Performance of SwiftScan planar and SPECT technology using low-energy high-resolution and sensitivity collimator compared with Siemens SPECT system

2021 ◽  
Vol Publish Ahead of Print ◽  
Author(s):  
Takayuki Shibutani ◽  
Masahisa Onoguchi ◽  
Hiroto Yoneyama ◽  
Takahiro Konishi ◽  
Kenichi Nakajima
2020 ◽  
Author(s):  
Takayuki Shibutani ◽  
Masahisa Onoguchi ◽  
Hiroto Yoneyama ◽  
Takahiro Konishi ◽  
Kenichi Nakajima

Abstract Background A new low-energy high-resolution-sensitivity (LEHRS) collimator was developed by General Electric Healthcare. SwiftScan planar and SPECT system using LEHRS collimator were formulated to achieve the low-dose and/or short-term acquisition. We demonstrated the performance of SwiftScan planar and SPECT system with LEHRS collimator using phantoms. Methods Line source, cylindrical and flat plastic dish phantoms were used to evaluate the performance of planar and SPECT images for four patterns of Siemens LEHR, GE LEHR, GE LEHRS and SwiftScan using two SPECT-CT scanners. Each phantom was filled with 99mTc solution, and the spatial resolution, sensitivity and image uniformity were calculated from the planar and SPECT data. Results The full-width at half maximum (FWHM) values as system spatial resolution of Siemens LEHR, GE LEHR and GE LEHRS were 7.3, 7.5 and 7.3 mm, respectively. GE LEHRS showed the lower FWHM value by increasing the blend ratio in Clarity 2D processing. The system sensitivities of Siemens LEHR, GE LEHR and GE LEHRS were 88.4, 67.6 and 89.8 cps/MBq, respectively. The system sensitivity of GE LEHRS increased by approximately 30% compared with that of GE LEHR and was similar to that of Siemens LEHR. The FWHM values of SPECT with an FBP method were 10.3, 10.4, 10.4 and 10.3 mm (p = n.s.). The FWHM values of the OSEM method were better with an increase in iteration values. The differential uniformities of Siemens LEHR, GE LEHR, GE LEHRS and GE SwiftScan were 15.3%, 15.1%, 15.4% and 14.6%, respectively, using the FBP method. The differential uniformity of OSEM method was higher with an increase in iteration value. Conclusion The SwiftScan planar and SPECT have a high sensitivity while maintaining the spatial resolution compared with the conventional system.


Author(s):  
Bertholdand Senftinger ◽  
Helmut Liebl

During the last few years the investigation of clean and adsorbate-covered solid surfaces as well as thin-film growth and molecular dynamics have given rise to a constant demand for high-resolution imaging microscopy with reflected and diffracted low energy electrons as well as photo-electrons. A recent successful implementation of a UHV low-energy electron microscope by Bauer and Telieps encouraged us to construct such a low energy electron microscope (LEEM) for high-resolution imaging incorporating several novel design features, which is described more detailed elsewhere.The constraint of high field strength at the surface required to keep the aberrations caused by the accelerating field small and high UV photon intensity to get an improved signal-to-noise ratio for photoemission led to the design of a tetrode emission lens system capable of also focusing the UV light at the surface through an integrated Schwarzschild-type objective. Fig. 1 shows an axial section of the emission lens in the LEEM with sample (28) and part of the sample holder (29). The integrated mirror objective (50a, 50b) is used for visual in situ microscopic observation of the sample as well as for UV illumination. The electron optical components and the sample with accelerating field followed by an einzel lens form a tetrode system. In order to keep the field strength high, the sample is separated from the first element of the einzel lens by only 1.6 mm. With a numerical aperture of 0.5 for the Schwarzschild objective the orifice in the first element of the einzel lens has to be about 3.0 mm in diameter. Considering the much smaller distance to the sample one can expect intense distortions of the accelerating field in front of the sample. Because the achievable lateral resolution depends mainly on the quality of the first imaging step, careful investigation of the aberrations caused by the emission lens system had to be done in order to avoid sacrificing high lateral resolution for larger numerical aperture.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Takayuki Shibutani ◽  
Masahisa Onoguchi ◽  
Yuka Naoi ◽  
Hiroto Yoneyama ◽  
Takahiro Konishi ◽  
...  

AbstractThe aim of this study was to demonstrate the usefulness of SwiftScan with a low-energy high-resolution and sensitivity (LEHRS) collimator for bone scintigraphy using a novel bone phantom simulating the human body. SwiftScan planar image of lateral view was acquired in clinical condition; thereafter, each planar image of different blend ratio (0–80%) of Crality 2D processing were created. SwiftScan planar images with reduced acquisition time by 25–75% were created by Poisson’s resampling processing. SwiftScan single photon emission computed tomography (SPECT) was acquired with step-and-shoot and continuous mode, and SPECT images were reconstructed using a three-dimensional ordered subset expectation maximization incorporating attenuation, scatter and spatial resolution corrections. SwiftScan planar image showed a high contrast to noise ratio (CNR) and low percent of the coefficient of variance (%CV) compared with conventional planar image. The CNR of the tumor parts in SwiftScan SPECT was higher than that of the conventional SPECT image of step and shoot acquisition, while the %CV showed the lowest value in all systems. In conclusion, SwiftScan planar and SPECT images were able to reduce the image noise compared with planar and SPECT image with a low-energy high-resolution collimator, so that SwiftScan planar and SPECT images could be obtained a high CNR. Furthermore, the SwiftScan planar image was able to reduce the acquisition time by 25% when the blend ratio of Clarity 2D processing set to more than 40%.


2010 ◽  
Vol 508 (2) ◽  
pp. 197-202
Author(s):  
M. Loewenhaupt ◽  
A. Metz ◽  
N. M. Pyka ◽  
D. McK. Paul ◽  
J. Martin ◽  
...  

2000 ◽  
Vol 639 ◽  
Author(s):  
Philomela Komninou ◽  
Joseph Kioseoglou ◽  
Eirini Sarigiannidou ◽  
George P. Dimitrakopulos ◽  
Thomas Kehagias ◽  
...  

ABSTRACTThe interaction of growth intrinsic stacking faults with inversion domain boundaries in GaN epitaxial layers is studied by high resolution electron microscopy. It is observed that stacking faults may mediate a structural transformation of inversion domain boundaries, from the low energy types, known as IDB boundaries, to the high energy ones, known as Holt-type boundaries. Such interactions may be attributed to the different growth rates of adjacent domains of inverse polarity.


1983 ◽  
Vol 27 (5) ◽  
pp. 1913-1926 ◽  
Author(s):  
C. H. Johnson ◽  
N. M. Larson ◽  
C. Mahaux ◽  
R. R. Winters

2008 ◽  
Vol 92 (3) ◽  
pp. 579-587 ◽  
Author(s):  
Seung H. Ko ◽  
Heng Pan ◽  
Costas P. Grigoropoulos ◽  
Jean M. J. Fréchet ◽  
Christine K. Luscombe ◽  
...  

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