Abstract: An interface module to connect a collimator to an X-ray generator, includes: a base plate, which forms a support area for an X-ray tube unit flange of the X-ray generator; an adjustment plate, which is rotatably connected to the base plate; and at least one swivel element movably connected to the base plate and adjustment plate such that, upon rotation of the adjustment plate, the at least one swivel element pivots between a clamping position and an open position.

Abstract: A multileaf collimator includes a plurality of movable leaves for shaping a radiotherapy beam, wherein each leaf is independently movable in a same linear travel direction. Each leaf includes a linear array of magnets disposed on a measurement surface of the leaf and an array of magnetoresistive sensors that is disposed proximate the measurement surfaces of the leaves.

Abstract: A multileaf collimator includes a plurality of movable leaves for shaping a radiotherapy beam, wherein each leaf is independently movable in a same linear travel direction. Each leaf includes a linear array of magnets disposed on a measurement surface of the leaf and an array of magnetoresistive sensors that is disposed proximate the measurement surfaces of the leaves.

Abstract: A real-time fluoroscopic imaging system includes a collimator and a detector which are rotationally movable independent of the support assembly, e.g., c-arm, to which they are mounted. Rotational movement of the collimator and the detector are coordinated such that the orientation of the detector with respect to the collimator does not change. The collimator may include a geared flange member to facilitate rotation, and may be a single molded piece formed of a plastic such as tungsten polymer material. The system may also include a plurality of interchangeable collimators characterized by different shapes. A display is provided to present an image to an operator, and image orientation logic displays a target anatomy in a selected orientation regardless of orientation of the target anatomy relative to the detector, and regardless of rotation of the detector.

Abstract: A real-time fluoroscopic imaging system includes a collimator and a detector which are rotationally movable independent of the support assembly, e.g., c-arm, to which they are mounted. Rotational movement of the collimator and the detector are coordinated such that the orientation of the detector with respect to the collimator does not change. The collimator may include a geared flange member to facilitate rotation, and may be a single molded piece formed of a plastic such as tungsten polymer material. The system may also include a plurality of interchangeable collimators characterized by different shapes. A display is provided to present an image to an operator, and image orientation logic displays a target anatomy in a selected orientation regardless of orientation of the target anatomy relative to the detector, and regardless of rotation of the detector.

Abstract: An apparatus including a scintillator arrangement including a plurality of optically isolated scintillators that extend lengthwise along a plurality of respective parallel axes and define respective scintillation channels, wherein each of the optically isolated scintillators extends lengthwise between an input interface and an output interface and is arranged to receive higher energy photons at the input interface, to convert high energy photons to lower energy photons, and to output lower energy photons from the output interface in a respective scintillation channel, wherein the optical isolation reduces transmission of lower energy photons between scintillation channels.

Abstract: The invention discloses a grating device for radiotherapy equipment. A tail-end position controller and a front-end position controller are simultaneously arranged, and can simultaneously verify a tail-end position and a middle position of each single grating blade and measure the time during which one grating blade arrives at the middle position from the tail-end position and/or the total number of revolutions of a motor at any time.

Abstract: A medical image capturing apparatus according to an embodiment includes image generation circuitry, detection circuitry, diagnosis support processing circuitry, setting circuitry, and imaging control circuitry. The image generation circuitry generates image data of a subject. The detection circuitry detects each of a plurality of parts of the subject in the image data generated as a positioning image. The diagnosis support processing circuitry executes diagnosis support processing corresponding to a predetermined part with regard to a region corresponding to the predetermined part of the subject detected. The setting circuitry sets an imaging condition of main imaging with respect to a part in which a lesion site is specified as a processing result of the diagnosis support processing. The imaging control circuitry controls an imaging mechanism to perform imaging with regard to an imaging region including the part in which the lesion site is specified based on the imaging condition.

Abstract: The present invention relates to automatic absorption means positioning in X-ray image acquisition. To improve image quality and to optimize the radiation exposure of an object, optimal position for X-ray absorption means is provided. A first sequence (113) of X-ray images is acquired (112). For each of the images, the optimal position (115) for X-ray absorption means is determined (114). A second sequence (117) of X-ray images is associated 10 (116) with corresponding images of the first sequence. The determined optimal position for the absorption means (14) of the associated corresponding images of the first sequence (113) is selected for an acquisition of the second sequence (117). Hence, a situation-specific database with optimized positions for the absorption means is generated on behalf of the first sequence in order to provide the generated position information for the actual acquisition of a 15 second sequence of images.

