1. A system for detecting a contraband object within an article, comprising: an acquisition subsystem including a three dimensional computed tomography scanner that produced volumetric data; a reconstruction subsystem adapted to identify and distinguish regions of interest from regions of no interest within an article; and an alternate modality subsystem adapted to analyze the regions of interest to identify a contraband object, wherein the alternate modality subsystem does not comprise a computed tomography modality, wherein the alternate modality subsystem comprises a detector having a modality with a sensitivity complementary to the computed tomography scanner, wherein the detector comprises an x-ray system with dual energy capability.