Diagnostic value of CT-localizer and axial low-dose computed tomography for the detection of drug body packing

• The value of CT-localizers lies in their high PPV for body packing.
• In cases of positive localizer a dose reduction of 94.52% is possible.
• The sensitivity of CT-localizer for detection of packs was 0.68 and specificity was 1.00.

ObjectivesThe purpose of this study was to assess the diagnostic performance of CT-localizers in the detection of intracorporal containers.MethodsThis study was approved by the research ethics committee of our clinic. From March 2012 to March 2013, 108 subjects were referred to our institute with suspected body packing. The CT-localizer and the axial CT-images were compared by two blinded observers retrospectively. Presence of body packs was assessed in consensus. Sensitivity and specificity, PPV and NPV of the CT-localizer were calculated.ResultsPackets were detected in the CT-localizer of 19 suspects. In 28 of 108 cases packs were detected in axial CT-images. Sensitivity of CT-localizer for detection of packs was 0.68, and specificity was 1.00. There were no cases rated as false positive. The PPV was 1.0 and the NPV was 0.89. The omission of the axial CT-images would have led to a mean radiation dose reduction of 1.94 ± 0.5 mSv.ConclusionsThe value of CT-localizers lies in their high PPV. Localizers are limited by low sensitivity, compared to axial CT-images in screening of potential body packers. However, in positive cases their high PPV may possibly allow to omit the complete axial abdominal CT to achieve even lower radiation exposure.