Abstract: Motion artifacts are suppressed for three-dimensional parametric ultrasound imaging. Motion tracking is performed so that the parameter values derived over time are based on return from the same locations. Distortion due to the scan pattern is accounted for in the results of the motion tracking, such as by re-sampling the results to deal with discontinuity in time between data from adjacent sub-volumes and/or by aligning the scan pattern based on a direction of motion.

Abstract: A radiation emitting apparatus includes a radiation source to generate radiation, a first collimator to define a maximum radiation field of the radiation; a second collimator to regulate the radiation field and direction of irradiation; a swing portion that swings in two directions orthogonal to each other; a displacement detector to detect displacement of the second collimator relative to a reference point; a drive mechanism to drive the swing portion; a control unit to control the drive mechanism; and a storage unit included in the control unit to store one or more parameters related to mechanical movement of the swing portion. The control unit generates feedforward control information based on an inputted target swing angle, a detected displacement, and the one or more parameters stored in the storage unit, and outputs a drive signal containing the feedforward control information to the drive mechanism.

Abstract: To overcome the difficulties inherent in conventional proton therapy systems, new techniques are described herein for synchronizing the application of proton radiation with the periodic movement of a target area. In an embodiment, a method is provided that combines multiple rescans of a spot scanning proton beam while monitoring the periodic motion of the target area, and aligning the applications of the proton beam with parameters of the periodic motion. For example, the direction(s) and frequency of the periodic motion may be monitored, and the timing, dose rate, and/or scanning direction and spot sequence of the beam can be adjusted to align with phases in the periodic motion.

Abstract: The present invention pertains to a system and method for adaptive X-ray filtration comprising a volume of X-ray attenuating material with a central less attenuating three-dimensional region. The volume of X-ray attenuating material can be positioned within 10 cm from an X-ray source and rotated around an internal axis of rotation. The volume of X-ray attenuating material can be symmetric around the internal axis while the central less attenuating region can be asymmetric around the internal axis. Rotating the volume by a predetermined angle around the internal axis can change the amount of attenuation of an X-ray beam through the filter. The volume can be rotated by the same predetermined angle as an imaging subject or X-ray source and detector are rotated during X-ray image acquisition.

Abstract: Methods for delivering radiation dose to a target area within a subject comprise: defining a trajectory comprising relative movement between a treatment radiation source and the subject and determining a radiation delivery plan; and, while effecting relative movement between the treatment radiation source and the subject along the trajectory, delivering a treatment radiation beam from the treatment radiation source to the subject according to the radiation delivery plan to impart a dose distribution on the subject. Delivering the treatment radiation beam from the treatment radiation source to the subject comprises varying an intensity of the treatment radiation beam over at least a portion of the trajectory. Varying the intensity of the treatment radiation beam comprises varying a radiation output rate of the treatment radiation source in accordance with the radiation delivery plan while effecting relative movement between the treatment radiation source and the subject along the trajectory.

Abstract: The disclosure provides a radiographic apparatus that allows suppression of needles radiation exposure to a subject. Specifically, the disclosure includes an X-ray tube, a collimator, and a visible light source. The spread of visible light beams through the collimator opening too largely may not possibly conform to the spread of radiation. Such a situation may occur when the apparatus is provided with the X-ray tube that emits narrow radiation. In order to avoid such a situation, the disclosure sets an upper limit of a degree of opening as an upper limit of a degree of opening of the collimator. With a construction of the disclosure, there is no need to perform further radiography. This achieves the radiographic apparatus that allows suppression of needless radiation exposure to a subject.

Abstract: An automatic collimator adjustment device and method for medical treatment equipment are disclosed. The medical treatment equipment includes an automatic collimator adjustment device, which includes a processor unit, a depth camera, and a collimator control device. The processor unit receives an instant image pixel depth signal acquired by the depth camera to compare with a predetermined image pixel depth signal of a predetermined human body portion of a target human body in order to generate at least one collimator adjustment signal to the collimator control device, so that the collimator control device controls the collimator to adjust the X-ray beam to align with the predetermined human body portion of the target human body.

Abstract: Methods of projecting an image onto a patient to aid delivery of proton therapy, including capturing a first image of a patient's treatment volume, processing the image to generate a treatment volume image corresponding to at least a portion of the treatment volume, generating a scan pattern to deliver a particle beamline to at least a portion of the treatment volume, projecting the treatment volume image and the scan pattern onto the skin of the patient proximate the treatment volume, and delivering the particle beamline to at least a portion of the treatment volume to match dimensions of the treatment volume image and the scan pattern.

