Purpose: The goal of these experiments was to investigate the use of a novel dual-energy Computed Tomography (DECT) acquisition system in imaging phantoms containing various contrast agents (Barium-containing Barium Sulfate, Iodine-containing Iohexol, Gadolinium-containing Gadodiamide) at various concentrations to determine optimal settings needed to use these concentrations later in living systems at the lowest concentrations possible.

Materials and Methods: Phantoms were created with Iodine (Iohexol 350 mg/mL), Gadolinium (Gadodiamide 287 mg/mL), and Barium (Barium Sulfate suspension 2.1 % weight/volume [wt/v]) at various dilutions in normal saline to simulate their corresponding concentrations in biological systems and studied with simultaneous dual energy acquisition at 80 and 140 kV in a background of water with a hydroxyappatite calcium standard phantom. Images were analyzed with a post-processing algorithm, which included filtering, setting cut-off thresholds, and calculating the quotient of Hounsfield units obtained at 80 and 140 kV to generate the final visualization of the data.

Results: For Iohexol, the lowest concentration clearly detected at a single Energy acquision (140 kV) was 6.0 mg Iodine/mL, while with the application of dual energy acquision, it was 1.5 mg Iodine/mL. For Gadodiamide, the lowest concentration clearly detected at 140 kV was 0.02 mol/L, while that with the dual energy acquisition was 0.005 mol/L. For Barium Sulfate, the lowest concentration detected at a single energy level was 2 % wt/v, while the dual energy acquisition improved this to 0.4 % wt/v.