X-RAY COMPUTED TOMOGRAPHY (CT) SCANNER

Abstract

An X-ray computed tomography (CT) scanner includes a plurality of X-Ray sources and detectors mounted about an opening where scanning takes place. The X-Ray sources and detectors are arranged to oscillate back and forth in opposing first and second rotational directions about the opening, or in the same rotational direction about the opening, in order to generate a cross-sectional image of an object located within the opening.

Claims

1. An X-ray computed tomography (CT) scanner comprising a scanning setup comprising a plurality of X-Ray sources and detectors mounted about an opening where scanning takes place, wherein the X-Ray sources and detectors are arranged to oscillate back and forth in opposing first and second rotational directions about the opening and an axis of rotation of the scanner that passes through the opening in order to generate scanned slice data of an object located within the opening.

2. The CT scanner of claim 1, wherein scanned slice data comprises one or more slices along the scanner's axis of rotation that are generally one aside the other.

3. The CT scanner of claim 2, wherein scanned slice data is arranged to provide a full whole-body (WB) image or part of a WB scan providing only a part of the cross section of the object or the body, wherein such full or partial WB images are obtained by advancing the object or body being scanned through the opening of the scanner where scanning takes place.

4. The CT scanner of claim 2, wherein the X-Ray sources and detectors are mounted on a frame that oscillates about the opening.

5. The CT scanner of claim 1, wherein the oscillating motion is at an angle that is less than about 360 degrees, and for example less than about 180 degrees possibly plus the fan angle about the scanner's axis of rotation.

6. The CT scanner of claim 1, wherein the X-Ray sources are arranged in sets and all X-Ray sources in a certain set are arranged to emit X-ray radiation towards a similar detector.

7. The CT scanner of claim 6, wherein X-Ray sources in a certain set are arranged circumferentially adjacent one to the other.

8. The CT scanner of claim 6, wherein not all X-Ray sources in a certain set are circumferentially adjacent one to the other.

9. The CT scanner of claim 6, wherein X-Ray sources are arranged to be sequentially activated and during each activation at least one X-Ray source in each set is activated.

10. The CT scanner of claim 9, wherein the at least one X-Ray source in each set that is activated is one X-Ray source.

11. The CT scanner of claim 1, wherein one or more X-Ray sources are arranged to be sequentially activated.

12. The CT scanner of claim 1, wherein the oscillating motion alpha is defined between a first angular spacing A1 and a second angular spacing A2, wherein A1=360 degrees divided by the number of X-ray tubes and A2=360 degrees divided by the number of detectors.

13. The CT scanner of claim 1, wherein at least some X-Ray tubes are arranged to be fired at least once while rotating in the first rotational direction, and at least once while rotating back in the opposing second rotational direction.

14. The CT scanner of claim 1, wherein at least some X-Ray tubes are arranged to be fired at least once while rotating in the first rotational direction, while not at all while rotating back in the opposing second rotational direction.

15. The CT scanner of claim 1 and comprising an n number of X-Ray tubes and an m number of detectors generally evenly spaced apart one from the other by about 360/n for the tubes and about 360/m for the detectors, and wherein scanned slice data of an object is obtained while oscillating between about 360/n and about 360/m around the object.

16. The CT scanner of claim 1 and comprising an n number of X-Ray tubes and an m number of detectors at least some of which being non-evenly spaced apart one from the other, and scanned slice data of an object is obtained while oscillating between about 360/n according to the tubes and about 360/m according to the detectors around the object.

17. The CT scanner of claim 15 or 16, wherein the n number of X-Ray tubes is any number such as one of: 4, 6, 8, 12, 36, and the m number of detectors is any number such as one of: 4, 6, 8, 12, 24.

18. The CT scanner of claim 17, wherein at least some X-Ray sources are controlled to emit X-ray radiation towards different detectors in different scans of the object.

19. The CT scanner of claim 18, wherein controlling an X-Ray source to emit radiation towards a different detector than previously is by controlling a collimator or the X-ray source and its associated collimator to direct the emitted radiation towards the different detector.

20. The CT scanner of claim 17 and comprising a plurality of scanning setups placed one aside the other along the axis of rotation of the scanner, wherein possibly a single detector of the CT scanner is arranged to receive X-Ray radiation from X-Ray sources of different preferably adjacent scanning setups.

21. The CT scanner of claim 1 and being arranged to utilize AI (Artificial Intelligence) based reconstruction methods to assist in creation of additional views to possibly further reduce rotational angles to generate slices.