Abstract: A multi-leaf collimator with electromagnetically actuated leaves. The multi-leaf collimator includes a plurality of leaves, a leaf guide configured to support the plurality of leaves, and a plurality of magnets. Each leaf includes a blocking portion that is radio opaque, a drive portion connected to the blocking portion, and a coil embedded in the drive portion. The coil is operatively connected to an electrical current source to generate a first magnetic field. The first magnetic field interacts with the magnetic field generated by the magnet to thereby move the leave to a desired state. The leaves have the capability of moving at speeds of 50 cm/s up to and higher than 1 m/s.

Abstract: According to an X-ray imaging device for performing CT imaging, a main body control section controls at least one of an X-ray revolution plane formed by an X-ray cone beam along with the revolution of a revolving arm and a revolution range of the revolving arm in accordance with a CT imaging area accepted by an imaging area setting screen. Such control is performed in order to decrease X-ray radiation to a high sensitivity site in the area that revolves during the CT imaging, the high sensitivity site being positionally set in a biological body as a site that is sensitive to X-rays.

Abstract: A mobile digital fluoroscopy system comprises either a G-arm (18) stand (1) having two X-ray beam transmitter (21,23)/receiver (22,24) pairs arranged at right angles to each other or a C-arm having a single transmitter/receiver pair. Protective collimator shutter plates (1060) at each transmitter limit the X-ray irradiation area. These collimator plates are properly adjusted via servo motors prior to or during the operation, by fingertip movements, touching collimator representations on a touchscreen for each transmitter/receiver pair, to provide both protection to the surgeon and patient and sufficient fluoroscopic view to the surgeon of the operation site of interest in the body.

Abstract: A variable mode X-ray transmission system is provided that can be operated in low or high dose rate modes depending upon the area or portion of the vehicle to be screened. In one embodiment, variable dose rate is achieved by use of a novel collimator. The systems disclosed in this application enable the scanning of a vehicle cab portion (occupied by people, such as a driver) at low dose rate, which is safe for human beings, while allowing the scanning of the cargo portion (unoccupied by people) at a high dose rate. Rapid switching from low dose rate to high dose rate operating mode is provided, while striking a balance between high material penetration for cargo portion and low intensity exposure that is safe for occupants in the cab portion of the inspected vehicle.

Abstract: A medical imaging system adaptively acquires anatomical images using a shape adaptive collimator including multiple different portions of X-ray absorbent material automatically adjustable to alter the dimensions of a spatial cross section of an X-ray beam of radiation into a non-rectangular shape, in response to a control signal. The synchronization processor provides a heart rate related synchronization signal derived from a patient cardiac function related parameter. The synchronization signal enables adaptive variation in timing of image acquisition within an individual heart cycle and between successive heart cycles of each individual image frame of multiple sequential image frames. The X-ray image acquisition device uses the shape adaptive collimator for acquiring anatomical images of the region of interest with reduced patient X-ray exposure in response to the synchronization signal. A display processor presents resultant images.

Abstract: A method of multileaf collimator (MLC) leaf positioning in tracking-based adaptive radiotherapy is provided. The method includes determining a radiotherapy beam pattern by transforming a treatment beam plan into radiotherapy beam coordinates, determining a dose discrepancy between the radiotherapy beam pattern and a deliverable MLC aperture, where the dose discrepancy includes a sum of an overdose cost and an underdose cost to a treatment volume, and minimizing the dose discrepancy, where the dose discrepancy minimization provides a determined deliverable MLC aperture for the radiotherapy beam.

Abstract: A radiographic image capturing device includes a capturing unit that captures a radiographic image based on radiation (for example, X-rays) which penetrates through an object. A system control section extracts one still image from the radiographic image that is captured by the capturing unit, and displays the extracted still image on a second display section of a graphical user interface. The system control section displays a mark on a predetermined portion, which corresponds to a portion to be subjected to surgery, of the still image that is displayed on the second display section. When the mark that is displayed on the still image is selected, the system control section performs control of capturing an image of a corresponding portion of the object that corresponds to the predetermined portion using the capturing unit.

