Imaging system and method

Claim 2

An imaging system characterised in that it comprises: a source of penetrative radiation (300); an area detector (312 or 353) having input (313 or 360) and output (314 or 359) portions; means for scanning radiation (300) from the source through a subject (302) and across the input portion (313 or 360) of the area detector (312 or 353) in a pattern covering at one time only a fraction of the input portion of the area detector, causing the area detector to produce at its output portion a moving representation of the radiation being scanned across its input portion; a second detector (325); means (322,323, 324) for projecting the moving representation of scanned radiation continuously onto a fixed portion (326) of the second detector and imaging circuitry coupled to the second detector (325 or 371) for producing an image representing internal structure of the subject.

Claim 3

An imaging system according to Claim 1 in which the penetrative radiation is x-radiation.

Claim 4

An imaging system according to either of the preceding Claims, wherein said second detector (325) is fixed in position with respect to said area detector (312).

Claim 5

An imaging system according to any one of the preceding Claims, wherein said imaging circuitry comprises time delay and integrate circuitry (327 or 374).

Claim 6

An imaging system according to any one of the preceding claims including transmission circuitry for restoring spatial definition to the imaged portions presented to the second detector using second detector output data, in a temporal sequence corresponding to the temporal scanning sequence of the radiation.

Claim 7

An imaging system according to any one of the preceding claims in which the means for scanning radiation (300) from the source comprises a structure (304 or 352) defining a slit (306 or 353) interposed between the radiation source and the subject (302 or 356); and a mechanism for moving the slit defining structure (304 or 352) transverse to the radiation path (300 or 350) in order to scan a slit pattern of said radiation across the input portion (313 or 360) of th= area detector to produce a moving slit pattern within one representation at said output portion (314 or 359).

Claim 8

An imaging system according to any one of the preceding claims in which the area detector (312 or 315) is an image intensifier tube, the moving representation being an optical representation.

Claim 9

An imaging system according to Claim 7 including a third detector (340 or 382) comprising a video camera, and means (320) for optically coupling the output portion (314 or 359) of the area detector (312 or 315) to both the second (325 or 371) and third detector (340 or 382).

Claim 10

An imaging system according to Claim 7 or Claim 8 including a pivotable mirror system (320, 322 or 362, 364) positioned to intercept light from the output portion of the image intensifier tube; apparatus (330 or 389) for pivoting said pivotable mirror system (320, 322 or 362, 364) and synchronization apparatus and circuitry (390, 392) coupled between said pivotable mirror system (320, 322 or 362, 364) and said movable slit defining structure for synchronizing the transverse movement of the slit defining structure with the pivoting motion of the pivotable mirror system to continuously direct and maintain the moving light from said output portion (314 or 359) incident continuously upon substantially said fixed portion of said second detector (325 or 371).

Claim 11

An imaging system according to any one of the preceding claims in which said second detector comprises a rectilinear matrix of individual detector elements having a plurality of rows of detector elements.

Claim 12

An imaging system according to Claim 10 when dependent on Claim 4 in which the time delay and integrate circuitry (327 or 374) is coupled to said respective rows of individual detector elements, the time delay and integrate circuitry including circuitry for shifting and integrating charge generated by said individual detector elements along each row of detector elements; the time delay and integrate circuitry (327 or 374) being clocked such that said charge shifting across said detector element rows (326 or 372) is dependent upon said movement of said representation across said area detector (312 or 353) output portion (314 or 359).

Claim 13

The system of Claim 1 wherein said time delay and integrate circuitry (327 or 374) comprises clocking circuitry for shifting said charge in a sense which is opposite in direction to the direction of movement of said representation.

Claim 14

The system of Claim 12 wherein said clocking circuitry shifts said charge at a rate which is a function of the average velocity of movement of said representation.

