CHICAGO – The best method for finding narcotics that smugglers, or drug "mules," hide within their bodies is the same CT medical imaging more commonly used to spot cancer, a small study by Swiss researchers suggests.
CT scans were far more accurate at detecting smuggled drugs than X-rays. But CT scanning machines and the image processing are expensive, too costly to regularly use to catch smugglers, some experts say.
In the study, all 18 CT scans on smugglers correctly detected drugs they had swallowed or stuffed inside bodily cavities. There was only one mistake — one non-smuggler was wrongly identified as hiding drugs.
By comparison, conventional digital X-rays accurately detected smuggled drugs in 21 cases, but missed nine. The X-rays also indicated drugs when there were none in six cases. A type of full-body X-ray was better than that, spotting six correctly and getting three cases wrong, but it wasn't as good as CT scanning.
X-rays are less expensive than CT scans, but also more prone to false readings, said Dr. Patricia Flach, the study's lead researcher. She is a forensic radiologist at University Hospital in Bern, Switzerland, which is especially equipped to handle drug mules.
"On plain X-rays, overlapping structures, intestinal gas and feces very often disguise intestinal packs causing false-positive and false negative read-outs," Flach said.
Her research was being presented Wednesday at the Radiological Society of North America's annual meeting in Chicago.
The study involved 50 suspected drug mules or "body packers," brought by customs officials to the Swiss hospital over a three-year period, or who showed up on their own because of overdose symptoms. Some were scanned with CT machines, some with X-rays and some with both.
The suspects were ages 16 to 45, most of them men; 43 of them were ultimately identified as drug mules, most smuggling cocaine from Africa on airplanes.
The research offers an intriguing glimpse into the world of drug smuggling. Flach said mules often swallow 50 to 100 packets of drugs, sometimes stored in condoms coated with wax to make them easier to gulp down. They sometimes practice by swallowing whole grapes and plums.
The packets may show up as distinct round or oblong-shaped white or dark spots on imaging tests.
Flach said the smugglers sometimes raise suspicion because they often don't drink or eat anything during long flights, to avoid losing their contraband in airplane toilets. Customs agents are then tipped off once the plane lands. Or sometimes the packets rupture during the flight, causing an overdose and the smugglers have to be rushed to the hospital.
In the United States, some major international airports have onsite medical centers with X-ray machines and special toilets, said John Saleh, a U.S. Customs and Border Protection officer in New York. Sometimes customs contracts with hospitals to run imaging tests on suspects, who must sign consent forms. If they refuse, they're held in custody long enough for any drugs to pass, Saleh said.
Dr. Nageswara Mandava dealt with drug mules for several years at a now-shuttered New York hospital that worked with customs agents at Kennedy International Airport.
His own research shows CT scan images are superior but too expensive and time-consuming to use routinely. X-rays generally are good enough at detecting drugs, costing about $50 each and producing an image in minutes, versus a few hundred dollars for a CT scan, which can take hours. Mandava said CT scans are probably most useful to confirm an inconclusive X-ray.
Dr. Luis Rivas, chief of trauma and emergency radiology at University of Miami Miller School of Medicine, agreed that CT scans produce superior images. But he said cost — more than $1 million per machine — makes them impractical at airports. Plus, they emit much more radiation so pose more health risks.
Rivas said his center used to help identify drug mules but stopped when customs priorities shifted after the Sept. 11, 2001, terrorist attacks. Before then, vans with X-ray machines on board were stationed at various airports, including Newark, Houston, and Miami — the busiest. X-ray scans of suspects were transmitted to a computer at his hospital, where doctors evaluated them, Rivas said.
"This method was very cost-effective for the customs department because the agents never had to leave the airport and the results were available to them within minutes," he said.
Radiological Society of North America: http://www.rsna.org