Magnetic resonance imaging was tried for explosives detection in suitcases about 10 years ago. It was found to lack specificity when compared with other techniques. The need for high magnetic fields and problems with commonly occurring metals also mitigated against its use. More recently, MRI has been looked at to examine liquid explosives. This system used the Earth’s field and was consequently very slow in its operation. An analogous technique, quadrupole resonance analysis, has been developed for detecting explosives containing nitrogen and systems are available commercially.
Additionally, magnetic resonance imaging is currently being considered as an alternative to using a polygraph, or, more probably, to use MRI scanning as an input to a polygraph to detect deception. Home Office scientists will be visiting King’s College London shortly to discuss the possibility of using MRI in this role.