DOI: 10.1148/rg.233025137
(Radiographics. 2003;23:731-757.)
© RSNA, 2003
Foreign Bodies1
Tim B. Hunter, MD and
Mihra S. Taljanovic, MD
1 From the Department of Radiology, University of Arizona Health Sciences Center, 1501 N Campbell Ave, Tucson, AZ 85724. Received August 2, 2002; revision requested August 28 and received October 15; accepted October 16. Address correspondence to T.B.H. (e-mail: tbh@3towers.com).
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Abstract
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Foreign bodies are uncommon, but they are important and interesting. Foreign bodies may be ingested, inserted into a body cavity, or deposited into the body by a traumatic or iatrogenic injury. Most ingested foreign bodies pass through the gastrointestinal tract without a problem. Most foreign bodies inserted into a body cavity cause only minor mucosal injury. However, ingested or inserted foreign bodies may cause bowel obstruction or perforation; lead to severe hemorrhage, abscess formation, or septicemia; or undergo distant embolization. Motor vehicle accidents and bullet wounds are common causes of traumatic foreign bodies. Metallic objects, except aluminum, are opaque, and most animal bones and all glass foreign bodies are opaque on radiographs. Most plastic and wooden foreign bodies (cactus thorns, splinters) and most fish bones are not opaque on radiographs. All patients should be thoroughly screened for foreign bodies before undergoing a magnetic resonance imaging study.
© RSNA, 2003
Index Terms: Extremities, injuries, 40.46 • Foreign bodies, 40.46, 70.46, 80.46 • Foreign bodies, in air and food passages, 70.46 • Gastrointestinal tract, 70.46 • Genitourinary system, 80.46
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Introduction
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Foreign bodies are relatively uncommon, but they are important and interesting. Sometimes, they may provide a great deal of lowbrow amusement. They may be overlooked and can cause harm to the patient. They can even simulate the appearance of a medical device. The interpretation of ultrasonographic (US), computed tomographic (CT), and magnetic resonance (MR) imaging studies is particularly fraught with error if one does not appreciate the presence of a medical device or a foreign body. It is crucial that all US, CT, nuclear medicine, and MR images be interpreted in light of any current radiographic studies of the same body region. The scout image obtained for CT and MR imaging studies should be examined carefully for unexpected foreign bodies and medical apparatus and for unexpected bone, bowel, and soft-tissue lesions not easily visualized on cross-sectional images.
This article illustrates a large variety of foreign bodies and discusses important principles relating to foreign body ingestions, insertions, and injuries. People are capable of ingesting, inserting, or injecting themselves or others with all manner of foreign objects. However, a discussion of the psychology of these ingestions, insertions, injections, and stabbings is beyond the scope of this work.
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Foreign Body Ingestions
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Foreign body ingestions or insertions are seen 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 or children with predisposing factors or injurious situational problems. This latter group 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.
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 1) (1–6) (Figs 1–4). 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 (Fig 5). The duodenal loop, duodenojejunal junction, appendix, and ileocecal valve region seem to be more predisposed to impaction from these types of objects (1–10). Large spherical or cylindrical objects may pass through the esophagus only to be halted at the pylorus (11). Some large, round objects (eg, coins, meat) can impact at the thoracic inlet, the gastroesophageal junction, or an area of stricture (Figs 6–8) (13–17).
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Figure 3. Digital radiograph of a 4-year-old girl shows a locket that she had swallowed. It passed without difficulty. (Courtesy of Stephen Smyth, MD, University of Arizona, Tucson.)
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Figure 4. Radiograph of a 15-year-old retarded child who had a history of repeatedly swallowing foreign objects shows a safety pin and a key in the jejunum and a rubber flexible Khrushchev doll head (arrow) in the descending colon. The objects passed without complications. (Courtesy of George Barnes, MD, University of Arizona, Tucson.)
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Figure 5. Radiograph shows a pencil (arrows) lodged in the ascending colon. It passed without difficulty. It is unusual for such an elongated object to pass through the intestinal tract without problems.