22. An X-ray computed tomography (CT) scanner comprising a scanning setup comprising more than two X-Ray sources and more than two detectors mounted about an opening where scanning takes place, wherein a scanning setup is arranged to rotate about an axis of rotation of the scanner in order to generate scanned slice data of an object located within the opening.

23. The CT scanner of claim 22, wherein the detectors are solid state detectors arranged for photon counting.

24. The CT scanner of claim 22, wherein the X-Ray sources and detectors are arranged to rotate in the same rotational direction about the axis of rotation.

25. The CT scanner of claim 24, wherein an angular rotation alpha of less than about 360 degrees, and possibly less than about 180 degrees, is arranged to provide scanned slice data of an object.

26. The CT scanner of claim 25, wherein scanned slice data comprises one or more slices along the scanner's axis of rotation that are generally one aside to the other.

27. The CT scanner of claim 25, wherein after completing an angular rotation of about alpha the scanner continues to rotate in the same rotational direction an additional angular rotation, possibly also of about alpha in order to obtain additional scanned slice data of the object.

28. The CT scanner of claim 25, wherein after completing an angular rotation of about alpha in a first rotational direction the scanner oscillates back to rotate in an opposing second rotational direction, possibly also of about alpha in order to obtain additional slice data of the object.

29. The CT scanner of claim 27, wherein alpha is defined between a first angular spacing A1 and a second angular spacing A2, wherein A1=360 degrees divided by the number of X-ray tubes and A2=360 degrees divided by the number of detectors.

30. The CT scanner of claim 22 and comprising an n number of X-Ray tubes and an m number of detectors generally evenly spaced apart one from the other by about 360/n for the tubes and about 360/m for the detectors, and wherein scanned slice data of an object is obtained while oscillating between about 360/n and about 360/m around the object.

31. The CT scanner of claim 22 and comprising an n number of X-Ray tubes and an m number of detectors at least some of which being non-evenly spaced apart one from the other, and scanned slice data of an object is obtained while rotating between about 360/n according to the tubes and about 360/m according to the detectors around the object.

32. The CT scanner of claim 25, wherein the X-Ray sources are arranged in sets and all X-Ray sources in a certain set are arranged to emit X-ray radiation towards a similar common detector.

33. The CT scanner of claim 32, wherein X-Ray sources in a certain set are arranged circumferentially adjacent one to the other.

34. The CT scanner of claim 32, wherein not all X-Ray sources in a certain set are circumferentially adjacent one to the other.

35. The CT scanner of claim 32, wherein X-Ray sources are arranged to be sequentially activated, and preferably during each activation only one X-Ray source is activated.

36. The CT scanner of claim 22, wherein at least some of the detectors are of inverse-geometry CT architecture.

37. The CT scanner of claim 22, wherein at least some of the detectors are regular CT detectors.

38. The CT scanner of claims 36 or 37 and being used for imaging and calculating calcium scoring with lower speed of rotation.

39. The CT scanner of claim 22 and being arranged to utilize AI (Artificial Intelligence) based reconstruction methods to assist in creation of additional views to possibly further reduce rotational angles to generate slices.

40. An X-ray computed tomography (CT) scanner comprising a scanning setup comprising a plurality of X-Ray sources and detectors mounted about an opening where scanning takes place, wherein the X-Ray sources and detectors are arranged to perform alpha sized rotational motions in the same rotational direction about the scanner's axis of rotation in order to generate scanned slice data of an object located within the opening.

41. The CT scanner of claim 40, wherein scanned slice data comprises one or more slices along the scanner's axis of rotation that are generally one aside to the other.

42. The CT scanner of claim 41, wherein scanned data is arranged to provide a full whole-body (WB) image or part of a WB scan providing only a part of the cross section of the object or the body, wherein such full or partial WB images are obtained by advancing the object or body being scanned through the opening of the scanner where scanning takes place.

43. The CT scanner of claim 41, wherein the X-Ray sources and detectors are mounted on a frame that rotates about the opening.

44. The CT scanner of claim 40, wherein alpha is less than about 360 degrees, and possibly less than about 180 degrees about the scanner's axis of rotation.

45. The CT scanner of claim 40, wherein the detectors are solid state detectors arranged for photon counting.

46. The CT scanner of claim 40, wherein alpha is defined between a first angular spacing A1 and a second angular spacing A2, wherein A1=360 degrees divided by the number of X-ray tubes and A2=360 degrees divided by the number of detectors.

