Abstract: A system and method for reconstructing single photon emission computed tomography data acquired with a pinhole collimator includes sub-dividing each voxel in the imaging target object space into sub-voxels and sub-dividing each of the detector bins in the gamma camera detector into sub-bins, connecting the centers of each of the sub-voxels to each of the detector sub-bins through a pinhole provided in the pinhole collimator by ray tracing and for each ray connecting the centers of each of the sub-voxels to each of the detector sub-bins, the transmission probability is calculated by analytically solving the intersections between the ray and the pinhole surfaces. Then, a geometric-response-function of the pinhole collimator is computed which is then convolved with the intrinsic-response-function of the detector to obtain the PSF.

Abstract: In imaging on the basis of list mode data of a list of radioactive count data detected by a nuclear medicine imaging apparatus for measuring radiation in a pulse mode, the processing from the measurement to imaging of radiation is accelerated substantially to the real time level by selecting the number of count data to be used for online imaging computations on the basis of the counting rate of radiation.

Abstract: A single photon emission computed tomography instrument is provided, which has a platform, at least one detector, at least one beam stopper, a signal processing device and a computer. The at least one detector is disposed at one side of the platform, and the at least one beam stopper is disposed between the platform and the detector. The signal processing device is electrically communicated with the at least one detector, and the computer is electrically communicated with the signal processing device. The present disclosure further provides an operating method which the beam stopper is added or removed respectively while scanning an analyze by the single photon emission computed tomography instrument in different angles. The projection dataset emitted from the focus could be estimated by subtracting the projecting data without the beam stopper from that with the beam stopper, and high resolution image could be obtained by using image reconstruction program.

Abstract: Device for locating and imaging gamma or X-radiation sources, comprising: (a) a detection assembly comprising at least two gamma or X-radiation detectors sensitive to position, as well as a coded mask made of a radiation opaque material; and (b) electronic means for processing the electrical pulses provided by said detectors, so as to locate the source and form a bi- or tri- dimensional image thereof. The device is characterized in that the electronic means are suitable for reconstructing a bi- or tri- dimensional image of an X or gamma radiation source by applying a data processing method which combines the principles of Compton imaging and coded-mask imaging.

Abstract: Systems, devices, and methods are provided for more efficient photon detection in nuclear medical imaging. By basing the density of photosensitive microcells in photosensors on a spatial distribution of photons across the array of photosensors, the non-linearity of the photosensors' output pulses can be reduced, and the negative effects of non-uniform distribution of light from a scintillator array can be ameliorated. As a result, the positioning and linearity information of typical photosensors used in nuclear medical imaging can be improved, and better quality images are produced.

Abstract: A gantry has a cylindrical shape and rotates around a subject on a top panel about the body axis. An X-ray irradiating part is arranged inside the gantry and emits an X-ray. An X-ray detector is arranged at a position facing the X-ray irradiating part and detects the X-ray transmitted through the subject. PET detectors are arranged in two separate regions facing the rotation center and detect ?-rays emitted from the positron-emitting nuclides. A moving mechanism moves the top panel and the gantry relatively to each other. An X-ray CT image generator generates an X-ray CT image of the subject based on the result of detection by the X-ray detector. A PET image generator generates a PET image of the subject based on the ?-rays detected by the PET detectors on the circumference in accordance with rotation of the gantry.

Abstract: The present invention relates to an apparatus (10) for generating countable pulses (30) from impinging X-ray (12, 14) in an imaging device (16), in particular in a computer tomograph, the apparatus (10) comprising a pre-amplifying element (18) adapted to convert a charge pulse (20) generated by an impinging photon (12, 14) into an electrical signal (22) and a shaping element (26) having a feedback loop (28) and adapted to convert the electrical signal (22) into an electrical pulse (30), wherein a delay circuit (38) is connected to the feedback loop (28) such that a time during which the feedback loop (28) collects charges of the electrical signal (22) is extended in order to improve an amplitude of the electrical pulse (30) at an output (56) of the shaping element (26). The invention also relates to a corresponding imaging device (16) and a corresponding method.

Abstract: A system of performing a volumetric scan. The system comprises a surface of positioning a patient in a space parallel thereto, a plurality of extendable detector arms each the detector arm having a detection unit having at least one radiation detector, and an actuator which moves the detection unit along a linear path, and a gantry which supports the plurality of extendable detector arms around the surface so that each the linear path of each respective the extendable detector arm being directed toward the space.

