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Sample records for panoramic dental radiography

  1. Leaded apron for use in panoramic dental radiography

    SciTech Connect

    Whitcher, B.L.; Gratt, B.M.; Sickles, E.A.

    1980-05-01

    The leaded aprons currently available for use during dental radiography do not protect the thyroid gland from radiation. Conventional aprons may produce artifacts when used with panoramic dental x-ray units. This study measures the dose reduction obtained with an experimental leaded apron designed for use with panoramic dental x-ray units. Skin exposures measured at the thyroid and at the sternum were reduced with the use of the apron. Films produced during the study were free from apron artifacts.

  2. Panoramic dental radiography image intensification employing minification techniques

    SciTech Connect

    Cushman, R.H.

    1981-09-01

    Panoramic dental x-ray machine wherein an x-ray source-camera assembly orbits a seated patient is described. A slot in the camera assembly collimates the x-rays which are continuously generated by the x-ray source, which x-rays are converted to light images of the patient's dental arch structure by only a single intensifying screen which remains stationary. This screen comprises about 1/40 the area of conventional intensifying screens and is made thicker for providing improved detection efficiency. A fiber optic minifying lens reduces the size of the image from the screen while proportionately increasing the light intensity of the image, thus making it possible to provide useable film images at reduced x-ray exposures due to non-linear film exposure versus optical density characteristics. The resultant minified, light-intensified image may now be recorded on 35 mm roll film, for example, as opposed to standard radiographic film of 5'' X 12'' size, or 12.70 cm X 30.48 cm.

  3. [The exposure dose of the sella turcica in panoramic dental radiography with an intraoral radiogenic source].

    PubMed

    Pastremoli, A; Cucchi, G; Ciminari, R

    1991-06-01

    Panoramic dental radiography using an intraoral X-ray source exposes critical organs, such as the crystalline and the thyroid, as well as organs of fundamental importance such as the pituitary gland, to X-rays. An experimental study was carried out to assess the exposure dose to the sella turcica during the radiological examination of the upper and lower dental arches using an X-ray source within the oral cavity. The comprehensive exposure dose for the upper and lower dental arches exceeded that found in orthopantomography (110 micro Gy/examination vs 47 micro Gy/examination) with errors which are respectively inferior to 15% and 30%. The authors conclude that the risk of provoking anatomical or functional changes of the pituitary gland is extremely remote using this type of examination.

  4. Dosimetric study of the effective doses resulting during dental X-ray and panoramic radiography

    NASA Astrophysics Data System (ADS)

    Shousha, Hany A.; Abd-El Hafez, A. I.; Ahmad, Fawzia

    2011-01-01

    The panoramic image is one of the most commonly used radiographic examinations in dentistry, owing to its low dose and large area for evaluation, including bone and teeth in the same image. Although digital images are usually reported to deliver a lower radiation dose to the patient, conventional images are still available, especially in countries where digital systems are not widely economically available. Dentists should weigh the benefits of dental radiographs against the consequences of increasing a patient's exposure to radiation, the effects of which accumulate from multiple sources over time. The "as low as reasonably achievable" principle should be followed to minimize the exposure to radiation. The purpose of this investigation is to measure the absorbed radiation doses at 12 anatomical sites of a Rando-phantom and calculate the effective doses result from a full-mouth survey and panoramic radiography. Organ-absorbed doses are measured using thermoluminescent dosimeters (TLD 100) and effective organ doses (μ Sv) are estimated according to the International Commission on Radiological Protection in 2007. The total effective dose results from the panoramic imaging system have so far been below those obtained using the full-mouth survey technique used in intra-oral radiographic examination.

  5. The current status of panoramic radiography.

    PubMed

    Hirschmann, P N

    1987-03-01

    The current status of dental panoramic tomography (rotational panoramic radiography) is reviewed. This technique is based on a combination of tomography and slit-beam radiography to provide an image of both jaws on a single film. There is a greater degree of image degradation when compared with conventional radiographic techniques due to tomographic blurring, magnification and distortion, secondary images and burn-out. Meticulous patient position is essential to accommodate their jaws to the image layer determined by the manufacturers. The absorbed doses from panoramic radiography are of a similar order to that from bitewing radiography and lower than those from a full-mouth periapical series. The individual risk of 1.3 X 10(-6) is compared with that from other radiographic examinations and smoking. The collective risk, 1.04 deaths in the UK in 1981, is relatively insignificant as is the genetic dose. The risk to the dentist and his staff is also low compared to other risks. The methods of dose limitation currently available are reviewed. The clinical indications are considered in relation to the guidelines of the American Dental Association and the Dental Estimates Board in the UK. The problems associated with attempts to measure diagnostic yield are considered. In view of the world-wide public concern at the potential dangers of ionising radiation, dentists are urged to maximize the diagnostic yield from their panoramic radiography by taking such radiographs only when clinically necessary, ensuring meticulous positioning and processing, followed by scrupulous assessment of the radiography for any sign of pathological change.

  6. Establishment of diagnostic reference levels for dental panoramic radiography in Greece.

    PubMed

    Manousaridis, G; Koukorava, C; Hourdakis, C J; Kamenopoulou, V; Yakoumakis, E; Tsiklakis, K

    2015-07-01

    The purpose of the present study was to present the national diagnostic reference levels (DRL) established for panoramic dental examinations in Greece. The establishment of DRL, as a tool for the optimisation of radiological procedures, is a requirement of national regulations. Measurements performed by the Greek Atomic Energy Commission on 90 panoramic systems have been used for the derivation of DRL values. DRL values have been proposed for exposure settings of different patient types (child, small adult and standard adult), both for film and digital imaging. The DRLs for different patient types are grouped in three categories: children, small adults (corresponding to female) and average adults (corresponding to male). Proposed DRLs for these groups are 2.2, 3.3 and 4.1 mGy, respectively. In order to investigate the correlation of DRLs with the available imaging modalities (CR, DR and film), this parameter was taken into account. DR imaging DRL is the lowest at 3.5 mGy, CR imaging the highest at 4.2 mGy and film imaging at 3.7 mGy. In order to facilitate comparison with other studies, kerma-width product values were calculated from Ki, air and field size.

  7. Panoramic Dental X-Ray

    MedlinePlus

    ... Physician Resources Professions Site Index A-Z Panoramic Dental X-ray Panoramic dental x-ray uses a ... Your e-mail address: Personal message (optional): Bees: Wax: Notice: RadiologyInfo respects your privacy. Information entered here ...

  8. Radiation absorbed from dental implant radiography: a comparison of linear tomography, CT scan, and panoramic and intra-oral techniques

    SciTech Connect

    Clark, D.E.; Danforth, R.A.; Barnes, R.W.; Burtch, M.L. )

    1990-01-01

    Absorbed radiation dose in bone marrow, thyroid, salivary gland, eye, and skin entrance was determined by placement of lithium fluoride thermoluminescent dosimeters (TLD's) at selected anatomical sites within and on a human-like x-ray phantom. The phantom was exposed to radiation from linear tomographic and computer-assisted tomographic (CT) simulated dental implant radiographic examinations. The mean dose was determined for each anatomical site. Resulting dose measurements from linear tomography and computer-assisted tomography are compared with reported panoramic and intra-oral doses. CT examination delivered the greatest dose, while linear tomography was generally lowest. Panoramic and intra-oral doses were similar to those of linear tomography.

  9. Clinical feline dental radiography.

    PubMed

    Lemmons, Matthew

    2013-05-01

    Dental radiography is a necessary diagnostic modality in small animal practice. It is not possible to accurately assess and diagnose tooth resorption, periodontal disease, endodontic disease, neoplasia and injury without it. Dental radiography is also necessary for treatment and assessment of the patient postoperatively.

  10. Thyroid dose distribution in dental radiography

    SciTech Connect

    Bristow, R.G.; Wood, R.E.; Clark, G.M. )

    1989-10-01

    The anatomic position and proven radiosensitivity of the thyroid gland make it an organ of concern in dental radiography. A calibrated thermoluminescent dosimetry system was used to investigate the absorbed dose (microGy) to the thyroid gland resultant from a minimum irradiated volume, intraoral full-mouth radiography technique with the use of rectangular collimation with a lead-backed image receptor, and conventional panoramic radiography performed with front and rear lead aprons. Use of the minimum irradiated volume technique resulted in a significantly decreased absorbed dose over the entire thyroid region ranging from 100% to 350% (p less than 0.05). Because this intraoral technique results in radiographs with greater image quality and also exposes the thyroid gland to less radiation than the panoramic, this technique may be an alternative to the panoramic procedure.

  11. Common positioning errors in panoramic radiography: A review

    PubMed Central

    Rondon, Rafael Henrique Nunes; Pereira, Yamba Carla Lara

    2014-01-01

    Professionals performing radiographic examinations are responsible for maintaining optimal image quality for accurate diagnoses. These professionals must competently execute techniques such as film manipulation and processing to minimize patient exposure to radiation. Improper performance by the professional and/or patient may result in a radiographic image of unsatisfactory quality that can also lead to a misdiagnosis and the development of an inadequate treatment plan. Currently, the most commonly performed extraoral examination is panoramic radiography. The invention of panoramic radiography has resulted in improvements in image quality with decreased exposure to radiation and at a low cost. However, this technique requires careful, accurate positioning of the patient's teeth and surrounding maxillofacial bone structure within the focal trough. Therefore, we reviewed the literature for the most common types of positioning errors in panoramic radiography to suggest the correct techniques. We would also discuss how to determine if the most common positioning errors occurred in panoramic radiography, such as in the positioning of the patient's head, tongue, chin, or body. PMID:24701452

  12. Usefulness of an energy-binned photon-counting x-ray detector for dental panoramic radiographs

    NASA Astrophysics Data System (ADS)

    Fukui, Tatsumasa; Katsumata, Akitoshi; Ogawa, Koichi; Fujiwara, Shuu

    2015-03-01

    A newly developed dental panoramic radiography system is equipped with a photon-counting semiconductor detector. This photon-counting detector acquires transparent X-ray beams by dividing them into several energy bands. We developed a method to identify dental materials in the patient's teeth by means of the X-ray energy analysis of panoramic radiographs. We tested various dental materials including gold alloy, dental amalgam, dental cement, and titanium. The results of this study suggest that X-ray energy scattergram analysis could be used to identify a range of dental materials in a patient's panoramic radiograph.

  13. High-yield criteria for panoramic radiography. Final report

    SciTech Connect

    White, S.C.; Forsythe, A.B.

    1982-06-01

    Panoramic radiographs should be obtained when the examination offers the prospect of providing information that will assist in patient care. The purpose of this study was to determine whether high-yield criteria could be developed for the use of panoramic radiographs in the treatment planning of patients seeking dental care. Clinicians were asked what signs or symptoms caused them to order a panoramic radiograph upon patient admission into the UCLA Dental Clinic. At the time the patient was radiographed, a variety of demographic and clinical measures were recorded. The most important high-yield criterion for the panoramic examination is whether the radiograph is ordered for 'general screening examination' (a negative predictor) and whether the radiograph was ordered for any specific examination (a positive predictor). The use of these (or any other) decision rules required clinical judgment of the costs (social and economic) of a missed positive finding relative to that of an unproductive examination.

  14. A dose monitoring system for dental radiography

    PubMed Central

    Lee, Chena; Kim, Jo-Eun; Symkhampha, Khanthaly; Lee, Woo-Jin; Huh, Kyung-Hoe; Yi, Won-Jin; Heo, Min-Suk; Choi, Soon-Chul; Yeom, Heon-Young

    2016-01-01

    Purpose The current study investigates the feasibility of a platform for a nationwide dose monitoring system for dental radiography. The essential elements for an unerring system are also assessed. Materials and Methods An intraoral radiographic machine with 14 X-ray generators and five sensors, 45 panoramic radiographic machines, and 23 cone-beam computed tomography (CBCT) models used in Korean dental clinics were surveyed to investigate the type of dose report. A main server for storing the dose data from each radiographic machine was prepared. The dose report transfer pathways from the radiographic machine to the main sever were constructed. An effective dose calculation method was created based on the machine specifications and the exposure parameters of three intraoral radiographic machines, five panoramic radiographic machines, and four CBCTs. A viewing system was developed for both dentists and patients to view the calculated effective dose. Each procedure and the main server were integrated into one system. Results The dose data from each type of radiographic machine was successfully transferred to the main server and converted into an effective dose. The effective dose stored in the main server is automatically connected to a viewing program for dentist and patient access. Conclusion A patient radiation dose monitoring system is feasible for dental clinics. Future research in cooperation with clinicians, industry, and radiologists is needed to ensure format convertibility for an efficient dose monitoring system to monitor unexpected radiation dose. PMID:27358817

  15. Method and apparatus for providing simultaneous displays in panoramic radiography

    SciTech Connect

    Cushman, R.H.

    1980-03-18

    Two different areas of a focal trough of a dental arch structure are simultaneously displayed on a radiograph when tubehead-camera assembly of an x-ray machine panoramically scans the dental arch structure. The different areas of the focal trough are obtained when a pair of parallel disposed film holding devices within the camera are caused to travel in proximate relationship to each other at different speeds. The x-rays activate and pass through one film before activating the other immediately therebehind.

  16. Optimization of exposure in panoramic radiography while maintaining image quality using adaptive filtering.

    PubMed

    Svenson, Björn; Larsson, Lars; Båth, Magnus

    2016-01-01

    Objective The purpose of the present study was to investigate the potential of using advanced external adaptive image processing for maintaining image quality while reducing exposure in dental panoramic storage phosphor plate (SPP) radiography. Materials and methods Thirty-seven SPP radiographs of a skull phantom were acquired using a Scanora panoramic X-ray machine with various tube load, tube voltage, SPP sensitivity and filtration settings. The radiographs were processed using General Operator Processor (GOP) technology. Fifteen dentists, all within the dental radiology field, compared the structural image quality of each radiograph with a reference image on a 5-point rating scale in a visual grading characteristics (VGC) study. The reference image was acquired with the acquisition parameters commonly used in daily operation (70 kVp, 150 mAs and sensitivity class 200) and processed using the standard process parameters supplied by the modality vendor. Results All GOP-processed images with similar (or higher) dose as the reference image resulted in higher image quality than the reference. All GOP-processed images with similar image quality as the reference image were acquired at a lower dose than the reference. This indicates that the external image processing improved the image quality compared with the standard processing. Regarding acquisition parameters, no strong dependency of the image quality on the radiation quality was seen and the image quality was mainly affected by the dose. Conclusions The present study indicates that advanced external adaptive image processing may be beneficial in panoramic radiography for increasing the image quality of SPP radiographs or for reducing the exposure while maintaining image quality.

  17. Location of mental foramen using digital panoramic Radiography

    PubMed Central

    Mohamed, Ajmal; Nataraj, Kannan; Mathew, Vinod B.; Varma, Beena; Mohamed, Shamil; Valappila, Nidhin J.; Meena, Aravind S.

    2016-01-01

    Objective: Comparative evaluation of the location of mental foramen in different age groups. Determine the variation in position of mental foramen with gender using digital panoramic radiography. Materials and Methods: Digital panoramic radiographs of 250 patients were reviewed. The study population was divided into five age groups with 50 patients each. Radiographic position of mental foramen was evaluated in each radiograph based on three parameters. Measurements were taken in each radiograph using Planmeca Dimaxis pro version 4.4.0 (Helsinki, Finland). The collected data were subjected to statistical analysis using paired Student's t-test. Results: The mean distance of position of mental foramen showed a significant variation within the five age groups. In the first group, female patients showed an increase in mean distance of mental foramen position in relation to three parameters. From the second to fifth groups, male patient showed an increase in the mean distance of mental foramen position. The first and fifth group showed a reduced mean distance of mental foramen position when compared to other age groups. Conclusion: This study concluded that the position of mental foramen varies with age. There was a gender-related variation in position of mental foramen within the population too. PMID:27555723

  18. Digital panoramic radiography versus cone beam computed tomography in the delineation of maxillomandibular tumors.

    PubMed

    Almeida-Barros, Renata Quirino de; Abilio, Vanessa Maria Freire; Yamamoto, Angela Toshie Araki; Melo, Daniela Pita de; Godoy, Gustavo Pina; Bento, Patricia Meira

    2015-01-01

    This research aimed to compare the efficacy of digital panoramic radiography (DPR) with that of cone beam computed tomography (CBCT) for delineation of odontogenic and nonodontogenic tumors. From November 2009 through March 2011, 23 tumors in the maxillomandibular complex were diagnosed by histopathological examination. All DPRs and CBCTs were obtained and analyzed by a single previously calibrated radiologist, who considered the following radiographic aspects: clarity of the lesion edges, relation with dental elements, involvement of adjacent anatomical structures, cortical bone expansion and disruption, and, if present, type of involved anatomical structures and site of bone expansion and disruption. Of 23 patients, 15 (65.2%) were male and 8 (34.8%) were female. The tumor was classified as odontogenic in 73.9% of patients and nonodontogenic in 26.1% of patients. Analysis revealed that 56.5% of the tumors were located in the mandible, 34.8% in the maxilla, and 8.7% in both arches. For all analyzed variables, CBCTs offered more accurate details than did DPRs. Panoramic radiography should not be the examination of choice to visualize lesions in the maxillomandibular complex.

  19. Effective doses from panoramic radiography and CBCT (cone beam CT) using dose area product (DAP) in dentistry

    PubMed Central

    Shin, H S; Nam, K C; Park, H; Choi, H U; Kim, H Y

    2014-01-01

    Objectives: We compared the effective dose from panoramic radiography with that from cone beam CT (CBCT) using dose area product under adult and child exposure conditions. Methods: The effective doses of the cephalo, panorama, implant and dental modes of Alphard 3030 (Asahi Roentgen Ind., Co. Ltd, Kyoto, Japan) CBCT and the Jaw, Wide, Facial and temporomandibular joint modes of Rayscan Symphony (RAY Co., Ltd, Hwaseong, Republic of Korea) CBCT were compared with those of CRANEX® 3+ CEPH (Soredex Orion Corporation, Helsinki, Finland) panoramic radiography equipment under adult and child exposure conditions. Each effective dose was calculated using a conversion formula from dose area product meter measured values (VacuTec Messtechnik GmbH, Dresden, Germany). The conversion formulae used were suggested by Helmrot and Alm Carlsson and Batista et al, and they were applied with the tube voltage taken into consideration. Results: The maximum effective doses from the Alphard 3030 and Rayscan Symphony were 67 and 21 times greater than that from panoramic radiography, respectively. The ratios of the effective dose under the child setting to that under the adult condition were 0.60–0.62 and 0.84–0.95, and the maximum differences in effective doses between the adult and child exposure settings were equivalent to 27 and 4 times greater than a panoramic examination in the Alphard 3030 and Rayscan Symphony, respectively. Conclusions: The effective CBCT doses were higher than those of panoramic radiography. The differences in effective doses between the adult and child CBCT settings were dependent on equipment type and exposure parameters. Therefore, adequate mode selection and control of exposure as well as further research are necessary to minimize the effective dose to patients, especially for radiosensitive children. PMID:24845340

  20. Clinical canine dental radiography.

    PubMed

    Bannon, Kristin M

    2013-05-01

    The purpose of this article is to provide small animal veterinarians in private practice a guideline for interpretation of the most common findings in canine intraoral radiology. Normal oral and dental anatomy is presented. A brief review of variations of normal, common periodontal and endodontic pathology findings and developmental anomalies is provided.