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Figure 7a. Scout view of the chest (a) and lateral view from a swallowing study (b) of an 18-month-old boy who was having difficulty keeping his food down and had a history of tracheoesophageal (TE) fistula repair show a coin lodged in his proximal esophagus. The coin was subsequently shown to be sitting above an esophageal stricture from his TE fistula repair.
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Figure 7b. Scout view of the chest (a) and lateral view from a swallowing study (b) of an 18-month-old boy who was having difficulty keeping his food down and had a history of tracheoesophageal (TE) fistula repair show a coin lodged in his proximal esophagus. The coin was subsequently shown to be sitting above an esophageal stricture from his TE fistula repair.
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Figure 8a. Radiograph (a) and images from a barium swallow study (b, c) of a 62-year-old man who accidently ingested a pill bottle cap while taking his medications demonstrate the cap (arrow in a) lodged in his proximal esophagus. It was removed at endoscopy. (Figure 8b and 8c reprinted, with permission, from reference 12).
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Figure 8b. Radiograph (a) and images from a barium swallow study (b, c) of a 62-year-old man who accidently ingested a pill bottle cap while taking his medications demonstrate the cap (arrow in a) lodged in his proximal esophagus. It was removed at endoscopy. (Figure 8b and 8c reprinted, with permission, from reference 12).
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Figure 8c. Radiograph (a) and images from a barium swallow study (b, c) of a 62-year-old man who accidently ingested a pill bottle cap while taking his medications demonstrate the cap (arrow in a) lodged in his proximal esophagus. It was removed at endoscopy. (Figure 8b and 8c reprinted, with permission, from reference 12).
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The occurrence of appendicitis secondary to an impacted foreign body is an interesting, albeit rare, phenomenon (9,10). There are reports of appendicitis, appendiceal perforation, and appendiceal abscess formation developing months to years after the ingestion of a foreign object (9). However, 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, BBs, and barium and mercury globules can reside in the appendix for years without apparent effect (Figs 9, 10). It is probable that sharp objects such as pins and toothpicks are more likely than small rounded objects to induce appendiceal inflammation 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 (10). 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 (10).
Disk (button) batteries such as those used in watches, calculators, hearing aids, and cameras are potentially very hazardous if ingested (Fig 11) (18,19). 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 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.
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Figure 11a. Sequential radiographs of a 4-year-old girl who ingested a watch battery show it first in the fundus of the stomach (a) and then later in the transverse colon (b). The battery passed without complications.
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Figure 11b. Sequential radiographs of a 4-year-old girl who ingested a watch battery show it first in the fundus of the stomach (a) and then later in the transverse colon (b). The battery passed without complications.
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The treatment for watch battery ingestion is controversial (18–20). 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 fluoroscopy-directed interventional techniques with magnets (the battery case contains nickel and is magnetic), Foley catheters, forceps, or some type of retrieval basket (20–22). Disk batteries impacted in the esophagus are considered to be especially dangerous and should be removed promptly.
Another seemingly innocuous but potentially extremely dangerous ingested foreign body is the plastic clip used to close plastic bags, such as those used for bread packages (23–27). These plastic clips have been noted to grip various portions of the bowel mucosa, producing inflammation and ulceration and eventually leading to severe complications such as perforation, obstruction, intussusception, fistula formation, abdominal abscess formation, and death (23–27). Unfortunately, these clips are not opaque on radiographs and are difficult to detect (Fig 12). They may become encrusted with mineral or bile salts and thereby are rendered opaque.
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Figure 12. Soft-tissue radiograph of a 1-year-old girl who was coughing after swallowing a red coinlike plastic wafer shows the object (arrowheads) lodged in her hypopharynx. She coughed it up a few minutes after the radiograph was taken. It is unusual for a plastic object to be opaque at radiography.