Abstract: An X-ray collimator for controlling an X-ray radiation field, having a lower base member, a pair of regulating members, a pair of surrounding members having substantially U-shaped forms in planar view, N columnar members surrounded by the pair of surrounding members (where N is 4, 6, or 8), a guiding member, a pair of moving members moving parallel to the opposed surfaces of the regulating members, an upper base member, a first motor for horizontally moving the pair of moving members, and a second motor for moving the columnar members. The first motor is driven to horizontally move the pair of moving members over the same distance in opposite directions. The second motor is configured to move one of the columnar members along an internal surface of the surrounding member surrounding the columnar member, thereby moving the other N?1 columnar members sequentially.

Abstract: In one embodiment, a system for aligning collimators in an imaging system includes a transmitter coupled to a first detector and configured to transmit a beam, and a receiver coupled to a second detector and configured to receive the beam transmitted from the first detector. The alignment system also includes a cart comprising an alignment device with the cart configured to hold at least two collimators. The system includes a control system configured to align the first and second detectors with the at least two collimators using the alignment device.

Abstract: A radiotherapy device includes a therapeutic radiation source for providing a beam for irradiating a moving target volume and a beam correcting apparatus for directing the beam onto the target volume. The beam correcting apparatus includes a collimator having a collimator aperture for delimiting the beam, a positioning apparatus for positioning the target volume relative to the beam, and a controller for selecting a position of the collimator aperture relative to the beam and for selecting a position of the positioning apparatus such that when the beam is correctively adjusted, the movement of the target volume in a first movement direction is compensated for by displacing the collimator aperture, and the movement of the target volume in a second movement direction is compensated for by repositioning the target volume with the positioning apparatus.

Abstract: In a radiographic image capturing apparatus, a biopsy region positional information calculator calculates a three-dimensional position of a biopsy region in an object to be examined based on two radiographic images which are acquired in a stereographic image capturing process, an irradiated field calculator calculates a new irradiated field covering the biopsy region based on the calculated three-dimensional position of the biopsy region and two angles at which a radiation source is disposed in the stereographic image capturing process, and a collimator controller controls a collimator to change the irradiated field of the radiation to the new irradiated field in a next stereographic image capturing process.

Abstract: A variable mode X-ray transmission system is provided that can be operated in low or high dose rate modes depending upon the area or portion of the vehicle to be screened. In one embodiment, variable dose rate is achieved by use of a novel collimator. The systems disclosed in this application enable the scanning of a vehicle cab portion (occupied by people, such as a driver) at low dose rate, which is safe for human beings, while allowing the scanning of the cargo portion (unoccupied by people) at a high dose rate. Rapid switching from low dose rate to high dose rate operating mode is provided, while striking a balance between high material penetration for cargo portion and low intensity exposure that is safe for occupants in the cab portion of the inspected vehicle.

Abstract: An adjustable collimator for shaping a beam of particles, such as for purposes of inspecting contents of a container. The adjustable collimator has an obscuring element substantially opaque to passage of the particles in a propagation direction that is radial with respect to the axis of rotation of a ring of apertures. A gap in the obscuring element may be characterized by a length taken along a long dimension and a jaw spacing taken along narrow dimension, and at least one of the length of the gap and the jaw spacing is subject to adjustment, either manual or automatic. The adjustable collimator may be disposed either inside or outside the ring of apertures, and, in some embodiments, the jaw spacing may be a function of distance along the long dimension relative to an edge of the gap.

Abstract: Multi-leaf collimators have a guide frame (1) with a plurality of metal plates (3) arranged in a displaceable fashion, by which each individual metal plate can be displaced by an electric motor (M), with the electric motor (M) being a rotary electromechanical motor (M), which operates according to the form-fit principle, with electromechanical actuators.

Abstract: A radiosurgery system is described that is configured to deliver a therapeutic dose of radiation to a target structure in a patient. In some embodiments, inflammatory ocular disorders are treated, specifically macular degeneration. In some embodiments, other disorders or tissues of a body are treated with the dose of radiation. In some embodiments, the target tissues are placed in a global coordinate system based on ocular imaging. In some embodiments, the target tissues inside the global coordinate system lead to direction of an automated positioning system that is directed based on the target tissues within the coordinate system. In some embodiments, a treatment plan is utilised in which beam energy and direction and duration of time for treatment is determined for a specific disease to be treated and/or structures to be avoided. In some embodiments, a fiducial marker is used to identify the location of the target tissues.

Abstract: A self-aligning collimator for a radiation imaging device that is secured and aligned through the use of a plurality of small magnets. The collimator allows for the rapid exchange, removal, or addition of collimators for the radiation imaging device without the need for tools. The accompanying method discloses the use of magnets and accompanying magnetic fields to align and secure collimators in a radiation imaging assembly.

