Apparatus and method for producing images corresponding to patterns of high energy radiation

Abstract

The disclosure relates to an apparatus and method for recording images on recording mediums which images correspond to high energy radiation patterns. A temporary storage medium, such as an infrared-stimulable phosphor or thermoluminescent material, is exposed to an incident pattern of high energy radiation. A time interval after exposure, a small area beam of long wave length radiation or heat scans the screen to release the stored energy as light. An appropriate sensor receives the light emitted by the screen and produces electrical energy in accordance with the light received. The information carried by the electrical energy is transformed into a recorded image by scanning an information storage medium with a light beam which is intensity modulated in accordance with the electrical energy. Although the invention can be used at any reproduction ratio, it is particularly usable in recording images representative of large format high energy patterns onto microfilm.

Description

This application is a reissue application for U.S. Pat. No. 3,859,527 issued on Jan. 7, 1975 on U.S. Ser. No. 320,028 filed Jan. 2, 1973.As previously described, the signal from amplifier 174 can also be otherwise modified, e.g. by signal modifying means 171, to obtain a better image. Some of the image modifications possible with available electrical apparatus, represented schematically by signal modifying means 171, are image intensification, signal-to-noise ratio improvement and edge-enhancement. Depending on the position of switch 173, the signal is either recorded onto magnetic tape by well known means such as a tape deck as represented by a block 175 or displayed on the face 177 of a high resolution cathode ray tube 176. The image can be recorded onto microfilm 178 from the display on tube face 177. If recorded onto microfilm 178, conventional supply and take up reels 179 and 180 can be appropriately controlled by conventional means to expose the microfilm in accordance with a particular format.

A direct electron recording film such as one incorporating diynes or polyynes can be used in a tube accommodating the passage of film through itself. Such a tube electrically rather than optically records an image.

A high intensity source of ultraviolet radiation can be modulated in accordance with the light released from the phosphor to record an image onto slow non-silver systems such as diazo films, iodoform-sensitized materials, photosensitive polymers and other such substances. An assembly of photomultipliers or photocellamplifiers combinations and recording devices may be also used to receive and record the phosphor output. A low light level television system can be utilized to amplify, display, and record light emitted from the stimulated phosphor. Combinations of an image intensifier tube with a silicon intensifier target tube (SIT) described by R. W. Engstrom and R. L. Rodgers in Optical Spectrum 5, pp. 26-31 (1971) are particularly suitable. A small format representation of the phosphor output can also be electrostatically recorded with an electrical discharge tube such as the "Printapix" tube, a trademark of Litton Industries, Inc.

FIG. 3 illustrates another embodiment of the invention. A hollow, transparent, screen drum 240 rotatably mounted on threaded shaft 236 carries a thermoluminescent phosphor temporary storage medium 241. Threaded shaft 236 supports a heat source 238. An electric current carried to the source by wires 239, which run through the tubular threaded shaft 236, activates heat source 238. Shaft 236 threadably engages a recording drum 244 holding a recording medium, such as microfilm 245. Drums 240 and 244 are driven so that they rotate at the same angular velocity. The threads and the circumferences of the drums have a fixed ratio to one another as in the FIG. 1 embodiment.

If the phosphor of medium 241 contains an image of a pattern of high energy radiation, it emits light from an area 264 when thermally stimulated by source 238. The light is preferably visible light but may be ultraviolet or infrared. A mirror 262 deflects the emitted light through a lens 268 onto the face 272 of an image intensifier tube 270. The tube 270 receives the light, converts it into electrical energy in the form of electrons, accelerates the electrons, and creates an intensified light pattern therefrom on its output face 274. Light from the output face 274 passes through a collimating lens 276 onto a mirror 278 which deflects the light beam through another lens 280. Lens 280 images the light onto an area 282 of the recording medium 245 on drum 244. Areas 264 and 282 correspond so that as the scanner operates, the microfilm mounted on drum 244 records an image representative of the high energy radiation pattern.

