Abstract: An example of sporadic motion that causes difficulty in CT scanning is gas pockets moving around the rectum. The invention allows the automatic detection of such movements, by enhancing low density features around the prostate in the individual X-ray images, projecting these features on the cranio-caudal axis (assuming that the gas predominantly moves in this direction) to form a 1-dimensional image, and combining successive ID projections to form a 2D image. Moving gas will produce tilted lines in this image, identifying an angular range that needs to be discarded. Such a process can be used in an image processing apparatus of a CT scanner.

Abstract: The present invention introduces a method for adjusting interference signal estimates provided by multi-channel biomagnetic field measurements. A so-called Signal Space Separation method (SSS) is applied in the calculatory analysis of the measurement signals, providing for the division of the sources causing the fields in objects of interest and external interferences. When the signal basis representing the interferences has been estimated, this interference signal estimate is adjusted by measuring the fields without the object to be measured and without changing the sensor assembly. Interference components obtained in this manner are analyzed in such a way as to include only the most significant interference components. In addition, it is taken into account that only those forms of interference of the measured interference components are included which are not yet present in the calculated SSS model.

Abstract: Methods and systems are provided for protecting a critical structure during the administration of radiation treatment to a patient. A register receives proposed positions for one or more radiation beams with respect to a critical structure. A processor predicts a cumulative dose volume for the critical structure based on the dose distribution, and determines if the cumulative dose volume exceeds a tolerance value. If the cumulative dose volume exceeds the tolerance value, the dose distribution may be translated at least in part based on a relationship between the cumulative dose volume and the dose distribution position.

Abstract: According to the present invention, there is provided a clamping device for locking two elements, e.g. rotatable shafts, having a substantially circular cross-section. The clamping device comprises a central holding part having two partly curved sections being adapted to at least partly encircle and hold the elements, which curved sections are inversely curved. Further, the clamping device comprises an upper holding part having a partly curved section arranged being adapted to at least partly encircle and hold a first element and a lower holding part having a partly curved section being adapted to at least partly encircle and hold a second element. The central, upper and lower holding parts are adapted to co-operate to lock the elements when pressed together by means of a tightening element. The curved sections are inversely curved in relation to each other and form together with the substantially rectangular section a substantially S-shaped central part.

Abstract: A positioning system for a body comprises a flexible bag of a gas-impermeable material/including a valve to permit evacuation of the interior thereof, the bag containing a flowable granular material and at least one bolster. The body can be at least part of a human form, such as a patient. Systems are generally provided for specific body regions such as the hip or thorax, and for the whole body. The bolster is larger than the grains of the granular material. A size dimension of the bolster is therefore preferably at least 5 times the- size dimension of the granular material, although it sill usually be one or more orders of magnitude larger. Various forms of bolster are possible. A bolster that includes a generally flat section and an upstanding section extending therefrom can be used to locate a shoulder region of the patient in a reproducible yet comfortable form. A bolster that is generally cylindrical in shape can be used to support various areas of a patient such as the neck or knee.

Abstract: Embodiments of the present invention provide a multi-leaf collimator with a plurality of leaves and at least one motor for each leaf. The motor for each leaf has a lateral width which is equal to or narrower than the corresponding leaf, and in this way the motors can be arranged within the lateral extent of the leaf. A cut-out section in the leaf allows the motor to lie at least partially within the depth of the leaf, and in this way the drive mechanism and the multi-leaf collimator as a whole are made extremely compact. This in turn allows the leaves to be deeper than would otherwise be the case, increasing their efficacy in blocking radiation.

Abstract: A radiotherapy apparatus is described which includes a source of radiation for generating a therapeutic beam towards a target region of a patient. A collimation apparatus is configured to act on the beam in a plane transverse to the beam axis. An imaging apparatus is configured to obtain imaging data of the target region. A control apparatus is configured to receive the imaging data from the imaging apparatus and control the collimation apparatus in dependence thereon. The imaging data includes at least one two-dimensional slice image including only a single two-dimensional slice image oriented in any one direction and which includes the target region.

Abstract: The present invention relates to a device for securing medical leads in a cranial burr hole, in particular, for securing a brain stimulation lead within such a burr hole. The device includes a circular socket element adapted to be secured within a burr hole of the skull of a patient, the circular socket element having a through lead passage arranged to have the lead pass therethrough, the lead passage including passage walls including at least one resilient partition wall extending from an inner wall of the circular socket element, and the circular socket element having at least one inner compartment delimited by the partition wall.

Abstract: We provide a radiotherapeutic apparatus comprising a patient support, magnetic coils disposed around the patient support for creating a magnetic field therewithin, a radiation source producing a beam of radiation directed toward the patient support and mounted on a rotatable support thereby to rotate the radiation source around the patient support, a slip ring for conveying electrical power to the radiation source and located around the patient support, including at least one electrical interruption therein. This creates a slip ring in which there is no continuous circumferential path, and one in which the current is therefore forced to take a route via one side or the other.

Abstract: Radiotherapy apparatus is disclosed, comprising a radiation source capable of emitting a beam of therapeutic radiation along a beam axis, collimation apparatus for delimiting the beam and comprising (i) a block of sufficient width to extend across the width of the beam, selectively movable into the beam from a first side of the beam axis, and (ii) an array of individually moveable elongate narrow leaves arranged side-by-side in a direction perpendicular to the beam, each being moveable longitudinally into the beam from a second and opposing side of the beam axis, in which there is no array of individually moveable elongate narrow leaves arranged side-by-side in a direction perpendicular to the beam moveable longitudinally into the beam from the first side of the beam axis. Thus, there is in effect a single bank of MLC leaves on one side of the aperture and a block collimator on the other.