47. The CT scanner of claim 40, wherein alpha is larger or equal to than the result of dividing 360 by the number of X-Ray sources.

48. The CT scanner of claim 40, wherein the X-Ray sources are arranged in sets and all X-Ray sources in a certain set are arranged to emit X-ray radiation towards a similar common detector.

49. The CT scanner of claim 48, wherein alpha is computed by dividing 360 by the number of sets.

50. The CT scanner of claim 48, wherein X-Ray sources in a certain set are arranged circumferentially adjacent one to the other.

51. The CT scanner of claim 48, wherein not all X-Ray sources in a certain set are circumferentially adjacent one to the other.

52. The CT scanner of claim 48, wherein some X-Ray sources are arranged to be sequentially activated, and preferably during each activation only one X-Ray source in a set is activated.

53. The CT scanner of claim 52, wherein at least some of the detectors are of inverse-geometry CT architecture.

54. The CT scanner of claim 52, wherein at least some of the detectors are regular CT detectors.

55. The CT scanner of claim 52 and being used for imaging and calculating calcium scoring with lower speeds of rotation.

56. The CT scanner of claim 52 and being arranged to utilize AI (Artificial Intelligence) based reconstruction methods to assist in creation of views and/or slices being scanned.

57. The CT scanner of claim 52, wherein the at least one X-Ray source in each set that is activated is one X-Ray source.

58. The CT scanner of claim 57, wherein X-Ray sources are arranged to be sequentially activated.

59. The CT scanner of claim 40 and comprising an n number of X-Ray tubes and an m number of detectors generally evenly spaced apart one from the other by about 360/n degrees for the X-Ray tubes and about 360/m degrees for the detectors, and wherein scanned data of an object is obtained while rotating between about 360/n and about 360/m degrees around the object.

60. The CT scanner of claim 40, wherein at least some X-Ray sources are controlled to emit X-ray radiation towards different detectors in different scans of the object.

61. The CT scanner of claim 60, wherein controlling an X-Ray source to emit radiation towards a different detector than previously is by controlling a collimator or the X-ray source and its associated collimator to direct the emitted radiation towards the different detector.

62. The CT scanner of claim 40 and comprising a plurality of scanning setups placed one aside the other along the axis of rotation of the scanner, wherein possibly a single detector of the CT scanner is arranged to receive X-Ray radiation from X-Ray sources of different preferably adjacent scanning setups.

63. The CT scanner of claim 40 and being arranged to utilize AI (Artificial Intelligence) based reconstruction methods to assist in creation of additional views to possibly further reduce rotational angles to generate slices.

64. A method for medical imaging comprising the stems of: providing an X-ray computed tomography (CT) scanner comprising a plurality of X-Ray sources and detectors mounted about an opening where scanning is designed takes place, locating an object to be scanned within the opening, and performing alpha sized rotational motions in the same rotational direction about the scanner's axis of rotation in order to generate scanned slice data of an object located within the opening.

65. The method of claim 64, wherein scanned slice data comprises one or more slices along the scanner's axis of rotation that are generally one aside to the other.

66. The method of claim 65, wherein alpha is less than about 360 degrees, and possibly less than about 180 degrees about the scanner's axis of rotation.

67. The CT scanner of claim 66, wherein alpha is defined between a first angular spacing A1 and a second angular spacing A2, wherein A1=360 degrees divided by the number of X-ray tubes and A2=360 degrees divided by the number of detectors.

68. A method for medical imaging comprising the stems of: providing an X-ray computed tomography (CT) scanner comprising a plurality of X-Ray sources and detectors mounted about an opening where scanning is designed takes place, locating an object to be scanned within the opening, and oscillating the X-Ray sources and detectors back and forth in opposing first and second rotational directions about the opening and an axis of rotation of the scanner that passes through the opening in order to generate scanned slice data of an object located within the opening.

69. The method of claim 68, wherein the oscillating motion is at an angle that is less than about 360 degrees, and for example less than about 180 degrees possibly plus the fan angle about the scanner's axis of rotation.

70. The method of claim 69, wherein the X-Ray sources are arranged in sets and all X-Ray sources in a certain set are arranged to emit X-ray radiation towards a similar detector.

71. The method of claim 70, wherein X-Ray sources in a certain set are arranged circumferentially adjacent one to the other.

