X-ray ct apparatus and x-ray detector

An X-ray CT apparatus comprising:

• an X-ray source configured to generate an X-ray;
• an X-ray detector configured to acquire an electric signal based on the X-ray;
• and
• a data acquisition system arranged on a side opposite to an X-ray incident side across the X-ray detector, wherein
• the X-ray detector comprising:
• a collimator having a threshold plate with a thickness Wc to eliminate scattered radiation from the X-ray;
• a plurality of scintillators configured to emit light based on the X-ray;
• a light reflector provided in a gap between adjacent scintillators of the plurality of scintillators;
• and
• a plurality of photodiodes configured to convert the light of each of the plurality of scintillators into the electric signal, wherein
• the thickness Wc of the threshold plate mounted on the X-ray incident side of the adjacent scintillators, and a thickness Ws of the gap has a relationship shown in a following expression:
• Wc≧Ws.