Radiology Quiz

This month is a practical spot radiology quiz. Try to identify the "abnormality" on each film.

Nipple shadows (fig 1)

Dense nipples may appear as "coin like" lesions in the lung fields. These may be mistaken for pathological pulmonary masses, such as metastases. A symmetrical contralateral shadow from the other nipple can aid the diagnosis but it is confirmed by requesting re-examination with "nipple markers." These are usually opened paper clips, bent around the nipples, holding them in place with sticky tape. This film can then be compared with the original. It is worth repeating the film in another phase of respiration as intrapulmonary lesions will move position. Nipples will not.

Figure 1

Objects in the alimentary canal (fig 2)

These fall into three broad categories:

Fetishism

Typically these foreign bodies are in the sigmoid colon or rectum (as in this case - the top of an aerosol canister). Their very regular outline or characteristic shape helps differentiate them from normal anatomical structures.

Figure 2

Pica

Pica is the ingestion of materials unsuitable as food - for example, coal, chalk etc. Swallowed foreign bodies, such as spoons, pens, needles, and coins, usually present little diagnostic difficulty. In adults there is usually an appropriate clinical history, except perhaps those with learning difficulties. However, in children there may be little clinical information. In addition, as toddlers have a propensity for swallowing everything, more subtle patterns can be observed-for example, dense flecks of lead from paint or old batteries mixed in with the normal faecal shadowing.

Smuggling

The use of ingested condoms to transport illegal drugs is well established. Diligent examination of the gas pattern within the abdomen can often reveal sausage shaped masses within the normal faecal pattern. The courier is often at great personal risk should any of these containers tear.

An important point to remember here is that, as the usual indication for taking an x ray examination of these patients is to establish the existence of such contraband, there may be no medical justification for the exposure. The doctor must therefore ensure that there is full informed consent from the patient before an ionising radiation exposure is made.

Prosthetic breasts (fig 3)

Improved standards in breast cancer care and fashion means that the implantation of prosthetic breasts is now increasingly common. They classically appear as well defined, shapely, marginated rounded discs projected over the normal breast positions. Prosthetic breasts may be unilateral (normally breast cancer) or bilateral (usually cosmetic). An additional film showing bilateral breast prostheses can be seen on the web version of this quiz. A mastectomy without reconstruction or implantation is seen as a unilateral loss of breast shadow, which in smaller women (and larger men) may be quite subtle. This is a crucial observation to make in a clinical examination.

Figure 3

This quiz is compiled by Ian C Bickle fourth year medical student, Queen's University, Belfast, and Barry Kelly consultant radiologist, Royal Victoria Hospital, Belfast

For extra help in spotting abnormalities in lung fields revise Chest x rays made easy in the November 2000 issue (Dicks E. studentBMJ 2000,8;408-10), or go to here

studentBMJ 2001;09:217-260 July ISSN 0966-6494