Digital automatic calculator for a meter for measuring the optical density of x-ray pictures

1988 ◽  
Vol 31 (2) ◽  
pp. 135-136
Author(s):  
A. A. Ketkovich ◽  
A. M. Lizunov ◽  
V. S. Fedosov
Keyword(s):  
Author(s):  
Oladotun A. Ojo ◽  
Peter A. Oluwafisoye ◽  
Charles O. Chime

The sensitivity of radiographic films is an important factor to the clarity and accuracy of X-ray exposure to patients during treatment or diagnostic periods. It is therefore important to do a thorough analysis of the sensitivity of the radiographic film before and after exposure to enhance the Quality Assurance (QA) and the Quality Control (QC), of the exposure procedures. The optical densities (OD) of each film was measured, with a densitometer model MA 5336, made by GAMMEX. These values were then converted to the absorbed dose (X mGy), which is the amount of dose absorbed by each patient. The optical density versus the dose curve, followed the expected pattern, showing a good prediction from the General model, that the films employed in the exposures were of good quality and standard. Hence the optical density versus dose sensitometric curves depicts the outcome of the various films sensitivity after an exposure to the X-ray radiation through the patients.


2017 ◽  
Vol 7 (3) ◽  
pp. 150-155 ◽  
Author(s):  
Emine S Kursun-Çakmak ◽  
Nihat Akbulut ◽  
Dogan D Öztas

ABSTRACT Introduction Ample radiopacity in order to distinguish from the surrounding tissues is a desirable property of dental graft materials. A total of 15 bone graft materials’ (BGMs) opacities were analyzed in this study. Materials and methods Graft materials were placed in the implant cavity (5 × 10 mm) in cadaver's mandible respectively. Cavity was exposed by using periapical film and a dental X-ray machine at 70 kVp and 8 mA. The optical density of the radiographic images was measured with a transmission densitometer. One-way analysis of variance (ANOVA) was conducted for statistical analysis. Results Among the materials tested, the most radiolucent bone grafts were Grafton and Allogenix with a statistical significance of p ≥ 0.05. 4Bone and Bego Oss exhibited the highest radiopacity with a statistical significance of p ≥ 0.05. Inadequate radiopacity of the dental graft materials may lead to confusion among clinicians in the radiographical follow-up. Among 15 BGMs tested, only three had higher density than bone tissue. Conclusion The radiopacity of the BGM was found to be higher than bone at only three of them. How to cite this article Kursun-Çakmak ES, Akbulut N, Öztas DD. Comparative Evaluation of the Radiopacity of Bone Graft Materials used in Dentistry. J Contemp Dent 2017;7(3):150-155.


2013 ◽  
Vol 4 (1) ◽  
pp. 95-100
Author(s):  
Jubaid Abdul Qayyum ◽  
Md Masum Howlader ◽  
Md Tamzeed-Al-Alam ◽  
Md Saiful Islam ◽  
Tahmid Latif ◽  
...  

Osteoporosis or bone loss affects many people, particularly the aged women, and leads to disabling bone fractures. An early diagnosis could provide preventive management. However, available bone densitometry equipment are very expensive and not available widely in the Third World. The present work presents the design & development of an innovative low cost bone densitometer based on conventional X-ray equipment available widely. The main innovation is the incorporation of a stack of aluminium with varying thickness placed beside the limb of a patient while taking an X-ray image. Then the optical density of the bone area in the developed film is compared to that from the aluminium stack, which eliminates variations due to all other processing factors, and gives a measure of the bone density. A low cost device has been developed to measure the optical density of the X-ray film over a circular area of about 1cm to give an average reading, which is more appropriate than spot metering in this application. Preliminary measurements of a few human subjects using this equipment clearly indicate the differences obtained due to expected osteoporosis. Calibration with standard bone densitometry equipment could provide values in standard units. This low cost innovative method and equipment appears to provide a low cost alternative to the diagnosis of osteoporosis. DOI: http://dx.doi.org/10.3329/bjmp.v4i1.14693 Bangladesh Journal of Medical Physics Vol.4 No.1 2011 95-100


2018 ◽  
Vol 25 (3) ◽  
pp. 833-847 ◽  
Author(s):  
Viatcheslav Berejnov ◽  
Boris Rubinstein ◽  
Lis G. A. Melo ◽  
Adam P. Hitchcock

