Contribution of dual-energy computed tomography in the differentiation of illicit drugs.

Abstract

The objective of this study was to compare the dual-energy behaviour of the main illicit substances as well as their cutting agents in order to be able to differentiate them. Cocaine, heroin, MDMA, and cannabis as well as 3 adulterants, 2 diluents, and water were scanned at 90 kV and then at 140 kV on a single X-ray tube computed tomography (CT) scanner. The data acquired enabled a mapping of the attenuation values to 90 and 140 kVp as well as a resulting dual-energy index (DEI) mapping. Drugs, cocaine, MDMA (pill), and cannabis had a positive DEI (0.014-0.008), while heroin and MDMA (powder) had a negative DEI (-0.016 and -0.013). The DEI of water was -0.01 and that of taurine was -0.018. Adulterants had negative DEI, while diluents had a positive DEI. All DEI were significantly different (p < 0.01). Cocaine and heroin can be clearly differentiated using DEI.