This is incorrect according to Merrill's and K.C. Clarke

Merrill's advice is as follows

"For decubitus positions of the chest and abdomen, the R or L marker should be placed on the side up (opposite the side laid on) and away from the anatomy of interest" Radiograhic Positions and Radiologic Procedures, volume 1, tenth edition, p 25

One point that I believe is universally accepted is that, irrespective of side marking conventions used, a right side marker should never be placed on the patient's left side and vice versa.

Some radiographers consider the position shown above to be correct. That is, the lateral view with the toes directed outwards rather than inwards. (The practice of multiple exposures on a single cassette is discouraged in CR imaging because of the adverse affect on the application ofimage processing algorithms)	This orientation is considered wrong by some radiographers- rule or idiosyncrasy?

Some centres will prefer the side marker to also refer to the intervertebral foramina demonstrated. i.e. If an oblique cervical spine image has a left side marker, the left intervertebral foramen are demonstrated (see left) This convention is a simple aid to the radiologist. The convention also has utility for the radiographer in terms of avoiding mislabelling through consistency and clarity of thinking. A further more general convention is to present the image in the anatomical position- AP oblique not PA oblique n.b. labelling has an English spelling with 2 "L"s and an American spelling with one "L"

X-ray images present three dimensional anatomy in two dimensions. There should be a minimum of two projections at right angles for all imaged anatomy. Whilst there are a considerable number of exceptions, this principle is a very sound one and should always be considered, particularly in the Emergency Department where compromise and innovation in radiography are commonplace. Interestingly, conventional wrist radiographic technique results in a single view of the ulna- this is never mentioned in the radiography literature. The reason for this is that the radius rolls around a fixed ulna in pronation and supination.

It is customary to mark the entry site (a lead shot dot is ideal) in cases of percutaneous foreign body where practical.

A long bone X-ray image that does not include at least one joint just looks wrong. More importantly, inclusion of at least one joint allows for the long bone to be identified and provides a reference point. Exceptions might include foreign body localisation where the foreign body provides the reference point and coned views of pathology where the pathology (and the routine views) provide the reference point.

Some consider that any long bone X-ray image should include two joints (joint above and joint below). This would require that, for example, all Colle's fractures should include the patient's elbow. I consider this rule to be inappropriate for a variety of reasons. Firstly, any anatomy should be imaged where there has been consideration of the cost vs the likely yield. To routinely image anatomy that is clinically normal is ludicrous (there are exceptions that should be assessed on their merits). In an effort to include the other normal joint, there will be distortion of the important anatomy associated with the oblique rays- a hand X-ray is not a wrist X-ray, is not a forearm X-ray, is not an elbow X-ray (irrespective of overlapping anatomy).

Will digital radiography spawn a whole new set of customs?

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