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Less than 1% of ingested foreign bodies cause perforation of the gastrointestinal tract. Sharp, elongated objects are the most likely to penetrate the bowel or esophageal mucosal lining and cause significant injury to the bowel wall or frank perforation (3,28–33). Perforations are more common in the ileocecal region, especially in a Meckel diverticulum or the appendix. Metallic objects such as needles or elongated objects such as fish bones, chicken bones, and toothpicks are the foreign bodies most frequently reported to have caused a perforation (3). In many cases, these types of perforations do not occur acutely or cause acute symptoms. The object may only partially perforate the bowel wall and produce a chronic inflammatory process that has few symptoms, being discovered months or years later. Sometimes, these chronic inflammatory processes are discovered when they produce unusual areas of opacity or lucency on radiographs obtained for other reasons. Sometimes, they are discovered at abdominal surgery performed for another reason. Even at surgery, the foreign body may be hard to diagnose because of its encrustation by bile and mineral salts.
Almost all objects composed of plastic and most thin aluminum objects, such as pull tabs on cans, are not radiopaque (Table 2). On the other hand, all chicken bones and most meat bones are opaque on radiographs (Figs 13–16), whereas the majority of fish bones are not, although some fish bones are readily evident (Fig 16) (3,33). Glass is always radiopaque, and its radiopacity does not depend on its lead content or other metal content (35–37). Glass foreign bodies, whether ingested, inserted into a body cavity, or deposited in the soft tissues of an extremity by an injury, should always be visible on radiographs. This visibility obviously depends on the size of the object. Submillimeter pieces of glass buried deep in the soft tissue of an obese person may not be visible. However, any substantial piece of glass 1–2 mm or larger should generally be visible.
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Figure 13. Radiograph of an 81-year-old man who swallowed a turkey bone shows the bone sliver (arrows) located just posterior to the calcified thyroid cartilage. The bone could not be seen at direct laryngoscopy but was removed at endoscopy.
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Figure 14. Xeroradiograph of an elderly man with painful swallowing after eating a bowl of "oxtail" soup shows a prominent piece of impacted bone lying anterior to the 7th cervical vertebra. Note the prominently calcified posterior margin of the cricoid bone (arrow). This normal variant can easily be mistaken for a foreign body. The impacted fragment was removed from the proximal esophagus at endoscopy.
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Figure 15. Radiograph of a 68-year-old man with difficulty in swallowing after eating fish shows a fish bone (arrow). Results of indirect laryngoscopy had been negative. The bone was removed at surgery following unsuccessful endoscopy. The bone had perforated the hypopharyngeal wall and was lodged in the soft tissues of the neck.
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Figure 16a. (a) Radiograph of a 36-year-old woman with painful swallowing after eating chicken shows a small calcific opacity in her neck (arrowhead). (b) Radiograph obtained after the patient swallowed a barium capsule shows it temporarily lodged at the point of obstruction. A chicken bone was impacted in her proximal esophagus and removed at rigid endoscopy. (Figure 16b reprinted, with permission, from reference 34.)
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Figure 16b. (a) Radiograph of a 36-year-old woman with painful swallowing after eating chicken shows a small calcific opacity in her neck (arrowhead). (b) Radiograph obtained after the patient swallowed a barium capsule shows it temporarily lodged at the point of obstruction. A chicken bone was impacted in her proximal esophagus and removed at rigid endoscopy. (Figure 16b reprinted, with permission, from reference 34.)
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Some radiologists and many other physicians are not aware that aluminum is relatively radiolucent, unlike most other common metals (38–40). Ingested or inhaled aluminum objects are not easily detected on radiographs. The U.S. federal government actually abandoned plans to produce an aluminum penny because many physicians pointed out the danger to children if a common coin were radiolucent (38–40). Coin ingestions are common in children and would be hard to diagnose if coins were not readily apparent on radiographs. Although most coin ingestions cause no harm, with the coin passing through the gastrointestinal tract in a few days, coins may enter the airway or become impacted at the thoracic inlet or the gastroesophageal junction. In these circumstances, some type of interventional therapy is required. The diagnosis of coin ingestion could be significantly delayed if radiolucent coins were common. In fact, aluminum pull tabs and Italian lira are radiolucent and have caused difficulty in the diagnosis of esophageal perforations.