Abstract: The invention specifies a radiation collimator, in particular an x-ray collimator, which can be arranged between a radiation source outputting radiation and an object. The radiation collimator includes absorber channels arranged adjacent to one another which form a two-dimensional collimator aperture in the form of a matrix and a first absorber element arranged in the absorber channel. The first absorber element blocks the radiation in a first position and allows the radiation at least partially through the absorber channel in at least one second position. The first absorber element is rod-shaped and can be moved in the absorber channel by a rotation about its longitudinal axis and/or by a longitudinal and/or transverse displacement from the first into the at least one second position. This is advantageous in that the two-dimensional collimator aperture can be modulated easily, rapidly and with high resolution.

Abstract: An X-ray computer tomography apparatus includes an X-ray tube, a two-dimensional array type X-ray detector, a rotating mechanism, a pair of collimators, a collimator moving mechanism which separately moves the pair of collimators in a direction almost parallel to a rotation axis, a reconstruction processing unit which reconstructs image data in a reconstruction range, and a collimator control unit. The collimator control unit controls the position of each collimator in accordance with the distance between an X-ray central plane corresponding to a cone angle 0° and an end face of the reconstruction range. The collimator moving mechanism moves each of the pair of collimators in the range from the outermost position corresponding to the maximum cone angle to the innermost position offset from a position corresponding to a cone angle of nearly 0° to the opposite side.

Abstract: The invention relates to a radiation screen for an X-ray device, comprising at least one radiation limiting means which is displaceably mounted and is embodied as a diaphragm. According to the invention, the radiation limiting means is displaceably mounted on a plane in a perpendicular manner in relation to a defining bundle of rays, and comprises a plurality of differently shaped diaphragm apertures for continuously limiting the different bundle of rays. It can, for example, be embodied as an essentially rotation-symmetrical perforated disk. In another embodiment, the radiation screen comprises two radiation defining means which are arranged in an overlapping manner in the direction of the bundle of rays which are to be defined.

Abstract: To reduce X-ray exposure, an area of interest is selected in the image. The image of the selected area is updated frequently, comparable to rate of updates used today for the whole image. The rest of the image is updated at a significantly lower rate. Since the area of interest normally is a small part of the overall area, the total exposure is reduced significantly. A movable X-ray shield placed near the X-ray source blocks the radiation from areas outside the area of interest. The shield automatically retracts when the complete image is updated. The area of interest can be selected by the user or automatically selected based on activity in the image.

Abstract: A collimator device has at least one masking device that is adjustable between two end positions for collimation of a beam fan in an x-ray CT device, wherein the x-ray fan is schematically not masked in a first end position. The x-ray beam is more than half-masked in a second end position of the masking device. In a method for operation of such a collimator device as well as an x-ray CT device for examination of a subject having an x-ray source, a collimator device, and a control device for regulation of the aperture width of the masking device, an x-ray detector is arranged opposite the x-ray source and the collimator device and that detects the x-rays modified due to the intervening examination subject; and an image construction device reconstructs an image of the examination subject therefrom.

Abstract: To reduce X-ray exposure, an area of interest is selected in the image. The image of the selected area is updated frequently, comparable to rate of updates used today for the whole image. The rest of the image is updated at a significantly lower rate. Since the area of interest normally is a small part of the overall area, the total exposure is reduced significantly. A movable X-ray shield placed near the X-ray source blocks the radiation from areas outside the area of interest. The shield automatically retracts when the complete image is updated. The area of interest can be selected by the user or automatically selected based on activity in the image.

Abstract: Radiation may be delivered in a number of segments shaped by a multi-leaf collimator. The collimator may be at different angles of rotation for the different segments. A method for planning radiation treatment involves obtaining an optimized set of collimator configurations by a direct aperture optimization method that takes into account collimator rotation. In some embodiments, area constraints are applied to the optimization. Methods according to embodiments of the invention can generate efficient treatment plans.

Abstract: A system is in a standby mode as an imaging preparation condition in step S1. If gripping of an operation handle is detected in step S2, the operation goes to step S3, in which an electromagnetic brake is released, thereby allowing a radiation detector to be rotated substantially around the center of an imaging region. If a rotation angle is detected in step S5, a first limiting device covering an effective imaging region of the radiation detector is changed to a second limiting device so as to be constantly arranged within the effective imaging region even during rotation of the radiation detector.

