Image position compensation method and apparatus

摘要

A method and apparatus of image position compensation are provided. The method may include: measuring an actual height at Z position and a corresponding drop offset of a scanning table; adjusting, according to the drop offset of the scanning table, a vertical coordinate of an image center in the process of post-reconstruction, so as to obtain an adjusted image; and performing an interpolation process on coordinate information and pixel values of a row in the adjusted image, to obtain pixel values of a row in a target image. The target image is an image which has been processed by position compensation. According to the present disclosure, an image generated by a CT apparatus can be compensated to obtain a correct tomographic image and provide accurate image information for medical diagnosis.

主权项

1. An image position compensation method, comprising:
calculating an actual height at Z position and a corresponding drop offset of a scanning table based on an image obtained by scanning; adjusting, according to the drop offset of the scanning table, a vertical coordinate of a center of the image in the process of post-reconstruction, so as to obtain an adjusted image; and performing an interpolation process on coordinate information and pixel values of each row in the adjusted image, to obtain pixel values of each row in a target image, wherein calculating an actual height at Z position and a corresponding drop offset of a scanning table based on an image obtained by scanning comprises:
obtaining a height of a X-ray source rotating center, a center coordinate of a preview image, a reconstruction field of view (FOV) of the preview image, and a matrix size of the preview image, searching the preview image row by row to obtain a greatest row number in which some pixel values are greater than a first threshold,according to the matrix size of the preview image, the height of the X-ray source rotating center, the center coordinate of the preview image, the reconstruction FOV of the preview image and the greatest row number in which some pixel values are greater than the first threshold, calculating an actual height of a scanning table in the preview image, and calculating a difference between the actual height of the scanning table and a nominal height of the scanning table, wherein the difference equals to a drop offset of the scanning table; orobtaining a height of a X-ray source rotating center, a center coordinate of a pilot image, a reconstruction FOV of the pilot image, and a matrix size of the pilot image, searching in each column of the pilot image to find a greatest row number in which pixel value is greater than a second threshold, according to the matrix size of the pilot image, the height of the X-ray source rotating center, the center coordinate of the pilot image, the reconstruction FOV of the pilot image and in each column the greatest row number in which pixel value is greater than the second threshold, calculating an actual height of a scanning table at Z position in the preview image, and calculating a difference between the actual height of the scanning table and a nominal height of the scanning table, where the difference equals to a drop offset of the scanning table at the Z position.