Radiography

摘要

In a computerised tomographic (CAT) X-ray apparatus passage of the radiation through high absorption (bone) regions can change a characteristic of the radiation, such as its frequency spectrum. This can introduce error into the final representation. Correction is provided by computing a first representation, identifying areas of bone and then determining corrections for those areas which can be used to provide a subsequent move accurate representation. Errors caused by scattering can also be compensated in this way.