Abstract: A system and method for collimation in diagnostic imaging systems is provided. One collimator includes a plurality of parallel hole segments and a plurality of collimator bores within each of the plurality of parallel hole segments. Additionally, all of the plurality of collimator bores in at least one of the plurality of parallel hole segments have a first pointing direction and all of the plurality of collimator bores in at least one other of the plurality of parallel hole segments have a second pointing direction, wherein the plurality of parallel hole segments are arranged in a fanbeam collimation configuration. Further, the first pointing direction is different than the second pointing direction.

Abstract: A patient bed drive mechanism, under control of a processor, is capable of continuously moving a patient bed through the a TOF-PET detector array having a stationary field of view (FOV) for a distance in excess of the physical extent of an axis of the array FOV. A direct memory access (DMA) rebinner card is coupled to the detector array to receive therefrom a stream of TOF-PET coincidence event data during the extent of movement of the bed. Image projection data are generated in real time from the acquired stream of TOF-PET coincidence event data via the DMA card.

Abstract: A positron emission tomography scanner system that includes detector modules arranged adjacent to one another to form a cylindrical detector ring. Each of the detector modules includes an array of scintillation crystal elements, a plurality of photosensors arranged to cover the array of crystal elements and configured to receive light emitted from the array of crystal elements, and a fiber optics plate arranged between the array of scintillation crystal elements and the plurality of photosensors, the fiber optics plate including a plurality of fibers configured to guide the light emitted from the scintillation crystal to the plurality of photosensors.

Abstract: A radiation sensitive detector array (112) includes a photo sensor (204) that detects a photon and generates a signal indicative thereof. The radiation sensitive detector array (112) also includes a signal analyzer (214) that energy bins and counts the signal when the signal analyzer (214) is able to identify the signal in the output of the photo sensor (204), and that integrates the output of the photo sensor (204) over an integration period when the signal analyzer (214) is not able to identify the signal in the output of the photo sensor (204).

Abstract: A method for tomographic nuclear imaging determines the distance between a non-parallel hole collimator surface and a region of interest (ROI) by obtaining difference images between images acquired at different view angles of the ROI. The distance may be used in a nuclear image reconstruction algorithm to more accurately reconstruct an image of the ROI. The method takes advantage of the non-stationary Point Spread Function of a non-parallel hole collimator to determine depth information of gamma events emitted from the ROI.

Abstract: A computed tomography (CT) imaging system is disclosed. The CT imaging system may be used in a multi-modality imaging context or other context. In one embodiment, the CT imaging system provides for both fast rotation of the rotating X-ray source and detection components and low dose of X-rays generated by the source providing several clinical and economic benefits such as low dose and sufficient image quality and no or insignificant investment in room shielding associated with diagnostic CT dose.

Abstract: A method and apparatus for producing a PET image of a tissue using a PET scanner that includes scintillation crystals and detectors. A first crystal group including a first subset of crystals is formed, and a second crystal group including a second subset of the crystals is formed. The crystals in the first crystal group are different from crystals in the second crystal group A first beam striking one or more crystals of the first crystal group is converted to a first electrical signal, while a second beam striking one or more crystals of the second crystal group is converted to a second electrical signal, wherein the second beam is scattered from the first beam. The second electrical signal is corrected using a correction factor derived from at least one of a first and second timing relationships to compensate for energy in the second signal scattered from the first signal. An image of the tissue is created using the corrected second electrical signal.

Abstract: It is provided a capacitive type proximity sensor, comprising a sensing electrode, whereas the sensing electrode has a surface with electroconductive areas 113 and not-electroconductive areas 117, whereas the sensor is adapted for measuring an electrical field 110, 112 between the sensing electrode and an object 109, 111. Further it is described an apparatus for medical x-ray diagnosis and/or x-ray therapy and/or nuclear diagnosis/therapy, e.g. SPECT, a system for medical x-ray diagnosis and/or x-ray therapy and/or nuclear diagnosis/therapy, e.g. SPECT, a method for avoiding collision between an apparatus for medical x-ray diagnosis and/or x-ray therapy and/or nuclear diagnosis/therapy, e.g. SPECT, and an object, a program element and a computer readable medium. It is disclosed a capacitance type proximity sensor whose sensitivity of approaching objects has an improved independence from the special geometry of the sensor itself.

