PROBLEM TO BE SOLVED: To provide a radiation detector which has an easily replaceable detector pack and can prevent direct incidence of radiation on a structure disposed outside the detector pack in an irradiation direction of the radiation, and to provide a detector module and a medical diagnostic imaging apparatus.SOLUTION: The radiation detector according to an embodiment comprises a plurality of detector modules, first and second radiation shielding plates, and a first support member. The first radiation shielding plate is disposed on the opposite side of a radiation incident surface of a first detector pack of a first detector module. The second radiation shielding plate is disposed so as to intersect a pathway of radiation passing through between the first detector pack and a second detector pack of a second detector module disposed adjacent to the first detector module. The first support member supports the first radiation shielding plate in such a manner that at least a part of the first radiation shielding plate overlaps the second radiation shielding plate on the pathway of the radiation.SELECTED DRAWING: Figure 1【課題】検出器パックを容易に交換することができるとともに、放射線の照射方向で検出器パックより外側に配置される構造物への放射線の直接入射を防ぐことができる放射線検出器、検出器モジュール、及び医用画像診断装置を提供すること。【解決手段】実施形態に係る放射線検出器は、複数の検出器モジュールと、第１及び第２の放射線遮蔽板と、第１の支持部材とを備える。第１の放射線遮蔽板は、第１の検出器モジュールが有する第１の検出器パックの放射線の入射面とは反対側に配置される。第２の放射線遮蔽板は、第１の検出器パックと第１の検出器モジュールの隣に配置された第２の検出器モジュールが有する第２の検出器パックとの間を通過する放射線の経路と交差するように配置される。第１の支持部材は、第１の放射線遮蔽板の少なくとも一部が放射線の経路上で第２の放射線遮蔽板と重複するように第１の放射線遮蔽板を支持する。【選択図】図１
