Abstract: A gel covered dental film for bettering the flavor of x-ray film includes an x-ray film slide having a first side edge, second side edge, an upper edge, and a lower edge. A gripping member is attached to the lower edge of the slide. A sleeve is extended over and is attached to the gripping member. The lower edge of the film is positionable in the sleeve when the gripping member and film are generally co-planar. A flavored gel is positioned on and generally coats the gripping member.

Abstract: A dental x-ray block to eliminate sheets of lead foil from dental x-ray film packets and to inhibit unnecessary x-ray exposure as well as backscattered reflections that can obscure x-ray images and methods of manufacturing and using the same. The dental x-ray block comprises a mouthpiece and a packet holder, which is coupled with the mouthpiece and configured to receive and engage a dental x-ray film packet. Being configured to significantly attenuate and/or absorb x-rays, an attenuation member is coupled with the dental x-ray block and is substantially in axially alignment with the dental x-ray film packet. Therefore, after the dental x-ray film packet has been exposed to a primary x-ray beam, the primary x-ray beam is significantly attenuated by the attenuation member to inhibit unnecessary x-ray exposure and secondary exposures due to backscattered reflections from obscuring x-ray images.

Abstract: A dental x-ray apparatus (10) includes a tube head (11) formed from a cast zinc material. Structural components of tube head (11) include such component (20) formed from a plastic material impregnated with a high molecular weight substance, such as barium sulfite. X-ray apparatus 10 has a control panel (15) in close proximity to the tube head (11), and is preferably DC powered.

Abstract: A receptor positioning device for taking dental bitewing radiographs of teeth inside a patient's mouth includes a rigid, fixed structure having a collimation plate defining a substantially rectangular opening. A receptor holding member is adapted to receive a receptor, and an elongated arm is adapted to receive and couple to the collimation plate. The elongated arm extends towards and couples with a rear portion of the receptor holding member, opposite the collimation plate, such that an unobstructed path is defined between the substantially rectangular opening of the collimation plate and the receptor. A biting surface is fixedly attached to a distal end of the elongated arm and adjacent to the receptor holding member such that the receptor is positioned behind the teeth on which the radiographs are being taken while the biting surface is gripped by the teeth on the opposite side of the patient's mouth.

Abstract: A dental roentgenogram film cover and method for improving the comfort of the roentgenogram are disclosed. Specifically, there is a soft porous foam envelope which eliminates patient discomfort. Uniquely, the foam envelope is coated with a flavoring material which improves patient comfort and the foam envelope can be used for multiple x-ray procedures on the same patient, thereby decreasing the cost of the procedure. The method of this invention involves placing the x-ray film into the cover. Positioning the film and cover within the mouth of a dental patient. Exposing the x-ray film to an external x-ray source. Removing the film and cover from within the mouth of a dental patient. Removing the cover from the film and reusing the cover on other x-ray film procedures as needed for the same patient.

Abstract: In a dental radiographic image acquisition and display unit, a radiographic sensor acquires a dental radiographic image generated by an X-ray emitting device, and transfers the image to a computer by means of a radio signal transmitting device, which employs an interface housed in the computer and operating to a standard commercial protocol.

Abstract: A receptor positioning device for taking dental bitewing radiographs of teeth inside a patient's mouth includes a rigid, fixed structure having a collimation plate defining a substantially rectangular opening. A receptor holding member is adapted to receive a receptor, and an elongated arm is adapted to receive and couple to the collimation plate. The elongated arm extends towards and couples with a rear portion of the receptor holding member, opposite the collimation plate, such that an unobstructed path is defined between the substantially rectangular opening of the collimation plate and the receptor. A biting surface is fixedly attached to a distal end of the elongated arm and adjacent to the receptor holding member such that the receptor is positioned behind the teeth on which the radiographs are being taken while the biting surface is gripped by the teeth on the opposite side of the patient's mouth.

Abstract: Systems and methods are described for integrating anatomical information from a plurality of sources of information. The system receives two or more three dimensional (3D) anatomical maps sharing a common plane specified by three or more marker points common to the two or more maps; and aligns the two or more 3D anatomical maps using the marker points.

