Discovery of a self-pumped, phase-conjugate mirror with high speed, high image quality, and large accepted incidence area

In our initial publication on this subject1) we reported results demonstrating that contrast is the most important factor in producing the high image quality required for reliable image analysis. We also listed the factors which enhance contrast in order of the experimentally determined magnitude of their effect. The two most powerful factors affecting image contrast attainable with sheet film are beam intensity and KV. At that time we had only qualitative evidence for the ranking of enhancing factors. Later we carried out the densitometric measurements which led to the results outlined below.Meaningful evaluations of the cause-effect relationships among the considerable number of variables in preparing EM negatives depend on doing things in a systematic way, varying only one parameter at a time. Unless otherwise noted, we adhered to the following procedure evolved during our comprehensive study:Philips EM-300; 30μ objective aperature; magnification 7000- 12000X, exposure time 1 second, anti-contamination device operating.

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Image quality vs data obtainment in biological electron microscopy

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100141950 ◽

1986 ◽

Vol 44 ◽

pp. 42-43

Author(s):

J. E. Johnson

Keyword(s):

Electron Microscopy ◽

Endoplasmic Reticulum ◽

Electron Beam ◽

Image Quality ◽

High Speed ◽

Early Period ◽

Early Years ◽

Fluorescent Screen ◽

Embedding Medium

In the early years of biological electron microscopy, scientists had their hands full attempting to describe the cellular microcosm that was suddenly before them on the fluorescent screen. Mitochondria, Golgi, endoplasmic reticulum, and other myriad organelles were being examined, micrographed, and documented in the literature. A major problem of that early period was the development of methods to cut sections thin enough to study under the electron beam. A microtome designed in 1943 moved the specimen toward a rotary “Cyclone” knife revolving at 12,500 RPM, or 1000 times as fast as an ordinary microtome. It was claimed that no embedding medium was necessary or that soft embedding media could be used. Collecting the sections thus cut sounded a little precarious: “The 0.1 micron sections cut with the high speed knife fly out at a tangent and are dispersed in the air. They may be collected... on... screens held near the knife“.

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Double phase-conjugate mirror: oscillation and amplification properties

Optics Communications ◽

10.1016/0030-4018(95)00005-s ◽

1995 ◽

Vol 115 (5-6) ◽

pp. 539-544

Author(s):

N.A Korneev ◽

S.L Sochava

Keyword(s):

Phase Conjugate ◽

Double Phase ◽

Phase Conjugate Mirror

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High-quality brain perfusion SPECT images may be achieved with a high-speed recording using 360° CZT camera

EJNMMI Physics ◽

10.1186/s40658-020-00334-7 ◽

2020 ◽

Vol 7 (1) ◽

Author(s):

Manon Bordonne ◽

Mohammad B. Chawki ◽

Pierre-Yves Marie ◽

Timothée Zaragori ◽

Véronique Roch ◽

...

Keyword(s):

Image Quality ◽

High Speed ◽

Brain Perfusion ◽

Fold Increase ◽

Brain Structures ◽

Czt Camera ◽

Recording Time ◽

Brain Perfusion Spect ◽

Central Brain ◽

Perfusion Spect

Abstract Objective The aim of this study was to compare brain perfusion SPECT obtained from a 360° CZT and a conventional Anger camera. Methods The 360° CZT camera utilizing a brain configuration, with 12 detectors surrounding the head, was compared to a 2-head Anger camera for count sensitivity and image quality on 30-min SPECT recordings from a brain phantom and from 99mTc-HMPAO brain perfusion in 2 groups of 21 patients investigated with the CZT and Anger cameras, respectively. Image reconstruction was adjusted according to image contrast for each camera. Results The CZT camera provided more than 2-fold increase in count sensitivity, as compared with the Anger camera, as well as (1) lower sharpness indexes, giving evidence of higher spatial resolution, for both peripheral/central brain structures, with respective median values of 5.2%/3.7% versus 2.4%/1.9% for CZT and Anger camera respectively in patients (p < 0.01), and 8.0%/6.9% versus 6.2%/3.7% on phantom; and (2) higher gray/white matter contrast on peripheral/central structures, with respective ratio median values of 1.56/1.35 versus 1.11/1.20 for CZT and Anger camera respectively in patients (p < 0.05), and 2.57/2.17 versus 1.40/1.12 on phantom; and (3) no change in noise level. Image quality, scored visually by experienced physicians, was also significantly higher on CZT than on the Anger camera (+ 80%, p < 0.01), and all these results were unchanged on the CZT images obtained with only a 15 min recording time. Conclusion The 360° CZT camera provides brain perfusion images of much higher quality than a conventional Anger camera, even with high-speed recordings, thus demonstrating the potential for repositioning brain perfusion SPECT to the forefront of brain imaging.

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