  1. Pain Sensation and Postsurgical Complications in Posterior Mandibular Implant Placement Using Ridge Mapping, Panoramic Radiography, and Infiltration Anesthesia

    PubMed Central

    2013-01-01

    Objectives. The aim of this study was to investigate intrasurgical and after surgical, pain and the incidence of after surgical alteration of sensation in the mandible and lower lip when placing implants in the posterior mandible using ridge mapping, panoramic radiography, and infiltration anesthesia. Methods. This was a longitudinal clinical study of healthy patients needing implant placement in the posterior mandible. After thorough examination and treatment plan using ridge mapping and panoramic radiography, all patients received dental implants under local infiltration anesthesia. The patients were then given a questionnaire to assess the pain during anesthesia and implant surgery. Change of sensation in the lower lip was evaluated by standard neurosensory examination tests at 7 days and 1 and 4 months. Prosthetic treatment was carried out 4 months postsurgery and the patients were followed for an average of 28.5 months afterwards. Results. A total of 103 implants were placed in 62 patients. Patients reported very minor pain during injection. No pain was reported during either implant placement or bone grafting procedures. No alteration of sensation in the mandible or lower lip was recorded postsurgery. Conclusion. In most cases, ridge mapping, panoramic radiography, and infiltration anesthesia are sufficient for posterior mandibular implant placement without pain or complications. PMID:23762571

  2. Fragile X syndrome: panoramic radiographic evaluation of dental anomalies, dental mineralization stage, and mandibular angle

    PubMed Central

    Sabbagh-Haddad, Aida; Haddad, Denise Sabbagh; Michel-Crosato, Edgard; Arita, Emiko Saito

    2016-01-01

    ABSTRACT Fragile X syndrome (FXS) is a disorder linked to the chromosome X long arm (Xq27.3), which is identified by a constriction named fragile site. It determines various changes, such as behavioral or emotional problems, learning difficulties, and intellectual disabilities. Craniofacial abnormalities such as elongated and narrow face, prominent forehead, broad nose, large and prominent ear pavilions, strabismus, and myopia are frequent characteristics. Regarding the oral aspects, deep and high-arched palate, mandibular prognathism, and malocclusion are also observed. Objective: The purpose of this study was to evaluate the dental radiographic characteristics as described in 40 records of patients with panoramic radiography. Material and Methods: The patients were in the range of 6–17 years old, and were divided into two groups (20 subjects who were compatible with the normality standard and 20 individuals diagnosed with the FXS), which were matched for gender and age. Analysis of the panoramic radiographic examination involved the evaluation of dental mineralization stage, mandibular angle size, and presence of dental anomalies in both deciduous and permanent dentitions. Results: The results of radiographic evaluation demonstrated that the chronology of tooth eruption of all third and second lower molars is anticipated in individuals with FXS (p<0.05). In this group, supernumerary deciduous teeth (2.83%), giroversion of permanent teeth (2.31%), and partial anodontia (1.82%) were the most frequent dental anomalies. In addition, an increase was observed in the mandibular angle size in the FXS group (p<0.05). Conclusion: We conclude that knowledge of dental radiographic changes is of great importance for dental surgeons to plan the treatment of these individuals. PMID:27812623

  3. Accuracy in the Diagnosis of the Mental Nerve Loop. A Comparative Study Between Panoramic Radiography and Cone Beam Computed Tomography

    PubMed Central

    do Couto-Filho, Carlos Eduardo Gomes; de Moraes, Paulo Hemerson; Alonso, Maria Beatriz Carrazzone; Haiter-Neto, Francisco; Olate, Sergio; de Albergaria-Barbosa, José Ricardo

    2016-01-01

    Summary Dental implant and chin osteotomy are executed on the mandible body and the mental nerve is an important anatomical limit. The aim of this research was to know the position of the mental nerve loop comparing result in panoramic radiography and cone beam computed tomography. We analyzed 94 hemimandibles and the patient sample comprised female and male subjects of ages ranging from 18 to 52 years (mean age, 35 years) selected randomly from the database of patients at the Division of Oral Radiology at Piracicaba Dental School State University of Campinas; the anterior loop (AL) of the mental nerve was evaluated regarding the presence or absence, which was classified as rectilinear or curvilinear and measurement of its length was obtained. The observations were made in the digital panoramic radiography (PR) and the cone beam computed tomography (CBCT) according to a routine technique. The frequencies of the AL identified through PR and CBCT were different: in PR the loop was identified in 42.6% of cases, and only 12.8% were bilateral. In contrast, the AL was detected in 29.8% of the samples using CBCT, with 6.4% being bilateral; Statistical comparison between PR and CBCT showed that the PR led to false-positive diagnosis of the AL in this sample. According to the results of this study, the frequency of AL is low. Thus, it can be assumed that it is not a common condition in this population. PMID:27667898

  4. 42 CFR Appendix G to Part 75 - Standards for Licensing Dental Hygienists and Dental Assistants in Dental Radiography

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... Dental Assistants in Dental Radiography G Appendix G to Part 75 Public Health PUBLIC HEALTH SERVICE...—Standards for Licensing Dental Hygienists and Dental Assistants in Dental Radiography The following section... individual State licensure processes, all of which include assessment of competence in dental radiography....

  5. 42 CFR Appendix G to Part 75 - Standards for Licensing Dental Hygienists and Dental Assistants in Dental Radiography

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... Dental Assistants in Dental Radiography G Appendix G to Part 75 Public Health PUBLIC HEALTH SERVICE...—Standards for Licensing Dental Hygienists and Dental Assistants in Dental Radiography The following section... individual State licensure processes, all of which include assessment of competence in dental radiography....

  6. 42 CFR Appendix G to Part 75 - Standards for Licensing Dental Hygienists and Dental Assistants in Dental Radiography

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... Dental Assistants in Dental Radiography G Appendix G to Part 75 Public Health PUBLIC HEALTH SERVICE...—Standards for Licensing Dental Hygienists and Dental Assistants in Dental Radiography The following section... individual State licensure processes, all of which include assessment of competence in dental radiography....

  7. 42 CFR Appendix G to Part 75 - Standards for Licensing Dental Hygienists and Dental Assistants in Dental Radiography

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... Dental Assistants in Dental Radiography G Appendix G to Part 75 Public Health PUBLIC HEALTH SERVICE...—Standards for Licensing Dental Hygienists and Dental Assistants in Dental Radiography The following section... individual State licensure processes, all of which include assessment of competence in dental radiography....

  8. The integral dose in panoramic intraoral x-ray tube radiography

    SciTech Connect

    Hayami, A.; Fujishita, M.; Sumida, A.; Kanke, M.; Fujiki, T.; Uemura, S.; Fuchihata, H.

    1983-07-01

    A Monte Carlo computer program was developed to estimate the integral dose to the head and thyroid for panoramic intraoral x-ray tube radiography. The advantage of this computer simulation is that it is able to avoid many of the difficulties associated with low-energy and low-dose x-ray dosimetry. The calculations were made for maxillary and mandibular projections separately, using 10 kv. increments between 40 and 60 kv. The results obtained were presented in terms of the integral dose per milliampere second. Typical integral doses for a routine examination of the head are 2.1 mJ. and 8.5 microJ for the thyroid during mandibular radiography and 1.7 microJ for the thyroid during radiography of the maxilla using 55 kv. and 0.5 mAs.

  9. Assessment of vertical facial and dentoalveolar changes using panoramic radiography.

    PubMed

    Nohadani, Nasila; Ruf, Sabine

    2008-06-01

    The purpose of the study was to analyse longitudinal vertical facial and dentoalveolar changes using panoramic radiographs (PRs) and to compare the results with measurements on lateral cephalometric radiographs (LCRs) in order to determine whether, under certain circumstances, the radiation dose for a patient may be reduced by taking only a PR instead of a PR and a LCR. Pre- and post-treatment PRs and LCRs of 30 (15 females and 15 males) orthodontically treated adolescents (mean age pre-treatment 10.9 years, post-treatment 13.4 years) were analysed using Pearson's correlation coefficients and gender differences using Fisher's z-transformation. The results revealed that most variables exhibited larger absolute values on PRs than on LCRs. Comparison of dentoskeletal morphology between the LCRs and the PRs revealed moderate to high, mostly statistically significant, interrelations both before and after orthodontic treatment. The lowest correlations were found for the maxillary jaw base angle (NL/H; r= 0.35***) and the highest for the gonial angle (ML/RL; r = 0.90***). However, when assessing the combined growth and treatment changes from before to after treatment, only weak to moderate, not statistically significant, interrelations were found between LCRs and PRs. Anterior face height (AFH; r = 0.43***), the mandibular plane angle (ML/H; r = 0.06*), and the distance of the incisal tip of the most extruded mandibular incisor to the ML-line (ii-ML; r = -0.21*) were the only statistically significant parameters. The average group differences for growth and treatment changes, however, were small for most parameters. Analysis of vertical facial and dentoalveolar parameters on PRs delivers a moderate approximation to the situation depicted on LCRs. However, PRs cannot be recommended for the analysis of individual longitudinal changes in vertical facial and dentoalveolar parameters.

  10. Diagnosis of simulated condylar bone defects using panoramic radiography, spiral tomography and cone-beam computed tomography: A comparison study

    PubMed Central

    Salemi, Fatemeh; Shokri, Abbas; Baharvand, Maryam

    2015-01-01

    Objectives: Radiographic examination is one of the most important parts of the clinical assessment routine for temporomandibular disorders. The aim of this study was to compare the diagnostic accuracy of cone-beam computed tomography(CBCT) with panoramic radiography and spiral computed tomography for the detection of the simulated mandibular condyle bone lesions. Study Design: The sample consisted of 10 TMJs from 5 dried human skulls. Simulated erosive and osteophytic lesions were created in 3 different sizes using round diamond bur and bone chips, respectively. Panoramic radiography, spiral tomography and cone-beam computed tomography were used in defect detection. Data were statistically analyzed with the Mann-Whitney test. The reliability and degrees of agreement between two observers were also determined by the mean of Cohen’s Kappa analysis. Results: CBCT had a statistically significant superiority than other studied techniques in detection of both erosive and osteophytic lesions with different sizes. There were significant differences between tomography and panoramic in correct detection of both erosive and osteophytic lesions with 1mm and 1.5 mm in size. However, there were no significant differences between Tomography and Panoramic in correct detection of both erosive and osteophytic lesions with 0.5 mm in size. Conclusions: CBCT images provide a greater diagnostic accuracy than spiral tomography and panoramic radiography in the detection of condylar bone erosions and osteophytes. Key words:Bone defect, Condyle, CBCT, Panoramic, radiography. PMID:25810839

  11. Comparison between DICOM-calibrated and uncalibrated consumer grade and 6-MP displays under different lighting conditions in panoramic radiography

    PubMed Central

    Haapea, M; Liukkonen, E; Huumonen, S; Tervonen, O; Nieminen, M T

    2015-01-01

    Objectives: To compare observer performance in the detection of anatomical structures and pathology in panoramic radiographs using consumer grade with and without digital imaging and communication in medicine (DICOM)-calibration and 6-megapixel (6-MP) displays under different lighting conditions. Methods: 30 panoramic radiographs were randomly evaluated on three displays under bright (510 lx) and dim (16 lx) ambient lighting by two observers with different years of experience. Dentinoenamel junction, dentinal caries and periapical inflammatory lesions, visibility of cortical border of the floor and pathological lesions in maxillary sinus were evaluated. Consensus between the observers was considered as reference. Intraobserver agreement was determined. Proportion of equivalent ratings and weighted kappa were used to assess reliability. The level of significance was set to p < 0.05. Results: The proportion of equivalent ratings with consensus differed between uncalibrated and DICOM-calibrated consumer grade displays in dentinal caries in the lower molar in dim lighting (p = 0.021) and between DICOM-calibrated consumer grade and 6-MP display in bright lighting (p = 0.038) for an experienced observer. Significant differences were found between uncalibrated and DICOM-calibrated consumer grade displays in dentinal caries in bright lighting (p = 0.044) and periapical lesions in the upper molar in dim lighting (p = 0.008) for a less experienced observer. Intraobserver reliability was better at detecting dentinal caries than at detecting periapical and maxillary sinus pathology. Conclusions: DICOM calibration may improve observer performance in panoramic radiography in different lighting conditions. Therefore, a DICOM-calibrated consumer grade display can be used instead of a medical display in dental practice without compromising the diagnostic quality. PMID:25564888

  12. Magnification rate of digital panoramic radiographs and its effectiveness for pre-operative assessment of dental implants

    PubMed Central

    Kim, Y-K; Park, J-Y; Kim, S-G; Kim, J-S; Kim, J-D

    2011-01-01

    Objectives The purpose of this study was to determine the accuracy and effectiveness of digital panoramic radiographs for pre-operative assessment of dental implants. Methods We selected 86 patients (221 implants) and calculated the length of the planned implant based on the distance between a selection of critical anatomical structures and the alveolar crest using the scaling tools provided in the digital panoramic system. We analysed the magnification rate and the difference between the actual inserted implant length and planned implant length according to the location of the implant placement and the clarity of anatomical structures seen in the panoramic radiographs. Results There was no significant difference between the planned implant length and actual inserted implant length (P > 0.05). The magnification rate of the width and length of the inserted implants, seen in the digital panoramic radiographs, was 127.28 ± 13.47% and 128.22 ± 4.17%, respectively. The magnification rate of the implant width was largest in the mandibular anterior part and there was a significant difference in the magnification rate of the length of implants between the maxilla and the mandible (P < 0.05). When the clarity of anatomical structures seen in the panoramic radiographs is low, the magnification rate of the width of the inserted implants is significantly higher (P < 0.05), but there is no significant difference between the planned implant length and actual inserted implant length according to the clarity of anatomical structures (P < 0.05). Conclusions Digital panoramic radiography can be considered a simple, readily available and considerably accurate pre-operative assessment tool in the vertical dimension for dental implant therapy. PMID:21239569

  13. Effects of dose reduction on the detectability of standardized radiolucent lesions in digital panoramic radiography.

    PubMed

    Dula, K; Sanderink, G; van der Stelt, P F; Mini, R; Buser, D

    1998-08-01

    Dose reduction in digital panoramic radiography was studied. Intentional underexposure was performed with the Orthophos DS while six different human mandibles were radiographed. Exposure settings were 69 kV/15 mA (standard), 64 kV/16 mA, and 60 kV/16 mA. Standardized spherical defects, each either 1 or 1.25 mm in diameter, were simulated in 288 of 432 images, and seven observers decided whether defects were present or not. Areas under the receiver operating characteristics curves were calculated. They showed no significant differences in the detectability of the 1-mm defect at 69, 64, or 60 kV. For the 1.25-mm defect, no difference was found between the 69 and 60 kV images, but a statistically significant different detectability was found for 64 kV images in comparison with both 69 and 60 kV images. A dose reduction of up to 43% was ascertained with a Pedo-RT-Humanoid phantom when panoramic radiography was performed at 60 kV/16 mA. The conclusion is that with the Orthophos DS, it seems possible to reduce the dose rate of x-rays without loss of diagnostic quality in the case of radiolucent changes.

  14. Dental panoramic image analysis for enhancement biomarker of mandibular condyle for osteoporosis early detection

    NASA Astrophysics Data System (ADS)

    Suprijanto; Azhari; Juliastuti, E.; Septyvergy, A.; Setyagar, N. P. P.

    2016-03-01

    Osteoporosis is a degenerative disease characterized by low Bone Mineral Density (BMD). Currently, a BMD level is determined by Dual Energy X-ray Absorptiometry (DXA) at the lumbar vertebrae and femur. Previous studies reported that dental panoramic radiography image has potential information for early osteoporosis detection. This work reported alternative scheme, that consists of the determination of the Region of Interest (ROI) the condyle mandibular in the image as biomarker and feature extraction from ROI and classification of bone conditions. The minimum value of intensity in the cavity area is used to compensate an offset on the ROI. For feature extraction, the fraction of intensity values in the ROI that represent high bone density and the ROI total area is perfomed. The classification will be evaluated from the ability of each feature and its combinations for the BMD detection in 2 classes (normal and abnormal), with the artificial neural network method. The evaluation system used 105 panoramic image data from menopause women which consist of 36 training data and 69 test data that were divided into 2 classes. The 2 classes of classification obtained 88.0% accuracy rate and 88.0% sensitivity rate.

  15. Anatomical variations of mandibular canal detected by panoramic radiography and CT: a systematic review and meta-analysis

    PubMed Central

    Dutra, Kamile; Porporatti, André Luís; Mezzomo, Luis A; De Luca Canto, Graziela; Flores-Mir, Carlos; Corrêa, Márcio

    2016-01-01

    Objectives: To investigate the anatomical variations of the mandibular canal through assessment in situ, panoramic radiography, CT or CBCT and assess their frequency. Methods: Articles were selected from databases (Cochrane Library, LILACS, ProQuest, PubMed, Scopus, Web of Science and Google Scholar), articles without limitations of language, in which the main objective was to evaluate the frequency of bifurcation of the mandibular canal through assessment in situ, panoramic radiography, CT or CBCT were selected. A meta-analysis of prevalence using random effects was performed. Results: Using a selection process in two phases, 15 articles were identified, and a meta-analysis was conducted. The results from these meta-analyses showed that the overall prevalence of anatomical variations for in situ studies was 6.46%, and through assessment of panoramic radiography and CT or CBCT the overall prevalence shown was 4.20% and 16.25%, respectively. Conclusions: There are two types of variations of the mandibular canal: the retromolar canal and bifid mandibular canal. The frequency variations through assessing in situ, panoramic radiography and CT or CBCT were 6.46%, 4.20% and 16.25%, respectively. PMID:26576624

  16. Development of a digital panoramic X-ray imaging system of adaptive image layers for dental applications

    NASA Astrophysics Data System (ADS)

    Choi, S. I.; Park, Y. O.; Cho, H. S.; Oh, J. E.; Cho, H. M.; Hong, D. K.; Lee, M. S.; Yang, Y. J.; Je, U. K.; Kim, D. S.; Lee, H. K.

    2011-10-01

    As a continuation of our digital radiographic sensor R&D, we have developed a prototyped digital panoramic X-ray imaging system for dental applications. The imaging system consists of a slit-collimated X-ray generator with a 0.4 mm focal spot size and a 3.5 mm Al filtration, a linear-array typed CMOS imager with a 48×48 μm 2 pixel size and a 128 (in the scan direction)×3072 (in the vertical direction) pixel format, a series of microstep motors for the precise motion control of the imaging system, and the designed sequences for the motion control and pixel readout required to make a specific plane of interest (POI) to be focused. With the several test phantoms we designed, we obtained useful digital panoramic X-ray images by moving the X-ray generator and the CMOS imager along a continuously sliding rotational center. In this study, we demonstrated that the prototype system can be applicable to any shaped POI or multi-POIs simultaneously to be focused, provided that adequate sequences for motion control and pixel readout are designed. We expect that the imaging system will be useful for our ongoing applications of dental panoramic radiography and nondestructive testing.

  17. Comparison of ionisation chamber and semiconductor detector devices for measurement of the dose-width product for panoramic dental units.

    PubMed

    Mitchell, S A; Martin, C J

    2013-06-01

    Doses for panoramic dental radiography are assessed in terms of the dose-width product (DWP) or dose-area product, which gives a measure of the radiation through a whole exposure. The DWP can be measured using a pencil ionisation chamber (IC) similar to that used for computed tomography dose assessment. However, ICs are sensitive to radiation incident from all directions and so backscatter from the image receptor may increase the recorded dose. This study compares measurements performed using four options: a pencil IC mounted straight on the image receptor, the IC mounted with a steel plate to the rear to standardise scatter conditions, the IC mounted with a steel plate and lead collimators in front to minimise the effect of extra-focal radiation, and a Quart Dido employing a one square centimetre semiconductor detector (SD) designed for panoramic measurements. The results indicate that modification of the current method by incorporating a steel plate reduced the measurement dose by 7% on average, but the reduction was greater for units with semiconductor imaging plates. The measurements with the SD agree more closely with the IC with the steel plate to the rear. An IC with a backing plate to standardise scatter or a suitable SD is recommended for measurement on panoramic dental units.

