A phantom calibration body for a method for determining at least one quantitative diffusion parameter extracted for characterization of a tissue being suspicious to a tumorous modification in magnetic resonance imaging, wherein the phantom calibration body is designed for being characterized during characterization of the tissue by the magnetic resonance imaging, the phantom calibration body comprising
- a first compartment having a first cross-section, the first compartment being filled with a first solution comprising a calibration substance having a first concentration;
- and
- a second compartment having a second cross-section, the second cross-section having at least two different partitions with differing diameters, wherein the second compartment is filled with a second solution comprising the calibration substance having a second concentration, the second concentration differing from the first concentration.