Commonly affect children, developmentally challenged or psychiatric patients, and inebriated adults
Most ingested foreign bodies traverse GI tract without problem: < 1% cause obstruction or perforation
– Elongated or sharp objects may impact at point of intestinal narrowing or sharp angulation
Foreign bodies vary in radiopacity and conspicuity on radiography vs. CT
For most nonsharp foreign bodies, begin with visual inspection of oropharynx and plain radiographs
For sharp objects at risk of complications, start with CT
– Avoid administering enteric contrast material; makes subsequent endoscopy more difficult
– IV contrast administration preferable to better evaluate potential complications
• Inserted foreign bodies
Rectum, vagina, and urethra are common sites
Objects may be inserted during sexual practice, as a result of an assault, or to hide drugs
Perforation of rectosigmoid colon may occur with original insertion or during attempted removal
• Retained surgical items
Most common in abdominal surgery (especially emergent)
Crucial to distinguish intentional or expected objects from unintended
– Common intentional devices: Surgical drains, rubber retention sutures, metallic clips for wound closure, hemoclips, or intraarterial, intravenous, and intraintestinal catheters
Most commonly woven cotton surgical sponge
– Most have radiopaque stripe interwoven into fabric or as attached strip of cloth
– Cotton fabric is invisible on radiographs but seen as swirled gas or soft tissue on CT scans
– Gossypiboma:Foreign body reaction to cotton fabric of sponge or towel producing inflammatory mass with sponge at center
Produces variable degree of inflammation, fibrosis, retraction, and adhesion to adjacent abdominal structures
Low-density heterogeneous mass with wavy, spongiform pattern and internal linear high density (representing the sponge itself)
• Intentionally retained surgical material
Oxidized regenerated cellulose (Gelfoam/Surgicel) deliberately left in place after surgery for hemostasis
Usually absorbed within 7-14 days
Tightly packed, swirled, or linear gas on CT
– May be mistaken for abscess but contains very little fluid and never shows air-fluid level
(Left) Plain film shows the appearance of a standard cylindrical-shaped battery after ingestion. Swallowing batteries is relatively common and can cause bowel perforation or obstruction as the acid in the battery may leak out.
(Right) Axial CECT in a patient with a retained surgical sponge demonstrates the characteristic CT appearance of a chronic gossypiboma . Note the wavy, serpiginous pattern within the mass and the well-defined wall.
(Left) Axial T2 MR in the same patient demonstrates the characteristic MR appearance of a gossypiboma , with wavy, high T2 signal and a well-defined T2-hypointense wall.
(Right) Transverse grayscale US in the same patient demonstrates a very similar appearance to the MR and CT images, with a well-defined mass and internal alternating bands of hyper- and hypoechogenicity. Some of the hyperechoic bands with posterior acoustic shadowing may reflect gas within the mass.
TERMINOLOGY
Abbreviations
• Foreign body (FB)
Definitions
• Ingestion or insertion of potentially injurious foreign objects into any site within body
IMAGING
General Features
• Best diagnostic clue
Radiopaque or radiolucent object on plain film or CT with characteristic appearance of common FBs
• Location
Gastrointestinal (GI) or genitourinary tract, peritoneal cavity, abdominal wall
Imaging Recommendations
• Best imaging tool
Plain radiograph or CT
Ingested Foreign Bodies
• Commonly affected patient groups
Children (vast majority of foreign body ingestions)
– Peak incidence between 6 months and 6 years of age
– Often swallow coins, toys, or virtually anything else
Developmentally challenged or psychiatric patients
– Common items include jewelry, batteries, silverware
Prisoners and future prisoners
– Razor blades (often covered in radiolucent tape to gain entry to hospital), drug packets
Edentulous, elderly, or inebriated adults
– May swallow bones, toothpicks (common in martini drinkers), plastic tops of medication bottles, etc.
– Food bolus impaction more common in edentulous older patients (often with esophageal pathology)
• General principles
Most ingested FBs traverse GI tract without problem
– < 1% cause obstruction or perforation of GI tract
– Need for intervention may be higher with intentional ingestions (surgery required in 12-16%)
– Overall mortality rate is very low
Distinguish accidental or intentional foreign body ingestion from ingestion of diagnostic devices
– pH meter capsule, capsule endoscopy, and migrated biliary/pancreatic duct stents can be confusing without clinical history
Elongated or sharp objects may impact at point of intestinal narrowing or sharp angulation
– (e.g., pylorus, duodenum, ileocecal valve, site of bowel stricture or adhesion)
Perforations are most common near ileocecal valve
– Long pointed objects (toothpick, needle) may lodge in and perforate appendix or Meckel diverticulum
Perforation may be incomplete or fail to present with acute symptoms; many are discovered weeks to years later
Common ingested foreign bodies and management
– Most small objects < 2.5 cm in size (i.e., coins) are likely to pass on their own
Coins account for > 3/4 of foreign body ingestions in children
Coins may obstruct in esophagus
– Longer objects > 6 cm in length (eating utensils, toothbrushes) are unlikely to traverse duodenum and should be retrieved endoscopically
– Ingested disk (e.g., watch) batteries are caustic
Should be removed from esophagus or stomach if possible
Often can retrieve from esophagus with balloon-tipped rubber catheter, magnet, or endoscope
– Sharp pointed objects (chicken/fish bones, paperclips, toothpicks, needles, etc.) have high risk of complications (1/3 of patients)
Should be endoscopically retrieved if in duodenum or stomach
Follow-up with radiographs if more distal
Surgery possible if FB fails to pass or complications
– Magnets
Can cause severe injury if multiple magnets are ingested, trapping bowel loops between 2 magnets’ attractive force
Can lead to bowel wall necrosis, fistulas, bowel obstruction, etc.
All magnets should be retrieved immediately
Foreign bodies vary in radiopacity and conspicuity on radiography vs. CT
– Plastic and thin aluminum (e.g., pull tabs from cans) are radiolucent
– Chicken and meat bones are opaque
– Fish bones are often lucent on plain films, opaque on CT
– Glass is always radiopaque, but very small slivers may not be detectable
– Coins, except for Italian lira, are opaque
– Wood is radiolucent (closer to air than soft tissue density)
– Medication pills and capsules are variably opaque
e.g., iron pills, Pepto-Bismol, phenothiazine, many enteric-coated pills
– Cocaine or heroin packets are variably opaque; usually wrapped in condoms or balloons and swallowed or inserted into rectum or vagina
May be visible as crescent of air density between 2 layers of wrapping surrounding drugs; double condom sign
May appear as well-defined round objects in bowel (of variable attenuation depending on type of drug)
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Most ingested foreign bodies traverse GI tract without problem: < 1% cause obstruction or perforation
after ingestion. Swallowing batteries is relatively common and can cause bowel perforation or obstruction as the acid in the battery may leak out.
. Note the wavy, serpiginous pattern within the mass and the well-defined wall.
, with wavy, high T2 signal and a well-defined T2-hypointense wall.
and internal alternating bands of hyper- and hypoechogenicity. Some of the hyperechoic bands with posterior acoustic shadowing 
may reflect gas within the mass.
Elongated or sharp objects may impact at point of intestinal narrowing or sharp angulation
Common ingested foreign bodies and management
Foreign bodies vary in radiopacity and conspicuity on radiography vs. CT