  18. The prevalence of foreign bodies in jaw bones on panoramic radiography

    PubMed Central

    Omezli, Mehmet Melih; Torul, Damla; Sivrikaya, Efe Can

    2015-01-01

    Objective: Foreign bodies can be deposited in the oral cavity either by traumatic or iatrogenic injury. The most common foreign bodies of iatrogenic origin encountered are restorative materials, like amalgam, and root canal fillings. The aim of this study was to determine the prevalence of foreign bodies detected with panoramic radiography in the jawbones, as well as to evaluate the etiology and characteristics of these pathologies. Materials and Methods: From March 2012 to January 2014, 11,144 panoramic radiographs were taken and retrospectively reviewed. The number, characteristics, location of the foreign bodies, age, and gender of the patients were recorded. Results: Of the 11,144 patients reviewed, 62 of them have a foreign body with a frequency of 0.6%. The patients who had a foreign body were between 14 and 81 years old. Female patients showed more foreign bodies than male patients. Among the 62 patients, 63 filling materials, one stapler, and five shrapnel were detected. Only 8 patients had symptoms associated with foreign bodies and these foreign bodies excised surgically. Conclusion: If possible, these pathologies must be removed at the time of detection to prevent further complications; however, in asymptomatic cases, according to location and the characteristic of the foreign body, they can be kept under observation without performing any operations. PMID:26752878

  19. Panoramic Radiography in the Diagnosis of Carotid Artery Atheromas and the Associated Risk Factors

    PubMed Central

    Guimarães Henriques, João César; Kreich, Eliane Maria; Helena Baldani, Márcia; Luciano, Mariely; Cezar de Melo Castilho, Julio; Cesar de Moraes, Luiz

    2011-01-01

    Atherosclerosis is a serious chronic disease, responsible for thousands of deaths worldwide and is characterized by thickening and loss of elasticity of the arterial walls, associated with the presence of atheromatous plaques. Various risk factors act directly on predisposition to the disease, among which the following are pointed out: diabetes mellitus, arterial hypertension and inadequate diet and eating habits. More recent researches have elucidated new risk factors acting in the development of this disease, such as, for example: periodontitis, chronic renal disease and menopause. The panoramic radiograph, commonly used in dental practice, makes it possible to see calcified atherosclerotic plaques that are eventually deposited in the carotid arteries. The aim of this review article was to emphasize the dentist’s important role in the detection of carotid artery atheromas in panoramic radiographs and the immediate referral of patients affected by these calcifications to doctors. In addition, the study intended to guide the dentist, especially the dental radiologist, with regard to differential diagnosis, which should be made taking into consideration particularly the triticeal cartilage when it is calcified. PMID:21760860

  20. Panoramic radiography in the diagnosis of carotid artery atheromas and the associated risk factors.

    PubMed

    Guimarães Henriques, João César; Kreich, Eliane Maria; Helena Baldani, Márcia; Luciano, Mariely; Cezar de Melo Castilho, Julio; Cesar de Moraes, Luiz

    2011-01-01

    Atherosclerosis is a serious chronic disease, responsible for thousands of deaths worldwide and is characterized by thickening and loss of elasticity of the arterial walls, associated with the presence of atheromatous plaques. Various risk factors act directly on predisposition to the disease, among which the following are pointed out: diabetes mellitus, arterial hypertension and inadequate diet and eating habits. More recent researches have elucidated new risk factors acting in the development of this disease, such as, for example: periodontitis, chronic renal disease and menopause. The panoramic radiograph, commonly used in dental practice, makes it possible to see calcified atherosclerotic plaques that are eventually deposited in the carotid arteries. The aim of this review article was to emphasize the dentist's important role in the detection of carotid artery atheromas in panoramic radiographs and the immediate referral of patients affected by these calcifications to doctors. In addition, the study intended to guide the dentist, especially the dental radiologist, with regard to differential diagnosis, which should be made taking into consideration particularly the triticeal cartilage when it is calcified.

  1. Comparison of state dental radiography safety regulations.

    PubMed

    McDaniel, Thomas F; Parashar, Vijay

    2015-01-01

    The aim of this study was to compare and provide an overview of state policies on occupational exposure, dosimetry, collimation, patient protection, and the use of portable handheld X-ray machines in dentistry. State government webpages containing radiation protection rules and regulations were scanned. The contents were compared against current federal regulations established by the Nuclear Regulatory Commission (NRC) and the US Food and Drug Administration (FDA). They were further evaluated in light of current recommendations from the National Council on Radiation Protection & Measurements (NCRP) and the American Dental Association (ADA). Most states' regulations mirror the exposure limits set forth by the NRC and FDA. Nonregulatory recommendations regarding use of dental radiography are periodically put forth by the NCRP and the ADA. State and federal agencies often follow recommendations from these scientific organizations when creating regulations. Clinicians must be aware of their state's radiation protection rules, as variations among states exist. In addition, recommendations published by organizations such as the NCRP and the ADA, while not legally binding, contribute significantly to the reduction of radiation risks for operators and patients alike.

  2. Digital versus conventional panoramic radiography in predicting inferior alveolar nerve injury after mandibular third molar removal.

    PubMed

    Szalma, József; Lempel, Edina; Jeges, Sára; Olasz, Lajos

    2012-03-01

    The aim of the study was to compare the accuracy of conventional and digital panoramic radiography (OPG) in relation to 4 specific high-risk signs (interruption of the superior cortical line, diversion, narrowing of the canal, and dark band of the root), which would indicate a close anatomic relationship between third molar roots and the inferior alveolar canal.Four hundred mandibular third molar surgical removals after conventional and 272 after digital radiographs were evaluated in the study. The association between postoperative inferior alveolar nerve (IAN) paresthesia and the presence of any preoperative high-risk signs in the OPG was investigated. Bivariate and multivariate logistic regression analyses were completed to compare the accuracy of conventional and digital radiographic techniques detecting high-risk signs predicting possible IAN paresthesia.Digital OPG results showed significantly higher sensitivity in diversion (P = 0.014) and narrowing (P < 0.002) of the canal, whereas the specificity of these signs was significantly lower (P < 0.001 and P = 0.035). The likelihood ratio analysis and multivariate logistic regression analysis did not prove the significant difference between digital and conventional imaging according to the examined high-risk signs. Positive predictive values of the signs were found in conventional radiography between 3.6% and 10.9%, whereas in the digital images, it ranged from 2.9% to 7.9%.The results of this study failed to prove significant difference between the accuracy of digital and conventional OPG for predicting IAN paresthesia, whereas low positive predictive values indicate both imaging techniques as inadequate screening methods for predicting IAN paresthesia after mandibular third molar removal.

  3. 42 CFR Appendix G to Part 75 - Standards for Licensing Dental Hygienists and Dental Assistants in Dental Radiography

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false Standards for Licensing Dental Hygienists and...—Standards for Licensing Dental Hygienists and Dental Assistants in Dental Radiography The following section... personnel who perform radiologic procedures. Currently, Dental Hygienists are credentialed...

  4. A benchmark for comparison of dental radiography analysis algorithms.

    PubMed

    Wang, Ching-Wei; Huang, Cheng-Ta; Lee, Jia-Hong; Li, Chung-Hsing; Chang, Sheng-Wei; Siao, Ming-Jhih; Lai, Tat-Ming; Ibragimov, Bulat; Vrtovec, Tomaž; Ronneberger, Olaf; Fischer, Philipp; Cootes, Tim F; Lindner, Claudia

    2016-07-01

    Dental radiography plays an important role in clinical diagnosis, treatment and surgery. In recent years, efforts have been made on developing computerized dental X-ray image analysis systems for clinical usages. A novel framework for objective evaluation of automatic dental radiography analysis algorithms has been established under the auspices of the IEEE International Symposium on Biomedical Imaging 2015 Bitewing Radiography Caries Detection Challenge and Cephalometric X-ray Image Analysis Challenge. In this article, we present the datasets, methods and results of the challenge and lay down the principles for future uses of this benchmark. The main contributions of the challenge include the creation of the dental anatomy data repository of bitewing radiographs, the creation of the anatomical abnormality classification data repository of cephalometric radiographs, and the definition of objective quantitative evaluation for comparison and ranking of the algorithms. With this benchmark, seven automatic methods for analysing cephalometric X-ray image and two automatic methods for detecting bitewing radiography caries have been compared, and detailed quantitative evaluation results are presented in this paper. Based on the quantitative evaluation results, we believe automatic dental radiography analysis is still a challenging and unsolved problem. The datasets and the evaluation software will be made available to the research community, further encouraging future developments in this field. (http://www-o.ntust.edu.tw/~cweiwang/ISBI2015/).

  5. Automatic Synthesis of Panoramic Radiographs from Dental Cone Beam Computed Tomography Data

    PubMed Central

    Luo, Ting; Shi, Changrong; Zhao, Xing; Zhao, Yunsong; Xu, Jinqiu

    2016-01-01

    In this paper, we propose an automatic method of synthesizing panoramic radiographs from dental cone beam computed tomography (CBCT) data for directly observing the whole dentition without the superimposition of other structures. This method consists of three major steps. First, the dental arch curve is generated from the maximum intensity projection (MIP) of 3D CBCT data. Then, based on this curve, the long axial curves of the upper and lower teeth are extracted to create a 3D panoramic curved surface describing the whole dentition. Finally, the panoramic radiograph is synthesized by developing this 3D surface. Both open-bite shaped and closed-bite shaped dental CBCT datasets were applied in this study, and the resulting images were analyzed to evaluate the effectiveness of this method. With the proposed method, a single-slice panoramic radiograph can clearly and completely show the whole dentition without the blur and superimposition of other dental structures. Moreover, thickened panoramic radiographs can also be synthesized with increased slice thickness to show more features, such as the mandibular nerve canal. One feature of the proposed method is that it is automatically performed without human intervention. Another feature of the proposed method is that it requires thinner panoramic radiographs to show the whole dentition than those produced by other existing methods, which contributes to the clarity of the anatomical structures, including the enamel, dentine and pulp. In addition, this method can rapidly process common dental CBCT data. The speed and image quality of this method make it an attractive option for observing the whole dentition in a clinical setting. PMID:27300554

  6. Removing Distortion of Periapical Radiographs in Dental Digital Radiography Using Embedded Markers in an External frame

    PubMed Central

    Kafieh, Rahele; Shahamoradi, Mahdi; Hekmatian, Ehsan; Foroohandeh, Mehrdad; Emamidoost, Mostafa

    2012-01-01

    To carry out in vivo and in vitro comparative pilot study to evaluate the preciseness of a newly proposed digital dental radiography setup. This setup was based on markers placed on an external frame to eliminate the measurement errors due to incorrect geometry in relative positioning of cone, teeth and the sensor. Five patients with previous panoramic images were selected to undergo the proposed periapical digital imaging for in vivo phase. For in vitro phase, 40 extracted teeth were replanted in dry mandibular sockets and periapical digital images were prepared. The standard reference for real scales of the teeth were obtained through extracted teeth measurements for in vitro application and were calculated through panoramic imaging for in vivo phases. The proposed image processing thechnique was applied on periapical digital images to distinguish the incorrect geometry. The recognized error was inversely applied on the image and the modified images were compared to the correct values. The measurement findings after the distortion removal were compared to our gold standards (results of panoramic imaging or measurements from extracted teeth) and showed the accuracy of 96.45% through in vivo examinations and 96.0% through in vitro tests. The proposed distortion removal method is perfectly able to identify the possible inaccurate geometry during image acquisition and is capable of applying the inverse transform to the distorted radiograph to obtain the correctly modified image. This can be really helpful in applications like root canal therapy, implant surgical procedures and digital subtraction radiography, which are essentially dependent on precise measurements. PMID:23724372

  7. A new screening pathway for identifying asymptomatic patients using dental panoramic radiographs

    NASA Astrophysics Data System (ADS)

    Hayashi, Tatsuro; Matsumoto, Takuya; Sawagashira, Tsuyoshi; Tagami, Motoki; Katsumata, Akitoshi; Hayashi, Yoshinori; Muramatsu, Chisako; Zhou, Xiangrong; Iida, Yukihiro; Matsuoka, Masato; Katagi, Kiyoji; Fujita, Hiroshi

    2012-03-01

    To identify asymptomatic patients is the challenging task and the essential first step in diagnosis. Findings of dental panoramic radiographs include not only dental conditions but also radiographic signs that are suggestive of possible systemic diseases such as osteoporosis, arteriosclerosis, and maxillary sinusitis. Detection of such signs on panoramic radiographs has a potential to provide supplemental benefits for patients. However, it is not easy for general dental practitioners to pay careful attention to such signs. We addressed the development of a computer-aided detection (CAD) system that detects radiographic signs of pathology on panoramic images, and the design of the framework of new screening pathway by cooperation of dentists and our CAD system. The performance evaluation of our CAD system showed the sensitivity and specificity in the identification of osteoporotic patients were 92.6 % and 100 %, respectively, and those of the maxillary sinus abnormality were 89.6 % and 73.6 %, respectively. The detection rate of carotid artery calcifications that suggests the need for further medical evaluation was approximately 93.6 % with 4.4 false-positives per image. To validate the utility of the new screening pathway, preliminary clinical trials by using our CAD system were conducted. To date, 223 panoramic images were processed and 4 asymptomatic patients with suspected osteoporosis, 7 asymptomatic patients with suspected calcifications, and 40 asymptomatic patients with suspected maxillary sinusitis were detected in our initial trial. It was suggested that our new screening pathway could be useful to identify asymptomatic patients with systemic diseases.

  8. Panoramic radiographic demonstration of bilateral tonsilloliths.

    PubMed

    Guevara, Carlo; Mandel, Louis

    2011-04-01

    Calcifications can develop within the crypts of the palatine tonsil. During routine dental panoramic radiography, these tonsillar calcifications, or tonsilloliths, may be visualized superimposed upon the mandibular ramus. Their anatomic location and radiographic appearance are such that confusion with parotid sialolithiasis may occur. This report defines the symptomatology and differential diagnosis of these tonsilloliths.

  9. Dental radiography exposure of the Hiroshima and Nagasaki populations

    SciTech Connect

    Antoku, S.; Hoshi, M.; Russell, W.J.; Kihara, T.; Sawada, S.; Takeshita, K.; Otake, M.; Yoshinaga, H.; Beach, D.R.

    1989-03-01

    Dental radiography doses in Hiroshima and Nagasaki were estimated on the basis of survey data from dental hospitals and clinics in Hiroshima and Nagasaki, and doses were measured by thermoluminescent dosimeters and a phantom. Doses to organs, including the lens, pituitary fossa, thyroid gland, and skin were calculated from data obtained during a 2-week survey in both cities. The mean caput doses were calculated from the data indicating frequency per year and were tabulated by organs, age, teeth examined, type of examination, population, sex, and city. No significant difference was observed by age, population, sex, or city. Currently the doses incurred during dental radiography may not be sufficiently high to cause bias in the assessments for late radiation effects among atomic-bomb survivors. However, the mean caput thyroid doses of 62 mrad and 67 mrad in Hiroshima and Nagasaki, respectively, cannot be ignored from the standpoint of their potential in contributing to radiation-induced carcinogenesis.

  10. Panoramic radiography and cone-beam computed tomography findings in preoperative examination of impacted mandibular third molars

    PubMed Central

    2014-01-01

    Background Preoperative radiographic examination of impacted mandibular third molars (IMTM) is essential to prevent inferior alveolar nerve injury during extraction. The purpose of this study was to evaluate the correlation between cone-beam computed tomography (CBCT) and digital panoramic radiography (DPR) findings in preoperative examination of IMTM. Methods This retrospective study included 298 teeth in 191 individuals. The relationship between the inferior alveolar canal (IAC) and the IMTM (buccal, lingual, interradicular or inferior), the position of the IMTM with respect to the IAC (contact, no contact), the morphologic shape of the mandible in the IMTM region (round, lingual extended, lingual concave), the type of IMTM (vertical, horizontal or angular) and the number of roots of the IMTM were evaluated on CBCT images. DPR images were evaluated for the number of roots of the IMTM and for the most common radiographic findings indicating a relationship between the IAC and the IMTM (darkening of the roots, diversion of the IAC, narrowing of the IAC and interruption of the white line). Data were statistically analyzed with Cramer V coefficient, Kappa statistic, chi-square and Fisher’s exact test. Results There was a significant difference in number of roots detected on DPR versus CBCT images. There was a significant association between the type of IMTM and the morphologic shape of the mandible on CBCT images. Darkening of the roots and interruption of the white line on DPR images were significantly associated with the presence of contact between the IMTM and the IAC on CBCT images. Conclusions Panoramic radiography is inadequate, whereas CBCT is useful to detect multiple roots of IMTM. When darkening of the roots and interruption of the white line are observed on panoramic images, there is increased likelihood of contact between the IMTM and the IAC. CBCT is required in these cases. PMID:24928108

  11. Computer-aided system for morphometric mandibular index computation (Using dental panoramic radiographs)

    PubMed Central

    Álvarez-López, Jose M.; Jané-Salas, Enrique; Estrugo-Devesa, Albert; Ayuso-Montero, Raul; Velasco-Ortega, Eugenio; Segura-Egea, Juan J.

    2012-01-01

    Objective: We propose and validate a computer—aided system to measure three different mandibular indexes: cortical width, panoramic mandibular index and, mandibular alveolar bone resorption index. Study Design: Repeatability and reproducibility of the measurements are analyzed and compared to the manual estimation of the same indexes. Results: The proposed computerized system exhibits superior repeatability and reproducibility rates compared to standard manual methods. Moreover, the time required to perform the measurements using the proposed method is negligible compared to perform the measurements manually. Conclusions: We have proposed a very user friendly computerized method to measure three different morphometric mandibular indexes. From the results we can conclude that the system provides a practical manner to perform these measurements. It does not require an expert examiner and does not take more than 16 seconds per analysis. Thus, it may be suitable to diagnose osteoporosis using dental panoramic radiographs. Key words:Osteoporosis, panoramic mandibular index, cortical width, mandibular alveolar bone resorption index. PMID:22322489

  12. An automatic early stage alveolar-bone-resorption evaluation method on digital dental panoramic radiographs

    NASA Astrophysics Data System (ADS)

    Zhang, Min; Katsumata, Akitoshi; Muramatsu, Chisako; Hara, Takeshi; Suzuki, Hiroki; Fujita, Hiroshi

    2014-03-01

    Periodontal disease is a kind of typical dental diseases, which affects many adults. The presence of alveolar bone resorption, which can be observed from dental panoramic radiographs, is one of the most important signs of the progression of periodontal disease. Automatically evaluating alveolar-bone resorption is of important clinic meaning in dental radiology. The purpose of this study was to propose a novel system for automated alveolar-bone-resorption evaluation from digital dental panoramic radiographs for the first time. The proposed system enables visualization and quantitative evaluation of alveolar bone resorption degree surrounding the teeth. It has the following procedures: (1) pre-processing for a test image; (2) detection of tooth root apices with Gabor filter and curve fitting for the root apex line; (3) detection of features related with alveolar bone by using image phase congruency map and template matching and curving fitting for the alveolar line; (4) detection of occlusion line with selected Gabor filter; (5) finally, evaluation of the quantitative alveolar-bone-resorption degree in the area surrounding teeth by simply computing the average ratio of the height of the alveolar bone and the height of the teeth. The proposed scheme was applied to 30 patient cases of digital panoramic radiographs, with alveolar bone resorption of different stages. Our initial trial on these test cases indicates that the quantitative evaluation results are correlated with the alveolar-boneresorption degree, although the performance still needs further improvement. Therefore it has potential clinical practicability.

  13. Automatic Molar Extraction from Dental Panoramic Radiographs for Forensic Personal Identification

    NASA Astrophysics Data System (ADS)

    Samopa, Febriliyan; Asano, Akira; Taguchi, Akira

    Measurement of an individual molar provides rich information for forensic personal identification. We propose a computer-based system for extracting an individual molar from dental panoramic radiographs. A molar is obtained by extracting the region-of-interest, separating the maxilla and mandible, and extracting the boundaries between teeth. The proposed system is almost fully automatic; all that the user has to do is clicking three points on the boundary between the maxilla and the mandible.

