An x-ray imaging system includes a detector positioned to receive x-rays, an x-ray tube configured to generate x-rays toward the detector from a focal spot surface, the x-ray tube includes a target having the focal spot surface, a cathode support arm, and a cathode attached to the cathode support arm. Segmented tip electrodes are disposed circumferentially about the distal tip of the lead body and are electrically-isolated from each other. When shutters for shutting out light from the optical connectors are collided with each other, the shutters move to positions where they do not shut out the light. In one example, the first search uses tight criteria in conjunction with the language of the user’s query.