FIGS. 4, 5 and 6 show an embodiment of the invention incorporating an X-Y scanner for scanning out information from a large format temporary storage medium and recording it onto a small format storage medium. A sturdy frame 300 supports the scanner. A first carriage 306 rides on tracks 302 and 304 mounted on frame 300. Track 302 and a third track, 308, support a second carriage 310. Tracks 302, 304 and 308 lie parallel in the X-direction, indicated by the double headed arrow labeled X. Carriages 306 and 310 ride on wheels 312 which roll on tracks 302, 304 and 308. The wheels 312 which ride on tracks 304 and 308 cannot be seen in FIGS. 4 and 5. A reversible motor 314 supplies X-directional drive for both carriages by driving a gear box 316 through a friction drive 318. Gear box 316 turns two screw threaded shafts 315 and 317 at the same rotational velocity through couplers 320 and 321. Screw shafts 315 and 317 thread through female receiving units 325 and 327 secured to the bases of carriages 306 and 310 so that as the threaded shafts turn, the carriages 306 and 310 move in the X-direction. The threads on shafts 315 and 317 are related by a fixed ratio so that carriages 306 and 310 move relative to one another in accordance with thread ratio. In the embodiment shown, the ratio is 4:1. Thus, carriage 306 moves four times the distance carriage 310 does for any given number of rotations of the threaded shafts 315 and 317.

Reversible electric motors 319 and 324 implement Y-directional movement as indicated by a double headed arrow Y. Motor 319 drives a platform 322 with a rotatable threaded shaft 323 riding in bearings 326 mounted on carriage 306. A base member 330, secured to platform 322, slides on a track 328 mounted atop carriage 306. Although FIG. 4 only shows one track, another is provided in the cutaway region to provide support to the other side of platform 322. The threaded shaft 323 drives platform 322 by rotating through a threaded female coupler 329 secured to platform 322.

Motor 324 rotating a threaded shaft 334 slides a platform 332 mounted on a base 339 across carriage 310. A groove 338 in base 339 slides on a track 336 secured to carriage 310. Motor 324 is synchronized with motor 319 by well known electrical means (not shown) to move plate 332 in the Y-direction at one fourth or other desired fraction of the speed motor 319 moves plate 322.

Plate 332 is provided with a vacuum connection 340 and a vacuum groove 342 for holding a small format recording medium on plate 332. Plate 322 supports a transparent pane of glass 344 which has a vacuum groove 350 and vacuum connections 346 and 348 for retaining a large format temporary storage medium thereon. Glass plate 344 fits over a removed center portion of plate 322 so that an infrared source can be operated from below the plate. An area 351 outlined with a dotted line represents the output area of the source. The source is kept stationary relative to frame 300 so that an X-Y scan results from operation of the scanner as above described.

FIG. 6 shows an optical system for use with the scanner of FIGS. 4 and 5. The optical system is stationarily supported above the glass plate 344 and plate 332 of the X-Y scanner of FIGS. 4 and 5 by means not shown. An infrared or heat source 360 disposed below mask 361 irradiates area 351 of plate 344 and an area 363 of temporary storage medium 362. The phosphor in irradiated area 363 emits an amount of visible light in accordance with any radiographic exposure thereon. Prism 366 reflects the emitted light through a lens 368 onto the input face 370 of an image intensifier tube 372. The image is electrically intensified by well known means in the tube. The intensified light output from tube 372 passes through a pentaprism 374 to a lens 376. The lens focuses the light onto an area 378 of a small format image recording medium such as microfilm 380. Area 378 on recording medium 380 corresponds to area 363 on phosphor medium 362 so that as the scanner operates, it records a representation of the radiographic image stored on the phosphor onto film 380.

It will be appreciated that alternative X-Y scanning devices and appropriate optical systems will be apparent to those skilled in the art and the invention is not restricted to the embodiment shown in FIGS. 4, 5 and 6.

One scanner installation can service several exposure stations so that a hospital need only have one scanner for several remote x-ray exposure installations. Exposed temporary storage phosphors can be transferred from various x-ray exposure installations to a scanner for recording.

In practicing the invention, there are no screen contact problems as in the contact printing art where x-ray film must intimately contact a phosphor screen in order to obtain a relatively high resolution image on the film. Since in practicing the invention, the phosphor screen does not come in contact with the film as do phosphors and radiographic film in conventional x-ray devices, thick overcoats or glass plates can enclose the screen to protect environmentally sensitive phosphors such as readily oxidizable or hydrophilic phosphors, from deterioration.