The diagnosis of an ingested foreign body is often overlooked in those patients who cannot furnish an adequate history or who have swallowed objects that are not inherently opaque (Fig 17) (1,2,13–16,41,42). In selected cases, contrast material studies with barium tablets, barium capsules (Fig 16), barium impregnated cotton balls, or barium-coated food may be useful (34). CT of the abdomen or chest may be helpful, particularly if an unusual area of opacity or lucency is found at radiography, and the diagnosis of a perforating foreign body is entertained (43). As mentioned, correlation of the CT findings with radiographic findings and careful examination of the scout image is critical for diagnosing foreign bodies or unexpected medical devices.
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Figure 17. Image from a barium enema study of a 73-year-old woman shows a polyp in the descending colon. At endoscopy, the "polyp" proved to be an undigested mushroom. (Courtesy of Kiyoshi Ohsiro, MD, Okinawa, Japan.)
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Young children with an esophageal foreign body may present with mainly respiratory symptoms and may not volunteer a history of foreign body ingestion. Stridor, wheezing, and pneumonia can be unsuspected sequelae from an ingested, impacted foreign body in the hypopharynx, esophagus, or respiratory tree (Figs 18 –21) (41,42). Whenever there is a history of foreign body ingestion, whether in an adult or child, the patient should be examined from the nasopharynx to the rectum—from the base of the skull to the anus (Figs 22, 23). Often, there is ingestion of more than one object, and the search for foreign bodies should not be suspended just because one has been found. Children are especially prone to ingest objects in multiples.
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Figure 19a. Ingested foreign body in a 2-year-old girl with severe left-sided pneumonitis and empyema that required a tracheostomy. For several days, the ringlike metallic opacity noted on her portable chest radiographs was assumed to be associated with her tracheostomy tube. Standard frontal (a) and lateral (b) radiographs reveal a foreign body in the girl’s hypopharynx. A bingo chip was removed at endoscopy.
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Figure 19b. Ingested foreign body in a 2-year-old girl with severe left-sided pneumonitis and empyema that required a tracheostomy. For several days, the ringlike metallic opacity noted on her portable chest radiographs was assumed to be associated with her tracheostomy tube. Standard frontal (a) and lateral (b) radiographs reveal a foreign body in the girl’s hypopharynx. A bingo chip was removed at endoscopy.
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Figure 20. Radiograph of a 37-year-old mentally retarded woman who was admitted comatose with a 24-hour history of difficulty in breathing shows a safety pin. The pin had perforated the wall of her esophagus and penetrated her larynx. It was extracted at laryngoscopy, and she recovered without sequelae. Of incidental note is the prominent diffuse idiopathic skeletal hyperostosis (DISH) in the cervical spine.
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Figure 21a. Frontal (a) and lateral (b) radiographs of a 13-year-old boy show a pin in his trachea. The boy had been playing with a blowgun and inhaled a corsage pin. It was removed at bronchoscopy. (Courtesy of George Barnes, MD.)
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Figure 21b. Frontal (a) and lateral (b) radiographs of a 13-year-old boy show a pin in his trachea. The boy had been playing with a blowgun and inhaled a corsage pin. It was removed at bronchoscopy. (Courtesy of George Barnes, MD.)
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Figure 22a. (a) First radiograph of an 8-year-old boy who was thought to have swallowed a foreign object shows no opaque object in the chest or stomach. The radiologist asked for a repeat radiograph to include all the abdomen and pelvis. (b) Second radiograph shows a metallic object in the child’s distal small bowel.