Abstract: A dental imaging system and apparatus, designed for receiving dental image data and transmitting dental image data in accordance with the IEEE 1394 protocol is disclosed. A digital image integration device is configured to (a) receive dental image data from any or all of a plurality of dental image recording devices, each of which is configured to record and output image data, and to (b) transmit digital image data, via a plurality of IEEE 1394 connectors, to any or all of a plurality of digital image receiving devices via the IEEE 1394 protocol At least one of the image recording devices is a single frame image recording device, preferably a filmless radiography sensor. The plurality of dental image recording devices further preferably includes an intraoral video camera configured to record and transmit intraoral video images. In addition, the plurality of digital image receiving devices preferably comprises at least one image display device.

Abstract: The film holder for dental technique comprises a bite portion (4) and an approximately U-shaped film clip (5) including an oral (6) and a facial (7) plate. For a safe retention also of thin digital picture plates or of films and picture plates having an uneven topography without damaging their sensitive surfaces, the facial plate (7) is provided with means allowing to obtain a pressure distribution adapted to different thicknesses and/or topographies of films or digital picture plates.

Abstract: An imaging plate guide formed in different configurations corresponding to the various intraoral dental plate sizes, which in turn correspond to the dental intraoral film sizes commonly referred to as sizes 0 through 4, the imaging plate guides dedicated to intraoral imaging providing for guides for each plate size so that a desired array of feed width guides can be positioned on the scanner for scanning the intraoral plates and which scan extraoral imaging plates as well. The embodiment of the imaging plate guides provides not only for interchangeability with respect to the intraoral plate size, but also allows for the feeding of extraoral imaging plates without the need to remove the intraoral plate guides. The size 4 is not specifically described, but is analogous to the other sizes as would be obvious to one skilled in the art.

Abstract: A dental x-ray bite block (10) for securing an x-ray sensor (40) has a first block section (11) having a primary clamp face (17) and a second block section (12) having a secondary clamp face (23). The first block section (11) is configured with receiving means (41) to receive the second block section (12), such that the primary and the secondary clamp faces (17,23) are positioned in a spaced, opposing relation when the second block section (12) is received within the first block section (11). There is also stepped rachet members (50, 51) for affixing the position of the second block section (12) relative to the first block section (11) when received therein.

Abstract: A radiographic bitewing for determining the depth for a dental implant comprising a patient bite portion and an extension portion, wherein said bite portion is adapted for placement between a patient's upper row of teeth and lower row of teeth, and wherein said extension portion is aligned in a substantially perpendicular position relative to said bite portion and comprises at least one radio-opaque calibration template, wherein said calibration template comprises a first vertical bar having a first dimension, a second vertical bar having a second dimension, a third vertical bar having a third dimension, and a fourth vertical bar having a fourth dimension.

Abstract: A holder for a sensor used in dental radiography is provided having an ultra-thin bite wing and a reinforced juncture between the bite wing and the integral sleeve such that a perpendicular orientation is maintained while the sensor is in the patient's mouth. The dimensions of the present invention allow the patient's teeth to be in close proximity while an image is formed using the sensor, and the disposable sensor provides a mechanism for indicating a previous use to ensure single use. The holder is formed using an injection molding process of polyethylene of 40 to 80 melt flow, with a preferred melt flow of 60. The thin bite wing is enabled because of a reinforced T-joint at the base of the sleeve along the spine connecting the bite wing, which maintains the sleeve and the holder in a perpendicular orientation with respect to the plane formed by the upper and lower surfaces of the mating teeth.

Abstract: The invention relates to a method for performing X-ray imaging in intraoral application. The method comprises irradiation of an object with a substantially low amount of X-radiation, and a substantially low amount of X-radiation passed through the object is received. The method comprises compiling a sample of image data from the received, substantially low amount of X-radiation.

Abstract: A device for determining exposure values in an X-ray panoramic and/or cephalometric apparatus (20) for imaging patient's head (3). The apparatus comprises adjustable support means (11) provided with support elements (1a, 1b) with a variable spacing (W1) therebetween, and said support means being adapted for positioning against the patient's head prior to exposure. A sensor (2) is connected to said support elements and it provides an electrical output proportional to the dimension (W2) of the patient's head therebetween. An exposure control means (10) adjust the tube current and/or the tube voltage of the X-ray tube and/or the exposure time to be at one of a plurality of predetermined levels.

