John Matthew Spiridigliozzi Wait BS, Presenter: Research Grant, General Electric Company

Srinivas Cheenu Kappadath PhD, Abstract Co-Author: Research Grant, General Electric Company

Dianna D. Cody PhD, Abstract Co-Author: In-kind support, General Electric Company

A. Kyle Jones PhD, Abstract Co-Author: Nothing to Disclose

Xiujiang John Rong PhD, Abstract Co-Author: Nothing to Disclose

Veera Baladandayuthapani PhD, Abstract Co-Author: Nothing to Disclose

To quantitatively investigate the accuracy and performance of material density images from the GE HD750 DECT scanner and evaluate its performance for assessing bone mineral density (BMD).

Utilizing constituent basis pairs, the concentrationsof various solutes in material decomposition images were measured for two-material syringe-phantoms under different experimental conditions together with SECT and DXA. The accuracy of the DECT concentration measurements in air was quantified by RMS error and linear regression was performed to compare measurements made in varying scanning conditions. Accuracy with concentric phantom (anthropomorphic) geometry was explored. The sensitivity of DECT and DXA to changes in BMD was evaluated. Correlations between DECT-derived areal bone mineral densities (aBMD) and DXA aBMD values were assessed for a variety of samples, including animal bones. 

The RMS error of DECT concentration measurements in air ranged from 9-244%. Concentration measurements made off-isocenter or with a different DECT protocol were within 5% but measurement in scattering conditions resulted in a reduction of 8-27%; similar trends were observed in SECT data. In concentric phantoms, higher-attenuating material in the outer chamber increased measured values of the inner material for all measurement methods. DECT was found to be more sensitive than DXA to changes in BMD at 2 mg/ml K2HPO4. Measurements of aBMD using DECT were highly correlated (R2 = 0.983) with those from DXA.

DECT material density images were linear in response but showed poor accuracy. However, its high sensitivity and correlation with DXA aBMD suggests, perhaps with additional corrections, that DECT could be used clinically for monitoring relative changes to BMD. 

New commercial dual-energy CT scanners bring renewed interest in potential applications of the technology. One such application is an accurate assessment of bone mineral density. 

Wait, J, Kappadath, S, Cody, D, Jones, A, Rong, X, Baladandayuthapani, V, Performance Evaluation of Material Decomposition with Rapid kVp-switching Dual-energy CT and Implications for Assessing Bone Mineral Density.  Radiological Society of North America 2014 Scientific Assembly and Annual Meeting, - ,Chicago IL. http://archive.rsna.org/2014/14012383.html