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Figure 22b. (a) First radiograph of an 8-year-old boy who was thought to have swallowed a foreign object shows no opaque object in the chest or stomach. The radiologist asked for a repeat radiograph to include all the abdomen and pelvis. (b) Second radiograph shows a metallic object in the child’s distal small bowel.
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We live in a world plagued by illicit drug traffic and use in which the importation of illegal drugs is a major industry. Some of the bit players in this trade are the "mules" or "body packers," who smuggle drugs by ingesting drug-filled packets or by inserting them into their rectum or vagina. These packets are usually filled with cocaine, although heroin is also common. The packing material is typically a condom or balloon, and the packets vary in their relative opacity. Some are opaque, whereas others are equal in opacity to or less opaque than the bowel (44). On serial abdominal radiographs (Fig 24), these packets may be detected by observing a definite crescent of air surrounding an ovoid area of opacity. This finding is sometimes called the double-condom sign. The packets may also be noted as multiple, well-defined areas of opacity in the stomach, small intestine, or colon. They may have a rosette configuration at one end (44). The main medical complications from this type of smuggling are bowel obstruction and acute drug toxicity. Bowel obstruction occurs in slightly less than 10% of documented cases (44). Acute drug overdose is a very serious risk to the smuggler if one or more of the condoms should rupture. There have been reports of sudden deaths from massive drug overdoses. Considering the large amount of smuggling that no doubt takes place by this means, the complication rate is rare.
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Figure 24a. (a-c) Radiographs of three adults who were smuggling drugs show a packet (arrow) in the transverse colon (a) and relatively opaque packets in the transverse and descending colon (b, c). (d) Radiograph of an adult who was in the habit of swallowing rubber gloves shows a mottled lucent area (arrow) in the right lower quadrant of the abdomen. The finding represents a rolled-up rubber glove in the terminal ileum. It has a similar appearance to swallowed drug packets. (Fig 24a-24d courtesy of Charles A. Rohrmann, Jr, MD, University of Washington, Seattle.)
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Figure 24b. (a-c) Radiographs of three adults who were smuggling drugs show a packet (arrow) in the transverse colon (a) and relatively opaque packets in the transverse and descending colon (b, c). (d) Radiograph of an adult who was in the habit of swallowing rubber gloves shows a mottled lucent area (arrow) in the right lower quadrant of the abdomen. The finding represents a rolled-up rubber glove in the terminal ileum. It has a similar appearance to swallowed drug packets. (Fig 24a-24d courtesy of Charles A. Rohrmann, Jr, MD, University of Washington, Seattle.)
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Figure 24c. (a-c) Radiographs of three adults who were smuggling drugs show a packet (arrow) in the transverse colon (a) and relatively opaque packets in the transverse and descending colon (b, c). (d) Radiograph of an adult who was in the habit of swallowing rubber gloves shows a mottled lucent area (arrow) in the right lower quadrant of the abdomen. The finding represents a rolled-up rubber glove in the terminal ileum. It has a similar appearance to swallowed drug packets. (Fig 24a-24d courtesy of Charles A. Rohrmann, Jr, MD, University of Washington, Seattle.)
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Figure 24d. (a-c) Radiographs of three adults who were smuggling drugs show a packet (arrow) in the transverse colon (a) and relatively opaque packets in the transverse and descending colon (b, c). (d) Radiograph of an adult who was in the habit of swallowing rubber gloves shows a mottled lucent area (arrow) in the right lower quadrant of the abdomen. The finding represents a rolled-up rubber glove in the terminal ileum. It has a similar appearance to swallowed drug packets. (Fig 24a-24d courtesy of Charles A. Rohrmann, Jr, MD, University of Washington, Seattle.)
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Esophageal and bowel strictures may be produced by improper ingestion of common prescription medications, such as potassium chloride or quinidine preparations. Most of the strictures develop in the middle or proximal esophagus. Risk factors for developing esophageal caustic injury related to medications include older age, male sex, left atrial enlargement, and prior esophageal structural abnormality. Ingestion of sustained release formulations appears to increase the risk for injury (45).
