Patients
We prospectively included 29 body stuffers admitted by the police to the emergency department from August 2009 to November 2010 because of suspected ingestion of CFP (mean age 31.9 years,
3 women).
In 13 (44.83%) out of them cocaine-filled packets were detected in the digestive tract.
Their number (range 1-25 per body stuffer) was then confirmed by a member of the emergency staff who had to collect and exactly analyse the faeces evacuated after the CT.
Only after elimination of all the CFP detected on CT the body stuffers could be discharged.
The body stuffers were subjected to continuous medical surveillance,
because of the large dose of cocaine situated in the digestive tract,
but none of the packets ruptured.
CT image acquisition
Twenty-nine body stuffers were examined on a 64 row multidetector CT (Lightspeed Ultra,
GE Healthcare,
Milwaukee,
Wisconsin,
USA).
We performed a routine acquisition including the whole digestive tract (120kV,
pitch 1.375,
100-300 mA and automatic tube current modulation in x-,y- and z-axis(auto mA),
noise index (NI) 10 UH,
rotation time 0.7sec and collimation 2.5mm) without any intravenous neither intestinal contrast medium administration.
Primary axial images were obtained with FBP technique,
followed by axial images with 30% and 60% ASIR.
The radiation dose necessary for the MDCT data acquisition was about 600 mGy.cm (range 247-648) corresponding to approximatively 9 mSv.
CT image analysis
After an introductory and explanatory session,
four abdominal radiologists (with 5-20 years of experience in emergency radiology) blindly and separately read the 87 anonymous CT (29 FBP-CT and 58 ASIR-CT (among them twenty-nine 30% ASIR-CT and twenty-nine 60% ASIR-CT) examinations on workstations complying with the DICOM 3.14 standard.
All radiologists had been previously taught to use the lung kernel instead of the usual soft tissue kernel for image analysis in order to better detect the typical image of ingested CFP,
which is an outer thin hypodense halo of air trapped within the cellophane surrounding a dense,
sometimes even hyperdense structure.
(5) (Fig.
2)
The four readers had to analyse each CT examination regarding the following points:
a. Subjective evaluation (five levels) of the overall image quality
b. Subjective evaluation (three levels) of the spatial resolution of a sharp structure,
defined as one of the two adrenal glands
c. Measurement of the density of the psoas muscle including the standard deviation by means of a region of interest (ROI) with a size of 200-300 mm2
d. Measurement of the density of a fluid-containing organ (gall-bladder or,
if absent,
bladder) including the standard deviation by means of a ROI with a size or 200-300mm2
e. Identification of the common bile duct (visible or not visible)
f. Detection of intestinal cocaine-filled packets including their number and their exact localisation in the gastrointestinal tract with the estimation of the diagnostic certitude (three levels)
g. Estimation time of reading of the whole CT