scholarly journals The Spectrum of Ossifying Fibroma

Author(s):  
Johanna Patricia A. Cañal

An ossifying fibroma is a monostotic lesion that occurs in craniofacial bones.  It usually presents as a painless well-circumscribed, slow-growing mass in the 3rd and 4th decade.  It is a benign fibro-osseous lesion that is part of the bigger spectrum of fibro-osseous lesions which includes fibrous dysplasia, juvenile active ossifying fibroma, psammomatous ossifying fibroma, and extragnathic ossifying fibroma of the skull.    An ossifying fibroma, because of its well-circumscribed nature, lends itself to surgery better than does fibrous dysplasia.  Simple enucleation is usually sufficient for ossifying fibromas whereas curettage is probably better suited for fibrous dysplasia.    Radiographically, it is seen as a well-demarcated radiolucency in the mandible or maxilla, more common in the former than the latter.  It typically measures anywhere from 1 to 5 cm.  There may or may not be a central opacity or calcification, depending on the maturity of the lesion.  An immature lesion may present as completely radiolucent whereas a mature lesion may be completely radiopaque, although most lesions demonstrate varying degrees of radiopacity.  The images above show 2 samples of the same lesion on opposite sides of the spectrum.  Both are well-circumscribed but one is relatively radiolucent while the other is floridly sclerotic.   Is there a pathognomonic finding on x-ray?  Unfortunately, there is not one single finding that will distinguish an ossifying fibroma from other fibro-osseous lesion.  Does it matter?  Yes.  X-rays will lead the clinician to one diagnosis or the other and help plan the intended surgery.        

2012 ◽  
Vol 2 ◽  
pp. 52 ◽  
Author(s):  
R Mithra ◽  
Pavitra Baskaran ◽  
M Sathyakumar

Cemento-ossifying fibroma is a benign fibro-osseous lesion belonging to the same category as fibrous dysplasia and cementifying dysplasia. These are slow-growing lesions that are seen in the third and fourth decades of life. Both the ossifying fibroma and cemento-ossifying fibroma represent two extremes of the same disease process since histologically both contain bone and cementum. However, the term cemento-ossifying fibroma is justified on the basis of clinical and radiological correlation. Radiographs have become an essential tool in the diagnosis of lesions in the jaw, where the anatomy is complex. Nowadays, CT provides information for diagnosis as well as treatment planning. In this case series, we report three cases of cemento-ossifying fibroma that were histologically confirmed and discuss the imaging findings.


1992 ◽  
Vol 2 (2) ◽  
pp. 43-46
Author(s):  
U. Fusco ◽  
R. Capelli ◽  
A. Avai ◽  
M. Gerundini ◽  
L. Colombini ◽  
...  

Between 1980 and 1987 we have implanted 46 isoelastic cementless THR in 40 patients affected with rheumatoid arthritis. We have reviewed 38 hips clinically and by X-ray. The mean follow-up was 8,5 years. Harris hip scores ranged from 30.6 preoperatively to 73,4 post-operatively when reviewed. While on the other hand Merle D'Aubigné hip scores ranged from 7,06 pre-operatively to 15,59 post-operatively. All patients have been satisfied, and X-rays showed an improvement for both Charnely and Gruen X-ray score.


1931 ◽  
Vol 53 (3) ◽  
pp. 405-411 ◽  
Author(s):  
James A. Hawkins

Areas on the abdomen of the same guinea pig were exposed to suberythemal doses of soft X-rays, to heat of an intensity below the critical dose for the production of burns, and to both radiations in sequence with various time intervals between the exposures. The only effect of exposure to X-ray or heat alone was a slight scaling of the skin. The areas exposed to heat and X-radiation developed well-marked and persistent burns when the exposure to one agent was made within 3 hours of the other. Scaling of the skin developed when the exposure to one agent was made 1 day after the other. This scaling was more marked and lasted longer than the scaling produced by either agent alone. The results were the same no matter in which sequence the agents were applied.


2020 ◽  
Vol 497 (3) ◽  
pp. 3234-3250 ◽  
Author(s):  
Diego A Farias ◽  
Alejandro Clocchiatti ◽  
Tyrone E Woods ◽  
Armin Rest

ABSTRACT Supersoft X-rays sources (SSSs) have been proposed as potential Type Ia supernova (SN Ia) progenitors. If such objects are indeed persistently X-ray luminous and embedded in sufficiently dense interstellar medium (ISM), they will be surrounded by extended nebular emission. These nebulae should persist even long after an SN Ia explosion, due to the long recombination and cooling times involved. With this in mind, we searched for nebular [O iii] emission around four SSSs and three SNRs in the Large Magellanic Cloud, using the 6.5-m Baade telescope at Las Campanas Observatory and the imacs camera. We confirm that, out of the four SSS candidates, only CAL 83 can be associated with an [O iii] nebula. The [O iii] luminosity for the other objects is constrained to ≲17 per cent of that of CAL 83 at 6.8 pc from the central source. Models computed with the photoionization code cloudy indicate that either the ISM densities in the environments of CAL 87, RX J0550.0-7151, and RX J0513.9-6951 must be significantly lower than surrounding CAL 83 or the average X-ray luminosities of these sources over the last ≲10  000 yr must be significantly lower than presently observed, in order to be consistent with the observed luminosity upper limits. For the three SNRs we consider (all with ages <1000 yr), our [O iii] flux measurements together with the known surrounding ISM densities strongly constrain the ionizing luminosity of their progenitors in the last several thousand years, independent of the progenitor channel.