Children, mentally incapacitated adults, and suicidal individuals may knowingly or inadvertently ingest poisonous substances. Most medications and toxic agents are probably not opaque enough to be easily detected by routine imaging methods. However, many metals and their compounds are sufficiently opaque to be seen on abdominal radiographs (Fig 25) (46–50). These substances include barium, lead, arsenic, bismuth, thorium, and iodine compounds.
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Figure 25. Radiograph of a typesetter shows opaque lead visible within the rectosigmoid portion of his colon. The man had inadvertently ingested high amounts of metallic lead over a period of years while eating his lunch at the plant. He had very high lead levels in his blood, neurologic symptoms, anorexia, and constipation.
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Iron poisoning is the leading cause of poisoning-related deaths in children under 6 years of age. Medications containing iron are widely used, and many adults do not appreciate the potential toxicity of iron tablets (50). The U.S. Food and Drug Administration requires the following statement on packages for preparations that contain iron or iron salts for dietary supplemental or therapeutic purposes: "WARNING: Accidental overdose of iron-containing products is a leading cause of fatal poisoning in children under six. Keep this product out of reach of children. In case of accidental overdose, call a doctor or poison control center immediately." Severe iron poisoning results in hemorrhagic gastroenteritis followed by a significant blood chemistry imbalance and subsequent multiorgan damage. Iron tablets that are intact, fragmented, or in a coarse powder form are usually visible in the stomach and small bowel (Fig 26). However, iron preparations that are dissolved or form a fine suspension may not be sufficiently radiopaque to be recognizable. Thus, although potentially helpful, abdominal radiography may not permit the diagnosis of iron ingestion or allow it to be convincingly ruled out. Also, abdominal radiography should not be relied on to gauge the success of efforts to remove iron from the gastrointestinal tract (50).
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Figure 26. Radiograph of a 3-year-old boy demonstrates multiple iron tablets probably containing ferrous gluconate and ferrous sulphate salts. He recovered without sequelae. (Courtesy of George Barnes, MD.)
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Although most poisonous substances are not sufficiently opaque to be visible on radiographs, many industrial solvents such as carbon tetrachloride are radiopaque. Most medications are radiolucent and will not be visible on radiographs. However, bismuth subsalicylate (Pepto-Bismol) is sufficiently opaque to be visible throughout the gastrointestinal tract if it has been ingested in a sufficient amount (Fig 27). Some other medications, such as chloral hydrate, the phenothiazines, and many enteric-coated pills, are radiopaque as well (47–49). CHIPES (chloral hydrate, heavy metals, iodides, phenothiazines, enteric-coated pills, and solvents) is a good mnemonic for remembering classes of radiopaque ingested compounds (48).
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Figure 27. Radiograph shows bismuth subsalicylate (Pepto-Bismol) tablets in the right lower quadrant of the abdomen producing a "pseudoappendicolith" appearance. (Courtesy of Charles A. Rohrmann, Jr, MD.)
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Foreign Body Insertions
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No matter the body opening, there are individuals who will attempt to insert something into it themselves or allow others to insert a foreign object into it. The rectum, vagina, urethra, nose, and ear are favorite sites for insertion of foreign objects. These types of insertions are most frequently seen in children (Figs 28, 29), but adult patients may derive sexual pleasure from it, be mentally incompetent (Fig 30), or do it merely out of curiosity (Fig 31) (Table 3).
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Figure 31. Radiograph of a 15-year-old boy shows a rectal thermometer lying free in the peritoneum. Its origin was unknown. He denied inserting any foreign objects into his rectum or urethra. He had had no treatments or hospitalizations since he was 1 year old. (Courtesy of George Barnes, MD.)
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Rectal, urethral, or bladder foreign bodies are usually purposefully introduced by the patient himself or herself (Figs 32, 33), although occasionally they are the result of a penetrating injury, past surgery, or past instrumentation (51–58). Their occurrence is more frequent in children or adults with mental illness. Bladder foreign bodies are particularly prone to being a site for deposition of mineral salts with the formation of one or more bladder calculi (Fig 34) (59). In fact, a bladder calculus in a child or young adult should raise the suspicion of an encrusted foreign body.