In the drum scanner embodiments of FIGS. 1-3, although exposure could be made onto the temporary medium when mounted onto its drum, the temporary storage medium used preferably should be flexible so that one may easily mount and remove the screen from the scanning drum. Too, a high energy radiation exposure is usually carried out with a flattened phosphor screen. After exposure, one mounts the screen on the scanning drum for release of the stored image.

In the X-Y scanner embodiment of FIGS. 4-6, the phosphor screens need not be flexible because exposures and scan outs are made with flat screens. Therefore, screens for use with X-Y scanners can comprise bindless phosphor layers prepared by evaporation, plasma-spraying, hot-pressing, and chemical vapor deposition. Because binderless screens have greater absorption per unit thickness than conventional radiographic screens, they offer the advantage of greater radiographic speed with retention of image quality.

Phosphors used in accordance with the invention should preferably have good storage efficiency at room temperature. However, losses of stored information by thermal decay or other phenomena are somewhat compensatable by scanning an area of the phosphor which has received a standard exposure, monitoring the image intensifier output, e.g. by output monitor circuit 284 (see FIG. 3),and adjusting the gain of the intensifier, e.g. by gain adjustment circuit 285,or the rate of scanning, e.g. by drive control 286, to produce an increased level of brightness. Phosphors which have high emission efficiency when stimulated are desirable because less expensive image amplification and optical equipment can be used with them.

In one embodiment, an infrared beam or heat source scans an appropriate temporary storage medium to release trapped carrier electrons. The electrons are collected to form an electrical signal which is amplified. The information carried by the signal is displayed on a cathode ray tube or recorded onto a small format image recording medium.

An appropriate sensor receives the intensity modulated light from the temporary image storage medium. Since, in a preferred embodiment, the stored high energy radiation image is scanned from the temporary storage medium, a sensor synchronizable with the scanning apparatus should be employed. Suitable sensors include photomultiplier tubes, photocell amplifier combinations, image intensifier tubes and low light level television camera tubes such as image isocon or the silicon intensifier target tube. Channel electron multipliers with appropriate photocathodes and output screens and other high gain, low noise detectors can also be used.

In practicing the invention, one may use a high gain image intensifier, such as the Varo intensifier, which has a minimum gain of about 35000 or the E.M.I. 9694 Image Intensifier Assembly which has a minimum gain of 1,000,000, with minimal optical distortion of the image. High gain and low distortion are advantageous, because they permit the use of less efficient storage phosphors and faster scanning rates. Fast scanning rates permit one scanner to serve several exposure installations with a consequent decrease in the cost per exposure. The use of intensifiers with fast decay output phosphors is advantageous, because it prevents blurring of the image and loss of sharpness.

An image intensifier based on the Bendix Chevron CEMA Model BX3040 can also be used.

The electrooptical amplification achieved in practicing the invention provides for the use of relatively slow image recording films which are rapidly processable with simple equipment.

Microfilm is the preferred recording medium because it is readily available and inexpensive. However, other materials suitable for recording the final images include diazo film, polyyne, photosensitive polymer layers, iodoformsensitized film, di-yne coatings, magnetic tape, embossed tape, and electrographic layers.

The invention has been described in detail with particular reference to preferred embodiments thereof, but it will be understood that variations and modifications can be effected within the spirit and scope of the invention.

Claims

1. An apparatus for producing an image corresponding to a an incident x-ray image pattern of radiation of a first wavelength, using a medium for releasably storing an energy image pattern representative of the such incident x-ray image pattern, said apparatus comprising:

means for applying a second wavelength of radiation to scanning successive sub-areas of said image storage medium with a beam of low energy radiation of a second wavelength to cause said respective storage medium sub-areas sequentially to emit a third wavelength of release the stored energy in the form of sequential, photoelectrically detectable radiation having emissions of a third wavelength which constitute an intensity pattern representative of the stored image;

means for sequentially sensing the third wavelength radiation emissions and for producing an electrical energy in accordance therewith signal representative of the incident x-ray image pattern; and

means for converting the electrical energy signal into an image corresponding to the pattern of first wavelength radiation x-ray image.