A dose integral of time-dependent X-ray absorption under conditions of variable photon energy and changing sample mass is derived from first principles starting with the Beer–Lambert (BL) absorption model. For a given photon energy the BL dose integralD(e, t) reduces to the product of an effective time integralT(t) and a dose rateR(e). Two approximations of the time-dependent optical density,i.e.exponentialA(t) =c+aexp(−bt) for first-order kinetics and hyperbolicA(t) =c+a/(b+t) for second-order kinetics, were considered for BL dose evaluation. For both models three methods of evaluating the effective time integral are considered: analytical integration, approximation by a function, and calculation of the asymptotic behaviour at large times. Data for poly(methyl methacrylate) and perfluorosulfonic acid polymers measured by scanning transmission soft X-ray microscopy were used to test the BL dose calculation. It was found that a previous method to calculate time-dependent dose underestimates the dose in mass loss situations, depending on the applied exposure time. All these methods here show that the BL dose is proportional to the exposure timeD(e, t) ≃K(e)t.


1978 ◽  
Vol 34 (1) ◽  
pp. 55-59 ◽  
Author(s):  
G. Agelao ◽  
G. Greco ◽  
M. C. Romano ◽  
D. Di Mariano

2018 ◽  
Vol 99 (4) ◽  
pp. 191-196
Author(s):  
N. A. Gorbunov ◽  
A. P. Dergilev ◽  
V. I. Kochura ◽  
Ya. L. Manakova ◽  
S. N. Volchenko ◽  
...  

Objective. To determine the opportunities of low-dose digital fluorography (LDDF) in differential diagnosis of phenotypic variants of chronic obstructive pulmonary disease (COPD).Material and methods. There were 107 patients with clinically diagnosed COPD of varying severity examined. The average age of the patients was 51.8±1.5 years (46–59 years). All patients for LDDF of the chest in the frontal projection in the inspiratory and expiratory phase of respiration were undergone.Results. The electron optical density of the lungs was determined in the upper, middle and lower zones of both lungs. As a result in patients with a predominance of emphysematous variant of COPD (n=15) the most characteristic radiological symptom was lung hyperventilation (14% of 107 patients) and inspiratory electron optical density value was 748.18±4.72 optical density units (ODU). In patients with a predominance of bronchitic variant of COPD (n=43) the most common radiological symptom was the presence of symptom amplification and deformation of lung pattern (40% of 107 patients) and inspiratory electron optical density value was 668.04±12.26 ODU. For patients with mixed phenotypic variant of COPD (n=49) it was characterized by a combination of X-ray symptom amplification and deformation of lung pattern with lung emphysema (46% of 107 patients); the average value of inspiratory electron optical density value was 815.24±17.25 ODU.Conclusion. The technique of LDDF can detect X-ray symptoms and determine inspiratory and expiratory electron optical density of the lungs in patients with COPD that allows optimizing the differential diagnosis of phenotypic variants of chronic obstructive pulmonary disease.


Author(s):  
V. N. Druzhinin ◽  
V. G. Suvorov ◽  
A. N. Cherny ◽  
S. N. Troynakov ◽  
U. T. Tukhtaev