Abstract: A blood counting device comprises a capillary conduit for drawing from a subject in which a radiotracer has previously been injected a quantity of blood in the micro-liter range to produce in the capillary conduit a flow of blood from which beta radiation is emitted. At least one direct beta radiation detector is placed closely adjacent to the capillary conduit. The direct beta radiation detector consists of a semiconductor photodiode which detects the beta radiation from the flow of blood when directly hit by this beta radiation.

Abstract: Measurements of a mobile object and particularly a living being are made using two techniques, normally radiation attenuation and radiation emission, in synchronization to provide images of the object state. Movement displacement fields from one phase to the next are estimated for both techniques, but the final images obtained by the emission technique are improved by the knowledge of the displacement field obtained by the other technique that is more precise.

Abstract: An imaging system (10) includes imaging modalities such as a PET imaging system (12) and a CT scanner (14). The CT scanner (14) is used to produce a first image (62) which is used for primary contouring. The PET system (12) is used to provide a second image (56), which provides complementary information about the same or overlapping anatomical region. After first and second images (62, 56) are registered with one another the first and second images (62, 56) are concurrently segmented to outline a keyhole (76). The keyhole portion of the second image (56) is inserted into the keyhole (76) of the first image (62). The user can observe the composite image and deform a boundary (78) of the keyhole (76) by a mouse (52) to better focus on the region of interest within previously defined keyhole.

Abstract: A method and an apparatus are disclosed for determining the effective count rate of photons in a combined MR/emission tomography recording.

Abstract: By simultaneously administering a chemical using a nuclear species releasing a single photon (a first chemical) and another chemical using a nuclear species releasing a positron to a subject, the cumulative distributions of the respective chemicals are monitored. A plural number of ?-ray detectors, which are circularly located, and a collimator covering some of the ?-ray detectors and rotates along the front face of the ?-ray detectors are provided. Also, an energy discriminating means for discriminating signals having a single photon ?-ray energy (first signals) from signals having annihilation ?-ray energy (second signals) among all of the signals detected by the detectors is provided. Further, the cumulative position of the first chemical is specified based on the signals corresponding to the ?-ray detectors covered with the rotating collimator from the first signals.

Abstract: A first ?-ray generating in a body, caused by a PET pharmaceutical, and a second ?-ray emitted from a ?-ray source and transmitting through the body are detected with a radiation detector. The emission image information (E image information), E0, E1 and E2, at each of patient motion phases, 0, 1 and 2, which divided a respiration period, are prepared by using information obtained from the detected first ?-ray. The transmission image information (T image information), T0, T1 and T2, at each of patient motion phases, 0, 1 and 2, respectively, are prepared, by using information obtained from the detected second ?-ray. Relative displacements, ([F10], [F20]), are determined by superimposing, on T image information T0, other T image information, T1 and T2. The E image information, E1, E2, are superimposed on the E image information E0, by using this relative displacement.

Abstract: A method and system for reducing scintillator afterglow. Methods for reducing afterglow include conditioning a scintillator by exposing it to high flux densities of ionizing radiation. One technique includes operating an x-ray tube at elevated amperage.

Abstract: A method for quantifying the uptake of at least one radiotracer in a body region of a patient of interest to a positron emission tomography measurement is disclosed. In at least one embodiment of the method, the uptake of the radiotracer in the body region of the patient of interest to the positron emission tomography measurement is quantified taking into account at least one permeability information item relating to the permeability of at least one blood vessel of the patient, in particular in the body region of interest.

Abstract: A multi-modality cancer screening and diagnosis system is provided that allows cancer screening and diagnosis of a patient using at least two different and sequential three-dimensional imaging techniques without patient repositioning. The system includes a first three-dimensional image acquisition device, a second three-dimensional image acquisition device having a probe with a transmitter mounted thereon, and a positioning paddle for positioning and immobilizing an object to be imaged during the cancer screening and diagnosis procedure. The positioning paddle is designed to facilitate visualization of the breast in both three-dimensional modalities without movement of the patient, and preferably is designed to position the patient with comfort during a diagnosis procedure which uses both imaging modalities.

