Dual-energy CT behavior of heroin, cocaine, and typical adulterants

To investigate the dual-energy CT behavior of cocaine and heroin and of typical adulterants, and to evaluate the elemental composition of pure cocaine and heroin compared with cocaine and heroin in bodypacks. Pure heroin and pure synthetic cocaine samples, eight different adulterants, and in each case ten different bodypacks containing cocaine or heroin, were imaged at 80, 100, 120, and 140 kVp in a dual source CT system at two different degrees of compression. Two radiologists, blinded to the samples, measured the attenuation. The dual-energy index (DEI) was calculated. We performed atomic mass spectrometry for the elemental analysis of pure cocaine, pure heroin, and heroin and cocaine in bodypacks, and 140 kVp in a dual-source CT system. Inter- and intra-observer agreement for attenuation measurements was good (r = 0.61-0.72; p < 0.01). The cocaine bodypacks had a positive DEI of 0.029, while the pure drugs and the heroin bodypacks had a negative DEI (-0.051 to -0.027). Levamisole was the only substance which expressed a positive DEI of 0.011, while the remaining adulterants had negative DEIs ranging between -0.015 and -0.215. Atomic mass spectrometry revealed a concentration of tin in the cocaine bodypack that was 67 times higher than in the pure synthetic cocaine sample. The different DEIs of bodypacks containing cocaine and heroin allow them to be distinguished with dual-energy CT. Although the material properties of pure cocaine, pure heroin, or common drug extenders do not explain the differences in DEI, tin contamination during illicit natural cocaine production may be a possible explanation.