2. The invention of claim 1 wherein said converting means comprises means for recording an image smaller than the x-ray image pattern of first wavelength radiation.

3. An apparatus, using a medium for releasably storing an energy image pattern representative of a an incident x-ray image pattern, of radiation of a first wavelength for producing an image corresponding to the pattern on a recording medium, said apparatus comprising:

means for scanning said storage medium with a second wavelength of beam of low energy radiation of a second wavelength to release therefrom, sequentially from successive scanned medium portions, a third wavelength of photo-detectable radiation emissions of a third wavelength and intensity modulated in accordance with the stored image pattern;

means synchronized with said scanning means for photoelectrically sensing the sequentially released third wavelength radiation emissions and for producing an electrical energy signal representative thereof of the x-ray image pattern; and

means for transforming converting the electrical energy signal into a recorded image representative of the x-ray image pattern.

4. The invention of claim 3 wherein said transforming converting means comprises:

means for producing a fourth wavelength of radiation intensity modulated in accordance with the electrical energy; and

means for recording the representative image on said recording medium with said fourth wavelength radiation.

5. A method for producing an image corresponding to a releasably stored image of a pattern of high energy radiation, the method comprising the steps of:

releasing the stored image as light energy modulated in accordance with the image;

converting the modulated light energy into corresponding electrical energy;

producing intensity modulated light which varies in accordance with the electrical energy; and

recording with the intensity modulated light to form an image corresponding

to the pattern of high energy radiation.

6. The invention of claim 5 wherein the image recorded is smaller than the high energy radiation

pattern. 7. A method of producing a recorded image corresponding to a releasably stored image of a pattern of high energy radiation, the method comprising the steps of:

releasing the stored image as emitted light on a point by point basis and converting the image into electrical energy modulated in accordance with the point by point intensity of the light emitted;

converting the modulated electrical energy into correspondingly modulated light; and

recording an image with said modulated light that represents the high

energy radiation pattern on a point by point basis. 8. The invention of claim 7 wherein the image recorded is smaller than the pattern of high

energy radiation. 9. The invention of claim 7 wherein the modulated light

is scanned to produce the recorded image. 10. An image forming method using an energy storing medium which is characterized by an ability to store radiant x-ray energy of a first wavelength and release that energy in the form of detectable photo-detectable radiation of a second wavelength when stimulated by radiant energy of a third wavelength, said method comprising:

simultaneously exposing the operative portions of said medium to a respective portions of an x-ray image pattern of radiation of said first wavelength to form in said medium a stored energy pattern corresponding to said x-ray image pattern;

sequentially stimulating successive portions of said medium to sequentially release stored energy in the form of emissions of said second wavelength having intensities respectively corresponding to portions of said stored x-ray energy pattern;

converting said energy emissions of said second wavelength to an electrical signal; and

using said electrical signal to control formation of an image corresponding

to said original pattern of radiation. 11. An image forming method using an intermediate medium capable of storing energy when exposed to x-radiation, which energy is releasable as light when stimulated by infrared radiation, said method comprising:

exposing said medium to a pattern of x-radiation to form a pattern of stored energy in said medium;

scanning said medium with stimulating infrared radiation to release light energy modulated in accordance with said pattern;

converting said light energy to an electrical signal;

using said electrical signal to modulate the intensity of a light beam; and

scanning said modulated light beam across a light sensitive recording material to form an image corresponding to said original pattern of

x-radiation. 12. Apparatus for producing a recorded image corresponding to a pattern of high energy radiation, using a medium having temporarily stored therein an image representative of said pattern as releasable energy, said apparatus comprising:

means for scanning said temporary storage medium to release the stored energy therefrom;

means coordinated with said scanning means for sensing the energy released and for transforming the released energy into electrical energy; and

means for converting said electrical energy into an intensified output

image corresponding to the pattern of high energy radiation. 13. The invention of claim 12 wherein said medium for temporarily storing an image comprises an infrared-stimulable phosphor screen and said scanning means

comprises a source of infrared radiation. 14. The invention of claim 12 wherein said medium for temporarily storing an image comprises a thermoluminescent screen and said scanning means comprises means for