72. The method of claim 70, wherein X-Ray sources are arranged to be sequentially activated and during each activation at least one X-Ray source in each set is activated.

73. The CT scanner of claim 68, wherein alpha is defined between a first angular spacing A1 and a second angular spacing A2, wherein A1=360 degrees divided by the number of X-ray tubes and A2=360 degrees divided by the number of detectors.

74. An X-ray computed tomography (CT) scanner comprising a plurality of X-ray tubes that are arranged to emit radiation towards a single detector in order to obtain scanned slice data of an object, wherein the CT scanner is defined having a maximal field of view (FOV) when all X-ray tubes are used for obtaining the scanned slice data, and wherein the CT scanner is configured to adapt the FOV to be smaller than the maximal FOV by activating only some of the X-ray tubes for obtaining the scanned slice data of an object.

75. The CT scanner of claim 74, wherein the adapted smaller FOV covers only a smaller portion of the object being scanned that would otherwise be scanned if the maximal FOV would be used.

76. The CT scanner of claim 74, wherein scanned slice data is obtained by rotating the X-Ray tubes and detector by an angle alpha that is less than 180 degrees about the object being scanned.

77. The CT scanner of claim 76, wherein scanned slice data comprises one or more slices along the scanner's axis of rotation that are generally one aside the other.

78. The CT scanner of claim 77, wherein the X-Ray tubes and detector are arranged to oscillate back and forth in the angle alpha in opposing first and second rotational directions about the object being scanned in order to obtain different sets of scanned slice data.

79. The CT scanner of claim 77, wherein the X-Ray tubes and detector are arranged to rotate in the same rotational direction in alpha sized rotational motions in order to obtain different sets of scanned slice data.

80. An X-ray computed tomography (CT) scanner comprising a plurality of X-ray tubes that are arranged to emit radiation towards a single detector in order to obtain scanned slice data of an object, wherein the CT scanner is controlled to activate at least some of the X-Ray tubes at different powers while obtaining scanned slice data of an object.

81. The CT scanner of claim 80, wherein activating an X-Ray tube at a different power comprises providing to the X-Ray tube different current and/or voltage.

82. The CT scanner of claim 80, wherein scanned slice data is obtained by rotating the X-Ray tubes and detector by an angle alpha that is less than 180 degrees about the object being scanned.

83. The CT scanner of claim 82, wherein scanned slice data comprises one or more slices along the scanner's axis of rotation that are generally one aside the other.

84. The CT scanner of claim 83, wherein the X-Ray tubes and detector are arranged to oscillate back and forth in the angle alpha in opposing first and second rotational directions about the object being scanned in order to obtain different sets of scanned slice data.

85. The CT scanner of claim 83, wherein the X-Ray tubes and detector are arranged to rotate in the same rotational direction in alpha sized rotational motions in order to obtain different sets of scanned slice data.

Description

BRIEF DESCRIPTION OF THE FIGURES

[0046] Exemplary embodiments are illustrated in referenced figures. It is intended that the embodiments and figures disclosed herein are to be considered illustrative, rather than restrictive. The invention, however, both as to organization and method of operation, together with objects, features, and advantages thereof, may best be understood by reference to the following detailed description when read with the accompanying figures, in which:

[0047] FIGS. 1A and 1B schematically show an embodiment of an X-ray computed tomography (CT) scanner in perspective and frontal views, respectively;

[0048] FIG. 2 schematically shows an embodiment of an X-ray computed tomography (CT) scanner, or part of such a CT scanner, illustrating three X-Ray sources and an opposing detector;

[0049] FIGS. 3A to 3C schematically show respective regions within a scanning volume of the CT scanner that can be scanned by different X-Ray sources of the CT scanner;

[0050] FIG. 4 schematically shows an embodiment of an X-ray computed tomography (CT) scanner including twelve X-Ray sources and four detectors, where each set of three X-Ray sources has an opposing detector;

[0051] FIGS. 5A to 5C schematically show an embodiment of an X-ray computed tomography (CT) scanner during an oscillating scanning process;

[0052] FIGS. 6A to 6C schematically show an embodiment of an X-ray computed tomography (CT) scanning process where groups of X-Ray tubes are sequentially switched on and off; and

[0053] FIG. 7 schematically shows an embodiment of an X-ray computed tomography (CT) scanner including twelve X-Ray sources;

