PURPOSE: A detector with an inserted light guide capable of easily determining a reaction depth and a PET(Positron Emission Tomography) using the same are provided to easily determine a reaction depth by inserting a light guide between scintillation crystal layers. CONSTITUTION: A reaction site determination PET detector with an inserted light guide is composed of a first scintillation crystal(100), a light guide(110), a second scintillation crystal(120), and an optical sensor(130). A block type light guide is inserted between the first scintillation crystal and the second scintillation crystal. The first scintillation crystal and the second scintillation crystal change radiation into a scintillation light signal by detecting desired radiation. The second scintillation crystal corresponds to a scintillation crystal close to a light source emitting the radiation. The light guide is inserted between each flash scintillation layer to distribute an output scintillation signal to a lower layer as much as is desired. An optical sensor changes the output scintillation signal of the first scintillation crystal and the second scintillation crystal into an electrical signal.본 발명은 광가이드를 삽입한 검출기에 관한 것으로서, 외부로부터 입사된 감마선을 검출하여 섬광신호로 변환하는 복수의 섬광결정들 및 복수의 섬광결정들 사이에 삽입되어, 어느 하나의 섬광결정에서 변환된 섬광신호를 다른 섬광결정으로 분산하여 전달하는 광가이드를 포함하는 것을 특징으로 하며, 반응깊이 판별을 쉽게 할 수 있으며, 기존 판매되어 사용되는 PET 기기에 섬광결정부를 광가이드가 삽입된 다층 섬광결정부로 교체하여 반응위치 판별가능한 PET으로 쉽게 업그레이드 할 수 있다.
