Dual energy CT enables material decomposition imaging (MDI). MDI can be used for quantitative analysis of contrast agent concentration, for instance in the context of myocardial perfusion imaging. Most contrast enhanced DECT studies have been performed with the use of iodinated contrast media, a safe contrast agent in most patients. However, ioindated contrast media is associated with contrast-induced allergic reactions and nephropathy which can cause acute renal dysfunction [1, 2] and significant morbidity and mortality, especially in high risk patients [3, 4]. In these patients...

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...

Excellent reproducibility was found for all scan repetitions at both 120 and 140 kVp (ICCs>0.99, CI 0.99-0.99). Correlation between measured and true gadolinium concentrations was excellent (R>0.99, P<0.001; ICCs>0.99, CI 0.99-0.99). All measurement were overestimated at 120 kVp with a mean measurement error of 0.7±0.7 mg/mL (9.6±7.2%). At 140 kVp measurements were over- and underestimated with a mean measurement error of -0.0±0.2 mg/mL (0.7±5.1%) and absolute measurement error of 0.1±0.2 mg/mL (3.0±4.1%). Measurement errors at 140 kVp were significantly lower than measurements errors at 120...

Quantification of gadolinium concentrations using SDCT at both 120 and 140 kVp is feasible and accurate. These results open up the possibilities for low gadolinium concentrations as a contrast agent in CT for quantitative assessment of contrast distribution in tissue, serving as a surrogate of tissue perfusion at a specified time point.

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