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Figure 32. Radiograph of a 19-year-old woman shows a bobby pin lodged in her uterus. She had attempted to induce an abortion with the pin. A subsequent self-inflicted abortion attempt was successful. (Courtesy of George Barnes, MD.)
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Figure 34. Radiograph of an 18-year-old man demonstrates bladder calculi that had formed on fine telephone wire. Six months before, he lost the wire in his bladder when he achieved an erection while inserting the wire into his urethra during masturbation. (Courtesy of George Barnes, MD.)
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Surprisingly, most foreign bodies inserted into the urethra or rectum do not cause significant injury even if they are large, sharp, or pointed. These tubular structures are capable of considerable expansion, and they are well lubricated by natural fluids. Patients also learn how to "dilate" these structures so that they will accommodate large objects (Figs 35, 36). Common rectal foreign bodies that result from medical procedures going awry include thermometers, rectal tubes, anal packs, light covers, enema tips and covers, suppository wrappers, and oral or topical medication used inappropriately in the rectum (60).
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Figure 36. Radiograph of a 51-year-old man who first declined to give a history other than "rectal pain" shows a bottle of gargling liquid in a Hartman pouch. Three weeks before this admission, he had undergone colon surgery to remove an impacted shampoo bottle in his distal colon. A Hartman pouch was constructed for him at that time. (Courtesy of Tyler Gibb, MD, Tacoma, Wash.)
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The supine view of the abdomen is often the first radiograph obtained to evaluate a patient with abdominal or pelvic pain with or without a history of foreign body insertion. If the object lies in the bladder, it will generally be oriented mediolaterally. If it lies in the vagina or rectum, it will generally be oriented craniocaudally. This rule is probably more applicable in children than in adults, because vaginal foreign objects may lie mediolaterally in adults. Oblique and lateral radiographs of the pelvis as well as endoscopy and contrast material studies can help determine the exact location of a foreign body.
Cleansing enemas are sometimes a source of complications for patients (60). There can be mucosal injury from the enema fluid being too hot or too caustic. The enema tube or its protective sheath may be retained in the rectum or sigmoid or the mucosa may be lacerated and perforated. Small, retained colonic foreign bodies usually pass spontaneously. Large ones may induce enough wall edema or bowel atony that they cannot be passed naturally. In such instances, they must be removed endoscopically; by perianal extraction with the patient under anesthesia; or surgically, with either direct removal of the object from the bowel or with laparotomy and anal removal of the object (60–63).
Retained rectal bodies may rarely form asymptomatic calcified fecaliths. More commonly, they cause acute and chronic discomfort and can produce severe bleeding, bowel obstruction, and perforation. Retained objects can also ascend higher into the colon, even as far as the hepatic flexure. If they perforate the colon, they may lodge in the retroperitoneal tissues, induce localized contained abscesses, lie free within the peritoneum, or even travel to distant sites in the body (60–66).
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Foreign Body Injuries
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Even the most sheltered individual has a life filled with a multitude of minor injuries, including falls, cuts, abrasions, scratches, and burns. Everyone has suffered puncture wounds from splinters, needles, and thorns and has been cut with glass. The entire range of possible foreign body injuries cannot be covered in this article. However, it is possible to illustrate many common types of accidents and point out general principles concerning these injuries (Table 4) (67–85).
