one limitation of CT scanning technology is that bags are scanned too slowly. This means only bags from suspicious passengers are scanned. Since this is not that effective, newer high-tech systems have been developed that are capable of detecting chemical components in individual items. The X-ray scanners most people see in airports are for screening carry-on bags. But these scanners are too small to scan all the luggage that goes into the cargo section of the plane. In busy airports, large trucks with built-in X-ray scanners (up to 5—7 meters long) are used. These trucks pull up beside containers that hold the suitcases, bags and other cargo. The entire container is scanned at once.