  14. Automated contralateral subtraction of dental panoramic radiographs for detecting abnormalities in paranasal sinus

    NASA Astrophysics Data System (ADS)

    Hara, Takeshi; Mori, Shintaro; Kaneda, Takashi; Hayashi, Tatsuro; Katsumata, Akitoshi; Fujita, Hiroshi

    2011-03-01

    Inflammation in the paranasal sinus is often observed in seasonal allergic rhinitis or with colds, but is also an indication for odontogenic tumors, carcinoma of the maxillary sinus or a maxillary cyst. The detection of those findings in dental panoramic radiographs is not difficult for radiologists, but general dentists may miss the findings since they focus on treatments of teeth. The purpose of this work is to develop a contralateral subtraction method for detecting the odontogenic sinusitis region on dental panoramic radiographs. We developed a contralateral subtraction technique in paranasal sinus region, consisting of 1) image filtering of the smoothing and sobel operation for noise reduction and edge extraction, 2) image registration of mirrored image by using mutual information, and 3) image display method of subtracted pixel data. We employed 56 cases (24 normal and 32 abnormal). The abnormal regions and the normal cases were verified by a board-certified radiologist using CT scans. Observer studies with and without subtraction images were performed for 9 readers. The true-positive rate at a 50% confidence level in 7 out of 9 readers was improved, but there was no statistical significance in the difference of area-under-curve (AUC) in each radiologist. In conclusion, the contralateral subtraction images of dental panoramic radiographs may improve the detection rate of abnormal regions in paranasal sinus.

  15. Computers in dental radiography: a scenario for the future

    SciTech Connect

    Webber, R.L.

    1985-09-01

    The recent emergence of cost-effective computing power makes it possible to integrate sophisticated data-sampling and image-interpretation techniques into dental radiography for the first time. A prototype system is being developed to permit clinical information expressed in three dimensions--plus time--to be made visible almost instantly. The associated X-ray dose for a complete three-dimensional survey of a selected dental region is predicted to be less than that required for a single conventional periapical radiograph exposed on D-speed film.

  16. A note on digital dental radiography in forensic odontology.

    PubMed

    Chiam, Sher-Lin

    2014-09-01

    Digital dental radiography, intraoral and extraoral, is becoming more popular in dental practice. It offers convenience, such as lower exposure to radiation, ease of storing of images, and elimination of chemical processing. However, it also has disadvantages and drawbacks. One of these is the potential for confusion of the orientation of the image. This paper outlines one example of this, namely, the lateral inversion of the image. This source of confusion is partly inherent in the older model of phosphor storage plates (PSPs), as they allow both sides to be exposed without clue to the fact that the image is acquired on the wrong side. The native software allows digital manipulation of the X-ray image, permitting both rotation and inversion. Attempts to orientate the X-ray according to the indicator incorporated on the plate can then sometimes lead to inadvertent lateral inversion of the image. This article discusses the implications of such mistakes in dental digital radiography to forensic odontology and general dental practice.

  17. Assessment of digital panoramic radiography's diagnostic value in angular bony lesions with 5 mm or deeper pocket depth in mandibular molars

    PubMed Central

    Saberi, Bardia Vadiati; Nemati, Somayeh; Malekzadeh, Meisam; Javanmard, Afrooz

    2017-01-01

    Background: Assessment of alveolar bone level in periodontitis is very important in determining prognosis and treatment plan. Panoramic radiography is a diagnostic tool used to screen patients. The aim of the present study was to assess the diagnostic value of digital panoramic radiography in angular bony defects with 5 mm or deeper pocket depth in mandibular molars. Materials and Methods: In this cross-sectional study, ninety angular bony defects in mandibular molars teeth with 5 mm or deeper pocket depth were selected in sixty patients with the diagnosis of chronic periodontitis. Before surgery, bone probing was performed. During the surgery, the vertical distance from cementoenamel junction to the most apical part of bony defect was measured using a Williams probe and this measurements were employed as gold standard. This distance was measured on the panoramic radiographs by a Digital Calliper and Digital Ruler. All data were compare dusing independent samples t-test and Pearson's correlation coefficient. Results: No significant difference was found between the results of bone probing and intra-surgical measurements (P = 0.377). The mean defect depth determined by Digital Caliper and Digital Ruler on panoramic radiographs was significantly less than surgical measurements (P < 0.001). The correlation between bone probing and surgical measurements in determining the defect depth was strong (r = 0.98, P < 0.001). Radiographic measurements made by Digital Ruler (r = 0.86), comparing to Digital Caliper (r = 0.79), showed a higher degree of correlation with surgical measurements. Conclusion: Based on this study, bone probing is a reliable method in vertical alveolar bone defect measurements. While the information obtained from digital panoramic radiographs should be used with caution and the ability of digital panoramic radiography in the determination of defect depth is limited. PMID:28348615

  18. Free focus radiography with miniaturized dental x-ray machines: a comparison of ''midline'' and ''lateral'' techniques

    SciTech Connect

    Jensen, T.W.

    1983-08-01

    The use of free focus radiography (FFR) employing miniaturized dental x-ray machines with radiation probes has never been generally accepted in dentistry despite its recognized radiographic potential. The present investigation studied ways to improve imaging and lower radiation burdens in dental free focus radiography. Relatively high air exposures ranging from 42,050 mR per film for high-resolution images to 3,214 mR per film for lower-resolution images using a current midline radiographic technique for panoramic FFR were found. In a proposed lateral FFR panoramic technique, reduced exposures ranged from 420 mR per film for high-resolution images to 14 mR per film for lower-resolution images. In each technique the lower exposure was obtained with a rare earth imaging system. A proposed modification of the current midline FFR technique using a rare earth imaging system and heavy added copper filtration was found to produce exposures in the range normally used in dentistry (207 mr), and the resultant image was high in contrast with relatively low detail. A comparison of essential characteristics of midline and lateral FFR techniques failed to identify specific advantages for the midline technique in current use. Lateral exposure modes in dental FFR should receive increased attention in the interest of good imaging and radiation control. It was noted that existing miniaturized dental x-ray machines may have been designed specifically for use of the midline FFR exposure technique, and modification of this equipment to support reliable lateral exposure modes was recommended.

  19. Risk factors associated with inferior alveolar nerve injury after extraction of the mandibular third molar--a comparative study of preoperative images by panoramic radiography and computed tomography.

    PubMed

    Hasegawa, T; Ri, S; Shigeta, T; Akashi, M; Imai, Y; Kakei, Y; Shibuya, Y; Komori, T

    2013-07-01

    In this study we investigated the relationships among the risk factors for inferior alveolar nerve injury (IANI), and the difference between preoperative imaging findings on panoramic radiographs and computed tomography (CT), by univariate and multivariate analyses. We determined the following to be significant variables by multivariate analysis: panoramic radiographic signs, such as the loss of the white line of the inferior alveolar canal or the diversion of the canal; excessive haemorrhage during extraction; and a close relationship of the roots to the IAN (type 1 cases) on CT examination. CT findings of type 1 were associated with a significantly higher risk (odds ratio 43.77) of IANI. In addition, many panoramic findings were not consistent with CT findings (275 of 440 teeth; 62.5%). These results suggest that CT findings may be able to predict the development of IANI more accurately than panoramic findings. Panoramic radiography alone did not provide sufficiently reliable images required for predicting IANI. Therefore, when the panoramic image is suggestive of a close relationship between the impacted tooth and the IAN, CT should be recommended as a means of conducting further investigations.

  20. Descriptive study of the bifid mandibular canals and retromolar foramina: cone beam CT vs panoramic radiography

    PubMed Central

    Muinelo-Lorenzo, J; Suárez-Quintanilla, J A; Fernández-Alonso, A; Marsillas-Rascado, S

    2014-01-01

    Objectives: To examine the presence and morphologic characteristics of bifid mandibular canals (BMCs) and retromolar foramens (RFs) using cone beam CT (CBCT) and to determine their visualization on panoramic radiographs (PANs). Methods: A sample of 225 CBCT examinations was analysed for the presence of BMCs, as well as length, height, diameter and angle. The diameter of the RF was also determined. Subsequently, corresponding PANs were analysed to determine whether the BMCs and RFs were visible or not. Results: The BMCs were observed on CBCT in 83 out of the 225 patients (36.8%). With respect to gender, statistically significant differences were found in the number of BMCs. There were also significant differences in anatomical characteristics of the types of BMCs. Only 37.8% of the BMCs and 32.5% of the RFs identified on CBCT were also visible on PANs. The diameter had a significant effect on the capability of PANs to visualize BMCs and RFs (B = 0.791, p = 0.035; B = 1.900, p = 0.017, respectively). Conclusions: PANs are unable to sufficiently identify BMCs and RFs. The diameter of these anatomical landmarks represents a relevant factor for visualization on PANs. Pre-operative images using only PANs may lead to underestimation of the presence of BMCs and to surgical complications and anaesthetic failures, which could have been avoided. For true determination of BMCs, a CBCT device should be considered better than a PAN. PMID:24785820

  1. Patient exposure trends in medical and dental radiography

    SciTech Connect

    Johnson, D.W.; Goetz, W.A.

    1986-01-01

    Patient exposure to medical and dental x rays has long been of interest to the radiological health community. With the cooperation of state and local agencies and professional groups, the Center for Devices and Radiological Health has conducted three major surveys of patient exposure to x rays. The latest of these surveys, the Nationwide Evaluation of X-ray Trends (NEXT), collected x-ray exposure data for each year starting in 1972. Two earlier studies, the 1964 and 1970 X-ray Exposure Studies collected x-ray data during the years these surveys were conducted. Exposure trends presented are based on results of all three studies. Major improvements in beam limitation are seen for medical and dental radiography. Since 1964, when the first nationwide survey was conducted, dental exposures have decreased about 75%. Decreases of up to one-third occurred in exposures for medical examinations. The current exposure data presented continue to show a wide variation in medical exposures. Also presented are organ doses for four organs (ovaries, testes, thyroid and active bone marrow).

  2. Influence of Experience and Training on Dental Students' Examination Performance Regarding Panoramic Images.

    PubMed

    Turgeon, Daniel P; Lam, Ernest W N

    2016-02-01

    Physician training has greatly benefitted from insights gained in understanding the manner in which experts search medical images for abnormalities. The aims of this study were to compare the search patterns of 30 fourth-year dental students and 15 certified oral and maxillofacial radiologists (OMRs) over panoramic images and to determine the most robust variables for future studies involving image visualization. Eye tracking was used to capture the eye movement patterns of both subject groups when examining 20 panoramic images classified as normal or abnormal. Abnormal images were further subclassified as having an obvious, intermediate, or subtle abnormality. The images were presented in random order to each participant, and data were collected on duration of the participants' observations and total distance tracked, time to first eye fixation, and total duration and numbers of fixations on and off the area of interest (AOI). The results showed that the OMRs covered greater distances than the dental students (p<0.001) for normal images. For images of pathosis, the OMRs required less total time (p<0.001), made fewer eye fixations (p<0.01) with fewer saccades (p<0.001) than the students, and required less time before making the first fixation on the AOI (p<0.01). Furthermore, the OMRs covered less distance (p<0.001) than the dental students for obvious pathoses. For investigations of images of pathosis, time to first fixation is a robust parameter in predicting ability. For images with different levels of subtlety of pathoses, the number of fixations, total time spent, and numbers of revisits are important parameters to analyze when comparing observer groups with different levels of experience.

  3. Dose measurements for dental cone-beam CT: a comparison with MSCT and panoramic imaging

    NASA Astrophysics Data System (ADS)

    Deman, P.; Atwal, P.; Duzenli, C.; Thakur, Y.; Ford, N. L.

    2014-06-01

    To date there is a lack of published information on appropriate methods to determine patient doses from dental cone-beam computed tomography (CBCT) equipment. The goal of this study is to apply and extend the methods recommended in the American Association of Physicists in Medicine (AAPM) Report 111 for CBCT equipment to characterize dose and effective dose for a range of dental imaging equipment. A protocol derived from the one proposed by Dixon et al (2010 Technical Report 111, American Association of Physicist in Medicine, MD, USA), was applied to dose measurements of multi-slice CT, dental CBCT (small and large fields of view (FOV)) and a dental panoramic system. The computed tomography dose index protocol was also performed on the MSCT to compare both methods. The dose distributions in a cylindrical polymethyl methacrylate phantom were characterized using a thimble ionization chamber and Gafchromic™ film (beam profiles). Gafchromic™ films were used to measure the dose distribution in an anthropomorphic phantom. A method was proposed to extend dose estimates to planes superior and inferior to the central plane. The dose normalized to 100 mAs measured in the center of the phantom for the large FOV dental CBCT (11.4 mGy/100 mAs) is two times lower than that of MSCT (20.7 mGy/100 mAs) for the same FOV, but approximately 15 times higher than for a panoramic system (0.6 mGy/100 mAs). The effective dose per scan (in clinical conditions) found for the dental CBCT are 167.60 ± 3.62, 61.30 ± 3.88 and 92.86 ± 7.76 mSv for the Kodak 9000 (fixed scan length of 3.7 cm), and the iCAT Next Generation for 6 cm and 13 cm scan lengths respectively. The method to extend the dose estimates from the central slice to superior and inferior slices indicates a good agreement between theory and measurement. The Gafchromic™ films provided useful beam profile data and 2D distributions of dose in phantom.

  4. Use of digital panoramic radiography as an auxiliary means of low bone mineral density detection in post-menopausal women

    PubMed Central

    Valerio, C S; Trindade, A M; Mazzieiro, Ê T; Amaral, T P; Manzi, F R

    2013-01-01

    Objectives: To correlate the radiomorphometric indices obtained using digital panoramic radiography (DPR) with bone mineral densities, evaluated by the dual-energy X-ray absorptiometry test, in a population of post-menopausal females to identify patients with asymptomatic low bone mineral densities. Methods: The morphology of the mandibular cortex was evaluated using the mandibular cortical index (MCI) and the inferior mandibular cortex width was evaluated using the mental index (MI) in 64 female patients who had undergone dual-energy X-ray absorptiometry assessment. Of these patients, 21 were diagnosed with osteopaenia and 20 with osteoporosis, and 23 were normal. Three new indices for evaluating the inferior mandibular cortex width were designed: the mental posterior index 1 (MPI1), MPI2 and MPI3. Statistical analyses were performed using the χ2 and Kruskal–Wallis tests and the receiver operating characteristic curve. Results: There were significant differences between the normal and lower bone mineral density groups (osteopaenia and osteoporosis) for MCI (p < 0.01). In the osteoporosis group, the MI, MPI1, MPI2 and MPI3 were significantly different from the normal and osteopaenia groups (p < 0.05). The MI, MPI1, MPI2 and MPI3 showed that there is an area in the mandibular cortex, located between the mental foramen and the antegonial region, which is valid for identifying females at high risk for osteoporosis. Conclusions: The MCI, MI, MPI1, MPI2, and MPI3 radiomorphometric indices evaluated using DPR can be used to identify post-menopausal females with low bone densities and to provide adequate medical treatment for them. PMID:24005062

  5. Automated classification of mandibular cortical bone on dental panoramic radiographs for early detection of osteoporosis

    NASA Astrophysics Data System (ADS)

    Horiba, Kazuki; Muramatsu, Chisako; Hayashi, Tatsuro; Fukui, Tatsumasa; Hara, Takeshi; Katsumata, Akitoshi; Fujita, Hiroshi

    2015-03-01

    Findings on dental panoramic radiographs (DPRs) have shown that mandibular cortical index (MCI) based on the morphology of mandibular inferior cortex was significantly correlated with osteoporosis. MCI on DPRs can be categorized into one of three groups and has the high potential for identifying patients with osteoporosis. However, most DPRs are used only for diagnosing dental conditions by dentists in their routine clinical work. Moreover, MCI is not generally quantified but assessed subjectively. In this study, we investigated a computer-aided diagnosis (CAD) system that automatically classifies mandibular cortical bone for detection of osteoporotic patients at early stage. First, an inferior border of mandibular bone was detected by use of an active contour method. Second, regions of interest including the cortical bone are extracted and analyzed for its thickness and roughness. Finally, support vector machine (SVM) differentiate cases into three MCI categories by features including the thickness and roughness. Ninety eight DPRs were used to evaluate our proposed scheme. The number of cases classified to Class I, II, and III by a dental radiologist are 56, 25 and 17 cases, respectively. Experimental result based on the leave-one-out cross-validation evaluation showed that the sensitivities for the classes I, II, and III were 94.6%, 57.7% and 94.1%, respectively. Distribution of the groups in the feature space indicates a possibility of MCI quantification by the proposed method. Therefore, our scheme has a potential in identifying osteoporotic patients at an early stage.

  6. Automated scheme for measuring mandibular cortical thickness on dental panoramic radiographs for osteoporosis screening

    NASA Astrophysics Data System (ADS)

    Matsumoto, T.; Hayashi, T.; Hara, T.; Katsumata, A.; Muramatsu, C.; Zhou, X.; Iida, Y.; Matsuoka, M.; Katagi, Ki.; Fujita, H.

    2012-03-01

    Findings of dental panoramic radiographs (DPRs) have shown that the mandibular cortical thickness (MCT) was significantly correlated with osteoporosis. Identifying asymptomatic patients with osteoporosis through dental examinations may bring a supplemental benefit for the patients. However, most of the DPRs are used for only diagnosing dental conditions by dentists in their routine clinical work. The aim of this study was to develop a computeraided diagnosis scheme that automatically measures MCT to assist dentists in screening osteoporosis. First, the inferior border of mandibular bone was detected by use of an active contour method. Second, the locations of mental foramina were estimated on the basis of the inferior border of mandibular bone. Finally, MCT was measured on the basis of the grayscale profile analysis. One hundred DPRs were used to evaluate our proposed scheme. Experimental results showed that the sensitivity and specificity for identifying osteoporotic patients were 92.6 % and 100 %, respectively. We conducted multiclinic trials, in which 223 cases have been obtained and processed in about a month. Our scheme succeeded in detecting all cases of suspected osteoporosis. Therefore, our scheme may have a potential to identify osteoporotic patients at an early stage.

  7. Volumetric image reconstruction in a dental panoramic imaging system with a limited-angle zigzag scan geometry

    NASA Astrophysics Data System (ADS)

    Hong, Daeki; Cho, Hyosung; Lee, Seonhwa; Oh, Jieun; Lee, Minsik; Kim, Hyojeong; Je, Uikyu; Park, Yeonok; Choi, Sungil; Koo, Yangseo; Cho, Heemoon

    2013-01-01

    As a continuation of our dental imaging R&D, we have proposed a novel idea that is capable of implementing cost-effective, low-dose, volumetric image reconstruction directly onto a dental panoramic imaging system. In the proposed geometry, a linear-type panoramic detector is rotated 90° from the orientation for panoramic imaging and scanned along a limited-angle zigzag trajectory in the axial direction to cover the whole imaging volume thickness. We used an effective reconstruction algorithm based on the total-variation (TV) minimization approach for the proposed geometry and performed systematic simulation work to demonstrate the viability of our proposed approach and its effectiveness for three-dimensional (3D) dental X-ray imaging. We have successfully reconstructed images of substantially high image accuracy from the proposed geometry and evaluated the reconstruction quality by using an image similarity metric, the universal-quality index (UQI). We expect the proposed method to be applicable to developing a cost-effective, low-dose, all-in-one dental X-ray imaging system.