Abstract: An intraoral x-ray film packet is taught which includes compounding flavor/scent chemistry into a thermoplastic material. The thermoplastic material is then used to form a molded thermoplastic frame (preferably injection molded) thereby providing an intraoral radiographic film packet which has a comfort enhancing perimetric edge which is preferably permanently integrated therewith during manufacture. The comfort of the intraoral radiographic film packet is augmented through the addition of pleasing flavors and/or scents incorporated into the thermoplastic material. This flavor and/or scent can be fully compounded into the comfort edge thermoplastic materials as noted above, or alternatively, it can be compounded directly into the thermoplastic materials used to produce the packet layers prior to film insertion and thermal seal.

Abstract: An X-ray film development device performs development, fixing, rinsing, and drying processes while transporting an exposed X-ray film. A rinsing unit is provided with a light source, which illuminates the X-ray film during transportation, and a reading unit, which receives the passing light and reads an image recorded on the X-ray film. The image signal from the reading unit is processed by a display device (CRT, LCD, etc.), and the film image can be provided to the doctor or patient without waiting until the film dries.

Abstract: A dental x-ray bite block (10) for securing an x-ray sensor (40) has a first block section (11) having a primary clamp face (17) and a second block section (12) having a secondary clamp face (23). The first block section (11) is configured with receiving means (41) to receive the second block section (12), such that the primary and said secondary clamp faces (17, 23) are positioned in a spaced, opposing relation when the second block section (12) is received within the first block section (11). There is also an adjustable securing means (50, 51) for affixing the position of the second block section (12) relative to said first block section (11) when received therein.

Abstract: In a method for imaging in digital dental radioscopy making use of a sensor array, the individual image elements of which are smaller than a desired local resolution so that a plurality of image elements forms a respective effective image element, first reference signals, which are generated by the image elements of the sensor array when said sensor array is not exposed to X-radiation, are initially detected. In addition, second reference signals, which are generated by the image elements of the sensor array when said sensor array is exposed to X-radiation, are detected. Subsequently, defective image elements are determined on the basis of the detected first and second reference signals, whereupon an image of an object is produced using exclusively the image elements that have been determined as being non-defective.

Abstract: A cushion attached to the edge of a hard film container for dental X-rays to reduce the pain of contact with dental tissue. The cushion is a foam, and flavoring can be applied to it.

Abstract: The film holder for dental technique comprises a bite portion (4) and an approximately U-shaped film clip (5) including an oral (6) and a facial (7) plate. For a safe retention also of thin digital picture plates or of films and picture plates having an uneven topography without damaging their sensitive surfaces, the facial plate (7) is provided with means allowing to obtain a pressure distribution adapted to different thicknesses and/or topographies of films or digital picture plates.

Abstract: An intraoral x-ray film packet is taught which has an outer envelope wherein one of the two opposing outer sheets is more rigid than the other and serves as a stiffening sheet such that it has a tensile modulus of at least about 700 Kg/cm2. This is preferably accomplished by making both sheets from a thermoplastic material such as PVC and reducing the amount of plasticizer in the more rigid of the two sheets to less than 30%. A continuous perimetric seal is formed affixing the two outer sheets together and forming a perimetric laminated edge which is substantially coplanar with the more rigid of the two sheets. A film chip resides between the two outer sheets. The coplanar perimetric laminated edge and the added rigidity aid in improving accurate sizing of each individual packet and prevention of deflection of the marginal area of individual packets in subsequent operations.

Abstract: A holder for a dental X-ray image sensor is provided which enables adjustment of the position of the sensor after placement of the holder and sensor in the mouth. A flexible, deformable or elastic loop holds the sensor in place but enables manipulation of the sensor position. The elastic loop is connected to a handle member. A slot also is provided in the handle for accommodating wire leads connected to the sensor.

Abstract: An intraoral x-ray film packet is taught which includes an integrally formed comfort enhancing perimetric bracket. The packet comprises a pair of opposing outer sheets and a continuous enclosing seal bonding the two outer sheets together to form an envelope with a perimetric projection with a film chip residing in the envelope. The perimetric projection is folded over and affixed to the packet to form an integral perimetric bracket with a rounded or creased perimetric edge.

Abstract: An apparatus and method used in dental transversal x-ray tomography provides off-line alignment of the patient denture impression with the bite block of a panoramic x-ray equipment, and allows accurate and reproducible patient positioning during the imaging process. An impression of the patient denture is taken on a special tray. The tray is mounted on the alignment apparatus and is aligned by using optical marking in correspondence with the target zone. The alignment apparatus is then mounted on a panoramic x-ray equipment, and the patient is invited to bite on the tray during the imaging process.