scanning said medium with heat concentrated in a small area. 15. The invention defined in claim 1 or 3 wherein said converting means includes means for modifying said electrical signal to improve the image information thereof. 16. The invention defined in claim 15 wherein said modifying means improves the signal to noise ratio of said electrical image signal. 17. The invention defined in claim 15 wherein said modifying means processes said electrical signal to provide image edge enhancement. 18. The invention defined in claim 15 wherein said modifying means processes said electrical image signal to modify image intensity. 19. The invention defined in claim 7 including, prior to the step of converting said electrical energy into recording light, the step of modifying said electrical energy to improve its image information. 20. The invention defined in claim 19 wherein the electrical energy is modified to improve signal to noise ratio. 21. The invention defined in claim 19 wherein the electrical energy is modified to provide image edge enhancement. 22. The invention defined in claim 19 wherein the electrical energy is modified as to image intensity. 23. The invention defined in claim 10 or 11 including the step of modifying said electrical signal, prior to its use in formation of a corresponding image, to improve the image information thereof. 24. The invention defined in claim 23 wherein said electrical signal is modified to improve signal to noise ratio. 25. The invention defined in claim 23 wherein said electrical signal is modified to provide image edge enhancement.

26. The invention defined in claim 23 wherein said electrical signal is modified as to image intensity. 27. A radiographic imaging system comprising:

(a) image storage means having an image zone which is: (i) responsive to an incident x-ray image pattern for producing a corresponding stored energy pattern and (ii) responsive to stimulating radiation for releasing energy so stored as light emissions;

(b) means for supporting said image storage means;

(c) scanning means for effecting sequential application of such stimulating radiation to successive image zone portions of said image storage means to release energy stored therein as respective sequential light emissions;

(d) detector means for optically collecting said sequential light emissions and for producing an electrical signal corresponding to said x-ray image pattern; and

(e) means for converting said electrical signal into an image corresponding

to said x-ray image pattern. 28. Radiographic imaging apparatus constructed to receive and cooperate with a storage means having an image zone which is: (i) responsive to an incident x-ray image pattern for producing a corresponding stored energy pattern and (ii) responsive to stimulating radiation for releasing energy so stored as light emissions, said apparatus comprising:

(a) scanning means for sequentially applying such stimulating radiation to successive image zone portions of a received image storage means to release energy stored therein as respective sequential light emissions;

(b) detector means for optically collecting said sequential light emissions and for producing an electrical signal corresponding to said x-ray image pattern; and

(c) means for converting said electrical signal into an image corresponding to said x-ray image pattern. 29. Radiographic imaging apparatus for receiving an image storage medium having an image storage zone which:

(i) has been exposed to the image elements of an x-ray image and stores energy in a pattern corresponding to said x-ray image and (ii) is responsive to stimulating radiation to release stored energy as light emission, said apparatus comprising:

(a) scanning means for sequentially applying such stimulating radiation to successive portions of such a received storage medium to release energy stored therein as respective sequential light emissions;

(b) detector means for optically collecting said sequential light emissions and for producing an electrical signal corresponding to said x-ray image pattern; and

(c) means for converting said electrical signal into an image corresponding to said x-ray image pattern. 30. An improved imaging system for medical radiography, said system comprising:

(a) image storage means having an image zone of a format that comprises a plurality of image point portions which: (i) are responsive to respective portions of an incident x-ray image pattern to discretely store corresponding energy pattern portions and (ii) are discretely responsive to stimulating radiation, of lower quantum energy than said x-ray image pattern, to release their stored energy pattern portions as respective emissions of light radiation;

(b) means for supporting said image storage means;

(c) scanning means for discretely providing such stimulating radiation sequentially on successive image point portions of said image zone so as to sequentially release successive light emissions in accordance with the stored energy pattern corresponding to the exposed x-ray pattern;

(d) detector means for sensing the sequential light emissions discretely and for producing, in response thereto, a time-varying electrical signal containing image point information corresponding to said x-ray image pattern; and

