X-ray characterization of breast phantom materials. Corrigendum. Phys. Med. Biol. vol. 43 p. 1367-1377

It has been pointed out by Dr Biao Chen of the University of Rochester that there is an error in the original version of the above article. The error occurs in table 3, in which the parameters for a least-square curve fit are given for the linear attenuation coefficients of the phantom materials tested. Two of the coefficients (a2 and a3) were expressed with too few significant digits. Unfortunately, these coefficients are for the highest degree terms, and round-off errors can produce rather dramatic changes in the values calculated from the equation in table 3, especially at high energy. For example, using the original values for CIRS: Gland, {a0, a1, a2, a3}={23.84, -16.2, 3.48, -0.25}, the linear attenuation appears to be 0.697 which is 271% greater than the value determined from the basis material technique given in table 2 (0.188). Using the parameters in the correct table which are expressed with greater precision, the linear attenuation is calculated to be 0.1886, yielding much better agreement (∼0.3%). In all cases, the linear attenuation coefficients calculated with the non-linear least-squares parameters from table 3 are within 4% of the coefficients determined in table 2. The correct table 3 is presented in full