1995 ◽  
Vol 78 (2) ◽  
pp. 407-412 ◽  
Author(s):  
David L Anderson ◽  
William C Cunningham ◽  
Tyler R Lemdstrom ◽  
Ilhan Olmez

Abstract Radioisotope x-ray fluorescence spectrometry was investigated as a potential screening method for Pb and other elements in housewares. Thirty-six commercial houseware items and 87 ceramic test tiles (85 fired with hobby glazes and 2 blank bisques) were examined qualitatively for the presence of Pb by using 109Cd-induced L x-ray fluorescence emission spectrometry. For the housewares, the technique provided fast, nondestructive analysis of areas with about 10 cm diameters (general regions) to about 4 mm diameters (isolated design regions). Pb was found in 25 of 28 ceramicware items, in all 8 other housewares, and in all the testtile glazes above the limit of detection of 1 count per second (cps) for Pb Lβ x-rays. For housewares, Pb identification did not always correspond to Pb leachability. For 68 test-tile glazes labeled as containing Pb (39 of which were also labeled ‘dinnerware safe’ or ‘safe for food containers’), count rates ranged from 290 to 730 cps, whereas for the other 17 glazes labeled (with one exception) ‘nontoxic,’ much lower count rates (5–61 cps) were obtained. Other elements found in the housewares or test glazes were As, Au, Ca, Co, Cr, Cu, Fe, Mn, Nb, Ni, Rb, Sr, Y, Zn, and Zr.


1999 ◽  
Vol 121 (1) ◽  
pp. 13-21 ◽  
Author(s):  
S. M. Ford ◽  
J. Davies ◽  
B. Kar ◽  
S. D. Qi ◽  
S. McWhorter ◽  
...  

Micromachining was performed in polymethylmethacrylate (PMMA) using X-ray lithography for the fabrication of miniaturized devices (microchips) for potential applications in chemical and genetic analyses. The devices were fabricated using two different techniques: transfer mask technology and a Kapton® mask. For both processes, the channel topography was transferred (1:1) to the appropriate substrate via the use of an optical mask. In the case of the transfer mask technique, the PMMA substrate was coated with a positive photoresist and a thin Au/Cr plating base. Following UV exposure, the resist was developed and a thick overlayer (∼3 μm) of Au electroplated onto the PMMA substrate only where the resist was removed, which acted as an absorber of the X-rays. In the other technique, a Kapton® film was used as the X-ray mask. In this case, the Kapton® film was UV exposed using the optical mask to define the channel topography and following development of the resist, a thick Au overlayer (8 μm) was electrodeposited onto the Kapton® sheet. The PMMA wafer during X-ray exposure was situated directly underneath the Kapton® mask. In both cases, the PMMA wafer was exposed to soft X-rays and developed to remove the exposed PMMA. The resulting channels were found to be 20 μm in width (determined by optical mask) with channel depths of ∼50 μm (determined by x-ray exposure time). In order to demonstrate the utility of this micromachining process, several components were fabricated in PMMA including capillary/chip connectors, injectors for fixed-volume sample introduction, separation channels for electrophoresis and integrated fiber optic fluorescence detectors. These components could be integrated into a single device to assemble a system appropriate for the rapid analysis of various targets.


2021 ◽  
Vol 290 ◽  
pp. 01013
Author(s):  
Dong Liang ◽  
Fu Shen ◽  
Zizhen Bao ◽  
Yuchen Liu ◽  
Honghui Li

X-ray radioactive rays are widely used with the continuous development of radioactive medicine and nuclear technology applications, as well as lead shielding material pollutions new no lead shielding material was needed. In this paper, the main properties of metal tungsten and bismuth as X-ray shielding materials were studied for the protection people avoid the 150 kV X-rays by the Monte Carlo method is used to study. According to simulation with 2 kg/m2, results show that performance of single metal material tungsten iron is superior to that of bismuth material. Tungsten-bismuth better than bismuth-tungsten with the case of equal-quality double-layer metal. The protection performance is better when the metal-mixed tungsten-bismuth ratio is 0.5: 0.5 or the tungsten ratio is large. The research provides effective support for the development of textile radiation protection materials.