[0054] FIGS. 8A and 8B schematically show an embodiment of an X-ray computed tomography (CT) scanner including 6 detectors and thirty six X-Ray sources and possible arrangement of such X-Ray sources in groups and sets, respectively;

[0055] FIGS. 9A to 9C schematically show another embodiment of an X-ray computed tomography (CT) scanner with eight X-ray sources and six detectors, where possible a direction of a fan angle of at least certain X-ray sources may be altered possibly via a controllable collimator;

[0056] FIG. 10 schematically shows yet another embodiment of an X-ray computed tomography (CT) scanner with six X-Ray tubes and six detectors, where the X-Ray Tubes can be switched sequentially, or any combination of two, three or six at the same time; and

[0057] FIGS. 11 to 13 schematically show yet further embodiments of X-ray computed tomography (CT) scanners in accordance with the present disclosure.

[0058] It will be appreciated that for simplicity and clarity of illustration, elements shown in the figures have not necessarily been drawn to scale. For example, the dimensions of some of the elements may be exaggerated relative to other elements for clarity. Further, where considered appropriate, reference numerals may be repeated within the figures to indicate like elements.

DETAILED DESCRIPTION

[0059] Attention is first drawn to FIGS. 1A and 1B schematically showing an embodiment of an X-ray computed tomography (CT) scanner 10 in perspective and frontal views, respectively.

[0060] CT scanner 10 includes a circular frame 12 that defines a volume useful field of view (FOV) 14 where scanning takes place. The frame includes a plurality of X-ray tubes 16 and opposing X-ray detectors 18 formed about FOV 14 and about an axis of rotation R of the scanner that passes through FOV 14, and the scanner includes a table platform 20 for advancing a patient through the scanning volume where computer-processed combinations of multiple X-ray measurements are taken to produce tomographic images of the body of the patient being scanned.

[0061] Attention is drawn to FIG. 2 illustrating a portion of a CT scanner showing a set three X-ray tubes 16, tagged 1, 2, 3; that are configured to emit X-ray radiation towards an opposing associated common detector 18 that is arranged to measure the flux, spatial resolution, Energy resolution, and/or other properties of X-rays emitted by the X-ray tubes.

[0062] Such measurements made at detector 18 are arranged to provide scanned slice data (or parts of slice data) relating to objects present within FOV 14. FIGS. 3A to 3C schematically show respective scan regions within FOV 14 seen in FIG. 2, that are scanned by different X-Ray sources tagged 1, 2, 3 of the CT scanner. As seen in FIGS. 3A to 3C, the X-Ray sources 16 and detector 18 are arranged to provide substantial full coverage of FOV 14 at least from the direction they are aimed at FOV 14.

[0063] A fan angle ? may be collimated by a collimator 17 for each X-ray beam being emitted by an X-ray source. In certain cases, the collimator may be controlled to change the fan angle of its associated X-ray source and/or to control the direction that an optical axis O along which the X-ray beam is emitted from the X-ray source points. In certain cases, the direction that an optical axis O along which a beam emitted from a given X-ray source may advancemay be controlled by tilting the given X-ray tube together with its associated collimator that can be possibly also controlled to change the fan angle of the given X-ray tube.

[0064] Attention is drawn to FIG. 4 schematically showing an embodiment of an X-ray computed tomography (CT) scanner 10 including twelve X-Ray sources, tagged 1 to 12. In this example, The CT scanner is arranged such that sets of three adjacent X-Ray sources (see, e.g., X-Ray sources tagged: 1-3, 4-6, 7-9 and 10-12) are arranged each to emit X-Ray radiation towards an opposing associated common detector 18.

[0065] Each one of the sets of X-Ray sources and associated detectors seen in FIG. 4may be generally similar to the set of X-ray sources and associated detector seen in FIG. 2 and the resultant scan regions seen in FIGS. 3A to 3C.

[0066] In certain embodiments, X-ray computed tomography (CT) scanners of the present invention may be arranged to perform incremental alpha sized rotational motions in a given rotational direction about axis R in order to capture during each such alpha sized rotation a single slice data scan of an object. In certain cases, CT scanners may be arranged to repeat such alpha sized rotational motions in the same given rotational direction as indicated by the dashed arrows in FIG. 4 in order to scan additional sets of slice data of the object.

