ライフサイエンスコーパス: collimator

1 scintillation camera equipped with a pinhole collimator.

2 er as well as scatter and penetration in the collimator.

3 of acquisition orbit but not by the type of collimator.

4 ator with a conventionally used, high-energy collimator.

5 e of a long focal length, asymmetric fanbeam collimator.

6 teral breast is decreased with the multileaf collimator.

7 phantom and a high-resolution parallel-hole collimator.

8 ources of 99mTc were placed directly on each collimator.

9 ollimator face of 10 cm or more for the HEGP collimator.

10 C-arm and a gamma camera with a four-pinhole collimator.

11 SPECT) or parallel-hole (conventional SPECT) collimator.

12 equipped with a dedicated clustered pinhole collimator.

13 rmed on a gamma-camera using a parallel-hole collimator.

14 ing a SPECT system equipped with a dedicated collimator.

15 rmed on a gamma-camera using a parallel-hole collimator.

16 of a camera system fitted with a high-energy collimator.

17 r the geometric response of the radionuclide collimator.

18 ng a camera system fitted with a high-energy collimator.

19 ty in comparison with standard parallel-hole collimators.

20 sensitivity compared with SPECT with 511-keV collimators.

21 rdial nonuniformity increased 10%) with LEHR collimators.

22 a triple-head camera equipped with fan-beam collimators.

23 fferent detector sizes collimated by fanbeam collimators.

24 c., Cleveland, OH) to image 18F with 511 keV collimators.

25 vity at similar resolution compared to other collimators.

26 e layers of gadolinium, were attached to the collimators.

27 tem fitted with medium-energy, parallel-hole collimators.

28 e (HEGP; for (131)I and (18)F) parallel-hole collimators.

29 llimators and from 53 to 175 cps/MBq for rat collimators.

30 ted images using a combination of converging collimators.

31 nd geometric blurring caused by radionuclide collimators.

32 d with all-purpose and ultra-high-resolution collimators.

33 m photomultiplier tubes, and a parallel-hole collimator (1.5-mm bore width, 23.6-mm bore length).

34 of the Inveon SPECT system using 6 different collimators: 3 dedicated for mouse imaging and 3 for rat

35 f the X-ray fluorescence through the pinhole-collimator allowed the two-dimensional elemental mapping

36 antification of 131I using SPECT with an UHE collimator and a constant calibration factor.

37 t that septal penetration and scatter in the collimator and other detector-head components are import

38 , while the agreement between SPECT using HE collimator and PET are moderate (kappa = 0.413).

39 eement (kappa = 0.736) between SPECT with UH collimator and PET, while the agreement between SPECT us

40 Between FDG-SPECT using an HE collimator and that using a 511-keV collimator, the latt

41 A combination of 2 HCB collimators and 1 fanbeam collimator, compared with a tr

42 tained with a combination of HCB and fanbeam collimators and compared with a triple-fanbeam circular

43 y for brain imaging, was combined with other collimators and compared with conventional parallel-beam

44 vity varies from 29 to 404 cps/MBq for mouse collimators and from 53 to 175 cps/MBq for rat collimato

45 e performed to calculate the efficiencies of collimators and their combinations and to quantitatively

46 face, (b) determines the rotations of couch, collimator, and gantry using three matrices about the ca

47 ependent of the gamma camera system, type of collimator, and orbit.

48 ependent of the gamma camera system, type of collimator, and orbit.

49 nal SPECT camera equipped with parallel hole collimators, and hybrid SPECT/CT images were acquired us

50 )Tc during FDG coincidence imaging with LEHR collimators, and the effect of the presence of FDG durin

51 d (d) customized fields, by adjusting width, collimator angle, and gantry angle and by using customiz

52 ew projection plane, (d) optimizes couch and collimator angles by selecting the least total unblocked

53 fields with beam's-eye-view optimization of collimator angles for axillary and breast coverage; (c)

54 al fields with adjustment of field width and collimator angles; and (d) customized fields, by adjusti

55 rein, the sensitivity and resolution of this collimator are reevaluated.

