MED
In the literature: open
Detection limit for K-edge contrast agents
In plain words
Elements like iodine and gadolinium absorb x-rays sharply above one energy, which lets a spectral scanner tell them apart. How little of an element can be detected is not pinned down.
Precise statement
Determine the minimum detectable concentration of K-edge elements (iodine at 33.2 keV, gadolinium at 50.2 keV, and higher-Z labels such as tantalum, gold and bismuth) in a 30 cm diameter water phantom at clinical dose, as a function of detector energy resolution, bin count and photon flux. An answer is a detection-limit formula in mg per cm^3 with its dependence on these quantities.
What would settle it
Phantom measurements across concentration and dose compared against a task-based detectability calculation using the measured detector response.