PROBLEM TO BE SOLVED: To reduce the number of components and perform shift correction accurately even when an X-ray is shielded and attenuated.SOLUTION: An X-ray CT apparatus includes an X-ray source for applying an X-ray onto a subject, a detector having detection elements for a plurality of channels for outputting a detection signal of the X-ray penetrating the subject, a shift position calculation part for calculating a shift position from a reference irradiation position of the X-ray applied by the X-ray source based on the detection signal by the detection elements for at least one channel assigned for the shift detection of the detection elements for the plurality of channels, an interference determination part for determining whether or not the shift position is within a predetermined range, and if the shift position is not within the predetermined range, determining that there is an interference between the X-ray source and the detector that attenuates the X-ray, and a correction processing part for correcting the X-ray irradiation position according to a correction value based on the shift position if it is determined that there is no interference, and correcting the X-ray irradiation position according to a prescribed interference correction value if it is determined that there is an interference.SELECTED DRAWING: Figure 1COPYRIGHT: (C)2017,JPO&INPIT【課題】 部品点数を削減すると共に、X線が遮られて減弱した場合でも正確にシフト補正を行う。【解決手段】 被検体に対してX線を照射するX線源と、複数チャネル分の検出素子を有し、被検体を透過したX線の検出信号を出力する検出器と、複数チャネル分の検出素子のうちシフト検出のために割り当てられた少なくとも1チャネル分の検出素子による検出信号に基づいて、X線源により照射されるX線の基準照射位置からのシフト位置を算出するシフト位置算出部と、シフト位置が所定の範囲内にあるか否かを判定し、シフト位置が所定の範囲内にない場合に、X線源と検出器との間にX線を減弱させる干渉があると判定する干渉判定部と、干渉がないと判定された場合にはシフト位置に基づく補正値に従ってX線の照射位置を補正し、干渉があると判定された場合には予め定めた干渉補正値に従ってX線の照射位置を補正する補正処理部と、を備えるX線CT装置を提供する。【選択図】図1
