X-ray backscatter imaging system including moving body tracking assembly

In an X-ray backscatter imaging system for searching a subject for concealed objects, a method comprising the steps of:

• moving the subject within a passageway, the passageway having an entrance and an exit;
• initiating operation of at least one X-ray source upon entry of the subject into the passageway;
• producing a pencil beam of X-rays having a low dose directed toward a scanning area at a plurality of scanning positions within the passageway;
• scanning the pencil beam of X-rays over the scanning area;
• tracking said pencil beam of X-rays to each of said plurality of scanning positions, wherein the tracking is substantially coordinated with forward progress of the subject through the passageway;
• using a plurality of detectors, detecting X-rays that are backscattered from said pencil beam as a result of interacting with the subject when positioned at each scanning position of the plurality of scanning positions;
• and
• displaying a digitally represented image of the detected backscattered X-rays.

An X-ray imaging system for detecting an object carried by or on a body, said system having an entrance and an exit, said system comprising:

• a passageway extending from said entrance to said exit;
• at least one X-ray source for producing a pencil beam of X rays directed toward said body in said passageway, said at least one X-ray source comprising a collimator mechanism for scanning said pencil beam in a parallel beam plane;
• a scanning assembly for scanning said parallel beam plane over a surface of said body as said body moves in a direction of movement from said entrance to said exit;
• a tracking assembly for causing said scanning assembly to substantially track said body as it moves with respect to said system from said entrance to said exit;
• a detector array for detecting an intensity of X-rays scattered from said body and for generating a detector signal representative of an intensity of said scattered X-rays, said detector array comprising at least one detector;
• and
• a processor assembly for presenting characteristics of said detector signal to an operator, and for controlling said X-ray source, said scanning assembly, said tracking assembly, and said detector array.

An apparatus for detecting an object carried by or on a body, said apparatus comprising:

• a flooring having a length, said body moving across said flooring in a direction of movement;
• at least one X-ray source positioned above said flooring and at a height sufficient to allow said body to pass below said at least one X-ray source, said at least one X-ray source emitting an X-ray pencil beam scanned in a horizontal plane to produce a horizontal beam plane, said horizontal beam plane directed toward said body;
• a tracking assembly for rotating said horizontal beam plane through a tracking angle and in a direction corresponding to said direction of movement, wherein a starting portion of said tracking angle directs said horizontal beam plane to a front area of said body, and an ending portion of said tracking angle directs said horizontal beam plane to a back area of said body;
• a detector array disposed in said flooring and positioned along said length, said detector array comprising at least one scatter detector for detecting an intensity of X-rays scattered from said body and for generating a detector signal representative of the intensity of the scattered X-rays;
• and
• a processor assembly for controlling said apparatus, said processor comprising an interface for presenting a representation of said detector signal to an apparatus operator.

An X-ray imaging system for detecting concealed objects on a body, said body having a body front, a body back, and body sides, said system comprising:

• a portal structure comprising a first side module, a second side module, and a ceiling module, said first side module and said second side module parallel and separated by a portal width, said ceiling module positioned above said first side module and said second side module to form a portal having an entrance and an exit;
• a detector array for producing a detector signal from scattered X-rays, said detector array having a first side detector array concealed within said first side module and a second side detector array concealed within said second side module;
• an X-ray source for emitting a pencil beam of X-rays scanned across a scanning plane, said X-ray source concealed within said ceiling module, said scanning plane directed toward said exit and at a downward angle;
• a tracking assembly for rotating said scanning plane through a tracking angle and in a direction progressing from said entrance to said exit to substantially track said body as it moves with respect to said system from said entrance to said exit;
• and
• a display means for presenting characteristics of said detector signal;
• wherein said body moves through said scanning plane as said body moves from said entrance to said exit, said pencil beam of X-rays of said scanning plane striking said body front and producing said scattered X-rays.