Medical Facts That Can and Cannot Be Proved by X-Ray: Historical Review and Present Possibilities

1943 ◽  
Vol 41 (5) ◽  
pp. 875
Author(s):  
Samuel W. Donaldson
Keyword(s):  
Historical Review ◽  
X Ray

Radiographic modalities for diagnosis of caries in a historical perspective: from film to machine-intelligence supported systems

2021 ◽  
pp. 20210010
Author(s):  
Ann Wenzel
Keyword(s):  
Panoramic Radiography ◽  
Ex Vivo ◽  
Cone Beam Ct ◽  
Historical Review ◽  
Machine Intelligence ◽  
Cone Beam ◽  
Radiographic Imaging ◽  
X Ray ◽  
Caries Lesions ◽  
Digital Intraoral Radiography

Radiographic imaging for the diagnosis of caries lesions has been a supplement to clinical examination for approximately a century. Various methods, and particularly X-ray receptors, have been developed over the years, and computer systems have focused on aiding the dentist in the detection of lesions and in estimating lesion depth. The present historical review has sampled accuracy ex vivo studies and clinical studies on radiographic caries diagnosis that have compared two or more receptors for capturing the image. The epochs of film radiography, xeroradiography, digital intraoral radiography, panoramic radiography and other extraoral methods, TACT analysis, cone-beam CT and artificial intelligence systems aiding in decision-making are reviewed. The author of this review (43 years in academia) has been involved in caries research and contributed to the literature in all the mentioned epochs.

Determination of Lattice Parameters by the Kossel and Divergent X-Ray Beam Techniques

1967 ◽  
Vol 11 ◽  
pp. 345-358 ◽  
Author(s):  
A. Lutts
Keyword(s):  
Historical Review ◽  
Lattice Parameters ◽  
General Relationship ◽  
Cubic Crystals ◽  
X Ray ◽  
Advantages And Disadvantages ◽  
Diffraction Patterns ◽  
Classical Means ◽  
High Degree ◽  
Beam Patterns

AbstractThe principal aim of this article is to develop in a clear and orderly manner a general relationship and show how it can be used to determine with a high degree of precision lattice parameters of tetragonal and hexagonal as well as cubic crystals. The introduction and extensive use of electron-probe microanalyzers provides a ready-made means of obtaining both Kossel and divergent X-ray beam patterns which could previously be produced only with specially constructed X-ray tubes. The present ease of their production as well as the continuing need for precise lattice parameters for the study of many problems associated with crystallized solids has stimulated a renewed interest in these two techniques. As has been recently shown by several experimental results limited to cubic crystals, these techniques are capable of giving lattice parameters with the same degree of precision as those obtained by the more classical means. The development of the general relationship is preceded by a brief historical review, a discussion of the relative merits of the methods, a short description of the nature of the diffraction patterns, and the geometrical conditions necessary for realizing precision parameter measurements. In conclusion, the advantages and disadvantages of the Kossel and divergentbeam methods compared with those of the classical powder techniques are enumerated and discussed.

scholarly journals Survey of New Solar Results

1971 ◽  
Vol 41 ◽  
pp. 233-250 ◽  
Author(s):  
R. Tousey
Keyword(s):  
Spatial Resolution ◽  
Solar Physics ◽  
Historical Review ◽  
Sounding Rockets ◽  
X Ray ◽  
Intensity Measurements ◽  
Line Identification ◽  
Fabry Perot ◽  
Made In ◽  
Objective Type

Following a brief historical review, new observations of the sun in the wavelength range 3000 to 20 Å are surveyed for the period since about 1958. Vehicles employed have been sounding rockets, the OSO (Orbiting Solar Observatories), balloons for the window 2300–1900 Å and for λ > 2700 Å, and small orbiting observatories such as Solrad, for XUV solar monitoring. Advances have been made in spectral resolution, using echelle gratings and also Fabry-Pérot interferometers. Much progress has been made towards increased spatial resolution, to obtain spectra of specific solar features and to analyse the chromosphere and corona. Methods employed include spectrographs that are stigmatic, or that have a stabilized solar image projected onto the slit; slitless objective-type spectrographs; and observations during a total eclipse. Spectra have been obtained of a solar flare, showing its form and intensity in the emission lines between 171 and 630 Å. From OSO 4–6 many XUV spectroheliograms and spectra have been obtained over the range 300 to 1350 Å, with spatial resolution 35 × 35 arc sec in OSO 6. Photographic XUV spectroheliograms have provided solar images with spatial resolution as great as 3 arc sec in some cases. Although much effort has been spent to increase the accuracy of XUV intensity measurements, a great deal remains to be done before the requirements of solar physics theory are satisfied. Line identification, however, is proceeding well, although more laboratory spectroscopy is needed. Not included in the survey is the Bragg Spectrometer X-ray range below about 20 Å.