Abstract: A holder for a dental X-ray image receptor is provided which enables adjustment of the position of the receptor after placement of the holder and receptor in the mouth. A flexible, deformable or elastic loop holds the sensor in place but enables manipulation of the sensor position. The elastic loop is connected to a handle member. A slot also is provided in the handle for accommodating wire leads connected to the receptor or sensor.

Abstract: A reusable bite block/film packet holder is taught which includes comfort enhancing features for holding intraoral radiographic film packets therein and for proper positioning in a patient's mouth. The bite block/film packet holder includes a bite-block and a support bracket extending at an angle of about 90° from the bite-block. There is a slot in the bite-block immediately adjacent the support bracket for engaging an edge of an intraoral film packet inserted therein. A perimetric border at the peripheral edge of the support bracket has a generally rounded cross-sectional configuration and extends beyond the dimensions of the intraoral film packet inserted in the slot. Thus, the sharp, die-cut edges of the film packet are prevented from uncomfortably engaging the soft/sensitive tissues of a patient's mouth. Rather the rounded, soft-feeling perimetric border of the bite block/film packet holder is the contacting element.

Abstract: A device for determining exposure values in an X-ray panoramic and/or cephalometric apparatus (20) for imaging patient's head (3). The apparatus comprises adjustable support means (11) provided with support elements (1a, 1b) with a variable spacing (W1) therebetween, and said support means being adapted for positioning against the patient's head prior to exposure. A sensor (2) is connected to said support elements and it provides an electrical output proportional to the dimension (W2) of the patient's head therebetween. An exposure control means (10) adjust the tube current and/or the tube voltage of the X-ray tube and/or the exposure time to be at one of a plurality of predetermined levels.

Abstract: A dental bite block (20) and sensor holder (21) assembly (11) has a bite block (20) configured (31) to detachably affix to a sensor holder (21). Affixing surfaces (30, 31) are provided between the bite block (20) and the sensor holder (21) such that the sensor holder (21) is removably affixed to the bite block (20).

Abstract: A dental roentgenogram film cover and method for improving the comfort of the roentgenogram are disclosed. One skilled in the art will appreciate the advantages of the roentgenographic film cover. Specifically, there is a soft porous foam envelope which eliminates patient discomfort. Uniquely, the foam envelope is coated with a flavoring material which improves patient comfort and the foam envelope can be used for multiple x-ray procedures on the same patient, thereby decreasing the cost of the procedure. The method of this invention involves placing the x-ray film into the cover. Positioning the film and cover within the mouth of a dental patient. Exposing the x-ray film to an external x-ray source. Removing the film and cover from within the mouth of a dental patient, Removing the cover from the film and reusing the cover on other x-ray film procedures as needed for the same patient.

Abstract: A container for an imaging plate includes a sealable envelope, in which the plate is inserted, and one or more flaps, fixed to the envelope, which are closed by an operator so as to seal the plate inside the envelope. The flaps are then pulled open by the operator in order to release the plate from the envelope substantially without physical contact by the operator with the plate. Typically, the flaps are folded over the envelope and fixed one to another, creating a fold that seals the envelope shut.

Abstract: A reusable comfort enhancing frame for holding an intraoral x-ray film packet is taught which includes four integrally formed side members with a single contiguous perimetric contact surface having a generally rounded cross-sectional configuration and rounded comers. There is a pocket formed in the four integrally formed side members adapted to have the intraoral x-ray film packet inserted and retained therein, and removed therefrom. In one embodiment, there is a slot in one of the four integrally formed side members through which the intraoral x-ray film packet can be inserted to reside in the pocket. In a second embodiment, the pocket is a snap-in pocket comprising at least one lip element projecting from an interior peripheral wall of the four integrally formed side members and at least two snap-fit elements also projecting the interior peripheral wall of the four integrally formed side members.