Abstract: The invention provides a radiation detection device (1) for obtaining an image of a part of a test animal or human using high-energy radiation, comprising a detection chamber, a plurality of pinholes distributed all around the detection chamber over at least one pinhole wall, at least one framing wall having an opening for the high-energy radiation, at least one detector which is designed for detecting high-energy radiation, in which a plurality of image fields are provided on the at least one detector, in each case having one beam path from a part of the detection chamber to at least one detector, in which at least one of the at least one pinhole wall and the at least one framing wall is displaceable in such a manner that at least one of the plurality of image fields can be modified in size and/or direction. This provides the possibility to image an object at several angles, or to image a larger or a different part thereof, so that the entire device can be used in a more flexible manner.

Abstract: A device for detecting signals is disclosed. In at least one embodiment, the device includes at least four detector elements for receiving the signals and converting them into useful signals, each being connected via at least two lines to at least one signal processing unit. Each detector element includes a polarity reversal unit by which polarity reversal of the useful signal of the respective detector element can be performed. The signal polarity reversal logic is unambiguously spatially direction-dependent within the detector array. An advantage of the device of at least one embodiment is that for signals to be received simultaneously by way of two detector elements, the detector elements involved become unambiguously identifiable by the polarity reversal of the useful signal.

Abstract: Upon detection of radiation by using a (three-dimensional) detector capable of distinguishing a detection position in a depth direction and energy, an energy window for distinguishing between a signal and noise is changed depending on the detection position in the depth direction, thus making it possible to obtain scattering components inside the detector. Alternatively, a weight is given to a detection event depending on the detection position in the depth direction and energy information to obtain scattering components inside the detector. Thereby, scattering components inside the detector can be obtained to increase the sensitivity of the detector. In this case, different detecting elements can be used depending on the detection position in the depth direction.

Abstract: A PET apparatus and a processing method according in this invention carry out arithmetic processes in parallel, in steps S4 (forward projection) and S5 (back projection), for every LOR, on list data (created from event data obtained by detecting gamma rays), and can therefore be applied to other arithmetic mechanisms and have versatility. Since parallel processing is carried out on the list data and the parallel processing is carried out in each of steps S4 (forward projection) and S5 (back projection), a competition for memory can be prevented to realize an improvement in speed. As a result, high versatility and an improvement in speed of the calculations can be attained.

Abstract: Methods and systems for producing an image. Measurement data is obtained for a coincidence photon event, and a line projector function is generated based on the obtained measurement data. Additional measurement data is obtained for a single photon event, and a cone-surface projector function is generated based on the additional measurement data. An image is reconstructed using the generated line projector function and the generated cone-surface projector function. In another example method for producing an image, a measurement is obtained, and a projector function is generated using the obtained measurement. The generated projector function is modified based on an a priori image. An image is reconstructed using the modified projector function.

Abstract: In a disclosed imaging method, the instantaneous speed or data acquisition dwell times of a detector head (14, 16) is optimized as a function of position along a path (P) of the detector head around a subject (S, SS, SXL). The optimization is respective to an expected radioactive emission profile (EPROI) of a region of interest (H, HS, HXL) that is less than the entire subject. The detector head is traversed along the path using the optimized instantaneous speed or data acquisition dwell times (40). During the traversing, imaging data are acquired using the detector head. The acquired imaging data are reconstructed to generate a reconstructed image of at least the region of interest. A gamma camera (10) configured to perform the foregoing imaging method is also disclosed.

Abstract: Apparatus for imaging an object, the apparatus comprising: an imaging device configured to image the object while the object is supported on a support, the support comprising a base for positioning on a surface, wherein the object and the support are stationary relative to the surface, and further wherein the imaging device is adapted to move relative to the surface, and hence relative to the object and to the support, during imaging; the imaging device comprising a housing having a bottom notch sized to accommodate the base of the support, whereby to allow the base of the support to extend into the housing during imaging.

Abstract: The invention relates to a method and a data processing device for evaluating measurement signals provided by a layered, pixelated radiation detector. A generalized detector response function is provided that describes the energy-related crosstalk caused by radiation incident in the d-th neighboring pixel. With the help of this GDR-function, crosstalk effects can be taken into account to achieve a more accurate determination of imaging parameters related to an imaged object. The approach can particularly be used in spectrally resolved, photon counting CT detectors with small, layered pixels.