Abstract: A radiotherapy apparatus is described which includes a patient support, a magnetic resonance imaging (MRI) apparatus for obtaining imaging data of a patient positioned on the patient support, and multiple linear accelerators, each aligned in a plane transverse to the patient support and arranged to provide a therapeutic beam of x-ray radiation to the patient.

Abstract: An approach to radiotherapy is disclosed which allows the therapeutic beam to be more accurately directed towards a target region. Instead of stopping acquiring images during treatment, the system continues to acquire images as treatment is ongoing. This ongoing pipeline of images is used to update the previously created 3D reconstructions of each breathing phase. Thus the position of the target region can also be updated. The surrogate is recorded simultaneously with the image acquisition although it is not used to determine the breathing phase. As new images are used to update the 3D reconstructions of each breathing phase the values of the surrogate associated with that phase are also updated. This means that the correlation with the surrogate can also continue to be evaluated, and the correlation refined, thus improving the ability of the system to track the motion of the target.

Abstract: The present invention provides an extendible support mechanism in which a counterbalance system allows extension and retraction of the arm to be carried out with the same level of mechanical effort. Embodiments of the present invention allow the system to be used in a plurality of orientations, and thus the invention has particular utility in the extension and retraction of peripheral devices for radiotherapy systems, where use of a rotatable gantry is common.

Abstract: It is desirable to achieve a co-incident investigative kV source for a therapeutic MV source—a so-called “beams-eye-view” source. It has been suggested that bremsstrahlung radiation from an electron window be employed; we propose a practical structure for achieving this which can switch easily between a therapeutic beam and a beam-eye-view diagnostic beam capable of offering good image resolution. Such a radiation source comprises an electron gun, a pair of targets locatable in the path of a beam produced by the electron gun, one target of the pair being of a material with a lower atomic number than the other, and an electron absorber insertable into and withdrawable from the path of the beam. In a preferred form, the electron gun is within a vacuum chamber, and the pair of targets are located at a boundary of the vacuum chamber. The lower atomic number target can be Nickel and the higher atomic number target Copper and/or Tungsten.

Abstract: Apparatus for location-detection of an object within a region comprising a reflective element mountable on the object, a scanning light source adapted to issue a beam of light in a scanning pattern illuminating a point that moves over the region, a detector for light reflected from the reflective element and a control unit adapted to report the position of an object based on the point in the scanning pattern at which the detector detects light returned from the reflective element relative to at least one point in the scanning pattern at which the detector detects light returned from a reflective object.

Abstract: The present invention provides a method of calibrating a radiotherapy apparatus, in which a beam measurement device is accurately located with respect to the radiation beam centre. The method comprises acquiring the centre of the radiation beam at two angles of rotation, separated by 180°, and aligning a beam measurement device with the midpoint of the respective centres.

Abstract: A method and a dose planning module for planning a treatment session of a patient by means of a radiation therapy system includes a radiation therapy unit having a fixed radiation focus point. The method includes obtaining a target volume of a region of a patient to be treated during a treatment of a patient in a radiation therapy unit, the target volume being modeled as a three-dimensional voxel representation; selecting an isodose level for the planned treatment; determining shots to be delivered during the treatment, each shot being modeled by a spatial dose volume distribution of radiation represented by a three-dimensional voxel representation, the shape of the spatial distribution depending on the specific collimator setting and the selected isodose level; and selecting shots in a decreasing volume order for the dose planning.

Abstract: An in-line 4D cone beam CT reconstruction algorithm queues a limited number of projection images such that the phase determination algorithm can look-ahead. At regular intervals, the queue is scanned and those images which have enough look-ahead to obtain phase information are filtered and back-projected. The algorithm thus keeps up with the image acquisition speed and produces a 4D reconstruction within a few seconds of the end of scanning.

Abstract: X-ray apparatus comprises a linear accelerator adapted to produce a beam of electrons at one of at least two selectable energies and being controlled to change the selected energy on a periodic basis, and a target to which the beam is directed thereby to produce a beam of x-radiation, the target being non-homogenous and being driven to move periodically in synchrony with the change of the selected energy. In this way, the target can move so that a different part is exposed to the electron beam when different pulses arrive. This enables the appropriate target material to be employed depending on the selected energy. The easiest form of periodic movement for the target is likely to be a rotational movement.

Abstract: In radiotherapy apparatus comprising an imager for the MV beam and a separate kV imaging system, it is common for there to be significant artefacts in the kV image arising from the MV pulse. We disclose such a radiotherapy apparatus which is adapted to (i) cause the therapeutic source to emit radiation while keeping the diagnostic source inactive, (ii) read an image from the detector associated with the therapeutic source, (iii) cause the diagnostic source to emit radiation and while keeping the therapeutic source inactive, (iv) read an image from the detector associated with the diagnostic source, and (v) repeat as necessary. The control unit is preferably adapted to, at steps (ii) and (iv), read an image from both of the detectors, or to clear the “inactive” detector. The detectors are ideally flat-panel detectors, capturing a two-dimensional image.