(e) means for converting said electrical signal into an image corresponding

to said x-ray pattern. 31. The system defined in claim 27 or 30, wherein said storage means is constructed to be readily insertable into, and removable from, its operative location relative to said scanning means. 32. The system defined in claim 31 wherein said storage means is flexible. 33. The system defined in claim 27 or 30, wherein said storage means is constructed for facile transfer between a separate operative location at which it is imagewise exposed and

said scanning means. 34. An improved medical-radiographic imaging apparatus useful with image storage means having an image zone of a format size which accommodates a medical x-ray image pattern and that comprises a plurality of image point portions which: (i) are responsive to respective portions of such an incident x-ray image pattern to discretely store corresponding energy pattern portions and (ii) are discretely responsive to stimulating radiation, of lower quantum energy than said x-ray image pattern, to release their stored energy pattern portions as respective emissions of light radiation, said apparatus comprising:

(a) scanning means for discretely providing stimulating radiation sequentially on successive image point portions of the image zone of such image storage means so as to sequentially release successive light emissions in accordance with the stored energy pattern corresponding to the exposed x-ray image pattern; and

(b) detector means for sensing the sequential light emissions discretely and for producing, in response thereto, a time-varying electrical signal containing image point information corresponding to said x-ray image pattern; and

(c) means for converting said electrical signal into an image corresponding

to said x-ray pattern. 35. Medical radiographic imaging apparatus constructed to receive and cooperate with image storage means having an image zone that comprises a plurality of image points which: (i) have been exposed to respective portions of an incident x-ray image pattern to discretely store corresponding energy pattern portions and (ii) are discretely responsive to stimulating radiation, of lower quantum energy than said x-ray image pattern, to release their stored energy pattern portions as respective emissions of light radiation, said apparatus comprising:

(a) scanning means for discretely providing stimulating radiation sequentially on successive image point portions of the image zone of a received image storage means so as to sequentially release successive light emissions in accordance with the stored energy pattern corresponding to the exposed x-ray image pattern;

(b) detector means for sensing the sequential light emissions discretely and for producing, in response thereto, a time-varying electrical signal containing image point information corresponding to said x-ray image pattern; and

(c) means for converting said electrical signal into an image corresponding

to said x-ray pattern. 36. The invention defined in claims 1, 3, 12, 27, 28, 29, 30, 34 or 35 wherein said converting means comprises: (i) means for storing an electrical image signal; (ii) means for receiving an electrical image signal and displaying a visible image corresponding to the information therein and (iii) means for receiving an electrical image signal and recording an image, corresponding to the information therein, on a record medium. 37. The invention defined in claims 1, 3, 12, 27, 28, 29, 30, 34 or 35 wherein said converting means comprises: (i) means for storing an electrical image signal and (ii) means for receiving an electrical image signal and displaying a visible image corresponding to the information therein. 38. The invention in claims 1, 3, 12, 27, 28, 29, 30, 34 or 35 wherein said converting means comprises: (i) means for receiving an electrical image signal and displaying a visible image corresponding to the information therein and (ii) means for receiving an electrical image signal and recording an image, corresponding to the information therein, on a record medium. 39. The invention defined in claims 1, 3, 12, 27, 28, 29, 30, 34 or 35 wherein said converting means comprises: (i) means for storing an electrical image signal and (ii) means for receiving an electrical image signal and recording an image, corresponding to the information therein, on a record medium. 40. The invention defined in claims 1, 3, 12, 27, 28, 29, 30, 34 or 35 wherein said converting means comprises: (i) means for storing an electrical image signal; (ii) means for receiving an electrical image signal and displaying a visible image corresponding to the information therein; (iii) means for imagewise processing such electrical image signal to provide image intensification, improved signal to noise or image edge-enhancement and (iv) means for receiving such image signal and recording a modified image pattern on a record medium. 41. The invention defined in claims 1, 3, 12, 27, 28, 29, 30, 34 or 35 wherein said converting means comprises: (i) means for storing an electrical image signal; (ii) means for imagewise processing an electrical image signal to provide image intensification, improved signal to noise or image edge-enhancement and (iii) means for receiving such image signal and recording a modified image pattern on a record medium. 42. The invention defined in claims 1, 3, 12, 27, 28, 29, 30, 34, or 35 wherein said converting means comprises: (i) means for storing an electrical image signal; (ii) means for receiving an electrical image signal and displaying a visible image corresponding to the information therein and (iii) means for imagewise processing such electrical image signal to provide image intensification, improved signal to noise or image edge-enhancement. 43. The invention defined in claims 27, 28, 29, 30, 34 or 35 including means for providing relative movement between said detector means and said image storage means. 44. The invention defined in claims 27, 28, 29, 30, 34 or 35 wherein said detector means includes: (i) photoelectric transducer means, (ii) light guide means, located proximate said image storage means, for directing emitted light to said transducer means; and (iii) means for providing relative movement between said light guide means and said image storage means during operation of said scanning means. 45. The invention defined in claim 44 wherein the relative movement between said light guide and image storage means is synchronized with said scanning means so that said light guide is sequentially in proximate locations respectively to stimulated point portions of said