  8. Evaluation of developmental dental anomalies in digital panoramic radiographs in Southeast Iranian Population

    PubMed Central

    Saberi, Eshagh Ali; Ebrahimipour, Sediqe

    2016-01-01

    Objectives: The objective of this study was to evaluate the prevalence of dental developmental anomalies in digital panoramic radiographs of the patients referred to the Zahedan medical imaging center and to evaluate the frequency of anomalies regarding the disorders in shape, position and number in the Southeast of Iran. Materials and Methods: A total of 1172 panoramic radiographs from 581 males and 586 females aged over 16 years were obtained from the files of the Zahedan medical imaging center between the years of 2014 and 2015. The selected radiographs were evaluated in terms of the anomalies such as dilacerations, taurodontism, supernumerary teeth, congenitally missing teeth, fusion, gemination, tooth impaction, tooth transposition, dens invagination, and peg lateral. Then, the anomalies were compared to each other regarding the frequency of the anomaly type (morphological, positional and numerical). Data were evaluated using descriptive statistics such as frequency and percent, and statistical tests such as X2 at 0.05 significant level using the Statistical Package for the Social Sciences version 16.5. Results: The prevalence of dental anomaly was 213 (18.17%), which was higher in females (9.90) than male, (8.28), however, this difference was not statistically significant (P > 0.05). The prevalence of dilacerated teeth was 62 (5.29%), taurodontism 63 (5.38%), supernumerary teeth 6 (0.51%), congenitally missing teeth 13 (1.11%), fusion 1 (0.09%), gemination 1 (0.09%), impaction 40 (3.41%), transposition 2 (0.18%), dens invagination 16 (1.37) and peg lateral was 9 (0.77%). The prevalence of morphological anomaly was 152 (71.36%), malposition 42 (19.72%) and numerous anomaly was 19 (8.92%). Conclusions: Dental anomalies are relatively common; although their occurrence is not symptomatic, they can lead to several clinical problems in patients. Detailed clinical and radiographic assessment and counseling during patient visits is a critical factor in assessing the

  9. Comparison of the diagnostic value of CBCT and Digital Panoramic Radiography with surgical findings to determine the proximity of an impacted third mandibular molar to the inferior alveolar nerve canal

    PubMed Central

    Saraydar-Baser, R; Dehghani-Tafti, M; Navab-Azam, A; Ezoddini-Ardakani, F; Nayer, S; Safi, Y; Shamloo, N

    2015-01-01

    Background: This study evaluated and determined the proximity of an impacted third mandibular molar (TMM) to the inferior alveolar canal (IAC) by using CBCT and digital panoramic radiography. Materials and Methods: This descriptive-analytic research applied CBCT and panoramic radiographs for 60 subjects (28 men, 32 women). Subjects selected showed a close proximity about the TMM to the inferior nerve canal on panoramic radiographs; these subjects then received CBCT radiographs. The CBCT findings for the proximity of the TMM to inferior nerve canal used the outcomes of surgical findings as the standard of comparison. Results: Eight cases showed positive surgical findings indicating vicinity of the third molar and the mandibular nerve canal. Only 13.3% of the cases in which panoramic views showed the proximity of the TMM and the IAC were confirmed during surgery. The result for CBCT radiographic diagnosis was 95%. Conclusion: It can be concluded that CBCT is preferred over panoramic radiography to determine the proximity of the impacted TMM to the IAC. Narrowing of the mandibular canal or root canal, disconnection of root borders in panoramic radiography, and the inferior-lingual proximity of the tooth to the root in CBCT strongly indicated the close nearness of the impacted TMM to the IAC. PMID:28316671

  10. [The specific panoramic radiographic signs and their relation with inferior alveolar nerve injuries after mandibular third molar surgery].

    PubMed

    Szalma, József; Lempel, Edina; Csuta, Tamás; Vajta, László; Jeges, Sára; Olasz, Lajos

    2011-03-01

    The aim of the authors was to describe the classic specific panoramic signs (indicating a close spatial relationship between dental canal and third molar's root) on panoramic radiographic images and determine their role in the risk assessment, predicting inferior alveolar nerve (IAN) paresthesia after lower third molar removal. The authors represented an informative case, where the IAN was visible during the surgery. The exact knowledge of classic panoramic radiographic signs should help the determination of "high risk" cases predicting IAN paresthesia after mandibular third molar removal. The authors keep panoramic radiography rather a routine than the most superior diagnostic tool in third molar surgery.

  11. Occlusal interferences related to dental panoramic radiographic changes in subjects treated with fixed prosthesis.

    PubMed

    Ettala-Ylitalo, U M; Syrjänen, S; Markkanen, H

    1987-09-01

    Because of contradictory reports between clinical and radiographic findings, occlusal analysis correlated to dental panoramic findings was completed in 147 patients treated with fixed prosthesis. Both occlusal interferences and radiographic changes in the TMJ area and/or in dentition were frequently discovered. Dysfunction and occlusal indices gave statistically significant correlations to radiographic changes (P less than 0.01 and P less than 0.05, respectively) in the TMJ area. Periodontal changes with vertical bone pocket formation and sclerotic lamina dura seem to be early radiographic findings and occlusal interferences were the only means to give a clear-cut correlation to the radiographic changes (P less than 0.001). However, if periodontal tissues with supporting bone structure fail to respond to occlusal trauma, changes in the TMJ area will probably appear. From the clinical changes the deviation on mouth opening, tenderness to palpation of TMJ, and slide from retrusion to intercuspidation (RP-IP) explained most of the radiological TMJ changes when tested by the discriminant analysis. The value of radiographic follow-up of subjects following prosthetic treatment is emphasized.

  12. Biological effects of radiation from dental radiography. Council on Dental Materials, Instruments, and Equipment

    SciTech Connect

    Gibbs, S.J.

    1982-08-01

    Clearly, there is ample evidence of adverse effects of radiation in sufficient doses. There is at present no proof of such effects from doses commonly employed in dental practice; however, it has not been possible to prove the absence of such effects. Most experts now agree that there may be a small, difficult to quantify risk of cancer or genetic mutation from diagnostic exposure in patients and in personnel exposed during work. Prudence dictates acceptance of this position until proof to the contrary is available. This report has presented recent attempts to quantify the risk to patients based on speculative calculations and extrapolations. Indices of population risks indicate that medical radiology is the largest source of human-made genetic and leukemogenic radiation burden to the American public. Dental radiology contributes a small-but not necessarily insignificant-portion. Of major concern is the increasing use of radiation for diagnostic purposes in both medicine and dentistry. Technological advances have reduced exposure per examination; presumably this trend will continue so that total exposure of populations to radiation in the healing arts will not increase. Recent analyses suggest that the cancer risk to a patient from a dental radiographic examination is of the order of one in a million; the genetic risk is substantially less, about one in a billion. The risks appear to be essentially equal for full-mouth intraoral and for panoramic examinations. These estimates are numerically quite small, but the effects are severe. Thus, these risks cannot be ignored. However, we currently accept risks of similar magnitude in our daily lives (Table 9)50,51 In addition, the risk of failure to make an accurate diagnosis may be greater than the risk from exposure to the radiation from a justified and properly conducted radiographic examination.

  13. Total variation minimization-based spiral CT reconstruction in a dental panoramic imaging system for cost-effective, low-dose dental X-ray imaging

    NASA Astrophysics Data System (ADS)

    Hong, D. K.; Lee, S. H.; Cho, H. S.; Oh, J. E.; Lee, M. S.; Kim, H. J.; Park, Y. O.; Je, U. K.; Choi, S. I.; Koo, Y. S.; Cho, H. M.

    2012-12-01

    In the paper, we proposed a pragmatic method capable of implementing a cost-effective, low-dose CT reconstruction directly onto a dental panoramic X-ray imaging system by adopting a spiral source trajectory. In the proposed geometry, a linear-type panoramic imaging sensor is rotated 90° from the orientation for panoramic imaging to imitate fan-beam image acquisition. For image reconstruction, we considered a total variation (TV) minimization-based algorithm that exploited the sparsity of the image gradient and was capable of reconstructing CT images with substantially high image accuracy against the image artifacts from sparse-view data. We implemented the algorithm for the proposed geometry and performed systematic simulation works to demonstrate its feasibility for dental imaging applications. CT images were successfully reconstructed from the proposed geometry, and the reconstruction quality was evaluated quantitatively by using an image similarity metric. We expect the proposed method to be applicable to developing a cost-effective, low-dose, all-in-one dental imaging system.

  14. Quality assurance in dental radiography: intra-oral image quality analysis.

    PubMed

    Bolas, Andrew; Fitzgerald, Maurice

    With the introduction of criteria for clinical audit by the Irish Dental Council, and the statutory requirement on dentists to introduce this into their practice, this article will introduce the basic concepts of quality standards in intra-oral radiography and the subsequent application of these standards in an image quality audit cycle. Subjective image quality analysis is not a new concept, but its application can prove beneficial to both patient and dental practitioner. The ALARA (as low as reasonably achievable) principle is fundamental in radiation protection, and therefore the prevention of repeat exposures demonstrates one facet of this that the dental practitioner can employ within daily practice.

  15. General Dental Practitioners’ Concept towards Using Radiography and Apex-Locators in Endodontics

    PubMed Central

    Raoof, Maryam; Heidaripour, Maryam; Shahravan, Arash; Haghani, Jahangir; Afkham, Arash; Razifar, Mahsa; Mohammadizadeh, Sakineh

    2014-01-01

    Introduction: Despite being the gold standard as well as a routine technique in endodontics, radiographic working length (WL) determination owns many drawbacks. Electronic apex-locators (EALs) are recommended to complement radiographies. The aim of this study was to evaluate the perceptions of Iranian general dental practitioners (GDPs) towards using radiography and EAL. Methods and Materials: Three hundred and ninety one GDPs attending the 53th Iranian Dental Association Congress completed a questionnaire focusing on the use of radiography and EALs during the various stages of root canal treatment. The data was analyzed with the chi-square test with the level of significance set at 0.05. The results were then calculated as frequencies and percentages. Results: More than half of the GDPs reported using radiographs as the sole method for WL determination. A total of 30.4% of the practitioners were using the combined approach during root canal therapy of a single-rooted tooth, while 38.9% used this method in multi-rooted teeth. Approximately half of the respondents would not order follow-up radiographies after root canal treatment. Conclusion: Radiography continues to be the most common method for WL determination in Iran. PMID:25386209

  16. A retrospective radiographic evaluation of the anterior loop of the mental nerve: Comparison between panoramic radiography and cone beam computerized tomography

    PubMed Central

    Vujanovic-Eskenazi, Aleksandar; Valero-James, Jesus-Manuel; Sánchez-Garcés, María-Angeles

    2015-01-01

    Objectives: To compare the prevalence and the length of mental loop, measured with panoramic radiography (PR) and cone beam computerized tomography (CBCT). Material and Methods: PG and CBCT images where analyzed by a single calibrated examiner to determine the presence and the position of the mental foramen (MF), its distance to the lower mandible border, the anterior length of the mental loop (ML) and the bone quality in 82 PR and 82 CBCT. Results: ML was identified in 36.6 % of PR and 48.8 % of CBCT. PR showed a magnification of 1.87 when compared to CBCT. The mean of anterior extension of the inferior alveolar nerve and the distance to the inferior border of the mandible was higher for PR (2.8 mm, sd 0.91 mm on the PR , range 1.5 to 4.7 mm and 1.59, sd 0.9 on the CBCT ,range 0.4 to 4.0 mm) Conclusions: There is a magnification in PR images with respect to those of CBCT. The differences between CBCT and PR with regards to the identification and length of the ML are not statistically significant. Identification and accuracy measurements of ML did not depend on the bone quality. Considering that two dimensional imaging provides less accurate and reliable information regarding the anterior loop, a CBCT scan could be recommended when planning implant placement in the anterior region. Key words:Mental loop, mental nerve, mental canal, preoperative implant planning, panoramic tomography, cone beam computerized tomography. PMID:25549693

  17. Automatic segmentation of mandible in panoramic x-ray

    PubMed Central

    Abdi, Amir Hossein; Kasaei, Shohreh; Mehdizadeh, Mojdeh

    2015-01-01

    Abstract. As the panoramic x-ray is the most common extraoral radiography in dentistry, segmentation of its anatomical structures facilitates diagnosis and registration of dental records. This study presents a fast and accurate method for automatic segmentation of mandible in panoramic x-rays. In the proposed four-step algorithm, a superior border is extracted through horizontal integral projections. A modified Canny edge detector accompanied by morphological operators extracts the inferior border of the mandible body. The exterior borders of ramuses are extracted through a contour tracing method based on the average model of mandible. The best-matched template is fetched from the atlas of mandibles to complete the contour of left and right processes. The algorithm was tested on a set of 95 panoramic x-rays. Evaluating the results against manual segmentations of three expert dentists showed that the method is robust. It achieved an average performance of >93% in Dice similarity, specificity, and sensitivity. PMID:26587551

  18. Dental age assessment on panoramic radiographs in a Swiss population: a validation study of two prediction models

    PubMed Central

    Kiliaridis, Stavros; Combescure, Christophe; Vazquez, Lydia

    2016-01-01

    Objectives: Dental age assessment methods are widely used for age estimation. This study aimed to analyse the accuracy of a meta-analysis method to estimate dental age in Swiss individuals and to detect potential limitations of the method. Precision of repeated tooth staging using Demirjian's classification on maxillary and mandibular teeth was also assessed. Methods: Panoramic radiographs of 50 Swiss white healthy children were analysed. Developing teeth on the left maxilla and mandible and all third permanent molars were staged following Demirjian's classification. Dental age was calculated for each subject, using a random effects model and a fixed effect model, and compared with chronological age. Results: The mean error of the dental age ranged between −3 and +1 months for both the calculation models. Dental age calculated with the fixed effect model overestimated the age of the subjects (average + 0.10 y, ranging from −1.95 y to +2.16 y) compared with their chronological age, whereas the random effects model underestimated the age (average −0.32 y, ranging from −2.24 y to +1.61 y). Conclusions: Demirjian's method allowed a precise repeated staging of maxillary and mandibular developing teeth. For both calculation models, dental age correlated well, on average, with chronological age of Swiss subjects younger than 12 years. The random effects model showed a better accuracy for these subjects than the fixed effect model. However, both models underestimated the chronological age in subjects older than 12 years. PMID:26250402

  19. High-speed dental radiography achieved with a kilohertz-range pulsed x-ray generator

    SciTech Connect

    Takabe, Akihito; Yamamoto, Mariko; Sakamaki, Kimio

    1995-12-31

    The development of a high-intensity kilohertz-range pulsed x-ray generator and its application to dental radiography are described. The pulsed x-ray generator consisted of the following major components: a constant high-voltage power supply, a high-voltage main condenser, a hot-cathode triode, a DC power supply for the filament (hot cathode), and a grid controller. The main condenser of 0.5 {micro}F-100 kV in the pulser was charged from 50 to 70 kV by the power supply, and the electric charges in the condenser were discharged to the triode by the grid controller. To be exact, the tube voltage decreased during the discharging for generating pulsed x-rays, yet the maximum value was equivalent to the initial charging voltage of the main condenser. The maximum values of the tube current and the repetition rate were about 0.5 A and 30 kHz, respectively. The pulse width of the x-rays ranged from approximately 20 to 400 {micro}s, and the x-ray intensity with a charging voltage of 70 kV and a total resistance of 5.1 M{Omega} was about 0.83 {micro}C/kg at 1.0 m per pulse. Using this generator, high-speed dental radiography, e.g., delayed radiography and multiple-shot radiography, was performed.

  20. Necessity of 3D visualization for the removal of lower wisdom teeth: required sample size to prove non-inferiority of panoramic radiography compared to CBCT.

    PubMed

    Roeder, Felix; Wachtlin, Daniel; Schulze, Ralf

    2012-06-01

    The availability of cone beam computed tomography (CBCT) and the numbers of CBCT scans rise constantly, increasing the radiation burden to the patient. A growing discussion is noticeable if a CBCT scan prior to the surgical removal of wisdom teeth may be indicated. We aimed to confirm non-inferiority with respect to damage of the inferior alveolar nerve in patients diagnosed by panoramic radiography compared to CBCT in a prospective randomized controlled multicentre trial. Sample size (number of required third molar removals) was calculated for the study and control groups as 183,474 comparing temporary and 649,036 comparing permanent neurosensory disturbances of the inferior alveolar nerve. Modifying parameter values resulted in sample sizes ranging from 39,584 to 245,724 respectively 140,024 to 869,250. To conduct a clinical study to prove a potential benefit from CBCT scans prior to surgical removal of lower wisdom teeth with respect to the most important parameter, i.e., nerval damage, is almost impossible due to the very large sample sizes required. This fact vice versa indicates that CBCT scans should only be performed in high risk wisdom tooth removals.

  1. Intracranial arachnoid cyst on dental radiography: a diagnostic challenge.

    PubMed

    Sun, Lisha; Sun, Zhipeng; Ma, Xuchen

    2013-03-01

    Intracranial arachnoid cysts (IACs) can present as congenital asymptomatic lesions that may predispose them to present as an incidental finding during radiographic examination. On the other hand, IACs may also give rise to a series of neurologic symptoms depending on their size and location, such as vomiting, seizures, headache, and ataxia. Skull deformities, including macrocephaly, may occur and become remarkable on dental radiology. We report 2 patients who were identified with IAC before orthodontic treatment. The dental radiologic appearance of IAC is discussed and may constitute a diagnostic challenge to both the dentist and radiologist.

  2. Toward early diagnosis of arteriosclerotic diseases: collaborative detection of carotid artery calcifications by computer and dentists on dental panoramic radiographs

    NASA Astrophysics Data System (ADS)

    Muramatsu, Chisako; Takahashi, Ryo; Hara, Takeshi; Hayashi, Tatsuro; Katsumata, Akitoshi; Zhou, Xiangrong; Fujita, Hiroshi

    2014-03-01

    Several studies have reported the presence of carotid artery calcifications (CACs) on dental panoramic radiographs (DPRs) as a possible sign of arteriosclerotic diseases. However, CACs are not easily visible at the common window level for dental examinations, and dentists, in general, are not looking for CACs. Computerized detection of CACs may help dentists in referring patients with a risk of arteriosclerotic diseases to have a detailed examination at a medical clinic. Downside of our previous method was a relatively large number of false positives (FPs). In this study, we attempted to reduce FPs by including an additional feature and selecting effective features for the classifier. A hundred DPRs including 34 cases with calcifications were included. Initial candidates were detected by thresholding the output of top-hat operation. For each candidate, 10 features and a new feature characterizing the relative position of a CAC with reference to the lower mandible edge were determined. After the rule-based FP reduction, candidates were classified into CACs and FPs by a support vector machine. Based on the leave-one-out cross-validation evaluations, an average number of FPs was 3.1 per image at 90.4% sensitivity using seven features selected. Compared to our previous method, the number of FPs was reduced by 38% at the same sensitivity level. The proposed method has a potential in identifying patients with a risk of arteriosclerosis early via general dental examinations.

  3. Continuous measurements of mandibular cortical width on dental panoramic radiographs for computer-aided diagnosis of osteoporosis

    NASA Astrophysics Data System (ADS)

    Kavitha, M. S.; Asano, Akira; Taguchi, Akira

    2011-03-01

    The aim of this study is to develop a computer-aided osteoporosis diagnosis system that automatically determines the inferior cortical width of the mandible continuously on dental panoramic radiographs to realize statistically more robust measurements than the conventional one-point measurements. The cortical width was continuously measured on dental panoramic radiographs by enhancing the original image, determining cortical boundaries, and finally evaluating the distance between boundaries continuously throughout the region of interest. The diagnostic performance using the average width calculated from the continuous measurement was compared with BMD at lumbar spine and femoral neck in 100 postmenopausal women of whom 50 to the development of the tool and 50 to its validation with no history of osteoporosis was evaluated. We experimentally showed the superiority of our method with improved sensitivity and specificity of identifying the development subjects were 90.0% and 75.0% in women with low spinal BMD and 81.8% and 69.2% in those with low femoral BMD, respectively. The corresponding values in the validation subjects were 93.3% and 82.9% at the lumbar spine and 92.3% and 75.7% at the femoral neck, respectively in terms of efficacy for diagnosing osteoporosis. We also assessed the diagnosis and classification of women with osteoporosis using support vector machine employing the average and variance of the continuous measurements gave excellent discrimination ability. It yields sensitivity and specificity of 90.9% and 83.8%, respectively with lumbar spine and 90.0% and 69.1%, respectively with femoral neck BMD. Performance comparison and simplicity of this method indicate that our computeraided system is readily applicable to clinical practice.

  4. Predictability of Dental Emergencies by Panography.

    DTIC Science & Technology

    1981-09-30

    population (recruits with little or no prior dental care) demonstrate a high incidence of 1,2dental disease . Various epidemiologic studies have shown the...Medical Center, Washington, DC 20012 I Abstract: A study was undertaken to evaluate the effectiveness and reliability of panoramic radiography for...dental complaints ranked second only to upper respiratory infections. The purpose of this study was to evaluate the effectiveness and reliability of

  5. Adaptive panoramic tomography with a circular rotational movement for the formation of multifocal image layers

    NASA Astrophysics Data System (ADS)

    Kim, D. S.; Cho, H. S.; Park, Y. O.; Je, U. K.; Hong, D. K.; Choi, S. I.; Koo, Y. S.

