epäsuoramuunnosdetektorit
Epäsuoramuunnosdetektorit, often translated as indirect conversion detectors, are a type of sensor used in digital radiography and other imaging modalities. Unlike direct conversion detectors, which convert X-ray photons directly into an electrical signal, indirect conversion detectors employ a two-step process. First, the incoming X-ray photons are absorbed by a scintillator material, such as cesium iodide (CsI) or gadolinium oxysulfide (Gd2O2S). This scintillator then emits visible light photons. These light photons are subsequently detected by a photodetector array, typically composed of amorphous silicon (a-Si) photodiodes or complementary metal-oxide-semiconductor (CMOS) active pixel sensors. The electrical charge generated by the photodiodes is then read out and processed to form the digital image.
The advantage of indirect conversion lies in the ability to use well-established and cost-effective photodetector technologies.