Iterative bone correction coefficient selection based on the normalized bone index of images

We proposed an IBO coefficient selection method that is based on the normalized bone index (NBI). The NBI is defined as the total bone amount normalized to the image display matrix and slice thickness. IBO coefficient is function of the NBI: the smaller the NBI, the higher the IBO coefficient. The exact dependency of the IBO coefficients on the NBI may be different for different tube voltages. Different IBO coefficients are used for different sections in the head or for different patients, providing more uniform correction for the beam hardening caused by bones of different amounts and densities. The proposed new method has been evaluated using 80 kV pediatric head scans, and demonstrated more uniform correction for the beam hardening caused by bones of different amounts and densities.