    2012-02-01

    Panoramic radiography with which only structures within a certain image layer are in focus and others out of focus on the panoramic image has become a popular imaging technique especially in dentistry. However, the major drawback to the technique is a mismatch between the structures to be focused and the predefined image layer mainly due to the various shapes and sizes of dental arches and/or to malpositioning of the patient. These result in image quality typically inferior to that obtained using intraoral radiographic techniques. In this paper, to overcome these difficulties, we suggest a new panoramic reconstruction algorithm, the so-called adaptive panoramic tomography ( APT), capable of reconstructing multifocal image layers with no additional exposure. In order to verify the effectiveness of the proposed algorithm, we performed systematic simulation studies with a circular rotational movement and investigated the image performance.

  6. Classifying degenerative joint disease by the RDC/TMD and by panoramic imaging: a retrospective analysis.

    PubMed

    Winocur, E; Reiter, S; Krichmer, M; Kaffe, I

    2010-03-01

    The purposes of the study were to evaluate the utility of diagnosing degenerative joint disease (DJD) by the clinical finding of coarse crepitus alone, without supporting imaging studies, as defined by the RDC/TMD, and to evaluate the contribution of panoramic radiography as an aid in the diagnosis of DJD. A retrospective analysis of 372 consecutive patients with TMD was conducted. Their panoramic radiographs were evaluated for the extent of their contribution to the final diagnosis. Panoramic radiography was of no diagnostic value in 94.4% of the cases when the group was considered as a whole. When patients diagnosed with DJD were considered separately, panoramic radiography was completely sufficient for reaching the final diagnosis in 20.0% of the cases. In almost 90% of these patients, however, the clinical examination did not support the diagnosis of DJD (no coarse crepitus was found). This raises some doubts about the effectiveness of the clinical examination according to the RDC/TMD and about the utility of panoramic radiography in the definitive diagnosis of DJD, because both techniques have low accuracy (11.1% and 20%, respectively). The present study supports the current recommendations that panoramic radiography should not be ordered routinely to assess DJD, but still it is first choice when any dental problem is suspected. Further additional imaging (computerized tomography, magnetic resonance imaging) should be considered only if there is reason to expect that the findings might affect diagnosis and management. This study adds to recent criticisms of the clinical validity of the RDC/TMD, with regard to DJD.

  7. Digital radiography in the dental practice: an update.

    PubMed

    Makdissi, Jimmy; Pawar, Ravikiran

    2013-01-01

    The implementation of digital imaging in dental practice should be considered. The vast number of advantages of digital imaging include time saving and image manipulation. Dose reduction is a big attraction but in practical terms this might not be fully taken advantage of, as a number of studies suggest. Challenges of images storage, back-up and exchange should be taken into account. Careful planning and integration with practice software should lead to a smooth transition. Remember, computer systems sometimes fail and contingency plans should be in place to avoid disruption to the workflow of the practice.

  8. Establishment of diagnostic reference levels for dental intraoral radiography.

    PubMed

    Manousaridis, G; Koukorava, C; Hourdakis, C J; Kamenopoulou, V; Yakoumakis, E; Tsiklakis, K

    2013-10-01

    Diagnostic reference levels (DRLs) is a tool for the optimisation of radiological procedures. Establishment of a DRL is a requirement of national regulations. Measurements performed by the Greek Atomic Energy Commission on 529 dental intraoral radiographic facilities have been used in order to define DRLs for digital and film imaging modalities, taking into account the region of the mouth to be imaged. Thus, different DRL values have been proposed for minimum (usually incisors), maximum (usually maxillary molars) and average exposure settings, both for film and digital imaging. The results have been compared with similar studies performed in Europe and the USA and are in line with the most recent ones.

  9. Clinical utility of dental cone-beam computed tomography: current perspectives

    PubMed Central

    Jaju, Prashant P; Jaju, Sushma P

    2014-01-01

    Panoramic radiography and computed tomography were the pillars of maxillofacial diagnosis. With the advent of cone-beam computed tomography, dental practice has seen a paradigm shift. This review article highlights the potential applications of cone-beam computed tomography in the fields of dental implantology and forensic dentistry, and its limitations in maxillofacial diagnosis. PMID:24729729

  10. Comparison between cone beam computed tomography and panoramic radiography in the assessment of the relationship between the mandibular canal and impacted class C mandibular third molars

    PubMed Central

    Dalili, Zahra; Mahjoub, Porousha; Sigaroudi, Ali Khalighi

    2011-01-01

    Background: Preoperative radiographic evaluation of impacted third molars is essential to determine the proximity to the mandibular canal to minimize the risk of nerve injury. Our study aim was to evaluate the relationship between the mandibular canal and impacted mandibular third molars using cone beam computed tomography (CBCT) and to compare findings therein with panoramic radiographic signs. Methods: CBCT images were taken from 29 patients having 43 Class C impacted mandibular third molars whose panoramic radiographs showed a close relationship between the mandibular canal and mandibular third molars. We evaluated their tomographs to determine the course of the canal, its proximity to the root, any narrowing of the canal, the presence of root grooving or hooks and the proximity of the root to the cortex. A Chi-square test was used for data analysis. Results: The lingual course of the canal was the most frequently detected course in all panoramic findings. Contact of the tooth with the canal was observed in all cases in which panoramic signs of deviation of the canal and darkening of the roots were found. The frequency of observing the narrowing of the canal in CBCT as compared to seeing the presence or the absence of canal narrowing in panoramic radiographs was significantly different (P=0.01). Conclusion: CBCT provides more precise diagnostic information to determine the relationship of impacted third molars to the canal. Deviation of the canal and darkening of the roots in panoramic view can be highly valuable to predict the risk of nerve injury. PMID:22135692

  11. Automated detection of abnormalities in paranasal sinus on dental panoramic radiographs by using contralateral subtraction technique based on mandible contour

    NASA Astrophysics Data System (ADS)

    Mori, Shintaro; Hara, Takeshi; Tagami, Motoki; Muramatsu, Chicako; Kaneda, Takashi; Katsumata, Akitoshi; Fujita, Hiroshi

    2013-02-01

    Inflammation in paranasal sinus sometimes becomes chronic to take long terms for the treatment. The finding is important for the early treatment, but general dentists may not recognize the findings because they focus on teeth treatments. The purpose of this study was to develop a computer-aided detection (CAD) system for the inflammation in paranasal sinus on dental panoramic radiographs (DPRs) by using the mandible contour and to demonstrate the potential usefulness of the CAD system by means of receiver operating characteristic analysis. The detection scheme consists of 3 steps: 1) Contour extraction of mandible, 2) Contralateral subtraction, and 3) Automated detection. The Canny operator and active contour model were applied to extract the edge at the first step. At the subtraction step, the right region of the extracted contour image was flipped to compare with the left region. Mutual information between two selected regions was obtained to estimate the shift parameters of image registration. The subtraction images were generated based on the shift parameter. Rectangle regions of left and right paranasal sinus on the subtraction image were determined based on the size of mandible. The abnormal side of the regions was determined by taking the difference between the averages of each region. Thirteen readers were responded to all cases without and with the automated results. The averaged AUC of all readers was increased from 0.69 to 0.73 with statistical significance (p=0.032) when the automated detection results were provided. In conclusion, the automated detection method based on contralateral subtraction technique improves readers' interpretation performance of inflammation in paranasal sinus on DPRs.

  12. The quality of dental radiography in the Czech Republic--results of a TLD and film postal audit.

    PubMed

    Novák, Leos

    2006-01-01

    Since 2002, the postal audit in dental radiography has been supplementing standard quality control (QC) tools for dental intraoral X-ray machines. An aim of the audit is to check basic X-ray machine parameters (field size, exposure reproducibility), and a quality of the whole process of diagnostic imaging (entrance surface air-kerma measurement, a check of film processing and an image quality evaluation). The standard QC tests, performed by private companies, check mainly the X-ray unit. Conversely, the audit gives better information about the patient examination practices. During the period of January 2002 to May 2004 approximately 4000 audits were performed. The results confirmed that main problems in dental radiography are due to incorrect film processing, non-optimised setting of the exposure parameters and use of obsolete X-ray machines. Only approximately 30% of performed audits were satisfactory with respect to all checked parameters.

  13. Effective dose equivalent to the operator in intra-oral dental radiography

    SciTech Connect

    de Haan, R.A.; van Aken, J. )

    1990-08-01

    The effective dose equivalent to the operator in intra-oral dental radiography has been determined. The exposure from a bitewing radiograph and periapical views of the left maxillary incisors and first molar was measured at nine heights and 16 positions, all 1 m from the patient. The effective dose equivalent was determined using data from ICRP 51 (International Commission on Radiological Protection: Data for Use in Protection Against External Radiation). The values presented are related to an exposure of 1 C kg-1 (3876 R) measured free in air at the tube-end. They thus constitute ratios which are not influenced by the sensitivity of the film or other detector used and form standard tables which permit the calculation of the effective dose equivalent in clinical situations.

  14. Curricular Guidelines for Clinical Competency by Dental Auxiliaries in Dental Radiography.

    ERIC Educational Resources Information Center

    Journal of Dental Education, 1984

    1984-01-01

    Guidelines developed for educational institutions as curriculum development aids are presented. They are the result of efforts within the American Association of Dental Schools (AADS) by the Section on Oral Radiology. Their use as course development aids is suggested by AADS policy. (MLW)

  15. Comparison of radiography and scintigraphy in the diagnosis of dental disorders in the horse.

    PubMed

    Weller, R; Livesey, L; Maierl, J; Nuss, K; Bowen, I M; Cauvin, E R; Weaver, M; Schumacher, J; May, S A

    2001-01-01

    Scintigraphy, with 99mTechnetium methylenediphosphonate (99mTc-MDP) and 99mTc-labelled leucocytes, was compared to radiography in the diagnosis of dental disease in the horse in a prospective case-controlled study, comprising 30 horses with clinical signs of dental disease and 30 control horses. In each case, right and left lateral, ventral and dorsal soft tissue and bone phase scintigraphic images were obtained after i.v. injection of 1 GBq/100 kg bwt 99mTc-MDP, using a gamma camera. The same views were acquired in 10 horses with clinical signs of dental disease and 12 control horses after injection of 99mTc-labelled leucocytes. Standard radiographic projections of the paranasal sinuses and of the apices of the maxillary and mandibular teeth were obtained. The scintigraphs and radiographs were assessed subjectively by 2 board-certified surgeons and one board-certified radiologist, with extensive experience of equine radiology, from who the clinical history was withheld. Sensitivity, specificity and kappa, as a measure of agreement, were calculated for the different methods. Bone phase images were also scored subjectively on a scale from 0 to 3 on the basis of isotope uptake over the teeth. Regions of interest were defined over the teeth, and normal teeth compared to diseased counterparts. Total scintigraphic counts were related to the age of the animal and to the disease process. Differences in density ratios between left and right teeth were evaluated using the Mann-Whitney Test. Dental disease was confirmed in 22 horses at surgery or postmortem examination. Horses with dental disease showed a significant increase in scintigraphic activity over the affected tooth compared to the contralateral tooth, with a typical pattern for different diseases. The sensitivity of scintigraphy with 99mTc-MDP proved to be excellent (95.5%), whereas the specificity was moderate (86.4%). In contrast, radiography had excellent specificity (95.0%) and a low sensitivity (51.5%). The

  16. Correlation of panoramic radiography and cone beam CT findings in the assessment of the relationship between impacted mandibular third molars and the mandibular canal

    PubMed Central

    Neves, F S; Souza, T C; Almeida, S M; Haiter-Neto, F; Freitas, D Q; Bóscolo, F N

    2012-01-01

    Objectives The aim of this study was to assess the reliability of four panoramic radiographic findings, both individually and in association, in predicting the absence of corticalization between the mandibular canal and the third molar on cone beam CT (CBCT) images. Methods The sample consisted of 72 individuals (142 mandibular third molars) who underwent pre-operative radiographic evaluation before extraction of impacted mandibular third molars. On panoramic radiographs, the most common signs of corticalization (darkening of roots, diversion of mandibular canal, narrowing of mandibular canal and interruption of white line) and the presence or absence of corticalization between the mandibular third molar and the mandibular canal on CBCT images were evaluated. Results Darkening of roots and interruption of white line associated with the absence of corticalization between the mandibular third molar and the mandibular canal on CBCT images were statistically significant, both as isolated findings (p = 0.0001 and p = 0.0006, respectively) and in association (p = 0.002). No statistically significant association was observed for the other panoramic radiographic findings, either individually or in association (p > 0.05). Conclusion Darkening of roots and interruption of white line observed on panoramic radiographs, both as isolated findings and in association, were effective in determining the risk relationship between the tooth roots and the mandibular canal, requiring three-dimensional evaluation of the case. PMID:22282507

  17. Observer performance in diagnosing osteoporosis by dental panoramic radiographs: results from the osteoporosis screening project in dentistry (OSPD).

    PubMed

    Taguchi, A; Asano, A; Ohtsuka, M; Nakamoto, T; Suei, Y; Tsuda, M; Kudo, Y; Inagaki, K; Noguchi, T; Tanimoto, K; Jacobs, R; Klemetti, E; White, S C; Horner, K

    2008-07-01

    Mandibular cortical erosion detected on dental panoramic radiographs (DPRs) may be useful for identifying women with osteoporosis, but little is known about the variation in diagnostic efficacy of observers worldwide. The purpose of this study was to measure the accuracy in identifying women at risk for osteoporosis in a worldwide group of observers using DPRs. We constructed a website that included background information about osteoporosis screening and instructions regarding the interpretation of mandibular cortical erosion. DPRs of 100 Japanese postmenopausal women aged 50 years or older who had completed skeletal bone mineral measurements by dual energy X-ray absorptiometry were digitized at 300 dpi. These were displayed on the website and used for the evaluation of diagnostic efficacy. Sixty observers aged 25 to 66 years recruited from 16 countries participated in this study. These observers classified cortical erosion into one of three groups (none, mild to moderate, and severe) on the website via the Internet, twice with an approximately 2-week interval. The diagnostic efficacy of the Osteoporosis Self-Assessment Tool (OST), a simple clinical decision rule based on age and weight, was also calculated and compared with that of cortical erosion. The overall mean sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of the 60 observers in identifying women with osteoporosis by cortical erosion on DPRs were 82.5, 46.2, 46.7, and 84.0%, respectively. Those same values by the OST index were 82.9, 43.1, 43.9, and 82.4%, respectively. The intra-observer agreement in classifying cortical erosion on DPRs was sufficient (weighted kappa values>0.6) in 36 (60%) observers. This was significantly increased in observers who specialized in oral radiology (P<0.05). In the 36 observers with sufficient intra-observer agreement, the overall mean sensitivity, specificity, PPV, and NPV in identifying women with osteoporosis by any cortical

  18. Comparative evaluation of the sensitometric properties of screen-film systems and conventional dental receptors for intraoral radiography

    SciTech Connect

    Kircos, L.T.; Staninec, M.; Chou, L.

    1989-12-01

    This investigation determined the sensitometric properties of 27 rare-earth screen-film combinations and compared them to E- and D-speed films and xeroradiography, the current standards for intraoral radiography. A series of exposures from base plus fog to film saturation were made to determine the Hurter and Driffield curve of each image receptor. The base plus fog, film saturation, speed, gamma, average gradient, and resolution were determined. When dental receptors and screen-film systems are compared on the basis of radiographic quality (contrast and resolution), many screen-film systems have similar resolution (greater than 10 line pairs/mm), significantly greater contrast (greater than 2.0), and a substantial speed advantage (greater than 10). Thus selected screen-film systems may be an alternative to conventional dental receptors for intraoral radiography.

  19. Dental radiography: efficacy in the assessment of intraosseous lesions of the face and jaws in asymptomatic patients

    SciTech Connect

    Zeichner, S.J.; Ruttimann, U.E.; Webber, R.L.

    1987-03-01

    In this investigation the efficacy of dental radiography for the detection of occult intraosseous lesions of the face and jaws was evaluated. An analysis of 30 million health insurance records indicated that the period prevalence of malignant lesions was less than 5 cases/million/year, and for benign lesions approximately 100 cases/million/year. Data from a controlled observer-performance study showed that radiographic sensitivities ranged between 50% and 80%. The cost per true-positive finding was estimated to be +8.6 million per malignant case and +430,000 per benign case. An assessment of the dosimetric literature indicated that the benefits of radiographic screening as a means for early detection of a malignancy appear to be counterbalanced by the risk of causing a radiation-induced malignancy. Taken together, these data demonstrate that dental radiography is not efficacious for the purpose of detecting occult lesions.

  20. Comparison of mesiodistal root angulation with posttreatment panoramic radiographs and cone-beam computed tomography

    PubMed Central

    Bouwens, Daniel G.; Cevidanes, Lucia; Ludlow, John B.; Phillips, Ceib

    2011-01-01

    Introduction Orthodontists assess mesiodistal root angulations before, during, and after orthodontic treatment as an aid in establishing proper root position. Panoramic imaging has been useful for this purpose and is a valuable screening tool in diagnosis and planning treatment of orthodontic patients. Cone-beam computed tomography (CBCT) for imaging of the craniofacial complex creates the opportunity to evaluate 3-dimensional images compared with traditional 2-dimensional images. The purpose of this project was to compare mesiodistal root angulations by using posttreatment panoramic radiographic images and CBCT scans. Methods Mesiodistal root angulations from panoramic images and CBCT scans of 35 orthognathic surgery patients after orthodontic treatment were compared. The panoramic images were measured by using VixWin (Gendex Dental Systems, Des Plaines, Ill), and the CBCT scans by using InvivoDental 3D (version 4.1, Anatomage, San Jose, Calif). The mesiodistal root angulation of each maxillary and mandibular tooth was measured by using the occlusal plane as the reference line. With an intercept-only linear regression for correlated data (with an unstructured covariance structure), the global test of whether the mean vector of all differences for the teeth is zero was performed separately for the 2 arches. Results The global test for both arches was statistically significant (P<0.001), indicating an overall difference in root angulation between measurements from panoramic and CBCT images. There was no discernible pattern in the average differences between panoramic and CBCT measurements. Conclusions The assessment of mesiodistal tooth angulation with panoramic radiography should be approached with caution and reinforced by a thorough clinical examination of the dentition. PMID:21195286

  1. Panorametry: suggestion of a method for mandibular measurements on panoramic radiographs

    PubMed Central

    Puricelli, Edela

    2009-01-01

    Background Orthopantomography (panoramic radiography) has been used for the study of measurements involving particularly the prediction of the eruption of impacted lower third molars and analyses of measurements of the ramus and head of mandible. The discrepancies involved with the projection of this radiographic image has stimulated the search for further ways to use it, particularly in orthodontic treatments and oral and maxillofacial surgeries. The author proposes a graphimetric method for the mandible, based on panoramic radiography. The results are expressed in linear and angular measurements, aiming at bilateral comparisons as well as the determination of the proportion of skeletal and dental structures, individually and among themselves as a whole. The method has been named Panorametry, and allows measurement of the mandible (Mandibular Panorametry) or the posterior mandibular teeth (Dental Panorametry). When combining mandible and maxilla, it should be referred to as Total Panorametry. It may also be used, in the future, with Cone Beam computed tomography (CT) images, and in this case it may be mentioned as CT Panorametry. PMID:19852787

  2. Preliminary Evaluation of an Educational Outcomes Assessment Process for Dental Interpretive Radiography.

    ERIC Educational Resources Information Center

    Weems, Richard A.; And Others

    1992-01-01

    A procedure for testing the ability of dental students to detect presence and depth of dental caries was evaluated. Students (n=40) from four experience groups examined radiographs obtained from a model. Results indicated that this method of assessing student competence in radiographic interpretation is valid. (MSE)

  3. Effect of rare earth filtration on patient exposure, dose reduction, and image quality in oral panoramic radiology

    SciTech Connect

    Tyndall, D.A.; Washburn, D.B.

    1987-01-01

    Rare earth intensifying screen material (Gd2O2S:Tb) was added to the standard Al filtration of an oral panoramic x-ray unit, resulting in a beam capable of achieving reductions in patient dose without a loss of image quality. The added rare earth filtration technique resulted in patient dose reductions of 21-56%, depending on anatomic sites, when compared to the conventional Al filtration technique. Films generated from both techniques were measured densitometrically and evaluated by a panel of practicing clinicians. Diagnostically significant differences were minimal. The results indicate that use of rare earth filters in oral panoramic radiography is an effective means of reducing exposures of dental patients to ionizing radiation.

