Calibration unit for a macroscopic medical imaging device, macroscopic medical imaging calibration system and use of a calibration unit

A calibration unit (28) for the calibration of a macroscopic medical imaging device (14), comprising a generally disk-shaped main body (40) having a front surface (42) being configured for being optically oriented towards the imaging device (14), wherein a fluorescent material (54) of a first type is arranged in a first sector (48) of the main body (40), the first sector (48) being a volumetric portion of the main body (40) and formed as a layer of the disk-shaped main body, and

• a. wherein a fluorescent material (58) of a second type is arranged in a second sector (56) of the main body (40), the second sector (56) being a volumetric portion of the main body (40), the first sector (48) and the second sector (56) being separate from one another and the fluorescent material (54) of the first type being different from the fluorescent material (58) of the second type and/or
• b. wherein an opaque, non-fluorescent material (68) is arranged in a third sector (66) of the main body (40), the third sector (66) being a volumetric portion of the main body (40), and the third sector (66) being separate from each of the first sector (48) and the second sector (56), and
• wherein a translucent material (64) is arranged in a fourth sector (60) of the main body (40), the fourth sector (60) being a volumetric portion of the main body (40), and the fourth sector (60) being separate from each of the first sector (48), the second sector (56), and the third sector (66), wherein the fourth sector (60) is formed as a layer of the disk-shaped main body and wherein the second sector (56) and/or the third sector (55) is fully or partially embedded in the fourth sector.