image storage means. 46. The invention defined in claims 27, 28, 29, 30, 34 or 35 wherein said converting means includes means for receiving said electrical image signal and recording an image which corresponds to said exposed x-ray image pattern, but which is reduced in format size relative to said exposed x-ray image pattern. 47. The invention defined in claims 27, 28, 29, 30, 34 or 35 wherein said converting means includes means for receiving said electrical image signal and displaying an image which corresponds to said exposed x-ray image pattern, but which is reduced in format size relative to said exposed x-ray image pattern. 48. A radiographic imaging method comprising:

(a) exposing the image zone of a temporary image storage medium, of the type that is: (i) responsive to an incident x-ray image pattern for producing a corresponding stored energy pattern and (ii) responsive to stimulating radiation for releasing energy so stored as light emissions, to an x-ray image pattern;

(b) sequentially applying such stimulating radiation to successive image zone portions of said image storage media to release energy stored therein as respective sequential light emissions;

(c) optically collecting and photoelectrically detecting said sequential light emissions to produce an electrical image signal corresponding to said x-ray image pattern; and

(d) converting said electrical image signal into an image corresponding to

said x-ray image pattern. 49. A radiographic imaging method using a storage medium having an image zone that is responsive to an incident x-ray image pattern for producing a corresponding stored energy pattern and is responsive to stimulating radiation for releasing energy so stored as light emissions, said method comprising:

(a) exposing the image zone portions of such storage medium to respective portions of an x-ray image pattern;

(b) sequentially applying such stimulating radiation to successive image zone portions of said exposed storage medium to release energy stored therein as respective sequential light emissions;

(c) optically directing said sequential light emissions to a detector and photoelectrically detecting the emissions to produce an electrical image signal corresponding to said x-ray image pattern; and

(d) converting said electrical image signal to an image corresponding to

said x-ray image pattern. 50. A radiographic imaging method for use with an image storage medium having image storage portions which: (i) have been exposed to an x-ray image and store energy in a pattern corresponding to said x-ray image and (ii) are responsive to stimulating radiation to release stored energy as light emission, said method comprising:

(a) sequentially applying such stimulating radiation to successive portions of said storage medium to release energy stored therein as respective sequential light emissions;

(b) optically collecting and detecting said sequential light emissions to produce an electrical image signal corresponding to said x-ray image pattern; and

(c) converting said electrical image signal into an image corresponding to said x-ray image pattern. 51. An improved imaging method for medical radiography, said method comprising:

(a) exposing, to an x-ray pattern constituting a medical radiographic image, the plurality of image point portions that comprise the image zone of an image storage medium, and that: (i) are responsive to respective portions of an incident x-ray image pattern to discretely store corresponding energy pattern portions and (ii) are discretely responsive to stimulating radiation, of lower quantum energy than said x-ray image pattern, to release their stored energy pattern portions as respective emissions of light radiation;

(b) discretely scanning such stimulating radiation sequentially onto successive image point portions of said storage medium so as to sequentially release successive light emissions in accordance with the stored energy pattern corresponding to the x-ray image pattern;

(c) discretely detecting the sequential light emissions and producing, in response thereto, a time-varying electrical image signal containing the image point information corresponding to said x-ray image pattern; and

(d) converting said electrical image signal into an image corresponding to

said x-ray image pattern. 52. An improved medical-radiographic imaging method useful with image storage medium having an image zone that comprises a plurality of image point portions which: (i) are responsive to respective portions of an incident x-ray image pattern to discretely store corresponding energy pattern portions and (ii) are discretely responsive to stimulating radiation, of lower quantum energy than said x-ray image pattern, to release their stored energy pattern portions as respective emissions of light radiation, said method comprising:

