| 摘要 |
Fast kV-switching is a dual energy acquisition technique in computed tomography (CT) in which alternating views correspond to the low and high tube voltages. Its high temporal resolution and its suitability to a variety of source trajectories make it an attractive option for dual energy data acquisition. Its disadvantages include a one-view misregistration between the data for high and low voltages, the potentially poor spectrum separation due to the more-like a sine wave rather than the desired square wave in fast kV-switching, and the higher noise in the low voltage data because of the technical difficulty in swinging the tube current to counter the loss of x-ray production efficiency and loss of penetration at lower tube voltages. Despite the disadvantages, symmetric view matching according to the current invention substantially improves streaks and other artifacts due to the view misregistration, sufficient spectrum separation even in a sinusoidal waveform swinging between 80 kV and 135 kV, and contrast-to-noise for the simulated imaging task maximized at monochromatic energy of 75 keV. |