[0067] In other embodiments, X-ray computed tomography (CT) scanners of the present invention may be arranged to oscillate in such alpha sized rotational motions back and forth about axis R in order to capture subsequent sets of slice data of an object as indicated by the dotted arrows in FIG. 4. In certain cases, such back and forth oscillating rotational motions may be in different angular rotations, e.g. any multiplier of alpha (so that the back and forth oscillation can have a wider angle compared to alpha). Preferably such alpha sized rotational motions (either in the same direction or in oscillations) may be less than about 360 degrees, in order to perform scanning of slice data, and for example less than about 180 degrees possibly plus the fan angle.

[0068] Attention is drawn to FIGS. 5A to 5C illustrating a back and forth oscillating motion that may be performed in certain embodiments by an X-ray computed tomography (CT) scanner 10 such as that seen and discussed with respect to FIG. 4.

[0069] The dashed arrows on the left hand side of the figures demonstrate rotational motion of the CT scanner in a first clock-wise rotational direction from the position seen in FIG. 5A to the position seen in FIG. 5C. The dotted arrows on the right hand side of the figures demonstrate a return rotational motion of the CT scanner in a second counter clock-wise rotational direction from the position seen in FIG. 5C to the position seen in FIG. 5A. The rotational motion of the CT scanner e.g. from its state seen in FIG. 5A to the state seen in FIG. 5C may be seen as the discussed alpha sized rotational motion (see marked in FIG. 4) that is suitable for obtaining scanned slice data of an object. In non-oscillating CT scanner embodiments that repeat performing such alpha sized rotational motions in the same rotational direction, the scanner may continue to perform such alpha sized rotational motions from the position reached in FIG. 5C in the same rotational direction indicated by the dashed arrows in order to capture additional sets of slice data of the object.

[0070] Attention is drawn to FIGS. 6A to 6C showing an embodiment of an X-Ray computed tomography (CT) scanner 10 in which switching on (i.e. activation) of X-Ray tubes may be performed sequentially.

[0071] In the shown example, during each activation possibly only one X-ray source in each one of the X-ray sets may be activated at a time to form groups of tubes not necessarily belonging to the same sets that are activated substantially together. Such grouped X-ray sources that are activated substantially at the same instance are those tagged 1, 4, 7 and 10 in FIG. 6A; those tagged 2, 5, 8 and 11 in FIG. 6B; and those tagged 3, 6, 9 and 12 in FIG. 6C.

[0072] Such sequential activation of the X-ray sources may be combined with rotational motions such as those seen and discussed with respect to FIGS. 5A to 5C, i.e. with oscillating CT scanner embodiments or non-oscillating CT scanner embodiments that are arranged to rotate in the same direction in order to perform scanning.

[0073] Attention is drawn to FIG. 7 schematically showing an embodiment of an X-ray computed tomography (CT) scanner 10 generally similar to that shown and discussed with respect to FIGS. 4 to 6 but with different angular spacing's between the X-ray tubes. Detectors used within this embodiment, as aforementioned as a possibility, may be of an inverse Geometry type (i.e. detectors that are sized to be smaller than the scanners FOV).

[0074] In this CT scanner embodiment, the twelve X-Ray tubes or sources are circumferentially spaced apart one from the other by about an angular spacing A1 in this example of about 30 degrees (i.e. A1=360/12), and the four detectors are circumferentially spaced apart one from the other by about an angular spacing A2 in this example of about 90 degrees (i.e. A2=360/4)and thus slice data of an object located within FOV 14 may be obtained while performing alpha sized rotational motions of between about A1 (here about 30?) and about A2 (here about 90?) around the object.

[0075] Such arrangement of X-ray sources and detectors as seen in the presented figures, may permit achieving relative high temporal resolutions at relative low rotational motions of the CT scanner.

[0076] In order to scan e.g. a dynamic object that is located within FOV 14, such as a heart beating at a rate of about 60 BPM, a temporal resolution of about 0.2 seconds may be preferred in order to capture about 5 sets of slice data during a full cycle of the heart from end diastole to end systole and possibly back.

[0077] To achieve such a temporal resolution of about 0.2 seconds with the CT scanner shown e.g. in FIG. 7, in this example according to the number of X-Ray tubes a rotation of about 25 RPM may be sufficient (300 RPM/12=25 RPM) and according to the number detectors at rotations of about 75 RPM (300 RPM/4=75 RPM).

[0078] Attention is drawn to FIG. 8A schematically showing an embodiment of an X-ray computed tomography (CT) scanner 10 including thirty six X-Ray sources, tagged 1 to 36 and six detectors.

