Examples are directed toward systems and methods relating to security screening. For example, a screening system includes a sensor array to sense a gravitational field caused by an item, and a conveyor to convey the item through sensing positions for scanning by the sensor array. A controller acquires weight measurement information from sensor elements, and gravitational measurement information from the sensor array. The conveyor incrementally advances the item through additional sensing positions to acquire weight measurement information and gravitational measurement information. The controller performs tomographic reconstruction to generate a tomographic image of the item, using a generated weight map as a static weight input vector and using a generated mass map as a static mass input vector for the tomographic reconstruction.