Abstract: An intraoral x-ray film packet is taught which includes a perimetric comfort enhancing feature. The intraoral x-ray film packet includes an envelope formed by a first outer sheet having a first generally semicylindrical perimetric element formed therein; a second outer sheet including a second generally semicylindrical perimetric element formed therein, the first and second generally semicylindrical perimetric elements forming a perimetric cushion; and a pair of continuous perimetric seals affixing the first and second outer sheets together, one perimetric seal residing on each side of the perimetric cushion. The packet also includes a film chip residing between the first and second outer sheets. The second outer sheet includes a pair of overlapping sections which are sealed together to form a tab portion to facilitate removal of the envelope after exposure.

Abstract: A radio therapy system includes measuring an actual position of a micro-radiation source and radiation dose actually generated from the source, at predetermined times, during a therapeutic treatment. An accumulative radiation dose distribution is constantly generated in realtime, during the treatment, from the actually measured position and radiation dose and reference radiation dose distribution. An operator can monitor, in realtime, how the radiation dose distribution is developed, temporally, during the treatment. As a result, it is possible to irradiate a lesion with a requisite dose of radiation, minimize any un-required irradiation to a normal area around the lesion and achieve a therapeutic treatment with high precision.

Abstract: Dental sensors receive X-rays and transmit signals showing the condition of a patients's teeth to a computer or other recorder, thereby replacing X-ray film packets. Such sensors vary in dimensions. Holders are provided which accommodate such variations. Thus, a clasp engaging one edge of a sensor is adjustably movable to cause a fixed portion of the holder to engage the opposite edge of the sensor. Interfitting ratchet teeth on clasp and holder retain the parts in the required position. The holder assists in properly and rapidly locating the sensor relative to the teeth being examined. For certain usages a bite block holds the patient's jaws apart. The sides of the bite blocks are non-parallel, thereby reducing the shadows of such sides on the X-ray usage.

Abstract: An improved dental x-ray aiming device for longitudinal radiographic analysis is provided. The device includes a bite block, a guiding rod, an aiming ring, and a supplemental ring. The bite block includes a film holder that is not perpendicular to a top surface of the bite block. The guiding rod is also attached to the bite block in a non-parallel relationship to accommodate the non-perpendicular arrangement of the film holder. As a result, a proper relationship is maintained between the aiming ring (and hence a dental radiography device) and the film holder. The aiming ring is attached to the guiding rod through a sliding member. The sliding member secures the aiming ring at a predetermined distance from the guiding rod, while allowing the aiming ring to move on an axis parallel with the guiding rod. The bite block includes a slot for receiving and holding a reference device for later density reference measurements.

Abstract: A ring shaped to fit over the nose of a dental X-Ray machine cone locates the cone relative to selected teeth of the patent. The ring is mounted on an arm having a clip which fits over a hub to oscillate to different positions. The hub is a part of the handle for a locator for an X-Ray film packet or an X-Ray electronic sensor.

Abstract: The Comfort Guard is made of a soft material that covers the stiff, slender and sharp edges of an intraoral x-ray film, during dental x-ray exposures. After the intraoral x-ray film is inserted or affixed into the Comfort Guard, the guard is positioned in the patient's mouth in between the teeth and tongue. Therefore, the film's edges will not be in direct contact with the patient's mouth or oral tissue. The patient can compress the handle with their anterior teeth, allowing the patient to become involved in securing the film in their mouth.

Abstract: A phosphor, an optical fiber plate containing lead particles, a CCD, and an X-ray shielding member consisting of copper tungsten are sequentially stacked on a substrate from an X-ray incident surface side and sealed in a container made of a light-shielding synthetic resin. The substrate has projecting portions projecting toward the direction of X-ray incident along three sides of the X-ray incident surface. Each of these projecting portions has an overhang portion projecting toward the optical fiber plate. The overhang portions are close to or in contact with corresponding side surfaces of the optical fiber plate so that the optical fiber plate is fixed at a predetermined position. The container has, in the inner surface, convex portions corresponding to the projecting portions, so the substrate is fixed in the container.

Abstract: Color coding the components of a dental positioner, including an aiming ring, a bite block and an indicator arm allows the operator to assemble the correct positioner for proper positioning and alignment according to a particular dental area to be X-rayed. The color coding corresponds to different dental areas including the anterior and posterior dental areas. For coronal areas, a bite-wing block is provided which also may be in the color coded.