Measurements of the intercombination and forbidden lines from the spectra of helium-like ions in tokamaks and electron beam ion traps

2008 ◽  
Vol 86 (1) ◽  
pp. 291-306 ◽  
Author(s):  
M Bitter ◽  
K W Hill ◽  
S von Goeler ◽  
W Stodiek ◽  
P Beiersdorfer ◽  
...  
Keyword(s):  
Electron Beam ◽  
Radial Profile ◽  
Historical Review ◽  
Ion Traps ◽  
X Ray ◽  
Spatially Resolved ◽  
X Ray Imaging ◽  
Radial Profiles ◽  
Theoretical Predictions ◽  
New Type

The paper reviews the results from tokamak experiments and measurements on electron beam ion traps for the line ratios x/w, y/w, and z/w in the spectra of helium-like ions with Z in the range from 14 to 28. With the exception of the DITE experiments, where these line ratios were found to be in agreement with theoretical predictions, all other tokamak experiments yielded values that were significantly greater than predicted. The reasons for these discrepancies are not yet understood. It is possible that radial profile effects were not properly taken into account in the majority of the tokamak experiments. The paper also gives a short historical review of the X-ray diagnostic developments and presents very recent data from a new type of X-ray imaging crystal spectrometer, which records spatially resolved spectra with a spatial resolution of about 1 cm in the plasma. These new data can be Abel inverted, so that it will be possible to determine line ratios at each radial position in the plasma. Effects of radial profiles, which may have affected the chord-integrated measurements of the past, will thus be eliminated in the future. PACS Nos.: 52.55.Fa, 32.30.Rj

scholarly journals X-ray therapy for chronic arthritis Appelrath (ref. Zentr. F. Ch., 1926, No. 12)

2021 ◽  
Vol 22 (8) ◽  
pp. 963-964
Author(s):  
M. Friedland
Keyword(s):  
Range Of Motion ◽  
Historical Review ◽  
Chronic Arthritis ◽  
Subjective Improvement ◽  
X Ray ◽  
Favorable Impression

X-ray therapy of chronic arthritis, considered by Appel rath (according to the ref. Zentr. F. Ch., 1926, No. 12) in the plane of the historical review leaves a very favorable impression: in many cases, a significant subjective improvement and increase in the range of motion of the joints is obtained.

scholarly journals The use of computed tomography in identifying radiologically occult hip fractures in the elderly

2014 ◽  
Vol 96 (3) ◽  
pp. 234-237 ◽  
Author(s):  
S Heikal ◽  
P Riou ◽  
L Jones
Keyword(s):  
Computed Tomography ◽  
Hip Fractures ◽  
Historical Review ◽  
The Elderly ◽  
Acetabular Fractures ◽  
Fractured Neck Of Femur ◽  
Neck Of Femur ◽  
X Ray ◽  
Magnetic Resonance Imaging Mri ◽  
Occult Hip Fractures