[0079] Such arrangement of X-ray sources and detectors as seen in FIG. 8, may permit achieving relative high temporal resolutions at even relative lower rotational motions of the CT scanner. For example, a CT scanner with a single X-ray tube with a temporal resolution of about 0.05 sec per slice data should rotate at about 1200 RPM in order to obtain such temporal resolution, while the discussed CT scanner arrangement in FIG. 8A could obtain such a similar temporal resolution of about 0.05 sec per slice data while rotating at only between about 33.3 and about 200 RPM (since 1200 RPM divided by 36 X-ray tubes?33.3 RPM and 1200 RPM divided by 6 detectors?200 RPM).

[0080] With reference to this example it may be seen that X-Ray tubes can be arranged together as sets to emit X-ray radiation towards a common similar detector with one such set being indicated and its associated detector being marked by numeral 18 in this view. The tubes forming this set are the encircled X-ray tubes tagged 27, 29, 30, 31, 32, 33 and 36. As seen in this example, some of the tubes in the set (those indicated with the dashed circles and tagged 29, 30, 31, 32, 33) may be located circumferentially adjacent one to the other, while other tubes (those indicated with the dotted circles and tagged 27, 36) may not necessarily be circumferentially adjacent to other tubes of their set. Choosing tubes not adjacent to other tubes in a similar set may assist e.g., in obtaining suitable coverage within the useful field of view of the scanner (or the like).

[0081] The table in FIG. 8B illustrates possible division of X-ray tubes into sets and groups in a CT scanner such as that shown in FIG. 8A that includes thirty six X-ray tubes. As seen in this example, each six circumferentially adjacent X-ray tubes are defined as a set, while X-ray tubes of different sets that form groups that are arranged to be activated substantially at the same instance can be seen laid out in the rows of the table.

[0082] In at least certain embodiments exhibiting CT scanning while oscillating back and forth, the x-rays and/or the detectors may be arranged to collect data only in one of the rotational directions. Thus, a non-collecting phase may be used e.g. to move the table IN (step-&-shoot)creating a combined oscillatory back and forth and table motion during e.g. the back phase. Another option may be to collect all the time during the oscillation back and forth while the table upon which patients are supported moves in to perform Whole Body Scan.

[0083] Attention is drawn to FIGS. 9A to 9C schematically showing an embodiment of an X-ray computed tomography (CT) scanner that includes eight X-ray tubes (tagged 1 to 8) and six detectors (tagged d1 to d6). In FIG. 9A all the X-ray tubes are de-activated.

[0084] In FIG. 9B a view of the CT scanner is provided where six out of the eight X-ray tubes are activated, while two of the x-ray tubes (in this example the ones tagged 4 and 7) are de-activated.

[0085] In FIG. 9C a view of the CT scanner is provided where again six out of the eight X-ray tubes are activated, while two of the x-ray tubes (this time the ones tagged 1 and 3) are de-activated. Also shown in this view is that the X-ray tube tagged 8, which previously (see FIG. 9B) emitted X-ray radiation towards detector d3, now (in FIG. 9C) has been re-directed to emit its radiation towards detector d4. Such re-direction of radiation may be accomplished in one example by controlling a collimator (see 17 in FIG. 3) associated with X-ray source 8 to direct the radiation previously emitted towards detector d3 to now be directed towards detector d4. Another example of controlling the X-Ray Tube 8 and its associated collimator to direct the radiation previously emitted towards detector d3 to now be directed towards detector d4may be by controlling the X-Ray Tube to tilt.

[0086] Attention is drawn to FIG. 10 schematically showing an embodiment of an X-ray computed tomography (CT) scanner that includes six X-ray tubes (tagged 1 to 6) and six detectors (tagged d1 to d6). Each pair of opposing X-ray tubes, e.g. 1 and 4, are arranged to provide full coverage of the useful field of view (FOV) where scanning takes place. The scanning can be performed while all six X-Ray Tubes are activated sequentially or every combination of pairs, three or all of the six at the same time.

[0087] Attention is drawn to FIG. 11 schematically showing two side by side views of an embodiment of an X-ray computed tomography (CT) scanner that includes in this example three X-ray tubes tagged 1 to 3 and an opposing detector d. It is noted that a CT scanner of this embodiment may include additional X-ray tubes and detectors as in the various embodiments disclosed herein.

[0088] In an embodiment, such CT scanner may be seen exhibiting an adaptive Field Of Viewwhere X-ray tubes may be switched on or off to control the size of the Field Of View (adaptive FOV) for example for smaller organs or people (e.g. children) being scanned.

