Improvement of detection in computed radiography by new single-exposure dual-energy subtraction.

It is reported that the use of the dual-energy subtraction method enhances the abnormal shadow detection capability. However, because the subtracted image is significantly inferior to the original in signal-to-noise ratio (SNR), the x-ray dosage normally used for chest x-rays has not yielded subtracted images with adequate SNRs. Under these circumstances, we focus on the fact that there is a correlation between the noise contents of bone-and soft-tissue-subtracted images although there is no correlation between the signal contents of these images. We propose an algorithm that improves SNRs of subtraction images by reducing the noise only.