(n.) A telescope arranged and used to determine errors of collimation, both vertical and horizontal.
(n.) A tube having a convex lens at one end and at the other a small opening or slit which is at the principal focus of the lens, used for producing a beam of parallel rays; also, a lens so used.
Example Sentences:
(1) The dual-probe system incorporates a central collimated probe for monitoring activity in the LV surrounded by an annular detector collimated in such a manner as to provide simultaneous real-time monitoring of the LV background activity.
(2) The second area of improved SPECT technology is camera collimation and related imaging techniques.
(3) Comparative clinical studies on temporomandibular joints (TMJ) between the LEGP and fan beam collimators also confirm the superior image quality obtained with the fan beam collimator.
(4) In work to determine whether X-radiation could be used to induce tumors of the colon in outbred Holtzman rats, a technique was devised so that only the descending colon could be irradiated with a collimated X-ray beam and tumorigenic exposures in the kilo-Roentgen range were delivered.
(5) In the RAO view with the collimator flat against the chest there was better resolution of the cardiac apex.
(6) As an initial feasibility study of computer-controlled radiation therapy, its application to produce wedge-shaped dose distributions by moving the collimator jaws has been evaluated.
(7) Analysis of the penumbra width of cross dose distributions, as a function of field sizes, allowed us to postulate that the dmax shift could be due to the phantom scattered photons, which in turn were generated by the collimator scattered photons.
(8) Larger detectors with converging collimation result in much higher photon input rates to the scintillation crystal in routine clinical studies than has occurred in the past.
(9) Neutron spectra at various locations in a phantom, irradiated by collimated beams of 14 MeV neutrons and neutrons from 252 Cf and Po-Be sources, were calculated using the Monte Carlo technique.
(10) Without scatter, the resolution was 4.7 mm (full width at half-maximum); in a scatter medium, the resolution was 5.3-10.0 mm with high resolution collimation and 7.7-18.8 mm with general purpose collimation, depending on filtering.
(11) Quantitative measurement of the scatter dose in polystyrene solid phantoms with a Farmer type chamber and effects of shielding blocks under the collimators were studied.
(12) Spatial resolution with parallel-hole or converging collimators was much less satisfactory with Ta-178 because of septal penetration by high-energy photons.
(13) Moving the collimator during imaging will reduce septal aberrations but will not increase resolution.
(14) The nonuniform response inherent in the use of the pinhole collimator has a significant effect, but with computer processing this is readily eliminated.
(15) The exchange of collimator pairs results in significant output differences but has a negligible effect on the depth-dose curves.
(16) This was consistent with the design of the line focus and the beam collimators used in this system.
(17) One-centimeter collimation contiguous scans through the chest were obtained in all patients.
(18) A further increase in photon utization is gained for small-organ imaging with converging collimators, which produce images with superior resolution and sensitivity to that obtained with equivalent parallel-hole collimators.
(19) Normal quantitative circumferential profile limits were established for a 30 degrees bilateral rotating slant-hole (RSH) collimator tomographic system.
(20) Central axis percentage depth doses and off-axis ratios measured with such a collimator show variations with the source-to-surface distance (SSD).
Parallel
Definition:
(a.) Extended in the same direction, and in all parts equally distant; as, parallel lines; parallel planes.
(a.) Having the same direction or tendency; running side by side; being in accordance (with); tending to the same result; -- used with to and with.
(a.) Continuing a resemblance through many particulars; applicable in all essential parts; like; similar; as, a parallel case; a parallel passage.
(n.) A line which, throughout its whole extent, is equidistant from another line; a parallel line, a parallel plane, etc.
(n.) Direction conformable to that of another line,
(n.) Conformity continued through many particulars or in all essential points; resemblance; similarity.
(n.) A comparison made; elaborate tracing of similarity; as, Johnson's parallel between Dryden and Pope.
(n.) Anything equal to, or resembling, another in all essential particulars; a counterpart.
(n.) One of the imaginary circles on the surface of the earth, parallel to the equator, marking the latitude; also, the corresponding line on a globe or map.
(n.) One of a series of long trenches constructed before a besieged fortress, by the besieging force, as a cover for troops supporting the attacking batteries. They are roughly parallel to the line of outer defenses of the fortress.