Introduction Fractured neck of femur (NOF) is a cause of significant morbidity and mortality. Approximately 4% of patients with an initial normal hip x-ray in the emergency department (ED) will in fact have an occult fracture. In cases where there is ongoing clinical suspicion of NOF fracture despite a normal hip x-ray, alternative imaging should be used. Although available evidence supports the use of magnetic resonance imaging (MRI) for this, it is often not readily accessible from the ED. In our department, it is common practice to request computed tomography (CT). Methods A historical review was undertaken of all patients who presented between October 2007 and January 2011 who had CT requested by ED staff. Patients included in the study were those who presented following low impact trauma in whom fractured NOF was suspected despite a normal x-ray. Results Of the 65 included patients, fractures (pelvic and hip) were identified in 38 patients on CT. Fractured NOFs were found in 13 patients. Acetabular fractures were found in nine patients, five of whom required further orthopaedic management. One patient went on to have MRI to confirm the diagnosis of an impacted NOF fracture, suspected both on x-ray and CT. Further review was undertaken of the medical notes of discharged patients to identify any who reattended or required further imaging. No such cases were found. Conclusions This review has shown the use of CT to be a practical approach to improving the care of patients with occult hip fractures.

Space and Time Distribution of Hard X-Ray Emission in a Loop at the Beginning of a Flare

1994 ◽  
Vol 144 ◽  
pp. 275-277
Author(s):  
M. Karlický ◽  
J. C. Hénoux
Keyword(s):  
Time Distribution ◽  
Electron Bombardment ◽  
Spatial Evolution ◽  
Superthermal Electrons ◽  
Flare Loop ◽  
X Ray ◽  
Superthermal Electron ◽  
Flare Loops ◽  
Chromospheric Evaporation ◽  
Temporal And Spatial

AbstractUsing a new ID hybrid model of the electron bombardment in flare loops, we study not only the evolution of densities, plasma velocities and temperatures in the loop, but also the temporal and spatial evolution of hard X-ray emission. In the present paper a continuous bombardment by electrons isotropically accelerated at the top of flare loop with a power-law injection distribution function is considered. The computations include the effects of the return-current that reduces significantly the depth of the chromospheric layer which is evaporated. The present modelling is made with superthermal electron parameters corresponding to the classical resistivity regime for an input energy flux of superthermal electrons of 109erg cm−2s−1. It was found that due to the electron bombardment the two chromospheric evaporation waves are generated at both feet of the loop and they propagate up to the top, where they collide and cause temporary density and hard X-ray enhancements.

Some Problems in Understanding the Solar Corona

1994 ◽  
Vol 144 ◽  
pp. 1-9
Author(s):  
A. H. Gabriel
Keyword(s):  
Solar Corona ◽  
Solar Atmosphere ◽  
Theoretical Modelling ◽  
Total System ◽  
Major Advance ◽  
X Ray ◽  
Proper Perspective ◽  
Space Observations

The development of the physics of the solar atmosphere during the last 50 years has been greatly influenced by the increasing capability of observations made from space. Access to images and spectra of the hotter plasma in the UV, XUV and X-ray regions provided a major advance over the few coronal forbidden lines seen in the visible and enabled the cooler chromospheric and photospheric plasma to be seen in its proper perspective, as part of a total system. In this way space observations have stimulated new and important advances, not only in space but also in ground-based observations and theoretical modelling, so that today we find a well-balanced harmony between the three techniques.

White-Light Coronal Structures: Streamers and CMEs

1994 ◽  
Vol 144 ◽  
pp. 82
Author(s):  
E. Hildner
Keyword(s):  
Emission Line ◽  
Electron Density ◽  
White Light ◽  
Coronal Mass Ejections ◽  
X Rays ◽  
Solar Cycles ◽  
Temperature Function ◽  
X Ray ◽  
Eclipse Observations ◽  
Coronal Structures

AbstractOver the last twenty years, orbiting coronagraphs have vastly increased the amount of observational material for the whitelight corona. Spanning almost two solar cycles, and augmented by ground-based K-coronameter, emission-line, and eclipse observations, these data allow us to assess,inter alia: the typical and atypical behavior of the corona; how the corona evolves on time scales from minutes to a decade; and (in some respects) the relation between photospheric, coronal, and interplanetary features. This talk will review recent results on these three topics. A remark or two will attempt to relate the whitelight corona between 1.5 and 6 R⊙to the corona seen at lower altitudes in soft X-rays (e.g., with Yohkoh). The whitelight emission depends only on integrated electron density independent of temperature, whereas the soft X-ray emission depends upon the integral of electron density squared times a temperature function. The properties of coronal mass ejections (CMEs) will be reviewed briefly and their relationships to other solar and interplanetary phenomena will be noted.

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