Abstract: A positron emission tomography apparatus (100) includes a plurality of radiation sensitive detector systems (106) and selective trigger systems (120). The selective trigger systems identify detector signals resulting from detected gamma radiation (310) while disregarding spurious detector signals (310). In one implementation, the apparatus (100) includes a time to digital converter which decomposes a measurement time interval (Tmax) according to a binary hierarchical decomposition of level H, where H is an integer greater than equal to one.

Abstract: A PET apparatus comprises a plurality of detector units in the circumferential direction, wherein the detector unit includes a plurality of unit substrates therein, and wherein the unit substrate includes: a plurality of detectors upon which a ?-ray is incident; and an analog ASIC and digital ASIC for processing a ?-ray detection signal outputted by each of the detectors. The analog ASIC includes two slow systems having mutually different time constants, each of which outputs a pulseheight value. A noise determination part of the digital ASIC determines whether a relevant detection signal is an intended ?-ray detection signal or a noise based on a correlation between the pulseheight values, and a noise counting part counts the number of times of noise determination, and a detector output signal processing control part controls the signal processing with respect to an output signal from a relevant detector based on the count.

Abstract: A positron emission tomography detector module that includes an array of optically isolated crystal elements and photomultiplier tubes that receive light emitted from the array of crystal elements and are arranged to cover the array of crystal elements. The photomultiplier tubes include photomultiplier tubes having two different sizes arranged in various patterns that minimize the number of edges. The axial extent of each detector module is at least three times longer than the other axis of the detector module.

Abstract: Problem: The problem is to provide a fluorescent material for a scintillator to be used in a radiation detector. In view of this, the fluorescent material must have a high fluorescent intensity and a low level of afterglow 1 to 300 ms after the termination of X-ray radiation. Solution: The above problem is solved in that the above fluorescent material contains Ce as an activator. In addition, the material contain at least Gd, Al, Ga, O, Si, and a component M. The component M is at least one of Mg, Ti, and Ni. In addition, the composition of the material must be expressed by the general formula: (Gd1?x?zLuxCez)3+a(Al1?u?sGauScs)5?aO12 wherein 0?a?0.15, 0?x?0.5, 0.0003?z?0.0167, 0.2?u?0.6, and 0?s?0.1, and wherein, regarding the concentrations of Si and M, 0.5?Si concentration (mass ppm)?10, and 0?M concentration (mass ppm)?50.

Abstract: A multi-modality imaging system for imaging of an object under study, e.g., a whole body or parts of the body of animals such as humans, other primates, swine, dogs, or rodents, that includes a magnetic resonance imaging apparatus and a cadmium zinc telluride (CZT)-family semiconductor, single-photon imaging apparatus within a magnetic field produced by the magnetic resonance imaging apparatus such that sequential or simultaneous imaging can be done with the two modalities using the same support bed of the object under study in the same, uninterrupted imaging session.

Abstract: A sandwich structure which attenuates the PET radiation minimally, is used as a support tube for the transmit antenna. In at least one embodiment, it includes a thin strong inner wall, a likewise thin and strong outer wall and an interior of the support tube which is of the honeycomb type or is made of foam material.

Abstract: An apparatus and method are provided for optimizing an amount of radiation dose and acquisition time in cardiac Single Photon Emission Computed Tomography (SPECT) imaging. The apparatus and method include providing an organ, acquiring images of the organ at projected views. Then a projected view that projects the organ as an annulus is selected; a region of interest (ROI) is also selected in the projected view, wherein the ROI is in a lateral wall of the organ. An average count in the ROI is determined; and an image quality of a reconstructed image based on the average count is predicted.

Abstract: A rich-media system allows a user to illustrate damage and request payment in accordance with an insurance policy or another arrangement. The rich-media system includes network servers that may operate and appear to remote client applications and remote computers as if the network servers were a single computer. A damage indicator tool resident to one of the network servers enables a remote user to visually illustrate damage to an item through a rich-media application. The damage indicator may support a relative pointing device and an absolute pointing device. An incident animator tool linked to the damage indicator tool in some rich media systems enables the remote user to visually recreate an event in a second rich media application. An optional scheduler linked to the incident animator tool and the damage indicator tool may enable the remote user to schedule an appointment to have the damage inspected or repaired.

