Medical Apparatus: Imaging Guide to Orthopedic Devices

Foreign Bodies

Foreign Bodies Introduction

Foreign Body Ingestions - page 3

Drug packets; medication

Endoscopic capsules

Delayed Presentations

Foreign body ingestions - Page 1

Foreign body ingestions - Page 2


Foreign Body Insertions


Foreign Body Injuries


Miscellaneous Foreign Bodies


Foreign bodies and MR imaging

MRI Safety Information


Foreign Bodies: References & Links




Foreign Bodies: Ingestions...continued

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


Drug Packets; Medications

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 (Beerman, 1986; Schmidt, 2008; Poletti, 2012; Zamani, 2018).

On serial abdominal radiographs (figure: ingested drug packets), 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. Recent work suggests low-dose unenhanced mutlidector CT (MDCT) without bowel preparation is an excellent means for detecting ingested cocaine-filled packets (Schmidt, 2008; Poletti, 2012). It is probably superior to abdominal radiography (Laberke, 2016).

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. 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, this complication is rare.

Opium related products are often sold according to weight and may be adultered by lead and other heavy metals (Zamani, 2018). Exposure to high concentrations of lead or other toxic substances can cause severe side effects including encephalopathy, seizures, altered mental status, abdominal pain, and vomiting. The use of lead-contaminated drugs is a public health concern in some parts of the world.

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 (McCord, 1990).

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 (figures: foreign body ingestions V) (Hilfer, 1962; Goldfrank, 1986; Spiegel, 1984; Gray, 1989; Staple, 1964). These substances include barium, lead, arsenic, bismuth, thorium, and iodine compounds.

Sometimes children or mentally incapacitated adults will ingest a substance that is not directly toxic but can lead to bezoar formation in the stomach or cause bowel obstruction (figure: bezoar). There is an accumulation of ingested material which most commonly forms a hard mass or concentration in the stomach. Diabetes with poor gastric emptying, peptic acid disease with gastric scarring, prior partial gastric resection, or medication which slows gastric emptying may be causal factors in the development of a gastric bezoar. Bezoars are generally classified according to their composition (Foreign bodies of the esophagus and gastrointestinal tract in children). Phytobezeoars are composed of vegetable material, those being caused by persimmons are the classic example of a phytobezoar. Trichobezoars are composed of hair, and those patients with a trichobezoar often have an underlying psychiatric illness.

Iron poisoning is the leading cause of poisoning-related deaths in young children (Morris, 2000). Medications containing iron are widely used, and many adults do not appreciate the potential toxicity of iron tablets. 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” (FDA).

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 (figure: iron tablets in the bowel). 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.

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 (figure: Pepto-Bismol).

Some other medications, such as chloral hydrate, the phenothiazines, and many enteric-coated pills, are radiopaque as well. CHIPES (chloral hydrate, condoms, cocaine; heavy metals; iodides, iron; psychotrophics-phenothiazines; enteric-coated pills, barium; and solvents) is a good mnemonic for remembering classes of radiopaque ingested compounds (Spiegel, 1984).

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Endoscopic Capsules; Endoscopic Clips

Many small bowel diseases are diagnosed or evaluated by (video) capsule endoscopy (VCE). Clinical applications include workup of obscure gastrointestinal bleeding and iron deficiency anemia, detection of small bowel polyps and tumors, and evaluation of celiac disease, Crohn's disease, and other inflammatory bowel diseases (Neuman, 2014; Mustafa, 2013). VCE may be particularly indicated when gastroscopy or colonoscopy fail to find the source of gastrointestinal bleeding.

VCE can be dangerous and even contraindicated in any situation where there is risk of retention or small bowel obstruction. Contraindications include pregnancy, patients with a swallowing disorder, history of previous abdominal surgery, or any other situation in which there is potential narrowing of the bowel lumen. Capsule retention is a feared complication of VCE occurring in up to 20% of patients with symptoms of chronic small bowel obstruction (Singeap, 2011). In a more diverse population of patients, 2.1% experienced capsule retention, and surgical or endoscopic retrieval was necessary in 1% (Rondonotti, 2010). The endoscopic capsules can be retained for long periods with minimal patient discomfort, and many eventually pass on their own. The decision to endoscopically or surgically remove a retained endoscopic capsule depends on the individual patient circumstance, though on rare occasions they may cause or worsen acute bowel obstruction or lead to bowel perforation. A retained endoscopic capsule is a contraindication for MRI (MRI Safety Information).

Endoscopic clips are now part of modern endoscopic therapy. They are deployed into the gastrointestinal tract under endoscopic guidance and function as hemostatic clips to close tissue defects and control gastrointestinal bleeding as well as securing stents and tubes. Sometimes, they are placed as markers for surveillance. They have largely been considered safe for MRI. However, recently that assumption has been called into question, and it is best that patient screening prior to MRI includes asking about the presence of endoscopic clips with cancellation or postponement of the study depending on the presence of an endoscopic clip and its type (Accorsi, 2017).

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Foreign Body Ingestions with Delayed Presentation

On rare occasions an ingested foreign body remains asymptomatic for months to years. Then at some point, it perforates the gut or in some other fashion causes symptoms, usually abdominal pain, peritonitis, or generalized sepsis. It may be discovered unexpectedly on abdominal radiographs or abdominal CT or not appreciated at all until found at surgery (Gharib, 2015, Shepherd, 2017). Examples of such delayed presentations include a perforating fish bone (Gharib, 2015) in one patient and a long piece of orthodontic wire in another patient who must have inadvertently and unknowingly swallowed the wire ten years earlier when her orthodontic braces were removed (Shepherd, 2017).

One gastric foreign body, a felt pen, was found in a 76 year-old woman 25 years after ingestion when an abdominal CT study was performed for another reason. The patient then remembered accidentally swallowing the pen. The pen was removed in a combined endoscopic and ear, nose, and throat procedure under general anesthesia. It was still working (Waters, 2011). There is also a report of a 36 year-old man who apparently deliberately swallowed a butane lighter double wrapped in cellophane. He presented 17 months later with hematemesis and melena with the lighter successfully removed from his stomach via flexible endoscopy using a polypectomy snare (Trgo, 2012).

Delayed presentations of foreign bodies are especially problematic as foreign body ingestion, insertion, or injury usually are not even in consideration when a patient presents with troubling symptoms far removed from possible foreign body insult. The foreign body ingestion or injury may have long been forgotten by the patient or even hidden from the physician. In most cases the foreign body is found on routine radiography or CT imaging. Sometimes, it is evident on imaging but mistaken for a benign, incidental finding. Foreign bodies are not common but important. They should always be part of a diagnostic evaluation when patients have serious symptomatology not otherwise easily explained.



Foreign Bodies References

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Tim Hunter

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