1 one limitation of CT scanning technology is that bags are scanned too slowly. 2 this means only bags from suspicion passengers are scanned .3 since this is not that effective,newer higt-tech systems have been developed that are capable of detecting chemical components in individual items. 4 the x-ray scanners most people see in airports are for screening carry-on bags. 5 but these scanners are too small to scan all the luggage that goes into the cargo section of the plane. 6 in busy airports, larg trucks with built-in x-ray scanners (up to 5..7 meters long) are used. 7 these trucks pull up beside containers that hold the suitcases,bags and other cargo. 8 the entire container is scanned at once.