  4. Determining the age of cats by pulp cavity/tooth width ratio using dental radiography.

    PubMed

    Park, Kyoungsun; Ahn, Jaesang; Kang, Sunmee; Lee, Euiri; Kim, Soohyun; Park, Sangwan; Park, Sungwon; Noh, Hyunwoo; Seo, Kangmoon

    2014-12-01

    The purpose of this study was to evaluate the effect of age on the ratio of pulp cavity/tooth width (P/T ratio) in healthy cats. The dental radiographs of 32 cats (16 males and 16 females) were generated with a digital dental X-ray unit with the animals under general anesthesia. Standardized measurement of the canine teeth was performed by drawing a line on the radiograph perpendicular to the cemento- enamel junction (CEJ) of the tooth. There was an inversely proportional correlation between chronological age and the P/T ratio. Moreover, a strong Pearson squared correlation (γ(2) = 0.92) was identified by the curved regression model. No significant differences in the P/T ratio based on gender or breed were found. These results suggest that determination of age by P/T ratio could be clinically useful for estimating the chronological age of cats.

  5. Assessment of dental abnormalities by full-mouth radiography in small breed dogs.

    PubMed

    Kim, Chun-Geun; Lee, So-Young; Kim, Ju-Won; Park, Hee-Myung

    2013-01-01

    This study was performed to evaluate full-mouth radiographic findings to determine the prevalence of dental abnormalities and analyze the relationship between dental abnormalities and age in small breed dogs. Sixteen predetermined categories of abnormal radiographic findings were evaluated in 233 small breed dogs. In total, 9,786 possible permanent teeth could be evaluated. Of those, 8,308 teeth were evaluated and abnormal radiographic findings were found in 2,458 teeth (29.6%). The most common teeth with abnormal radiographic findings were the mandibular first molars (74.5% on the left and 63.9% on the right) and the maxillary fourth premolars (40.5% on the left and 38.2% on the right). Bone loss of any type (15.8%) was the most commonly detected radiographic abnormal finding among the 16 categories. Dental conditions with a genetic predisposition were frequently occurred in the mandibular premolar teeth. Shih tzu frequently had unerupted teeth and dentigerous cysts. Among the teeth with abnormal radiographic findings, 4.5%, 19.8%, and 5.3% were considered incidental, additional, and important, respectively. Findings that were only detected on radiographs, which were not noted on routine oral examination, were more common in older dogs. Full-mouth radiographic evaluation should be performed to obtain important information for making accurate diagnoses.

  6. Technique-dependent decrease in thyroid absorbed dose for dental radiography.

    PubMed

    Wood, R E; Bristow, R G; Clark, G M; Nussbaum, C; Taylor, K W

    1989-06-01

    A LiF thermoluminescent dosimetry (TLD) system, calibrated in the tissue of interest with the beam used for experimentation, was employed to investigate dosages (muGy) to the thyroid region of an anthropomorphic phantom resultant from two dental complete-mouth radiographic procedures. Both techniques were compared in terms of dosages associated with combinations of lead apron and thyroid collar shielding while using a 70-kVp or 90-kVp x-ray beam for a 20-film complete-mouth series. Lead shielding significantly decreased the dose to the thyroid using both techniques (p less than 0.05). The use of the 90-kVp beam resulted in a significant reduction in the thyroid absorbed dose when using the bisecting angle technique (p less than 0.05) but caused a significant increase in the thyroid absorbed dose when the paralleling technique was used (p less than 0.05). The implementation of higher kilovoltage techniques in dental offices must therefore be dependent on the radiographic technique employed.

  7. Technique-dependent decrease in thyroid absorbed dose for dental radiography

    SciTech Connect

    Wood, R.E.; Bristow, R.G.; Clark, G.M.; Nussbaum, C.; Taylor, K.W.

    1989-06-01

    A LiF thermoluminescent dosimetry (TLD) system, calibrated in the tissue of interest with the beam used for experimentation, was employed to investigate dosages (muGy) to the thyroid region of an anthropomorphic phantom resultant from two dental complete-mouth radiographic procedures. Both techniques were compared in terms of dosages associated with combinations of lead apron and thyroid collar shielding while using a 70-kVp or 90-kVp x-ray beam for a 20-film complete-mouth series. Lead shielding significantly decreased the dose to the thyroid using both techniques (p less than 0.05). The use of the 90-kVp beam resulted in a significant reduction in the thyroid absorbed dose when using the bisecting angle technique (p less than 0.05) but caused a significant increase in the thyroid absorbed dose when the paralleling technique was used (p less than 0.05). The implementation of higher kilovoltage techniques in dental offices must therefore be dependent on the radiographic technique employed.

  8. Stitched large format CMOS image sensors for dental x-ray digital radiography

    NASA Astrophysics Data System (ADS)

    Liu, Xinqiao (Chiao); Fowler, Boyd; Do, Hung; Jaffe, Mark; Rassel, Richard; Leidy, Bob

    2012-10-01

    In this paper, we present a family of large format CIS's designed for dental x-ray applications. The CIS areas vary from small 31.5mm x 20.1mm, to medium 34.1mm x 26.3mm, to large 37.1mm x 26.3mm. Pixel size is 19.5um x 19.5um. The sensor family was fabricated in a 0.18um CIS process. Stitching is used in the CIS fabrication for the medium and large size sensors. We present the CIS and detector system design that includes pixel circuitry, readout circuitry, x-ray trigger mechanism, scintillator, and the camera electronics. We also present characterization results including the detector performances under both visible light and x-ray radiation.

  9. Panoramic Dental X-Ray

    MedlinePlus

    ... sometimes create a slightly blurry image where accurate measurements of your teeth and jaw are not possible. ... accredited facilities database . This website does not provide cost information. The costs for specific medical imaging tests, ...

  10. Accuracy of Panoramic Radiograph in Assessment of the Relationship Between Mandibular Canal and Impacted Third Molars

    PubMed Central

    Tantanapornkul, Weeraya; Mavin, Darika; Prapaiphittayakun, Jaruthai; Phipatboonyarat, Natnicha; Julphantong, Wanchanok

    2016-01-01

    Background: The relationship between impacted mandibular third molar and mandibular canal is important for removal of this tooth. Panoramic radiography is one of the commonly used diagnostic tools for evaluating the relationship of these two structures. Objectives: To evaluate the accuracy of panoramic radiographic findings in predicting direct contact between mandibular canal and impacted third molars on 3D digital images, and to define panoramic criterion in predicting direct contact between the two structures. Methods: Two observers examined panoramic radiographs of 178 patients (256 impacted mandibular third molars). Panoramic findings of interruption of mandibular canal wall, isolated or with darkening of third molar root, diversion of mandibular canal and narrowing of third molar root were evaluated for 3D digital radiography. Direct contact between mandibular canal and impacted third molars on 3D digital images was then correlated with panoramic findings. Panoramic criterion was also defined in predicting direct contact between the two structures. Results: Panoramic findings of interruption of mandibular canal wall, isolated or with darkening of third molar root were statistically significantly correlated with direct contact between mandibular canal and impacted third molars on 3D digital images (p < 0.005), and were defined as panoramic criteria in predicting direct contact between the two structures. Conclusion: Interruption of mandibular canal wall, isolated or with darkening of third molar root observed on panoramic radiographs were effective in predicting direct contact between mandibular canal and impacted third molars on 3D digital images. Panoramic radiography is one of the efficient diagnostic tools for pre-operative assessment of impacted mandibular third molars. PMID:27398105

  11. Panoramic lens applications revisited

    NASA Astrophysics Data System (ADS)

    Thibault, Simon

    2008-04-01

    During the last few years, innovative optical design strategies to generate and control image mapping have been successful in producing high-resolution digital imagers and projectors. This new generation of panoramic lenses includes catadioptric panoramic lenses, panoramic annular lenses, visible/IR fisheye lenses, anamorphic wide-angle attachments, and visible/IR panomorph lenses. Given that a wide-angle lens images a large field of view on a limited number of pixels, a systematic pixel-to-angle mapping will help the efficient use of each pixel in the field of view. In this paper, we present several modern applications of these modern types of hemispheric lenses. Recently, surveillance and security applications have been proposed and published in Security and Defence symposium. However, modern hemispheric lens can be used in many other fields. A panoramic imaging sensor contributes most to the perception of the world. Panoramic lenses are now ready to be deployed in many optical solutions. Covered applications include, but are not limited to medical imaging (endoscope, rigiscope, fiberscope...), remote sensing (pipe inspection, crime scene investigation, archeology...), multimedia (hemispheric projector, panoramic image...). Modern panoramic technologies allow simple and efficient digital image processing and the use of standard image analysis features (motion estimation, segmentation, object tracking, pattern recognition) in the complete 360° hemispheric area.

  12. Hand skeletal maturity and its correlation with mandibular dental development

    PubMed Central

    Pousti, Maryam; Adelianfar, Elahe

    2014-01-01

    Objectives: Assessment of pubertal status and pubertal growth spurt in orthodontic patients has a considerable impact on the diagnosis, treatment plan and the outcome of orthodontic treatments. Hand-wrist radiography is routinely used to evaluate skeletal development. Some studies have shown that there is an association between bone development and different stages of dental calcification; therefore, the stages of dental calcification can be used as the first tool for diagnosis, in case there is an association. This study was performed with the aim to evaluate the association between the phases of dental development and the stages of skeletal maturity. Study design: In this study, a total of 52 patients (26 males and 26 females), referring to Mashhad School of Dentistry for orthodontic treatment, were evaluated; the subjects were within the age range of 9-14 years. Hand-wrist radiographic evaluation of skeletal maturation was performed using Fishman method. Also, the Demirjian method was used to identify the stages of dental calcification by panoramic radiographs. Independent t-test and Spearman correlation coefficient were used for data analyses. Results: The mean age of males and females was 11.05 ± 1.05 and 10.62 ± 1.12 years, respectively (p=0.156). The Spearman correlation coefficients between skeletal maturity indicators (SMIs) and developmental stages of mandibular left and right canines and second molars were significant in males only (p<0.05). Also, correlation coefficients were significant between adductor sesamoid ossification and mandibular right and left canines developmental stages in males (p<0.05). Conclusions: Findings of this study showed that the correlation between dental developmental stages and skeletal maturity only were significant in males; thus, different skeletal maturity patterns in males and females might be perceptible. Key words:Skeletal maturation, hand-wrist radiography, panoramic radiography. PMID:25136430

  13. Panoramic stereo sphere vision

    NASA Astrophysics Data System (ADS)

    Feng, Weijia; Zhang, Baofeng; Röning, Juha; Zong, Xiaoning; Yi, Tian

    2013-01-01

    Conventional stereo vision systems have a small field of view (FOV) which limits their usefulness for certain applications. While panorama vision is able to "see" in all directions of the observation space, scene depth information is missed because of the mapping from 3D reference coordinates to 2D panoramic image. In this paper, we present an innovative vision system which builds by a special combined fish-eye lenses module, and is capable of producing 3D coordinate information from the whole global observation space and acquiring no blind area 360°×360° panoramic image simultaneously just using single vision equipment with one time static shooting. It is called Panoramic Stereo Sphere Vision (PSSV). We proposed the geometric model, mathematic model and parameters calibration method in this paper. Specifically, video surveillance, robotic autonomous navigation, virtual reality, driving assistance, multiple maneuvering target tracking, automatic mapping of environments and attitude estimation are some of the applications which will benefit from PSSV.

  14. Using the Monte Carlo method for assessing the tissue and organ doses of patients in dental radiography

    NASA Astrophysics Data System (ADS)

    Makarevich, K. O.; Minenko, V. F.; Verenich, K. A.; Kuten, S. A.

    2016-05-01

    This work is dedicated to modeling dental radiographic examinations to assess the absorbed doses of patients and effective doses. For simulating X-ray spectra, the TASMIP empirical model is used. Doses are assessed on the basis of the Monte Carlo method by using MCNP code for voxel phantoms of ICRP. The results of the assessment of doses to individual organs and effective doses for different types of dental examinations and features of X-ray tube are presented.

  15. Exposure Geometry And Film Contrast Differences As Bases For Incomplete Cancellation Of Irrelevant Structures In Dental Subtraction Radiography

    NASA Astrophysics Data System (ADS)

    Ruttimann, Urs E.; Okano, Tomohiro; Grondahl, Hans-Goran; Grondahl, Kerstin; Webber, Richard L.

    1981-11-01

    Subtraction radiography for longitudinal studies requires both reproducible imaging geometry and film contrast characteristics to permit perfect alignment of the radiographs, and achieve good cancellation of diagnostically irrelevant background structures. The standard deviation (SD) of gray levels about the mean in a subtraction image was used as a relative measure of the residual structured noise. In order to estimate the effects of improperly standardized radiographs on SD in the subtraction image, both the imaging angle and film exposure time were systematically varied. The results showed that SD changed linear for small misalignment angles of the central beam, the variance attributable to this error source reaching about the same magnitude as the variance due to anatomical differences for angulation errors within ±20. The SD increase due to large film contrast disparity could be partly reverted for angulation errors within this bound by using a quadratic transformation which matched the first two moments of the gray level distributions in the two parent radiographs. Therefore, in order to use some of the retrospective data obtained under less stringent standardizations for subtraction imagery, it appears possible to adjust for differences in film contrast, and, perhaps, correct for geometric misalignment by a separate algorithm.

  16. Digital radiography: an overview.

    PubMed

    Parks, Edwin T; Williamson, Gail F

    2002-11-15

    Since the discovery of X-rays in 1895, film has been the primary medium for capturing, displaying, and storing radiographic images. It is a technology that dental practitioners are the most familiar and comfortable with in terms of technique and interpretation. Digital radiography is the latest advancement in dental imaging and is slowly being adopted by the dental profession. Digital imaging incorporates computer technology in the capture, display, enhancement, and storage of direct radiographic images. Digital imaging offers some distinct advantages over film, but like any emerging technology, it presents new and different challenges for the practitioner to overcome. This article presents an overview of digital imaging including basic terminology and comparisons with film-based imaging. The principles of direct and indirect digital imaging modalities, intraoral and extraoral applications, image processing, and diagnostic efficacy will be discussed. In addition, the article will provide a list of questions dentists should consider prior to purchasing digital imaging systems for their practice.

  17. Wireless networking for the dental office: current wireless standards and security protocols.

    PubMed

    Mupparapu, Muralidhar; Arora, Sarika

    2004-11-15

    Digital radiography has gained immense popularity in dentistry today in spite of the early difficulty for the profession to embrace the technology. The transition from film to digital has been happening at a faster pace in the fields of Orthodontics, Oral Surgery, Endodontics, Periodontics, and other specialties where the radiographic images (periapical, bitewing, panoramic, cephalometric, and skull radiographs) are being acquired digitally, stored within a server locally, and eventually accessed for diagnostic purposes, along with the rest of the patient data via the patient management software (PMS). A review of the literature shows the diagnostic performance of digital radiography is at least comparable to or even better than that of conventional radiography. Similarly, other digital diagnostic tools like caries detectors, cephalometric analysis software, and digital scanners were used for many years for the diagnosis and treatment planning purposes. The introduction of wireless charged-coupled device (CCD) sensors in early 2004 (Schick Technologies, Long Island City, NY) has moved digital radiography a step further into the wireless era. As with any emerging technology, there are concerns that should be looked into before adapting to the wireless environment. Foremost is the network security involved in the installation and usage of these wireless networks. This article deals with the existing standards and choices in wireless technologies that are available for implementation within a contemporary dental office. The network security protocols that protect the patient data and boost the efficiency of modern day dental clinics are enumerated.

  18. Are Panoramic Radiographs Reliable to Diagnose Mild Alveolar Bone Resorption?

    PubMed Central

    Semenoff, Larissa; Semenoff, Tereza Aparecida Delle; Pedro, Fabio Luiz Miranda; Volpato, Evaristo Ricci; Machado, Maria Aparecida de Andrade Moreira; Borges, Álvaro Henrique; Semenoff-Segundo, Alex

    2011-01-01

    It is extremely important to assess variations between the most used radiographs in dental practice, since minimum distortion on obtained images may change diagnosis, treatment plan, and prognosis for the patient. For this, the distance between the enamel-cementum junction and the alveolar bone crest was measured on conventional and digitized periapical, bitewing, and panoramic radiographs and compared among them. From a total of 1484 records, 39 sets of radiographs that fulfilled the inclusion criteria of the study sample were selected. The measurements were grouped according to the intensity of bone loss. Statistically significant difference was found in the averages of the measurements assessed in radiographs with absence of bone loss between conventional panoramic and periapical radiographs, between digitized panoramic and periapical radiographs and between digitized bitewing and panoramic radiographs. By analyzing the results of this work and considering the research protocol used, one can conclude that small losses in height of alveolar bone crest observed in panoramic radiographs should be cautiously evaluated, as they may be overestimated. PMID:21991470

  19. Are panoramic radiographs reliable to diagnose mild alveolar bone resorption?

    PubMed

    Semenoff, Larissa; Semenoff, Tereza Aparecida Delle; Pedro, Fabio Luiz Miranda; Volpato, Evaristo Ricci; Machado, Maria Aparecida de Andrade Moreira; Borges, Alvaro Henrique; Semenoff-Segundo, Alex

    2011-01-01

    It is extremely important to assess variations between the most used radiographs in dental practice, since minimum distortion on obtained images may change diagnosis, treatment plan, and prognosis for the patient. For this, the distance between the enamel-cementum junction and the alveolar bone crest was measured on conventional and digitized periapical, bitewing, and panoramic radiographs and compared among them. From a total of 1484 records, 39 sets of radiographs that fulfilled the inclusion criteria of the study sample were selected. The measurements were grouped according to the intensity of bone loss. Statistically significant difference was found in the averages of the measurements assessed in radiographs with absence of bone loss between conventional panoramic and periapical radiographs, between digitized panoramic and periapical radiographs and between digitized bitewing and panoramic radiographs. By analyzing the results of this work and considering the research protocol used, one can conclude that small losses in height of alveolar bone crest observed in panoramic radiographs should be cautiously evaluated, as they may be overestimated.

  20. Prevalence of Pathologic Findings in Panoramic Radiographs: Calcified Carotid Artery Atheroma

    PubMed Central

    Gonçalves, Jéssica Rodrigues da Silva Noll; Yamada, Juliana Laís Yoshie; Berrocal, Cristina; Westphalen, Fernando Henrique; Franco, Ademir

    2016-01-01

    Objectives To assess the prevalence of images suggestive of calcified carotid artery atheromas (ISCCAA) in panoramic radiographs of patients under dental treatment. Materials and methods The sample consisted of 8.338 panoramic radiographs from female (n=5.049) and male (n=3.289) patients under dental treatment between 4 and 94 years of age. The panoramic radiographs were evaluated searching for ISCCAA. The obtained findings were statistically associated with sex and age. Results ISCCAA were found in 579 radiographs (6.9%). No statistically significant differences were observed between females and males (p>0.05). ISCCAA were more prevalent in patients having a mean age of 50 (p<0.05). Conclusion The potential cases of ISCCAA that were assessed on panoramic radiographs are of utmost clinical significance because they can ensure early and correct diagnosis. PMID:27847396

  1. [Aplication of demineralized human bone matrix in the surgical dental fusion treatment. Report of a case].

    PubMed

    Mora-Rincones, Oscar A; Corona-Rodríguez, Julio C; Díaz-Carvajal, Alvaro L; Franco-Carrero, Isabel C

    2008-06-01

    The purpose of this work is to present a surgical alternative in the treatment of the dental fusions through the placement of demineralized human bone matrix (DHBM) (Grafton Putty)*, immediately after the separation and extraction of the fused tooth to the permanent one. The dental fusion is a dental anomaly of union, that consists in the union of two dental germs during development. It could happen at any of the dental germ evolution stages from the dental sheet or from more advanced processes of differentiation. For the clinical treatment, an allograft of DHBM with osteoinductive and osteoconductive properties was used. This had several factors of bone growth, it allowed the gradual growth of a new bone that helped to correct the bone defects post-extraction and to cover the exposed distal wall of the remaining permanent tooth. The clinic evaluation and the periapical and panoramic radiographies images were used for the clinical control. It can be concluded that the surgical separation and the extraction of the tooth with less anatomical likeness to the contralateral and the placement of the DHBM, represent a surgical treatment alternative of the dental fusion.