Introduction. Timely and adequate diagnosis and treatment of degenerative-dystrophic diseases of the bone and joint apparatus, which include epicondylitis (epicondylosis), including professionally caused, continues to be a serious health problem today, since they cause significant economic damage associated with temporary and persistent disability of the active part of the world’s population. In this regard, the search for methods and methodological approaches to improve the radiation diagnosis of this disease remains relevant. The study is devoted to solution of important medical problems, including occupational diseases-optimization of X-ray of the ulnar epicondylitis based on the use of new methodological approaches quantifying the density of pathological remodeling of bone structures in the subject area, that allow to objectify the direction of changes in monitoring intensity changes in the estimated structures.The aim of the study is to improve the quality of x-ray diagnostics of ulnar epicondylitis based on a precision assessment of the optical density of bone and periarticular tissues using digital radiography.Materials and methods. A comparative analysis of the results of a comprehensive clinical and radiological examination of patients, workers of the main group (fitters and laborers machine-building plants) working age range of 30–50 years with a clinical picture of subacute phase of the ulnar epicondylitis in the absence of a pathognomonic ultrasound findings and x-ray morphological signs of the disease. X-ray studies were performed using digital low-dose x-ray diagnostic devices. Visualization, processing, analysis of medical images and comparison of results in the dynamics of research were carried out using the programs «Lins machaon doctor’s workstation». To measure the conditional optical density of bone and soft tissues, we used the ROI tool (zone of interest), which allows us to determine the desired value in areas of different dimensions. Measurements were performed on digital radiographs and computer monitor screens in the areas of interest: the lateral parts of the humerus condyles and adjacent periarticular tissues with the calculation of the average values of the optical density index (ID) and optical density gradients (IDG) relative to the density of periarticular soft tissues.Results. Analysis of the results of a posteriori osteodensitometry of the distal humerus within the framework of the developed algorithm, which includes the use of absolute and relative indicators of conditional optical density after preliminary color correction of digital x-ray images of bone and paraossal tissue structures, allowed us to expand our understanding of the topography of the distribution of mineral saturation in the condyles of at-risk individuals relative to those of the control group. It was found that the indicators of optical density of bone and paraossal tissues can be a kind of (conditional), sometimes the only indicators of the degree of severity of changes, positive or negative dynamics of pathophysiological processes. Density differences in the distal parts of the right and left humerus (bony and soft -tissue paraossal structures of the condyles) in the control group (conditional norm) in terms of absolute optical density and its gradient, regardless of the assessment area, were insignificant (statistically unreliable), although they were multidirectional. In patients with clinical signs of epicondylitis in the absence of x-ray morphologically detectable structural changes, a decrease in ID and the dynamics of its recovery at various stages of observation were revealed. Even when the ID of the actual bone structure is relatively equal, the IDG differs in different people, since it is largely determined by metabolic processes that are dynamically more labile than in the bones, and thus serve as a kind of indicator of their intensity. Taking into account the relative torpidity of perestroika processes in the structures of the bone tissue of the condyles in epicondylitis, IDG should be considered a more informative indicator of their dynamics. The importance of optical density indicators as predictors of the considered pathology is particularly evident in the process of analyzing the results of its diagnosis and development in the dynamics of observations not so much at the collective as at the individual level of assessment.Conclusions. The application of the developed methodological approach allows us to significantly expand our understanding of the topographical distribution of the density of bone and soft tissue structures of the distal humerus at various stages of examination of patients, including the early subclinical phases of possible pathology, even in the absence of visually detectable x-ray morphological changes. The use of an original algorithm for evaluating tissue density will reduce the negative role of the so-called «human factor» and thus significantly ensure the objectivity of the interpretation of research results.Funding. The study had no funding.Conflict of interests. The authors declare no conflict of interests.


2018 ◽  
Vol 25 (6) ◽  
pp. 57-67
Author(s):  
D. A. Domenyuk ◽  
S. Z. Chukov ◽  
O. I. Anfinogenova ◽  
I. V. Rzhepakovsky ◽  
O. O. Ivanyuta

Aim. The research was designed to assess the capabilities of the microcomputer tomography method with the subsequent image analysis and determination of the mineral optical density of demineralized areas to improve the early diagnosis of fissure caries of permanent molars after the eruption.Materials and methods. Using a high-resolution X-ray microtomograph “Skyscan 1176” (“Bruker”, Belgium) followed by post-processing and analysis of the obtained tomograms, 75 molars of children aged 8-11 were removed by orthodontic indications. Of the total number of teeth removed, research groups were formed – teeth without signs of demineralization and teeth with carious lesions in the stage of white, light brown, brown and black spots. In the reconstructed 2D and 3D images were identified the zones in the outer (0.05-0.5 mm), middle (0.75-1.25 mm) and inner (1.5-2.0 mm) thirds of the thickness of the enamel layer followed by the computation in the CTvox program (3.3.0-1403, Bruker-micro CT) of the averaged X-ray (mineral) density indicators. Results. According to the tomograms of the teeth of the studied groups, the average indicators of the mineral optical density of the intact teeth enamel were identified as well as the average indicators of teeth with various types of carious lesions within the enamel. The following sequence was revealed in descending order of the parameters of optical density: healthy enamel (2.47±0.12 g/cm3) – caries in the white spot stage (2.41±0.11 g/cm3) – caries in the light brown spot stage (2.32±0.07 g/cm3) – caries in the brown spot stage (2.18±0.12 g/cm3) – caries in the black spot stage (1.81±0.12 g/cm3). Identifying the correlations between the color of carious lesion and mineral density of tooth enamel broadens the understanding of the mechanisms of the development of caries pathogenesis and contributes to the improvement of therapeutic and preventive measures aimed at improving caries resistance.Conclusion. The use of microcomputer tomography in combination with other special methods characterizes fissure caries as a sequential, gradually progressing destructive process of hard tooth tissues (from focal demineralization to cavity formation), which establishes the relationship between the intensity of internal disturbances and external damage.


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