X-ray ct apparatus and method

The X-ray CT apparatus 1 and X-ray CT method, the thickness of the test object based on the number of transmitted X-rays in a specific energy range set in K absorption edge and below the X-ray contrast agent as a test object is calculated, it reconstructed CT images based on the thickness of the computed test object. Such X-ray CT apparatus 1 and X-ray CT method can generate a stable X-ray CT images without depending on the subject of the size and X-ray tube voltage (energy distribution of the X-ray) Become.