Medical Apparatus: Imaging Guide to Orthopedic Devices

Foreign Bodies

Foreign Bodies Introduction

Foreign Body Ingestions - Page 1

  • basic principles

  • appendicitis

  • disk batteries; cylindrical magnets

  • Foreign body ingestions - Page 2

    Foreign body ingestions - Page 3


    Foreign Body Insertions


    Foreign Body Injuries


    Miscellaneous Foreign Bodies


    Foreign bodies and MR imaging

    MRI Safety Information


    Foreign Bodies: References & Links





    Foreign Bodies: Ingestions

    by Tim B. Hunter, MD and Mihra S. Taljanovic, MD, PhD


    Foreign Body Ingestions

    Foreign body ingestions or insertions are seen most commonly in four broad categories of patients: (a) children, (b) mentally handicapped or mentally retarded persons, (c) adults with unusual sexual behavior, and (d) “normal” adults. The latter often have predisposing factors or injurious situational problems. This includes individuals who may abuse drugs or alcohol, engage in criminal activities, engage in extreme sporting activities, or may be subject to child or spousal abuse. Mentally handicapped or mentally retarded individuals are often repeat offenders and will present multiple times for unusual injuries and foreign body insertions and ingestions. On occasion, an adult or child may inadvertently ingest a foreign body with their food or drink. It may not be recognized due its small size and unexpected nature, or there may be confusion between a normally occurring anatomic landmark or calcification and a foreign body (Gharib, 2015, Senar, 2017).


    Foreign Body Ingestions, basic principles

    Category Description
    General Principles

    Most foreign objects traverse the GI tract without a problem.

    Elongated or sharp objects (e.g., needles) may impact at a point of intestinal narrowing or bending (e.g., duodenal loop, duodenojejunal junction, terminal ileum, or area of bowel stricture).

    Always consider esophageal or airway foreign bodies if there is unexplained stridor, drooling, or respiratory distress in a child or mentally impaired individual.

    Always look for a second or third foreign body after the first foreign body - never rest: examine the entire GI tract from the base of the skull to the anus.

    Predisposed Patients

    Infants and young children

    Mentally incapacitated individuals

    Individuals with reduced palatal sensitivity due to denture use, advanced age, or excessive drug and alcohol use

    Those ingesting especially hot or cold liquids

    Persons with poor vision who eat rapidly


    Esophageal or intestinal perforation or obstruction

    peritonitis, mediastinitis, abscess formation

    generalized septicemia


    Foreign Body Ingestions - figures I

    Swallowed pins and razor blades Swallowed nut Swallowed box cutter blade 15 year-old mentally incapacitated child who periodically swallowed objects.
    Open saftey pin in bowel Metal nut in stomach Boxcutter in bowel Khruschev doll in colon
    28 year old woman who periodically swallowed pins and razor blades. The open safety pin in her descending colon passed without mishap. From Hunter, 1994 Small child who swallowed a metal nut Box cutter blade in descending colon This radiograph shows a safety pin and key in the jejunum and rubber flexible Khrushchev doll head in the descending colon. It passed without difficulty. (Courtesy of George Barnes, MD). From Hunter, 1994
    Swallowed pencil Swallowed coffee cup fragment Quarter in hypopharynx  
    Pencil in bowel Porcelain in esophagus Coin in throat Coin in throat
    The arrows show a pencil lodged in the ascending colon. It passed without difficulty which is unusual for such an elongated object. Elderly patient with a coffee cup fragment lodged in the distal esophagus. From Hunter, 1994 35 month-old infant who swallowed a quarter  


    Foreign body ingestions are common in children and mentally handicapped adults. Typical examples include children swallowing coins and mentally handicapped adults swallowing razor blades and silverware. Fortunately, the vast majority of all swallowed objects pass through the gastrointestinal tract without a problem (Table) (figures: foreign body ingestions I).

    Elongated or sharp objects, such as needles, eating utensils, bobby pins, or razor blades, are more likely to lodge at areas of narrowing (from bowel adhesions or strictures) or to impinge at regions of anatomic acute angulation (figure: swallowed pencil). The duodenal loop, duodenojejunal junction, appendix and ileocecal valve region seem to be more predisposed to impaction from these types of objects (Balch, 1971; Eldridge, 1961; Himadi, 1977; Maleki, 1970; Maglinte, 1979; McPherson, 1957; Price, 1988; Schwartz, 1976; Segal, 1980; Selivanov, 1984).

