Material differentiation in forensic radiology with single-source dual-energy computed tomography

Abstract

The goal of this study was to investigate the use of dual-energy computed tomography (CT) in differentiating frequently encountered foreign material on CT images using a standard single-source CT scanner. We scanned 20 different, forensically relevant materials at two X-Ray energy levels (80 and 130 kVp) on CT. CT values were measured in each object at both energy levels. Intraclass correlation coefficient (ICC) was used to determine intra-reader reliability. Analysis of variance (ANOVA) was performed to assess significance levels between X-Ray attenuation at 80 and 130 kVp. T test was used to investigate significance levels between mean HU values of individual object pairings at single energy levels of 80 and 130 kVp, respectively. ANOVA revealed that the difference in attenuation between beam energies of 80 kVp compared to 130 kVp was statistically significant (p \ 0.005) for all materials except brass and lead. ICC was excellent at 80 kVp (0.999, p \ 0.001) and at 130 kVp (0.998, p \ 0.001). T test showed that using single energy levels of 80 and 130 kVp respectively 181/190 objects pairs could be differentiated from one another based on HU measurements. Using the combined information from both energy levels, 189/190 object pairs could be differentiated. Scanning with different energy levels is a simple way to apply dual-energy technique on a regular single-energy CT and improves the ability to differentiate foreign bodies with CT, based on their attenuation values.

Forensic age estimation based on the trabecular bone changes of the pelvic bone using post-mortem CT

“…Previous studies have tested quantitative approaches in the quantification of the variation of the trabecular bone in femur [31] and humerus [32] and pubic bone [20]. Trabecular bone changes could be also investigated using the variation of the Hounsfield Units (HU), although particular attention has to be paid to factors such as the position and the dimension of the region of interest, the model and the setting of the CT scanner [33], that can influence the reliability and the reproducibility of any resultant method.…”

Detection and Characterization of Crystal Suspensions Using Single-Source Dual-Energy Computed Tomography

“…8 An increasing research interest in the potential of DECT expands applications beyond the narrow field of cardiovascular 11,12 and gout imaging as well as renal stone characterization 13 to other techniques such as iodine subtraction 14 and quantification 15 as well as bone marrow and ligament imaging. They include helical scanning with fast kilovolt switching or photon-counting spectral CT. [18][19][20][21][22] The principle of dual-energy imaging is based on physical properties of the examined material in terms of how the material interacts with electromagnetic radiation. Nonetheless, some strategies have been proposed to develop a single-source DECT system into a viable alternative.…”

Imaging and virtual autopsy: looking back and forward

“…With the HU values determined by CT, possibly bomb-associated fragments, e.g. fragments consisting of steel, aluminium, copper, etc., can be located and extracted rapidly for further analysis [37]. …”