Technologies are generally described for employing ultra-short pulsed X-rays in X-ray computer tomography. Timing parameters of binary modulation applied to the X-rays at the source may be adjusted based on detector characteristics, industry standards, and/or user input. The timing for minimum X-ray intensity during each pulse may be selected to minimize afterglow effect. The timing for the maximum X-ray intensity may then be determined based on one or more of the minimum X-ray intensity timing, desired X-ray dosage, and/or other similar parameters.