(a) exposing the image point portions of said storage medium to an x-ray pattern constituting a medical radiographic image;

(b) scanning such stimulating radiation sequentially onto successive image point portions of said storage medium so as to sequentially release successive light emissions in accordance with the stored energy pattern corresponding to the x-ray image pattern;

(c) detecting the sequential light emissions discretely and sequentially, and photoelectrically producing, in response thereto, an electrical image signal containing the image point information of said x-ray image pattern; and

(d) converting said electrical image signal into an image corresponding to

said x-ray image pattern. 53. The method defined in claims 48, 49, 51 or 52 further including the step of transferring said storage medium between x-ray exposing and scan-stimulating locations after said exposing step. 54. A medical radiographic imaging method useful with image storage medium having an image zone that comprises a plurality of image points which: (i) have been exposed to respective portions of an incident x-ray image pattern to discretely store corresponding energy pattern portions and (ii) are discretely responsive to stimulating radiation, of lower quantum energy than said x-ray image pattern, to release their stored energy pattern portions as respective emissions of light radiation, said method comprising:

(a) scanning such stimulating radiation sequentially onto successive image point portions of such storage medium so as to sequentially release successive light emissions in accordance with its stored energy pattern;

(b) photoelectrically detecting the sequential light emissions discretely so as to produce a time-varying electrical image signal containing image point information corresponding to said x-ray image pattern; and

(c) converting said electrical image signal into an image corresponding to said x-ray image pattern. 55. The invention defined in claims 48, 49, 50, 51, 52 or 54 wherein said detecting step includes providing relative movement between a photoelectric detector means and said image storage medium. 56. The invention defined in claims 48, 49, 50, 51, 52 or 54 wherein said detecting step includes, during said scanning step, relatively moving said storage medium and a light guide which is located proximate said image storage medium for directing light emissions to a photoelectric transducer. 57. The invention defined in claim 56 wherein the relative movement between said light guide and image storage means is synchronized with said scanning of stimulating radiation so that said light guide is sequentially in proximate locations respectively to stimulated point portions of said image storage means. 58. The method defined in claims 48, 49, 50, 51, 52 or 54 wherein said converting step includes: (i) storing said electrical image signal; (ii) receiving said electrical image signal and displaying a visible image corresponding to the information therein or (iii) receiving said electrical image signal and recording an image corresponding to the information therein on a record medium. 59. The method defined in claims 48, 49, 50, 51, 52 or 54 wherein said converting step includes: (i) receiving said electrical image signal and displaying a visible image corresponding to the information therein and (ii) receiving said electrical image signal and recording an image corresponding to the information therein on a record medium.

60. The method defined in claims 48, 49, 50, 51, 52 or 54 wherein said converting step includes: imagewise processing said electrical image signal to provide image intensification, improved signal to noise or image edge-enhancement. 61. The method defined in claims 48, 49, 50, 51, 52 or 54 wherein said converting step includes: (i) imagewise processing said electrical image signal to provide image intensification, improved signal to noise or image edge-enhancement and (ii) receiving such image signal and recording a modified image on a record medium. 62. The method defined in claims 48, 49, 50, 51, 52 or 54 wherein said converting step includes: (i) receiving said electrical image signal and displaying a visible image corresponding to the information therein and (ii) imagewise processing said electrical image signal to provide image intensification, improved signal to noise or image edge-enhancement. 63. The method defined in claims 48, 49, 50, 51, 52 or 54 further comprising the steps of monitoring the photoelectrically detected output of a stimulated medium test portion, which has received a test exposure, and adjusting the storage medium's exposures to stimulating

radiation in response to such detected output. 64. The method defined in claim 63 wherein said adjusting step comprises varying the scan rate of said stimulating radiation in response to such detected output. 65. The method defined in claims 48, 49, 50, 51, 52 or 54 further comprising the steps of monitoring the photoelectrically detected output of a stimulated medium test portion, which has received a test exposure, and adjusting the amplification of the electrical image signal in response to such detected test output.