Keywords:
Tissue characterisation, Contrast agent-intravenous, CT, Contrast agents, Cardiac
Authors:
R. W. van Hamersvelt, M. J. Willemink, A. Schilham, P. A. de Jong, T. Leiner; Utrecht/NL
Methods and Materials
The cardiac cavity of an anthropomorphic thoracic phantom was filled with a plastic holder containing eleven tubular inserts,
each filled with a different concentration gadolinium (0-26.3 mg/mL).
Concentrations were chosen to mimic an estimated clinical range of gadolinium distribution in (patho-)physiological tissues encountered at 0.2 mmol/kg gadolinium administration.
Images were acquired using a novel 64-slice SDCT scanner at 120 and 140 kVp and 200 mAs.
Scans were repeated five times to asses reproducibility.
Three regions of interest (ROIs) were drawn in each insert on different slices.
For each ROI,
Hounsfield units at different energy levels for 70-200 keV were extracted of which attenuation profiles were reconstructed (Fig. 1).
In-house developed software was used to fit the reconstructed attenuation profile to a combination of the known attenuation profiles of pure water and pure gadolinium (Fig. 2).
The software calculated the amount each material constituted to create the fitted line and determined the amount of water and gadolinium (Fig. 2).