    Large spherical or cylindrical objects may pass through the esophagus only to be halted at the pylorus (Muhletaler, 1980). Some large rounded objects (e.g., coins, meat) can impact at the thoracic inlet, the gastroesophageal junction or an area of stricture (foreign body ingestions II) (Hunter, 1991; Jackson, 1957; Nandi, 1978; Chaikhouni, 1985; Vizcarrondo, 1983; Bunker, 1962). The indications for foreign body removal by endoscopy or surgery vary depending on local experience as do suggested radiographic protocols for monitoring the progress of foreign body passage through the gastrointestinal tract, though broad general principles have been published (Guelfguat, 2014; Webb, 1995; Ikenberry, 2011).

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    Foreign Body Ingestions - figures II

    Pill bottle cap lodged in proximal esophagus Metallic mercury in the appendix
    Pill cap ingestion Pill cap ingestion Pill cap ingestion Mercury in appendiix
    Radiograph and images from a barium swallow of a 62 year-old man who accidentally ingested a pill bottle cap while taking his medications. The cap was lodged in his proximal esophagus. It was removed at endoscopy. From Hunter, 1991. Metallic mercury in the appendix of an asymptomatic patient from rupture of mercury bag on a Miller-Abbott tube. From Hunter, 1994
    BB's in the appendix Watch battery ingestion Ingested cylindrical magnets Plastic wafer lodged in hypopharynx
    BBs in appendix Watch battery in stomach

    Watch battery in colon

    Cylindrical magnets in the stomach

    Cylindrical magnets in sigmoid colon

    Plastic in throat
    72 year-old man with no symptoms. BB's are in the appendix. He used to eat BB's as child. From Hunter, 1994 Sequential radiographs of a 4 year-old girl who ingested a watch battery show it first in the stomach and later in the transverse colon. The battery passed without complications. From Hunter, 1994  A three year-old boy swallowed four cylindrical magnets which were evident in his stomach. The next day they were in the sigmoid colon and passed with no patient harm. Soft tissue neck radiograph of a 1 year-old girl who was coughing after swallowing a red coin-like plastic wafer. The plastic is lodged in her hypopharnyx (arrowheads). She coughed it up a few minutes later. Most plastic objects are not visible on radiographs. From Hunter, 1994

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    The occurrence of appendicitis secondary to an impacted foreign body is an interesting, though rare occurrence (Balch, 1971; Price 1988). There are reports of appendicits, appendical perforation, and appendical abscess formation months to years after an ingestion of a foreign body. Appendicitis is a common disease, and its association with a foreign body may be coincidental. It is certainly well known that small rounded objects, such as lead shot, BB's, barium, and mercury globules can reside in the appendix for years without apparent effect (figures: mercury in appendix; BB's in appendix).

    It is probable sharp objects such as toothpicks and pins are more likely than small rounded objects to induce appendical inflinflammation or perforation. In general, small rounded objects are probably harmless as far as the appendix is concerned. Larger rounded objects such as an air gun pellet lodged in the appendix may predispose a patient to appendicitis. However, if a large rounded foreign body is discovered in the appendix in an otherwise asymptomatic patient, there is no consensus on whether there should be elective surgery to remove the object and the appendix (Price, 1988).


    Disk Batteries; Cylindrical (Button) Magnets

    Disk (button) batteries such as those used in watches, calculators, hearing aids, and cameras are potentially very hazardous if ingested (figure: watch battery ingestion). More than 3500 button battery ingestions are reported each year in the United States (American Academia of Pediatrics. Button Battery Task Force). Because of their small size and resemblance to a dime, watch batteries are attractive to children and mentally incapacitated persons. They are seemingly harmless because their small rounded contour should permit easy passage through the gastrointestinal tract, and in fact, most of them pass without difficulty. However, they can cause grave injury or even death. Batteries about the size of a nickel (~ 20 mm) are likely to get lodged in a small child's esophagus (American Academia of Pediatrics. Button Battery Task Force). Sometimes, batteries are evident by the peripheral halo or "double ring sign" around the battery when viewed en face. This is caused by the beveled edge of the battery and may help one distinguish between a battery ingestion versus a coin ingestion.