Claim 15

An imaging method comprising:scanning penetrative radiation relative to a subject to collectively define a single area pattern of radiation emergent from the subject; scan imaging in a temporal sequence a succession of spatially distinct portions of the pattern; the method being characterised in that it includes the steps of presenting the temporal sequence of the spatially distinct imaged portions of the pattern to a single spatially non-varying portion of a detector input to produce detector output signals; restoring spatial definition to the portions presented to the spatially non-varying detector portion by removing detector output signals produced in response to said presenting step in a second temporal sequence corresponding to the temporal sequence in which the spatailly distinct succession of x-ray pattern portions were imaged in said imaging step; and utilizing the second temporal sequence of removed detector data to reconstruet a consolidates image corresponding to the succession of spatially distinct x-ray pattern portions imaged in said imaging step, whereby an image corresponding to all the imaged pattern portions is produced by a detector having a field size sufficient to accommodate only one of the imaged pattern portions at a time.

Claim 16

An imaging method comprising:scanning penetrative radiation relative to a subject to collectively define a single area pattern of radiation emergent from the subject; scan imaging in a temporal sequence a succession of spatially distinct portions of the pattern; the method being characterised in that it includes the steps of presenting the temporal sequence of the spatially distinct imaged portions of the pattern to a single spatially non-varying portion of a detector input to produce detector output signals; restoring spatial definition to the portions presented to the spatially non-varying detector portion by removing detector output signals produced in response to said presenting step in a second temporal sequence corresponding to the temporal sequence in which the spatailly distinct succession of x-ray pattern portions were imaged in said imaging step; and utilizing the second temporal sequence of removed detector data to reconstruet a consolidates image corresponding to the succession of spatially distinct x-ray pattern portions imaged in said imaging step, whereby an image corresponding to all the imaged pattern portions is produced by a detector having a field size sufficient to accommodate only one of the imaged pattern portions at a time.

Claim 17

The method of Claim 14, wherein the detector utilized comprises rows of individual detector elements defining a rectangular array, and time delay and integrate circuitry coupled to respective rows of the individual detector elements, said spatial definition restoring step comprising: clocking the time delay and integrate circuitry to shift and accumulate charge signals along said rows in a directional sense opposite that of the temporal sequence of imaging of successive spatially distinct x-ray pattern portions; and removing accumulated and shifted data from the detector as it reaches end elements of said rows.

Claim 18

The method of Claim 15, wherein said clocking step comprises: shifting and accumulating detector element signals at a scalar average velocity which corresponds to the average scanning velocity of said x-rays.

Claim 19

An imaging method utilizing a source for directing penetrative radiation (300 or 350) through a subject (302 or 356), a first area detector aligned to receive radiation emergent from the subject, the first detector being responsive to such emergent radiation over a field to produce a representation of the pattern of such emergent radiation over the field, and a second detector (325 or 371), said method being characterised in that it comprises the steps of: inhibiting exposure of said area detector to radiation over all but a predetermined time variable portion of the field of said first detector, such that the representation produced by the first detector is only of radiation corresponding to the time varying portion of the field of the area detector; continuously transmitting said positionally time varying representation to said second detector during said time variance along a path which is, at the point of incidence on said second detector, stationary with respect to said second detector; sampling the output of said second detector over time; and employing said sampled output information to produce a tangible representation of internal subject structure.

Claim 20

An imaging method utilizing a source for directing penetrative radiation (300 or 350) through a subject (302 or 356), a first area detector aligned to receive radiation emergent from the subject, the first detector being responsive to such emergent radiation over a field to produce a representation of the pattern of such emergent radiation over the field, and a second detector (325 or 371), said method being characterised in that it comprises the steps of: inhibiting exposure of said area detector to radiation over all but a predetermined time variable portion of the field of said first detector, such that the representation produced by the first detector is only of radiation corresponding to the time varying portion of the field of the area detector; continuously transmitting said positionally time varying representation to said second detector during said time variance along a path which is, at the point of incidence on said second detector, stationary with respect to said second detector; sampling the output of said second detector over time; and employing said sampled output information to produce a tangible representation of internal subject structure.

Claim 21

An imaging method according to Claim 17 in which the pattern representation produced by the area detector (312 or 353) is in the form of visible light; and said transmitting step comprises: reflecting the representation off a pivotable mirror system (320, 322 or 361, 364) and pivoting the mirror system in synchrony with said positional time variance to maintain an image of the visible light representations directed onto a uniform portion of the second detector (325 or 371).

Claim 22

An imaging method according to any one of Claims 14 to 17 including the step of scanning a slit defining structure across a portion of the field of said area detector.