Foreign Body Localization

Foreign Body Definition

• An alien object that enters the body

• Localization refers to determining the actual site of the object

• Ways foreign objects enter the body

  • Aspirated

  • Ingested

  • Inserted

  • Trauma

• Foreign objects that enter the body should receive medical attention promptly

• If no attended to then can cause severe infection, pain and potentially fatal obstructions or perforations of the bowel

Foreign Bodies by Ingestion

• Children, handicapped, and mentally challenged are the populations most targeted by this type of foreign body

• Four main areas of the alimentary canal that ingested objects may become lodged:

  • Larynx

  • Tracheosphageal bifurcation

  • Aorta/Esophagus intersection

  • Cardiac sphincter

• Objects such as marbles, pebbles, and batteries usually pass through the GI tract with no medical repercussions

• Though ingested object are no usually harmful, more detrimental objects like razor blades and open safety pins are often swallowed

• It is important that these objects are removed as soon as possible because perforation of the bowel is much more likely the longer the object remains inside

Projections for Foreign Body Localization

• When lodged in the esophagus an oblique in the RAO position and an AP of the abdomen should be obtained

• When in the bowel only one AP radiograph is necessary

• If the foreign body is discovered after it passes the ileocecal valve a precautionary 24 hour KUB is necessary until the object is eliminated

Foreign Bodies by Aspiration

• When an object is aspirated, it is inhaled and usually gets lodged in the larynx, the epiglottis, or the bronchi

• Right bronchus is more prone to house these foreign bodies because it is larger, more vertical, and closer to the midline than the left bronchus

• Common aspirated objects

  • Pins

  • Needles

  • Nails

Foreign Bodies by Insertion

• Four common sites

  • Rectal

  • Vaginal

  • Ear

  • Nose

• Projections

  • To radiograph objects inserted into the rectum, vagina, or bladder a supine abdomen film is usually taken

  • Obliques and laterals are also taken to survey the precise location of the foreign object

Foreign Bodies by Trauma

• Car accidents and industrial accidents provide a familiar territory for foreign objects to enter the body

• Trauma induced foreign bodies occur mostly in adults

• Projections

  • In head trauma an AP and a lateral of the skull are usually obtained

  • For chest trauma and AP is done to first access the patient, then a lateral may possibly follow

Intraorbital Foreign Bodies

• 80% of the time IOFB’s are metal therefore MRI should be avoided

• CT and US have replaced specialized localization method mentioned below

• An AP axial, a lateral, and a Water’s view is the protocol used to locate foreign bodies in the orbit

• To clear a patient for MRI - Water’s view usually performed

Technical Factors

• Short scale of contrast is desirable for extremities and longer scales are ideal for thicker parts

• A small focal spot should be used for maximum recorded detail

• Immobilization and clean IR (always clean before procedure begins) are a must for precise location

Conclusion

• When removing foreign objects from the alimentary canal endoscopy is usually used

• If an object is aspirated, bronchoscopy is used

• Surgery, is the last resort if all other options fail

• CT, MRI, and Ultrasound can also be used for localization

• Even though these alternatives can be successful diagnostic x-ray is still the most conventional and cheapest method of locating foreign bodies