X-ray detector and X-ray CT apparatus

An X-ray CT apparatus, comprising:

• an X-ray tube that radiates X-rays onto a subject;
• and
• an X-ray detector that includes a scintillator array in which a plurality of scintillators configured to convert the X-rays into visible light are arranged in a first direction and a second direction intersecting the first direction and a photodiode array including photodiodes each of which is installed for a different one of the scintillators and each of which has an active area configured to convert the visible light into an electrical signal, wherein
• the photodiodes are arranged in such a manner that widths of the active areas in the first direction are equal to one another, while a difference in the width between any two of the active areas positioned adjacent to each other in the second direction is within a predetermined range;
• and
• widths of the active areas in the second direction increase from an end part of the photodiode array toward a center thereof.

An X-ray detector, comprising:

• a scintillator array in which a plurality of scintillators are arranged in a first direction and a second direction intersecting the first direction;
• and
• a photodiode array including photodiodes, each of which is installed for a different one of the scintillators and each of which has an active area configured to convert visible light emitted by the scintillator into an electrical signal, wherein
• the photodiodes in the photodiode array are arranged in such a manner that widths of the active areas in the first direction are equal to one another;
• widths of the photodiodes in the first direction decrease from an end part of the photodiode array toward a center thereof;
• and
• widths of the active areas in the second direction increase from an end part of the photodiode array toward a center thereof.