56 al, beam-shaping filters, and dynamic z-axis collimators are important, and education to successfully

57 PSF due to collimator penetration for the PC collimator as compared with the HEGP collimator (e.g., 0

58 The literature treats this collimator as having the same sensitivity as a single-pi

59 Multileaf-collimator blocking for primary breast treatment is simi

60 m collimator, compared with a triple-fanbeam collimator, can increase the photon detection efficiency

61 8 in.) and high-resolution, ultrahigh-energy collimators capable of 511 keV imaging has permitted FDG

62 eared after recalibration (first scanner) or collimator cleaning (second scanner).

63 rain scans showed improved quality with this collimator combination due to increased sensitivity and

64 A slit-slat collimator combines a slit along the axis of rotation wi

65 mbination of 2 HCB collimators and 1 fanbeam collimator, compared with a triple-fanbeam collimator, c

66 rs by means of a novel cylindric high-energy collimator containing 162 narrow pinholes that are group

67 ted data from 2 and 4 views of the 9-pinhole collimator demonstrated good lesion definition and also

68 The fanbeam collimator demonstrated high resolution SPECT performanc

69 PECT imaging with an ultra-high-energy (UHE) collimator designed for imaging 511-keV photons.

70 A high-sensitivity half-cone-beam (HCB) collimator, designed specifically for brain imaging, was

71 with the effects of nonuniform attenuation, collimator-detector response and scatter.

72 tion, photon scatter, and distance-dependent collimator-detector response are major degrading factors

73 The energy- and distance-dependent collimator-detector response was modeled with precalcula

74 luded the effects of nonuniform attenuation, collimator-detector response, and scatter.

75 A half-cone beam collimator does not have the problem of truncation.

76 the PC collimator as compared with the HEGP collimator (e.g., 0.9 vs. 1.4 cm in full width at half m

77 he LEHR and HEGP collimators than for the PC collimator (e.g., 3.1 x 10(-5) vs. 2.9 x 10(-5) counts p

78 nd realized here using an 'inelastic thermal collimator' element.

79 clinical PET system uses a clustered-pinhole collimator, enabling high-resolution, simultaneous imagi

80 e for (131)I and (18)F at distances from the collimator face of 10 cm or more for the HEGP collimator

81 n collimator, over the range 0-6 cm from the collimator face.

82 The collimator focal length was 16 cm and the distance from

83 overy coefficients as compared with the HEGP collimator for (131)I and (18)F.

84 oefficients were similar for the PC and LEHR collimators for (99m)Tc but that the PC collimator signi

85 The use of cone-beam collimators for brain imaging with triple-camera SPECT s

86 tonics will find applications in lightweight collimators for displays, as well as chromatically corre

87 New high-energy collimators for single photon emission computed tomograp

88 a conventional Anger camera with cardiofocal collimators for the assessment of left ventricular (LV)

89 transmission was reduced with the multileaf collimator from 4% to 1%.

90 reconstructed projection data of a 9-pinhole collimator from a digital heart phantom with a basal les

91 y were analyzed as a function of the type of collimator, gamma camera system, and type of orbit (180d

92 This collimator has a sensitivity that increases for points n

93 a single-slice prototype of the proposed PC collimator has shown the potential for significantly imp

94 the underlying radionuclide and the related collimator have a major influence on the calibration, no

95 tems equipped with a high-energy, or 511-keV collimator, have been proposed to offer a less expensive

96 This predicts that a 9-pinhole collimator having the same spatial resolution as a paral

97 ed with either a high-energy general-purpose collimator (HE), or the dedicated 511-keV collimator (UH

98 ing the same sensitivity as a single-pinhole collimator, ignoring the effect of the axial septa.

