X-Ray Screening and Image Interpretation Flashcards

On an X-ray image, a flat knife positioned edge-on to the beam will most likely appear as which of the following?

Answer: A thin, dark line that is easy to overlook

Viewed edge-on, a blade presents its narrowest profile, so it shows up only as a thin dense line.

A screener sees an area so dense that the X-rays cannot get through it, and image enhancement tools do not clear it up. What is the correct action?

Answer: Treat it as an unresolved alarm and send the bag for a physical search

An area the X-ray cannot see through could be hiding a threat, so it must be resolved with a physical search.

What is the main purpose of Threat Image Projection (TIP) on checkpoint X-ray machines?

Answer: To insert fictional threat images into real bag images to test and train screeners

TIP places virtual threat images into real bag images to measure how alert screeners are and to train their detection skills.

Which group lists the basic parts usually needed for an improvised explosive device (IED)?

Answer: Power source, initiator, explosive, and switch

A working IED generally needs a power source, an initiator (detonator), a main explosive charge, and a switch, connected together.

When two or more objects overlap in a bag and hide each other's shapes on the X-ray image, this is called what?

Answer: Superimposition

Superimposition happens when overlapping items block each other, which makes threats harder to pick out.

On a computed tomography (CT) checkpoint scanner, which feature most helps a screener separate items stacked on top of each other?

Answer: Rotating and slicing the 3D image to view items from any angle

CT builds a 3D volume that can be rotated and sliced, so overlapping objects can be viewed one at a time.

A screener uses the 'inorganic stripping' function on an image. What happens to the display?

Answer: Inorganic materials are faded or removed so organic materials stand out

Inorganic stripping suppresses inorganic materials so organic items, such as possible explosives, are easier to examine.