Abstract: A method for estimating randoms in PET imaging data includes acquiring imaging data that includes a plurality of singles and a plurality of randoms, where the randoms exhibit a non-exponential decay, generating a randoms correction estimate based on the non-exponential decay, and applying the randoms correction estimate to the imaging data to generate corrected imaging data. The method further includes generating an image using the corrected image data. An imaging system and computer readable medium programmed to estimate randoms is also provided.

Abstract: An apparatus for recognizing and determining the position of at least one teat of a milking animal includes a scanning head comprising a light source and a camera. The light source emits light into a region which is expected to contain a teat or teats and the camera captures images formed by the light. In a first scanning mode, the scanning head is moved from a low initial position upwards in a circular coil until the position of at least a first teat has been established. Thereafter, in a second scanning mode, the scanning head is moved upwards in a to circular coil until the positions of all teats have been established, or a predetermined time limit has elapsed during the scanning procedure. The coil traversed during the first scanning mode is wider than the coil traversed during the second scanning mode.

Abstract: A method is disclosed for determining radiation attenuation as a result of an object in a positron emission tomography scanner. In at least one embodiment, a phantom object is arranged in the positron emission tomography scanner during the method. First raw radiation data of the phantom object is acquired while the object is not arranged in the positron emission tomography scanner. A first image of the phantom object is calculated from the first raw radiation data. The object then is arranged in the positron emission tomography scanner (2) and preliminary radiation attenuation of the object is identified. Second raw radiation data of the phantom object is acquired while the object is arranged in the positron emission tomography scanner. A second image of the phantom object is calculated from the second raw radiation data taking into account the preliminary radiation attenuation. The radiation attenuation is determined on the basis of the first image and the second image.

Abstract: A high resolution single photon emission computed tomography (SPECT) imaging system comprising: a rotating ring for surrounding anatomy which is to be imaged; at least one camera mount movably mounted to the rotating ring so that the camera mount can be moved radially relative to the axis of rotation of the rotating ring; and at least one gamma camera carried on the at least one camera mount, wherein the at least one gamma camera is focused on a single SPECT focal point; whereby, when the rotating ring is rotated about the anatomy which is to be imaged and the at least one camera mount is moved radially on the rotating ring, the single SPECT focal point of the at least one gamma camera carried by a camera mount follows a spiral pattern through the anatomy, whereby to produce a scan of the anatomy.

Abstract: A method is described for acquiring and analysing the data produced by Positron Emission Tomography (PET), which method provides for an accurate estimation of vascular compartment volume, VB. An MRI scan and the PET scan is performed simultaneously and the results of the former is used to derive a value for VB. The value so derived is then used in pharmacokinetic modelling along with the results of the functional scan.

Abstract: Methods and systems for performing a patient scan using a three-dimensional (3D) cylindrical Positron Emission Tomography (PET) imaging system are provided. The method includes acquiring a count-rate profile of a brain, repositioning at least one of a detector and the brain based on the count-rate profile and a detector sensitivity profile, and scanning the brain when the acquired count-rate profile substantially matches the detector sensitivity profile.

Abstract: A method and system for use in positron emission tomography, wherein a first processor element (234) is configured to reconstruct a plurality of positron annihilation events detected during a positron emission tomography scan using a list-based reconstruction technique to generate first volumetric data. A second reconstructor (226) is configured to reconstruct the plurality of events using a second reconstruction technique to generate second volumetric data for determining an error correction (228), the error correction applied to the first volumetric data to generate corrected volumetric data for generating a human-readable image (234). In one embodiment a multiplicative error correction is performed on the plurality of events, the first processor element (234) reconstructing the corrected plurality of events; and the second volumetric data error correction comprises an additive error correction.

Abstract: A method and apparatus for correcting misalignment between fields of view of a CT device and a NM device of a modular multimodality medical imaging system, by providing a Field Of View Calibration Matrix (FOV-CM) containing rotational and translational transformations between coordinate systems of the CT and NM systems.

Abstract: A detector for a nuclear imaging system includes a scintillator including an array of scintillator elements and a light guide including a grid which defines light guide elements. Light from scintillations in the scintillation crystal in response to received radiation, passes through the light guide and strikes light sensitive elements of a light sensitive element array. The light sensitive element array includes larger elements in an array in the center surrounded by smaller light sensitive elements located in a peripheral array around the central array.