Low-dose abdominal CT is superior to plain film for imaging suspected body packers
January 4, 2013, 2:16 am
Screening of Illegal Intracorporeal Containers (“Body Packing”): Is abdominal Radiography Sufficiently Accurate? A Comparative Study with Low-Dose CT. Poletti PA et al. Radiology 2012 Dec;265:772-9.
The answer to the question posed in the title of this paper is clearly “No!”. The authors — from the University Hospital of Geneva in Switzerland — prospectively studied 230 consecutive adults brought to their institution for suspicion of having ingested drug packets. (Unfortunately, no additional information about these subjects is provided. Were they smugglers? Were they trying to get through customs? Why were they under suspicion.)
For each subject, a supine abdominal x-ray was obtained and immediately interpreted by the radiologist on call (fellow or resident). Subsequently, a non-contrast low-dose abdominal CT (technical parameters in paper) was performed and interpreted.
The authors found that — using the low-dose CT as the gold standard — the plain abdominal x-ray was quite specific (96%) but only 77% sensitive, detecting only 42 of 53 subjects with packets seen on CT. They calculated that the effective radiation dose was similar between the 2 tests: 1.3 – 2.0 mSv for the abdominal film and 1.2 – 1.7 mSv for the low-dose abdominal CT.
The authors conclude that:
The use of low-dose CT may constitute a reasonable alternative to abdominal radiography to improve the detection of illegal intraabdominal packets.
Despite some flaws, this study clearly shows the superiority of low-dose abdominal CT over plain film for detecting drug packets, and suggests that this increased sensitivity can be achieved without markedly increasing radiation exposure. The reader should note that subjects with negative CT scans were discharged from the hospital, and that the authors do not report any clinical follow-up. All drug packets in subjects with positive CT scans contained powdered cocaine (or, in 3 cases, bank notes). No heroin was detected.