Abstract: Direct X-ray films are disclosed capable of being handled in room light prior to and during processing. The films contain silver halide grains responsive to X-radiation that are sulfur sensitized. The films also contain a combination of processing solution bleachable dyes chosen to provide prior to processing (a) an average density of greater than 3.0 over a first, continuous spectral sensitivity range extending from a minimum wavlength of 320 nm over which the silver halide grains exhibit an absorption coefficient of at least 0.5 cm.sup.-1 and (b) a density of greater than 3.0 throughout a second spectral range including wavelengths of from 600 to 650 nm.

Abstract: A ring is shaped to fit over the nose of a dental x-ray machine to direct the x-rays to the desired portions of the patient's mouth. Known film retainers which support x-ray film packets at the desired location behind the gums have handles which extend outside the mouth. The ring has adjustable means to fit onto the handle to adjust the position of the ring relative to the film both angularly and distance-wise. An adapter may be used to connect the ring to the handle of the retainer. Alternatively, the handle may slide through an aperture in a tab fixed to the ring.

Abstract: A dental X-ray film structure includes a dental X-ray film packet in combination with a strip of soft, flexible cushion material. The strip moisture resistant includes a first portion adhered in partially overlapping engagement with a corresponding portion of one of the film packet surfaces along a selected edge of the packet, and a second portion contiguous with the first portion which extends outside the perimeter of the packet. The second portion serves to cushion the selected edge when the packet is positioned within the mouth of a dental patient for taking a dental X-ray. To completely cover the selected edge, the strip may include a third portion which is contiguous with the second portion, and which is adhered in partially overlapping engagement with a corresponding portion of the film packet surface opposite to the surface to which the first portion is adhered.

Abstract: A novel x-ray image receptor holder physically links to the collimated tube of a lightweight, portable and preferably hand-held X-ray generator for use in intraoral and other X-ray applications. The image receptor holder has a horizontal member with a vertical member attached to the distal end of the horizontal member. The image receptor is held between the vertical member and a sliding member which is also mounted on the horizontal member.

Abstract: Intraoral dental radiography based on X-ray photography. The radiography is performed with either a conventional film or a picture plate, in which case the dimensions of the picture may be corrected by means of a computer program while viewing the picture on a monitor. Problems caused by a shallow palate because of the oblique position of the film holder may thus be eliminated, and the top of the roots of the tooth is also visible in the picture. The picture plate or film holder used in the method comprises three interlinked parts, namely a film holder, a bite portion, and an alignment rod, and one sliding part, i.e. the positioning block.

Abstract: A film positioning system for dental X-ray and digital radiography procedures including a number of film or digital sensor carriers (bite wing, anterior, etc) each including a film or sensor holder on one end and an extending attachment rod, and an X-ray tube aiming device including an attachment rod holder, the attachment rod and the attachment rod holder keyed to correctly align the film holder with respect to an X-ray cone or tube. One example includes a non-equilateral pentagon shaped rod holder receptacle and a non-equilateral pentagon shaped attachment rod.

Abstract: The invention is an apparatus for use in serial radiography which provides replicable projection geometry between an energy source, an intraoral target area, and an image receptor. The device uses a biting surface bearing the impressions of a patient's tooth surfaces and an alignment arm which terminates in an alignment ring. The alignment ring is received by a sensor ring affixed to an x-ray source to provide proper projection geometry. Sensors in communication with electronic means may be disposed about the sensor ring to indicate proper alignment. The biting surface may comprise an acrylic stent or a platform supporting a quantity of an impressionable material.

Abstract: A radiographic film retaining device for holding a film packet while producing a radiographic image of selected teeth of a patient's mouth is disclosed. The retaining device includes a substantially thin bite portion configured for placement between upper and lower teeth of the patient's mouth and a retaining structure positioned distally of the bite portion. The retaining structure has a film packet gripping structure for holding the film packet lingually adjacent the selected teeth when the bite portion is gripped between the upper and lower teeth. The retaining structure comprises a narrow extension of the bite portion. The film packet gripping structure includes a slit formed and extending through the retaining structure from the distal end thereof toward the bite portion. The device also has means for locating an x-ray machine cone in proper position relative to the film packet.

Abstract: The invention is an apparatus for use in serial radiography which provides replicable projection geometry between an energy source, an intraoral target area, and an image receptor. The device uses a stent and an alignment arm which terminates in an alignment ring. The alignment ring is received by a sensor ring affixed to an x-ray source to provide proper projection geometry. Sensors in communication with electronic means may be disposed about the sensor ring to indicate proper alignment.