SET T0029 -
Emergency Department -
Foreign Bodies

A small ceramic foreign body is visualised; in the volar aspect of the middle finger adjacent to the proximal interphalangeal (PIP) joint.

COMMENTS:

• It is not only glass and metal that will be detected by plain film radiography. 
• Radiographs can be very useful for demonstrating, and helping to locate, different types of foreign bodies.
• Penetrating foreign bodies: a good clinical history combined with good radiographic technique is really important in the detection of very small fragments.
• Note the marker highlighting the injury site. The radiographer will usually place a marker (often the tip of a ball point pen) close to the surface wound.
• Penetrating Foreign bodies . . . See : Accident & Emergency Radiology : A Survival Guide (3rd edition) : Pages 343-348

Multiple, strange looking, foreign bodies (FBs) are identified in the soft tissues of the knee.

These are sea urchin spines.

Comments: all glass and most metals are visualised on soft tissue radiography - provided that the FB is not obscured by overlying bone. Occasionally some timber fragments will be visualised . . . but, in general, most wooden splinters are not detectable. In this patient these unusual FBs proved to be radio-opaque.

If a FB is not visualised and yet clinical suspicion remains high then additional imaging will be necessary. Ultrasound is very useful if a FB is lying fairly superficially. Occasionally, CT or MRI will be employed.

Penetrating foreign bodies . . .  See : Accident & Emergency Radiology : A Survival Guide (3rd edition) : Pages 343-348

• Bandages account for the streaky densities on the radiograph.
• A small glass foreign body is evident in the region of the thenar eminence. But the doctor needed to be absolutely certain, and also the bandaging could be obscuring other fragments.
• The lateral view was repeated after the bandaging was removed. This improved the examination/visualisation of the injured soft tissue. 
• The repeat view shows the glass fragment very clearly, and confirms that a single glass fragment is present.

• Initially nothing abnormal was detected on the radiographs. The patient was unconvinced by the negative result.
• So, the radiographs were inspected again by a more senior practitioner. A very tiny fragment was suspected - overlying the distal phalanx of the thumb.
• The radiographs were then repeated, after moving the thumb out of the way. A tiny glass fragment was revealed - situated at the base of the index finger.
• The fragment was removed - and the longstanding pain disappeared.

MESSAGES:

1. All glass is radio-opaque and even exceptionally tiny pieces of glass can be identified.
2. But - excellent radiographic technique and positioning is required.
3. Overlying bone can easily obscure a glass fragment.
4. Usually two radiographic projections are obtained when a penetrating foreign body is suspected. It is essential that any overlying bone " be removed " from the site of interest; sometimes it requires that an adjacent digit be moved and taped out of the way. In other instances it will require that the radiographer obtains oblique or tangential views.