Bullet wounds are far too common in the United States. A discussion of these injuries is beyond the scope of this article except for a few general comments from more extensive reviews on the subject (84,85). Bullets are usually described by their caliber, which is a measurement of their diameter in inches or in millimeters. Although the caliber of a bullet is important, it has only a loose relationship to the weight of the bullet and the size of its charge. These latter parameters help determine the kinetic energy of the bullet, which is an important factor in determining its wounding potential. Bullets are usually composed of lead, and they may be fully or partially covered by an outer metal jacket (full metal jacket) that is usually composed of copper. If a bullet has a hollow cavity at its tip (hollow-point bullet), it will deform more on impact and produce more tissue damage. When it comes to rest, a hollow-point bullet typically has a mushroom shape. Bullets are not sterile, and gunshot wounds can deposit live bacteria and other contaminants deep into the body.
Shotgun pellets are measured by their gauge: the larger the number, the smaller the pellet size. Because the pellets are round, they do not travel through air or tissue as well as the more aerodynamically shaped bullets. However, the combined mass of multiple pellets striking someone at a small distance from the gun barrel can cause severe soft-tissue and bone damage, because a relatively large mass is decelerated over a short distance, and its kinetic energy is deposited in a small volume of tissue (Fig 37). Shotgun pellets used for hunting are now composed of steel. They were formerly composed of lead, which is not ferromagnetic. However, lead pellets left in the environment produce considerable toxic effects on waterfowl. Because steel pellets are ferromagnetic, they may undergo dangerous motion if a patient with imbedded steel shotgun pellets is exposed to a strong magnetic field; therefore, MR imaging may be contraindicated in such patients.
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Figure 37a. (a, b) Initial frontal and lateral CT scout views of a young man who accidentally shot himself in the chest and right arm with a shotgun show multiple shotgun pellets in the right shoulder and right anterior chest wall. Note the pellet overlying the heart inferiorly on the lateral view. (c) CT image of the lower portion of the chest shows the inferior pellet in the right ventricle. It had penetrated the right subclavian vein and embolized to the right ventricle. It was visible bouncing in the right ventricle when fluoroscopy was performed during right upper extremity angiography. The pellet was successfully removed at cardiac catheterization. (Courtesy of Michael Rosellini, MD, Portland, Ore.)
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Figure 37b. (a, b) Initial frontal and lateral CT scout views of a young man who accidentally shot himself in the chest and right arm with a shotgun show multiple shotgun pellets in the right shoulder and right anterior chest wall. Note the pellet overlying the heart inferiorly on the lateral view. (c) CT image of the lower portion of the chest shows the inferior pellet in the right ventricle. It had penetrated the right subclavian vein and embolized to the right ventricle. It was visible bouncing in the right ventricle when fluoroscopy was performed during right upper extremity angiography. The pellet was successfully removed at cardiac catheterization. (Courtesy of Michael Rosellini, MD, Portland, Ore.)
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Figure 37c. (a, b) Initial frontal and lateral CT scout views of a young man who accidentally shot himself in the chest and right arm with a shotgun show multiple shotgun pellets in the right shoulder and right anterior chest wall. Note the pellet overlying the heart inferiorly on the lateral view. (c) CT image of the lower portion of the chest shows the inferior pellet in the right ventricle. It had penetrated the right subclavian vein and embolized to the right ventricle. It was visible bouncing in the right ventricle when fluoroscopy was performed during right upper extremity angiography. The pellet was successfully removed at cardiac catheterization. (Courtesy of Michael Rosellini, MD, Portland, Ore.)
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It is sometimes possible to distinguish steel and lead pellets from one another at radiography (84). Lead pellets tend to be deformed and fragmented by impact with soft tissues and bone. Steel pellets usually remains round. Unjacketed bullets are composed of lead and should not cause any problems for MR imaging. On the other hand, some bullet jackets are composed of steel rather than copper. If the nature of the bullet injury is unknown, it may not be safe to perform MR imaging on a bullet wound victim if radiographic findings suggest that the imbedded bullets are jacketed (84). Most lead bullet fragments can be left in place, because they usually become encapsulated with fibrous tissue (Fig 38). Lead toxicity is a potential problem if the lead fragments are in a joint space, bursal space, or disc space. Lead fragments left in a joint space also can lead to a severe, destructive synovitis (85).
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Abstract
Introduction