(n.) A character consisting of two parallel vertical lines (thus, ) used in the text to direct attention to a similarly marked note in the margin or at the foot of a page.
(v. t.) To place or set so as to be parallel; to place so as to be parallel to, or to conform in direction with, something else.
(v. t.) Fig.: To make to conform to something else in character, motive, aim, or the like.
(v. t.) To equal; to match; to correspond to.
(v. t.) To produce or adduce as a parallel.
(v. i.) To be parallel; to correspond; to be like.
Example Sentences:
(1) When the data correlating DHT with protein synthesis using both labelling techniques were combined, the curves were parallel and a strong correlation was noted between DHT and protein synthesis over a wide range of values (P less than 0.001).
(2) The time-course and dose-response for this modification of pp60c-src paralleled PDGF-induced increases in phosphorylation of pp36, a major cellular substrate for several tyrosine-specific protein kinases.
(3) We present a mathematical model that is suitable to reconcile this apparent contradiction in the interpretation of the epidemiological data: the observed parallel time series for the spread of AIDS in groups with different risk of infection can be realized by computer simulation, if one assumes that the outbreak of full-blown AIDS only occurs if HIV and a certain infectious coagent (cofactor) CO are present.
(4) There was no correlation between serum LH and chronological or bone age in this age group, which suggests that the correlation found is not due to age-related parallel phenomena.
(5) The cyclical nature of pyromania has parallels in cycles of reform in standards of civil commitment (Livermore, Malmquist & Meehl, 1958; Dershowitz, 1974), in the use of physical therapies and medications (Tourney, 1967; Mora, 1974), in treatment of the chronically mentally ill (Deutsch, 1949; Morrissey & Goldman, 1984), and in institutional practices (Treffert, 1967; Morrissey, Goldman & Klerman (1980).
(6) Stimulation of parallel fibers or iontophoresis of acetylcholine excited P cells.
(7) Label was found widely distributed among all the organs except the nervous system and its rate of disappearance from the tissues paralleled its disappearance from the circulation.
(8) The bundles may lie parallel to the plasma membrane and to the long axis of the cell.
(9) Alterations in DNA synthesis induced by a single dose of cyclophosphamide in normal and tumorous tissues in vivo paralleled in many respects the changes seen when the more time-consuming techniques of the LI or granulocyte colony formation were employed.
(10) Dose distributions were evaluated under thin sheet lead used as surface bolus for 4- and 10-MV photons and 6- and 9-MeV electrons using a parallel-plate ion chamber and film.
(11) The influences of the inhibitor(s) for both tumours and in both culture systems were parallel.
(12) Parallel studies in vivo were carried out to determine the contribution of the phosphatidylserine decarboxylase pathway, relative to pathways utilizing ethanolamine directly, to the synthesis of brain ethanolamine glycerophospholipids.
(13) Plasma renin activities (PRA) and aldosterone concentrations increased in parallel over a wide range of plasma volume deficits produced in unanesthetized rats by extravascular administration of polyethylene glycol (PEG) solution.
(14) Combined study of lungs of 85 foetuses and newborns of various gestational age and 8 newborns dying during the first month of life showed the lung surfactant (LS) system to develop in parallel with formation of respiratory parts and lung capillary network.
(15) Ordering of these filaments into a parallel array is the basis of birefringence in the A region, and loss of birefringence is therefore a measure of decreased order.
(16) Comparing the regression lines of HR-QT and HR-QS2 separately for both groups, we found that both intervals decreased in parallel and the mean QT remained shorter than QS2 in both groups during exercise.
(17) Parallel changes in free T4 and the free T4 index indicate adequacy of the index in representing pineal-induced changes in free T4.
(18) In the course of its history, psychiatry has grown richer parallel to the development of its spatiotemporal system of the reference.
(19) Furthermore, the changes in both interstitial fluid and testicular venous blood levels of testosterone do not always parallel those in peripheral venous blood, suggesting that changes in testicular blood flow and peripheral clearance rates of testosterone may also be important in the control of circulating testosterone concentrations.
(20) On the basis of these data, the computer, upon the basis of a program specially developed for this purpose, automatically calculates the corresponding amount of negative-points, which parallels the severity of the joint changes, i.e.