    Batteries contain a variety of alkaline corrosive agents, such as aqueous potassium hydroxide, and heavy metals, such as mercury and cadmium. If their containers fracture, they can spill their caustic content, which may lead to perforation and systemic toxicity from heavy metal poisoning. A child or even an adult with an ingested disk (button) battery lodged in the esophagus or hypopharynx should be considered an emergency. Significant tissue damage may occur within two hours. A coin lodged in the hypopharynx or esophagus is also an urgent situation with the tissue damage probably occuring more slowly due to pressure necrosis rather than both pressure and caustic material necrosis in the case of a battery ingestion. In all cases of a lodged foreign body in the hypopharynx or esophagus, aspiration pneumonitis is a potential complication.

    The 3-volt lithium batteries are larger than the disk (button) 1.5-volt batteries and probably present a much greater risk if ingested. They are more likely to be lodged in the hypopharynx or upper esophagus and react quickly with saliva. They posses a strong electrical charge hydrolyzing water and generating hydroxide producing a caustic alkaline injury to the surrounding tissues (Reilly, 2013). Urgent removal of an impacted 3-volt lithium battery is necessary and best performed by physicians with specialized skills.

    The treatment for watch battery ingestion is controversial (Kuhns, 1989; Studley, 1990; Jaffe, 1984; Ikenberry, 2011). Most authorities avoid surgery or endoscopy in routine cases in which the battery is found in the stomach. Any evidence for lack of progression through the gastrointestinal tract is cause for concern and probable intervention. Batteries usually can be removed from the esophagus, stomach, and duodenum by endoscopy-or fluoroscope-directed interventional techniques with magnets (the battery case contains nickel and is magnetic), Foley catheters, forceps, or some type of retrieval basket (Jaffe, 1984; Shaffer, 1986; Volle, 1986). Disk batteries impacted in the esophagus are considered to be especially dangerous and should be removed promptly (Ikenberry, 2011).

    Those patients who have severe mucosal injury at endoscopy at battery removal should have CT, CT-angiography, or MRI follow-up (Riedesel, 2020). This allows assesment of the mediastinum, mediastinal vascular structures, and the esophagus for unanticipated or delayed injures. Endoscopic visual inspection of the esophagus during battery removal may underestimate esophageal injury after disk (button) battery injestion and its removal. These imaging techniques may provide more information and may partially displace traditional radiography and esophagography for patient evaluation after battery removal. The role of MRI particularly following patients after disk (button) battery removal remains to be defined but looks promising (Riedesel, 2020).

    Small cylindrical (button) magnets, such as those used to hold notes on a refrigerator door (figure: cylindrical magnets), are seemingly harmless and may pass through the gastrointestinal tract without mishap. These magnets may be especially high powered and are often composed of neodymium. They are sometimes known as “rare earth” magnets and are often available as desk “toys” and “stress relievers” with many small magnets clustered as balls, cubes, cylinders, or other objects. They are marketed for adults only, but they can get in the hands of young children or mentally incapacitated adults (Brown, 2013; Kazikdas, 2017) (figure: button magnets in the nose).

    If more than one magnet has been ingested, they may cause severe harm to the gut. One or more of the magnets may be attracted to the others by their magnetic pull and tear or perforate the mucosa of the stomach or intestinal tract by pressure necrosis leading to fistula formation, volvulus, perforation, and severe hemorrhage if mesenteric vessels are trapped between magnets in different portions of the bowel. A particularly worrisome finding is a gap between magnets on radiographs (Guelfguat, 2014). The magnets may be entrapping bowel wall between them, leading to pressure necrosis. They can also lodge in the hypopharnyx, distal esophagus, or at other points of narrowing in the bowel. Endoscopy or other intervention is recommended if a cylindrical magnet is lodged in the esophagus or cylindrical magnets do not show rapid progression out of the stomach and through the small and large bowel (see Foreign body ingestions in children).

    Fidget spinners are popular toys enjoyed by both children and adults to relieve nervous energy or psychologic stress. The basic fidget spinner consists of two to three prongs attached to a center circular pad containing a bearing which permits manual or battery powered spinning of the prongs. The center pad is held while the fidget spins. As with other relatively small toys, they may be ingested whole or in pieces by a child or an adult (Otjen, 2018). If thrown at someone or spun so fast they come apart, they have the potential for serious external injury.

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    Foreign Body Ingestions - Page 2



    Author contact information

    Tim Hunter

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