[0089] On the right hand side of the figure, the X-ray tubes tagged 2 and 3 can be seen being switched off so that only (in this example) the central tube tagged 1 is used for directing radiation to a smaller region being scanned (here a patient's head), and by that e.g. exposure to un necessary radiation of organs that are not required to be scanned, such as shoulders of the patient, can be avoided.

[0090] The CT scanner seen in FIG. 12 illustrates an example of a scanning procedure that may be performed where different X-Ray tubes are activated with different current or voltage (power) in order to adapt the radiation to the object being scanned. In this example three X-Ray tubes and a single detector are shown, however it is noted that a CT scanner of this embodiment may include additional X-ray tubes and detectors as in the various embodiments disclosed herein.

[0091] While a regular CT scanner may use a so called Bowtie filter that is fixed and typically it is a hardware type filter in order to reduce unnecessary radiation doses to e.g. peripheries of a patient being scanned, CT scanner embodiments of the present disclosure that make use of a plurality of X-Ray tubescan be controlled to activate certain tubes with different current, e.g. lower current for lower absorption body parts and higher current for high absorption body parts to form a so-called adaptive Bowtie filter that can be controllable by software e.g. by dynamically adjusting the current supplied to each one of the X-ray tubes.

[0092] In this example, the tubes tagged 2 and 3 that capture the thinner periphery of the patient may be activated at lower current relative to the more central tube tagged 1 that emits radiation to a thicker section of the patient.

[0093] Activating X-ray tubes in lower electrical currents may also assist in avoiding saturation in the detector that receives the radiation, which may harm the scanning.

[0094] The voltage at which an X-ray tube is activated can affect the extent of penetration of radiation into the object being scanned. For example, if the portion of the object being scanned during a certain instance comprises mainly bone that is harder to penetrate (as opposed e.g. to lungs)then the voltage being used opposite the bone may be higher than that when scanning the lungs.

[0095] In an embodiment, prior taken scout views obtained for aiding in planning of a subsequent computed tomography (CT) examination, may be used for determining instances during the CT examination where certain tubes of the CT scanner may be activated at different (e.g. lower) powers as discussed.

[0096] Attention is drawn to FIG. 13 illustrating use of multiple scanning set ups of X-Ray tubes placed one aside the other along the Z direction (which may also be referred to as the R axis direction as indicated in the former figs)in order to provide a larger FOV of the patient's body while minimizing e.g. the cone beam reconstruction. In the cross sections AA and BB seen in the upper side of the figure, two exemplary scanning set ups of circumferentially spaced apart X-ray tubes (in this example each including 12 tubes) that are located about the patientcan be seen being placed one aside the other in the Z direction.

[0097] In an embodiment, axially extending detectors that extend along the Z axis may be used for receiving X-Ray radiation from X-Ray tubes of different axially adjacent setups.

[0098] In an embodiment, different tubes may be activated at different voltages in order to separate the energies and by that assist in differentiating different scanned materials and/or organs one from the other.

[0099] In the description and claims of the present application, each of the verbs, comprise include and have, and conjugates thereof, are used to indicate that the object or objects of the verb are not necessarily a complete listing of members, components, elements or parts of the subject or subjects of the verb.

[0100] Further more, while the present application or technology has been illustrated and described in detail in the drawings and foregoing description, such illustration and description are to be considered illustrative or exemplary and non-restrictive; the technology is thus not limited to the disclosed embodiments. Variations to the disclosed embodiments can be understood and effected by those skilled in the art and practicing the claimed technology, from a study of the drawings, the technology, and the appended claims.

[0101] In the claims, the word comprising does not exclude other elements or steps, and the indefinite article a or an does not exclude a plurality. A single processor or other unit may fulfill the functions of several items recited in the claims. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures can not be used to advantage.

[0102] The present technology is also understood to encompass the exact terms, features, numerical values or ranges etc., if in here such terms, features, numerical values or ranges etc. are referred to in connection with terms such as about, ca., substantially, generally, at least etc. In other words, about 3 shall also comprise 3 or substantially perpendicular shall also comprise perpendicular. Any reference signs in the claims should not be considered as limiting the scope.

[0103] Although the present embodiments have been described to a certain degree of particularity, it should be understood that various alterations and modifications could be made without departing from the scope of the invention as hereinafter claimed.