Coded aperture compressive X-ray spectral CT

Spectral computed tomography (SCT) makes use of the spectral dependence of X-ray attenuation in tissues and contrast agents to separate the attenuation data into more than two energy bins. Current SCT detectors are costly and the measured data have low signal to noise ratio due to the detector's narrow bin bandwidth and quantum noise. A new approach called coded aperture compressive X-ray SCT that combines a conventional rotating X-ray CT system with a set of pixelated K-edge coded apertures is introduced. In this method, the amplitude and spectra of the X-ray source are filtered by a particular pattern of K-edge filters in each view angle. Compressed sensing (CS) reconstruction algorithms are then used to recover the spectral CT image from the coded measurements. Simulations results for random coded apertures are shown, and their performance is compared to the use of uncoded measurements.