99 ow had either scattered in or penetrated the collimator, indicating the significance of collimator in

100 e collimator, indicating the significance of collimator interactions.

101 a equipped with a low-energy high-resolution collimator interfaced with a computer.

102 dicated cardiac SPECT system with 19 pinhole collimators interfaced with 64-slice CT.

103 This collimator is placed in an existing SPECT system (U-SPEC

104 The sensitivity of this collimator is proportional to h(-1) and has resolution i

105 A gamma camera with a pinhole collimator is used to acquire projections of the radionu

106 from SPECT systems with uniform sensitivity collimators is considerably lower than the theoretical o

107 The reason for combining collimators is to ensure both high sensitivity and suffi

108 requires only a gamma camera with a pinhole collimator, it has the potential to be applied in any ho

109 Pinhole collimators made of high-density and high atomic number

110 oth short-bore (35 mm) and long-bore (50 mm) collimators, matched to the geometry of the detector ele

111 Buildup data for the multileaf collimator most closely resembled the surface dose when

112 fficiency of a 9-pinhole and a parallel-hole collimator mounted to a standard nuclear medicine gamma-

113 fication is 10.9 +/- 0.8%, while without the collimator no rectification is detectable (<0.3%).

114 quality, beam-limiting devices (apertures or collimators), noise power spectrum (NPS) analysis algori

115 coupled, in a coaxial geometry, to a pinhole collimator of small diameter.

116 d with PET, SPECT with the dedicated 511-keV collimator offers a low-cost, practical alternative to P

117 performed to investigate the effect of LEHR collimators on FDG coincidence imaging with a hybrid PET

118 systems with a high-energy, general-purpose collimator, on the other hand, are inadequate in such st

119 mera equipped with an ultra-high- resolution collimator, over the range 0-6 cm from the collimator fa

120 showed reduced broadening of the PSF due to collimator penetration for the PC collimator as compared

121 ne-shaped holes, which was designed to limit collimator penetration while preserving resolution and s

122 on computed tomography system with a pinhole collimator (pinhole SPECT) for high-resolution cardiovas

123 d of view, ranging from 0.6 to 1 mm with the collimator plates dedicated to mouse imaging and from 1.

124 ging and from 1.2 to less than 2 mm with rat collimator plates.

125 tem comes with several types of multipinhole collimator plates.

126 Cone-beam collimators provide increased sensitivity at similar res

127 ed that although FDG-SPECT, using a HE or UH collimator, provided concordant viability information as

128 /maximum count) showed a small dependence on collimator resolution and pixel size but was altered sig

129 ra system equipped with parallel and fanbeam collimators, respectively.

130 cross talk, attenuation, distance-dependent collimator response (DCR), and partial-volume effect.

131 maximization, incorporating corrections for collimator response and attenuation using both a uniform

132 onuclide (either (99m)Tc or (111)In) and (b) collimator response based on experimentally measured dep

133 tter correction (3 methods), depth-dependent collimator response correction (frequency-distance princ

134 the MLEM method with photon attenuation and collimator response corrections.

135 Correction for the depth-dependent collimator response improved spatial resolution from 13.

136 ation for scatter, attenuation, and variable collimator response led to significantly better performa

137 uce a patient-specific attenuation map and a collimator response model based on the body contour prod

138 The collimator response model used the coregistered CT image

139 es reconstructed without the depth-dependent collimator response model.

140 with corrections for photon attenuation and collimator response showed less background activity and

141 of corrections for scatter, depth-dependent collimator response, attenuation, and finite spatial res

142 of corrections for scatter, depth-dependent collimator response, attenuation, and finite spatial res

143 Use of the UHE collimator resulted in a large reduction in 131I penetra

144 equipped with ultra-high-resolution fanbeam collimators (scan duration = 210 min).

145 In 131I SPECT, object scatter as well as collimator scatter and penetration are significant.

146 accuracy of such measurements is scatter and collimator septal penetration.