2020 ◽  
pp. 1-3
Author(s):  
M. Darrsana ◽  
Venkatachalam. K ◽  
Ampalaya Manu R ◽  
Haemanath P

Fibrous dysplasia is an ailment , that can include , one or a few bones and is portrayed by bone deformations, pain and fractures, arising due to bone weakening. A few patients can also present with endocrine dysfunction ( precocious puberty) and cutaneous cafe '- au - lait spots.[1] Determination depends on X-ray assessment. Anticipation is to be surveyed with X-rays and markers of bone remodelling. A few newer comprehensions , of the patho - physiology have been made in the past I0 years. It is presently perceived that fibrous dysplasia is brought about , by a physical initiating transformation of the Gs alpha subunits , of the protein G, bringing about an expanded cAMP fixation and in this way, brings about anomalies of osteoblasts separation, and then subsequently these osteoblasts, creates abnormal bone. There is also an expansion in interleukin-6-initiated osteoclastic bone resorption, which forms the basis of reasoning, for treating these patients with bisphosphonates. In the previous 10 years, the bisphosphonate pamidronate has been utilized by imbuement for fibrous dysplasia (two courses for each year), with great outcomes regarding pain and, in about half of patients, the topping off of osteolytic sores.[2]


2021 ◽  
Vol 15 (1) ◽  
pp. 235-248
Author(s):  
Mayank R. Kapadia ◽  
Chirag N. Paunwala

Introduction: Content Based Image Retrieval (CBIR) system is an innovative technology to retrieve images from various media types. One of the CBIR applications is Content Based Medical Image Retrieval (CBMIR). The image retrieval system retrieves the most similar images from the historical cases, and such systems can only support the physician's decision to diagnose a disease. To extract the useful features from the query image for linking similar types of images is the major challenge in the CBIR domain. The Convolution Neural Network (CNN) can overcome the drawbacks of traditional algorithms, dependent on the low-level feature extraction technique. Objective: The objective of the study is to develop a CNN model with a minimum number of convolution layers and to get the maximum possible accuracy for the CBMIR system. The minimum number of convolution layers reduces the number of mathematical operations and the time for the model's training. It also reduces the number of training parameters, like weights and bias. Thus, it reduces the memory requirement for the model storage. This work mainly focused on developing an optimized CNN model for the CBMIR system. Such systems can only support the physicians' decision to diagnose a disease from the images and retrieve the relevant cases to help the doctor decide the precise treatment. Methods: The deep learning-based model is proposed in this paper. The experiment is done with several convolution layers and various optimizers to get the maximum accuracy with a minimum number of convolution layers. Thus, the ten-layer CNN model is developed from scratch and used to derive the training and testing images' features and classify the test image. Once the image class is identified, the most relevant images are determined based on the Euclidean distance between the query features and database features of the identified class. Based on this distance, the most relevant images are displayed from the respective class of images. The general dataset CIFAR10, which has 60,000 images of 10 different classes, and the medical dataset IRMA, which has 2508 images of 9 various classes, have been used to analyze the proposed method. The proposed model is also applied for the medical x-ray image dataset of chest disease and compared with the other pre-trained models. Results: The accuracy and the average precision rate are the measurement parameters utilized to compare the proposed model with different machine learning techniques. The accuracy of the proposed model for the CIFAR10 dataset is 93.9%, which is better than the state-of-the-art methods. After the success for the general dataset, the model is also tested for the medical dataset. For the x-ray images of the IRMA dataset, it is 86.53%, which is better than the different pre-trained model results. The model is also tested for the other x-ray dataset, which is utilized to identify chest-related disease. The average precision rate for such a dataset is 97.25%. Also, the proposed model fulfills the major challenge of the semantic gap. The semantic gap of the proposed model for the chest disease dataset is 2.75%, and for the IRMA dataset, it is 13.47%. Also, only ten convolution layers are utilized in the proposed model, which is very small in number compared to the other pre-trained models. Conclusion: The proposed technique shows remarkable improvement in performance metrics over CNN-based state-of-the-art methods. It also offers a significant improvement in performance metrics over different pre-trained models for the two different medical x-ray image datasets.


1970 ◽  
Vol 14 ◽  
pp. 102-126 ◽  
Author(s):  
Frank L. Chan ◽  
W. Barclay Jones

AbstractAn x-ray spectrometer with experimental results is herewith described using a radiosotope source Fe55 having a halflife of 2.6 years. As a result of the disintegration, the managanese x-rays are capable of exciting fluorescent x-rays of such elements as sulfur, chlorine, potassium, calcium, scandium and titanium in aqueous solutions. These elements with the Ka wavelengths ranging from 5.3729 Å to 2.7496 Å may be designated as between the very soft x-rays on the one hand and the hard x-rays on the other. The x-ray spectrometer presently described has achieved a resolution of 136 ev, FWHM.Simultaneously, these elements have also been quantitatively determined by conventional x-ray fluorescent spectrometers. Since one of the spectrometers is designed to operate in vacuum as well as in helium or air, determination of sulfur, potassium and calcium were carried out in vacuum. Determination of chlorine was carried out in a helium atmosphere, Calcium, scandium and titanium were determined in air with an air-path spectrometer.In the present study aqueous solutions containing these elements were used. The use of aqueous solutions has the inherent advantages of being homogeneous and free from effect of particle size.


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