In-room imaging and MR planning

Photon Counting Principle

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Gd S 7.44 g/cm 3 2 O 2

CdTe 6.20 g/cm 3

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Semiconductor-based detector: • Continuous crystal with a pixelated anode • Conversion of the x-ray photons into free charge carriers • Drift of the charge cloud towards the pixelated anode by a bias voltage

Scintillator-based detector: • Detector divided up into small blocks (pixelated) • Conversion of the x-ray photon into the visible light • Isotropic emission of the light collected by reflection at the septa and then detected by the photodiode