147 The acquisition parameters, such as the collimator set and the radius of rotation, offer a wide

148 ed data from 1 angular view of the 9-pinhole collimator showed the expected loss of spatial resolutio

149 LEHR collimators for (99m)Tc but that the PC collimator significantly improved the contrast recovery

150 The focal line is 114 cm from the collimator surface and shifted 20 cm from the detector m

151 When 10-cm from the collimator surface, the planar spatial resolutions FWHM

152 was found to be higher for the LEHR and HEGP collimators than for the PC collimator (e.g., 3.1 x 10(-

153 e therefore have investigated a multipinhole collimator that could improve the detection efficiency i

154 9 solid-state detector columns with tungsten collimators that rotate independently.

155 ents confirm both effects: with pyramids and collimator the thermal rectification is 10.9 +/- 0.8%, w

156 ng an HE collimator and that using a 511-keV collimator, the latter showed marked reduction in septal

157 With the jaws and multileaf collimator, the primary beam component of 0.5% was elimi

158 modulate the photon flux density and a slat collimator to collimate the TCT source beam in the axial

159 microscopy allows for the use of a minibeam collimator to reduce the total volume of material probed

160 B) SPECT uses a pair of dissimilar cone-beam collimators to expand the axial field of view for brain

161 c accuracy of SPECT, with either an UH or HE collimator, to that of PET in myocardial viability studi

162 aps estimated with a line source and fanbeam collimators (transAC).

163 With the UHE collimator, typical patient images showed an improvement

164 se collimator (HE), or the dedicated 511-keV collimator (UH), when imaging 511-keV photons, and compa

165 scans by shifting the animal bed through the collimator using an automated xyz stage.

166 The SPECT imaging performance of the fanbeam collimator was also characterized.

167 le-slice prototype of the parallel-cone (PC) collimator was capable of improving the image quality of

168 The image quality of the PC collimator was quantitatively compared with that of clin

169 On the basis of this comparison, the UHE collimator was selected for this investigation, which wa

170 Spatial resolution with the long-bore collimator was superior to that of a conventional large

171 Second, a prototype PC collimator was used in an experimental phantom study to

172 r half-cone beam, fan-beam and parallel-beam collimators were 5.2 (85.6), 5.1 (55.6) and 5.9 (39.7),

173 e where conventional sources have been used, collimators were employed to produce spatially coherent

174 atial resolutions and sensitivities of three collimators were measured.

175 s 30% poorer than that for the parallel-hole collimator, whereas the detection efficiency was increas

176 apart were separately detectable for the PC collimator, whereas this was not the case for (131)I and

177 r of the two sets of wedges on the multileaf collimator, which is closer to the patient and thus enha

178 e same spatial resolution as a parallel-hole collimator will have 5 times greater efficiency.

179 A cylindric collimator with 54 focused 2.0-mm-diameter conical pinho

180 that the spatial resolution of the 9-pinhole collimator with 8-mm diameter pinholes was 30% poorer th

181 ulations were carried out to compare the UHE collimator with a conventionally used, high-energy colli

182 A collimator with a nonuniform sensitivity function reduce

183 to which performance might be improved by a collimator with a nonuniform sensitivity profile.

184 ma-camera as a function of distance from the collimator with a point source array.

185 phantom and a high-resolution parallel-beam collimator with and without photon attenuation.

186 This study investigated a parallel-hole collimator with cone-shaped holes, which was designed to

187 The combination of a multichannel collimator with diamond anvil cells enabled the measurem

188 A half-cone beam collimator with the focal point located towards the base

189 g standard low-energy high-resolution (LEHR) collimators with hybrid PET to obtain coincidence and SP

190 lf-cone beam with parallel-beam and fan-beam collimators with similar resolution characteristics for

191 ting isotopes, such as (131)I, parallel-hole collimators with thick septa are required to limit septa