X-ray CT apparatus

An X-ray CT apparatus, comprising:

• a reconstruction processor configured to carry out first reconstruction processing to be carried out at a first image thickness based on detection data to be sequentially acquired by X-ray scanning the desired site of a subject, and to carry out second reconstruction processing to be carried out at a second image thickness based on all detection data acquired by the X-ray scanning;
• a setting unit configured to set the first image thickness based on the second image thickness set in advance so that the first image thickness is less than the second image thickness;
• and
• a controller configured to allow the reconstruction processor to initiate the first reconstruction processing in parallel with the X-ray scanning at the set first image thickness, to judge whether further X-ray scanning is necessary or not once the first reconstruction processing is completed, to allow the reconstruction processor to initiate the second reconstruction processing at the second image thickness when further X-ray scanning is judged unnecessary, and to not allow the reconstruction processor to initiate the second reconstruction processing when further X-ray scanning is judged necessary.