Abstract: The supporter supports a patient and is disposed movably along the body axis direction of said patient. The imaging part includes an X-ray-generator and an X-ray-detector. The X-ray-generator irradiates X-rays while rotating around the body axis. The X-ray-detector detects the X-rays that have permeated the patient. The collimator changes the irradiation field of the X-rays to be irradiated. The scan controller controls the movement of the supporter and the imaging part. The image-reconstructing part reconstructs image data based on the X-rays that have been detected by the X-ray detector. The movement amount-detector detects the amount of movement of the patient by the supporter. The collimator controller controls so as to change the size of the opening of the collimator based on the amount of movement.

Abstract: A method for identifying non-body structures in digitized medical images including the steps of providing a digitized image comprising a plurality of intensities corresponding to a domain of points on an N-dimensional grid, wherein said image includes a representation of a body and of non-body structures separate from said body, initializing a surface in said image on a side of said non-body structures opposite from said body, defining a plurality of forces acting on said surface, and displacing said surface through said non-body structures using said forces until said body is encountered.

Abstract: A system and method for capturing a portal image using a linear accelerator having a multi-leaf collimator (MLC) and an imager allows the portal image field to be automatically clipped using the multi-leaf collimator so that the projection of the portal image field onto the imager falls within the allowed image area of the imager. In this manner, portal images may be obtained in instances where the projection of the portal image field onto the flat-panel imager is larger than an allowed image area of the imager, or where the projection of the portal image field onto the imager is not centered and would extend beyond the allowed image area, so that radiation sensitive electronics outside of the allowed image area are protected from undesirable exposure to radiation.

Abstract: An automated X-ray imaging system and method for producing a plurality of X-ray imaging signals having selectively enhanced volumetric image resolutions, e.g., for magnifying the field of view and providing a volumetric display image having features not otherwise visible to an unaided human eye. Successive doses of X-ray radiation are applied to a portion of the subject to produce corresponding volumetric image signals. Such doses of X-ray radiation are controlled by controlling X-ray radiation characteristics, such as intensity, focal spot size, focal spot location, focal spot shape, or collimation, to cause a subsequent volumetric image signal to differ from a prior volumetric image signal in one or more volumetric image characteristics, such as volumetric image resolution.

Abstract: A multileaf collimator includes a first leaf block group including plural leaf blocks, a second leaf block group including plural leaf blocks arranged in the same direction as the first leaf block group and disposed opposite the leaf blocks of the first leaf block group, plural magnetic layers located on the respective leaf blocks of the first and second leaf block groups so as to be positioned on faces of the leaf blocks along a moving direction of the leaf blocks, plural magnetic sensors mounted on the respective leaf blocks and varying output signals when the respective leaf blocks are moved in an oncoming direction or a departing direction, and a control device controlling drive mechanisms according to the output signals delivered by the respective magnetic sensors so that spacing between the leaf blocks of the first and second leaf blocks is adjusted into a target configuration.

Abstract: A collimator control method for an X-ray CT apparatus includes changing an aperture of the collimator according to a position of a helical scan on the body axis of the subject in the progress of the helical scan.

Abstract: A system for x-ray optical alignment. The system includes an x-ray source, an optic, a collimation element, and alignment sensors. The x-ray source generates an x-ray beam that is directed by the optic at a sample. The collimation element is located between the optic and the sample to define the profile of the x-ray beam. The sensors receive the x-ray beam from the optic and generated signal indicative of the system alignment. The sensors may be located on a surface of the collimation element facing the optic. The inner edge of the sensors may be located at equal intervals radially about the collimation element and may form an aperture having a symmetric shape.

Abstract: A collimator including an inner border whose inner perimeter defines an aperture, an outer border positioned outwards of the inner border, an enclosure being defined and bounded between the inner and outer borders, the enclosure being sufficiently filled with a radiopaque pliable material so as to block a predefined amount of radiation from passing through the enclosure, while allowing radiation to pass through the aperture, and at least one actuator attached to at least one point of the inner border operable to deform the inner border so as to modify a shape of the aperture.

Abstract: The present invention is intended to provide a collimator control method that does not cause blades to get stuck. In a homing phase, blades are positioned based on a blade sense signal sent from a sensor. If the sensor has not sensed the blades but the rotational velocity of a motor has decreased to fall below a predetermined velocity, control states are switched. In a working phase, when an overshoot made by the blades returning to zero positions exceeds a predetermined limit, the control states are switched. Moreover, the rotating direction of the motor is reversed in order to withdraw the blades. Moreover, a collimator is reset to the control state based on tentative zero positions or the control state based on the sense signal sent from the sensor according to whether the sensor has failed.