  2. Chemical intensification of dental radiographs

    SciTech Connect

    Price, C.

    1983-04-01

    The potential applications of chemical intensification in dental radiography are explored. Three standard photographic intensifiers and three methods designed for radiographic use are evaluated. One of these methods is shown to be capable of reducing radiation dose to one half, without loss of diagnostic quality. Further work is necessary to achieve a system sufficiently practicable to deserve widespread use in routine clinical dental radiography.

  3. Tonsillolith: a panoramic radiograph presentation.

    PubMed

    Babu B, Balaji; Tejasvi M L, Avinash; Avinash, C K Anulekha; B, Chittaranjan

    2013-10-01

    Tonsilloliths are calcifications within a tonsillar crypt, involve primarily the palatine tonsil caused by dystrophic calcification as a result of chronic inflammation. Tonsilloliths are very uncommon and are microscopic. Tonsillar concretions sometimes produce symptoms which include non-specific chronic halitosis, irritable cough, dysphagia, otalgia and foreign body-like sensation or foul taste. Patients with tonsillolithiasis may also be asymptomatic, with their lesions being discovered incidentally on panoramic radiographs. This article presents an unusual case of multiple bilateral and asymptomatic tonsilloliths which were found during a routine panoramic radiographic examination.

  4. Utilization of computer-aided detection system in diagnosing unilateral maxillary sinusitis on panoramic radiographs

    PubMed Central

    Ohashi, Yasufumi; Katsumata, Akitoshi; Fujita, Hiroshi; Nakayama, Miwa; Fukuda, Motoki; Nozawa, Michihito; Ariji, Eiichiro

    2016-01-01

    Objectives: It is unclear whether computer-aided detection (CAD) systems for panoramic radiography can help inexperienced dentists to diagnose maxillary sinusitis. The aim of this study was to clarify whether a CAD system for panoramic radiography can contribute to improved diagnostic performance for maxillary sinusitis by inexperienced dentists. Methods: The panoramic radiographs of 49 patients with maxillary sinusitis and 49 patients with healthy sinuses were evaluated in this study. The diagnostic performance of the CAD system was determined. 12 inexperienced dentists and 4 expert oral and maxillofacial radiologists observed the total of 98 panoramic radiographs and judged the presence or absence of maxillary sinusitis, under conditions with and without the support of the CAD system. The receiver operating characteristic curves of the two groups were compared. Results: The CAD system provided sensitivity of 77.6%, specificity of 69.4% and accuracy of 73.5%. The diagnostic performance of the inexperienced dentists increased with the support of the CAD system. When the inexperienced dentists diagnosed maxillary sinusitis with CAD support, the area under the curve (AUC) was significantly higher than that without CAD support. When the focus was only on panoramic radiographs in which CAD support led to a correct diagnosis, the AUC of the inexperienced dentists increased to an equivalent level to that of the experienced radiologists. Conclusions: The CAD system supported the inexperienced dentists in diagnosing maxillary sinusitis on the panoramic radiographs. If the accuracy of the CAD system can be increased, the benefits of CAD support will be further enhanced. PMID:26837670

  5. Automatic panoramic thermal integrated sensor

    NASA Astrophysics Data System (ADS)

    Gutin, Mikhail A.; Tsui, Eddy K.; Gutin, Olga N.

    2005-05-01

    Historically, the US Army has recognized the advantages of panoramic imagers with high image resolution: increased area coverage with fewer cameras, instantaneous full horizon detection, location and tracking of multiple targets simultaneously, extended range, and others. The novel ViperViewTM high-resolution panoramic thermal imager is the heart of the Automatic Panoramic Thermal Integrated Sensor (APTIS), being jointly developed by Applied Science Innovative, Inc. (ASI) and the Armament Research, Development and Engineering Center (ARDEC) in support of the Future Combat Systems (FCS) and the Intelligent Munitions Systems (IMS). The APTIS is anticipated to operate as an intelligent node in a wireless network of multifunctional nodes that work together to improve situational awareness (SA) in many defense and offensive operations, as well as serve as a sensor node in tactical Intelligence Surveillance Reconnaissance (ISR). The ViperView is as an aberration-corrected omnidirectional imager with small optics designed to match the resolution of a 640x480 pixels IR camera with improved image quality for longer range target detection, classification, and tracking. The same approach is applicable to panoramic cameras working in the visible spectral range. Other components of the ATPIS sensor suite include ancillary sensors, advanced power management, and wakeup capability. This paper describes the development status of the APTIS system.

  6. Panoramic cone beam computed tomography

    SciTech Connect

    Chang Jenghwa; Zhou Lili; Wang Song; Clifford Chao, K. S.

    2012-05-15

    Purpose: Cone-beam computed tomography (CBCT) is the main imaging tool for image-guided radiotherapy but its functionality is limited by a small imaging volume and restricted image position (imaged at the central instead of the treatment position for peripheral lesions to avoid collisions). In this paper, the authors present the concept of ''panoramic CBCT,'' which can image patients at the treatment position with an imaging volume as large as practically needed. Methods: In this novel panoramic CBCT technique, the target is scanned sequentially from multiple view angles. For each view angle, a half scan (180 deg. + {theta}{sub cone} where {theta}{sub cone} is the cone angle) is performed with the imaging panel positioned in any location along the beam path. The panoramic projection images of all views for the same gantry angle are then stitched together with the direct image stitching method (i.e., according to the reported imaging position) and full-fan, half-scan CBCT reconstruction is performed using the stitched projection images. To validate this imaging technique, the authors simulated cone-beam projection images of the Mathematical Cardiac Torso (MCAT) thorax phantom for three panoramic views. Gaps, repeated/missing columns, and different exposure levels were introduced between adjacent views to simulate imperfect image stitching due to uncertainties in imaging position or output fluctuation. A modified simultaneous algebraic reconstruction technique (modified SART) was developed to reconstruct CBCT images directly from the stitched projection images. As a gold standard, full-fan, full-scan (360 deg. gantry rotation) CBCT reconstructions were also performed using projection images of one imaging panel large enough to encompass the target. Contrast-to-noise ratio (CNR) and geometric distortion were evaluated to quantify the quality of reconstructed images. Monte Carlo simulations were performed to evaluate the effect of scattering on the image quality and

  7. Digital Radiography

    NASA Technical Reports Server (NTRS)

    1986-01-01

    System One, a digital radiography system, incorporates a reusable image medium (RIM) which retains an image. No film is needed; the RIM is read with a laser scanner, and the information is used to produce a digital image on an image processor. The image is stored on an optical disc. System allows the radiologist to "dial away" unwanted images to compare views on three screens. It is compatible with existing equipment and cost efficient. It was commercialized by a Stanford researcher from energy selective technology developed under a NASA grant.

  8. Image preprocessing for vehicle panoramic system

    NASA Astrophysics Data System (ADS)

    Wang, Ting; Chen, Liguo

    2016-10-01

    Due to the problem that distortion exist for panoramic image stitching in terms of vehicle panoramic system, the research on image preprocessing for panoramic system was carried out. Firstly, the principal of vehicle panoramic vision was analyzed and the fundamental role that image preprocessing procedure plays in panoramic vision is found out. And then, the camera was calibrated with Hyperboloid model and the correction for distorted image is realized. Oriented by panoramic system, the effect of mounting position was taken into consideration for image correction and the suggested angle of camera installation for different mounting position is given. Through analyzing the existing problem of bird-eye image, a method of transforming twice with calibration plates is proposed. Experiment results indicate that the proposed method can weaken the existing problem of bird-eye image effectively and it can contribute to reduce the distortion in terms of image stitching for panoramic system.

  9. Diagnostic quality versus patient exposure with five panoramic screen-film combinations

    SciTech Connect

    D'Ambrosio, J.A.; Schiff, T.G.; McDavid, W.D.; Langland, O.E.

    1986-04-01

    Five film-screen combinations were used to make five density-matched panoramic radiographs of a tissue-equivalent phantom skull using the Midwest/Morita Panoral x-ray machine. The radiographs were evaluated as to their diagnostic quality by twenty dental radiologists. The results demonstrate that proper screen-film selection can significantly reduce patient exposure without compromising diagnostic quality.

  10. Differences between panoramic and Cone Beam-CT in the surgical evaluation of lower third molars

    PubMed Central

    Rodriguez y Baena, Ruggero; Beltrami, Riccardo; Tagliabo, Angelo; Rizzo, Silvana

    2017-01-01

    Background The aim of this study was to evaluate the ability to identify the contiguity between the root of the mandibular third molar and the mandibular canal (MC) in panoramic radiographs compared with Cone Beam-CT. Material and Methods Panoramic radiographs of 326 third molars and CBCT radiographs of 86 cases indicated for surgery and considered at risk were evaluated. The following signs were assessed in panoramic radiographs as risk factors: radiolucent band, loss of MC border, change in MC direction, MC narrowing, root narrowing, root deviation, bifid apex, superimposition, and contact between the root third molar and the MC. Results Radiographic signs associated with absence of MC cortical bone are: radiolucent band, loss of MC border, change in MC direction, and superimposition. The number of risk factors was significantly increased with an increasing depth of inclusion. CBCT revealed a significant association between the absence of MC cortical bone and a lingual or interradicular position of the MC. Conclusions In cases in which panoramic radiographs do not exclude contiguity between the MC and tooth, careful assessment the signs and risks on CBCT radiographs is indicated for proper identification of the relationships between anatomic structures. Key words:Panoramic radiography, Cone-Beam computed tomography, third molar, mandibular nerve. PMID:28210446

  11. [Digital radiography].

    PubMed

    Haendle, J

    1983-03-01

    Digital radiography is a generally accepted term comprising all x-ray image systems producing a projected image which resembles the conventional x-ray film image, and which are linked to any type of digital image processing. Fundamental criteria of differentiation are based on the production and detection method of the x-ray image. Various systems are employed, viz. the single-detector, line-detector or fanbeam detector and the area-beam or area-detector image converters, which differ from one another mainly in the manner of conversion of the radiation produced by the x-ray tube. The article also deals with the pros and cons of the various principles, the multitude of systems employed, and the varying frequency of their use in x-ray diagnosis work.

  12. Distortion of digital panoramic radiographs used for implant site assessment

    PubMed Central

    Kayal, Rayyan Abdulhamid

    2016-01-01

    Aims: This study is conducted to determine the amount of distortion of digital panoramic radiographs. Materials and Methods: Panoramic radiographs of all patients who received dental implants in the years 2012 and 2013 were selected from the records at the faculty of dentistry, King Abdulaziz University. Radiographs were analyzed using the R4 Kodak Software for linear measurements of implants length and width. The measurements were compared to the actual size of the implant, and the amount of distortion was calculated. Results: A total of 169 implants were analyzed. Horizontally, there was a statistically significant increase of 0.4 mm in width in the radiographic measurement compared to the actual size in the incisor region. Vertically, the sample overall exhibited a decrease by 0.4 mm compared to the actual size. Incisors had the highest difference with a decrease of 1.7 mm in the radiographic measurements compared to actual size. The highest distortion was found in the incisor region for both diameter and length (1.1 and 0.86), respectively. Conclusion: Digital panoramic radiographs show minimal to no distortion. The highest distortion is found in the anterior area. PMID:27843885

  13. Design on catadioptric panoramic imaging system

    NASA Astrophysics Data System (ADS)

    Wang, Ye; Hao, Chenyang; Li, Wenhua

    2016-01-01

    With the VR(Virtual Reality) technology becoming a hot spot nowadays, one of the key technology-panoramic imaging technology is particularly important. This paper simply introduces various types of panoramic imaging technology, and compares the advantages and disadvantages of the hyperboloidal and paraboloidal catadioptric panoramic imaging system in principle and other aspects. The mathematical models of the hyperboloidal and paraboloidal system is established, and the related system is also designed.

  14. Thermal infrared panoramic imaging sensor

    NASA Astrophysics Data System (ADS)

    Gutin, Mikhail; Tsui, Eddy K.; Gutin, Olga; Wang, Xu-Ming; Gutin, Alexey

    2006-05-01

    Panoramic cameras offer true real-time, 360-degree coverage of the surrounding area, valuable for a variety of defense and security applications, including force protection, asset protection, asset control, security including port security, perimeter security, video surveillance, border control, airport security, coastguard operations, search and rescue, intrusion detection, and many others. Automatic detection, location, and tracking of targets outside protected area ensures maximum protection and at the same time reduces the workload on personnel, increases reliability and confidence of target detection, and enables both man-in-the-loop and fully automated system operation. Thermal imaging provides the benefits of all-weather, 24-hour day/night operation with no downtime. In addition, thermal signatures of different target types facilitate better classification, beyond the limits set by camera's spatial resolution. The useful range of catadioptric panoramic cameras is affected by their limited resolution. In many existing systems the resolution is optics-limited. Reflectors customarily used in catadioptric imagers introduce aberrations that may become significant at large camera apertures, such as required in low-light and thermal imaging. Advantages of panoramic imagers with high image resolution include increased area coverage with fewer cameras, instantaneous full horizon detection, location and tracking of multiple targets simultaneously, extended range, and others. The Automatic Panoramic Thermal Integrated Sensor (APTIS), being jointly developed by Applied Science Innovative, Inc. (ASI) and the Armament Research, Development and Engineering Center (ARDEC) combines the strengths of improved, high-resolution panoramic optics with thermal imaging in the 8 - 14 micron spectral range, leveraged by intelligent video processing for automated detection, location, and tracking of moving targets. The work in progress supports the Future Combat Systems (FCS) and the

  15. Calcified carotid artery atheromas on panoramic radiographs of head and neck cancer patients before and after radiotherapy

    PubMed Central

    Markman, Renata-Lucena; Conceição-Vasconcelos, Karina-Gondim-Moutinho; Brandão, Thais-Bianca; Prado-Ribeiro, Ana-Carolina; Santos-Silva, Alan-Roger

    2017-01-01

    Background The aims of this study were to verify if head and neck radiotherapy (RT) is able to induce calcified carotid artery atheroma (CCAA) in a large head and neck cancer (HNC) population and also to compare the socio-demographic and clinical findings of patients with and without CCAA detected on panoramic radiographs. Material and Methods Panoramic radiographs taken before and after head and neck radiotherapy (RT) of 180 HNC patients were selected and analyzed in order to identify the presence of CCAA. In addition, CCAA presence or absence on panoramic radiographs were compared and correlated with clinicopathological findings. Results A high overall prevalence of CCAA was found on panoramic radiographs (63 out of 180 = 35%) of HNC patients. No significant difference of CCAA before and after RT was observed. There were also no differences between groups (with and without CCAA) regarding age, gender, tobacco and alcohol use, arterial hypertension, diabetes mellitus, acute myocardial infarction, hypercholesterolemia, tumor location, clinical stage of disease and RT dose. However, there was a greater prevalence of strokes in patients with CCAA (p<0.05). Conclusions Although CCAA were frequently found in panoramic radiographs of patients with HNC, RT seems not to alter the prevalence of these calcifications. Key words:Head and neck cancer, radiotherapy, carotid artery diseases, panoramic radiography. PMID:28160583

  16. Conventional radiography and cross-sectional imaging when planning dental implants in the anterior edentulous mandible to support an overdenture: a systematic review.

    PubMed

    Shelley, A M; Glenny, A-M; Goodwin, M; Brunton, P; Horner, K

    2014-01-01

    The objectives for this systematic review were to determine if the pre-operative availability of cross-sectional imaging, such as cone beam CT, has a diagnostic impact, therapeutic impact or impact on patients' outcome when placing two dental implants in the anterior mandible to support an overdenture. The Cochrane Oral Health Group's Trials Register (CENTRAL), MEDLINE® and Embase were searched up to, and including, February 2013. Studies were considered eligible for inclusion if they compared the impact of conventional and cross-sectional imaging when placing dental implants in sites including the anterior mandible. An adapted quality assessment tool was used for the assessment of the risk of bias in included studies. Pooled quantitative analysis was not possible and, therefore, synthesis was qualitative. Of 2374 potentially eligible papers, 5 studies were included. Little can be determined from a synthesis of these studies because of their small number, clinical diversity and high risks of bias. Notwithstanding, it may be tentatively inferred that cross-sectional imaging has a therapeutic impact in the more challenging cases. In terms of impact, this review has found no evidence to support any specific imaging modality when planning dental implant placement in any region of the mouth. Therefore, those who argue that cross-sectional imaging should be used for the assessment of all dental implant sites are unsupported by evidence.

  17. Age estimation based on Kvaal's technique using digital panoramic radiographs

    PubMed Central

    Mittal, Samta; Nagendrareddy, Suma Gundareddy; Sharma, Manisha Lakhanpal; Agnihotri, Poornapragna; Chaudhary, Sunil; Dhillon, Manu

    2016-01-01

    Introduction: Age estimation is important for administrative and ethical reasons and also because of legal consequences. Dental pulp undergoes regression in size with increasing age due to secondary dentin deposition and can be used as a parameter of age estimation even beyond 25 years of age. Kvaal et al. developed a method for chronological age estimation based on the pulp size using periapical dental radiographs. There is a need for testing this method of age estimation in the Indian population using simple tools like digital imaging on living individuals not requiring extraction of teeth. Aims and Objectives: Estimation of the chronological age of subjects by Kvaal's method using digital panoramic radiographs and also testing the validity of regression equations as given by Kvaal et al. Materials and Methods: The study sample included a total of 152 subjects in the age group of 14-60 years. Measurements were performed on the standardized digital panoramic radiographs based on Kvaal's method. Different regression formulae were derived and the age was assessed. The assessed age was then correlated to the actual age of the patient using Student's t-test. Results: No significant difference between the mean of the chronological age and the estimated age was observed. However, the values of the mean age estimated by using regression equations as given previously in the study of Kvaal et al. significantly underestimated the chronological age in the present study sample. Conclusion: The results of the study give an inference for the feasibility of this technique by calculation of regression equations on digital panoramic radiographs. However, it negates the applicability of same regression equations as given by Kvaal et al. on the study population. PMID:27555738

  18. Patient risk from interproximal radiography

    SciTech Connect

    Gibbs, S.J.; Pujol, A. Jr.; Chen, T.S.; Malcolm, A.W.; James, A.E. Jr.

    1984-09-01

    Computer simulation methods for determining patient dose from dental radiography have demonstrated that patient risk from a two-film interproximal examination ranges from 1.1 X 10(-8) to 3.4 X 10(-7) using 90-kVp beams, depending on film speed, projection technique, and age and sex of the patient. Further, changing from a short-cone round-beam to a long-cone technique with rectangular collimation reduces risk by a factor of 2.9, independent of other factors.

  19. Performance analysis of panoramic infrared systems

    NASA Astrophysics Data System (ADS)

    Furxhi, Orges; Driggers, Ronald G.; Holst, Gerald; Krapels, Keith

    2014-05-01

    Panoramic imagers are becoming more commonplace in the visible part of the spectrum. These imagers are often used in the real estate market, extreme sports, teleconferencing, and security applications. Infrared panoramic imagers, on the other hand, are not as common and only a few have been demonstrated. A panoramic image can be formed in several ways, using pan and stitch, distributed aperture, or omnidirectional optics. When omnidirectional optics are used, the detected image is a warped view of the world that is mapped on the focal plane array in a donut shape. The final image on the display is the mapping of the omnidirectional donut shape image back to the panoramic world view. In this paper we analyze the performance of uncooled thermal panoramic imagers that use omnidirectional optics, focusing on range performance.

  20. Single-Camera Panoramic-Imaging Systems

    NASA Technical Reports Server (NTRS)

    Lindner, Jeffrey L.; Gilbert, John

    2007-01-01

    Panoramic detection systems (PDSs) are developmental video monitoring and image-data processing systems that, as their name indicates, acquire panoramic views. More specifically, a PDS acquires images from an approximately cylindrical field of view that surrounds an observation platform. The main subsystems and components of a basic PDS are a charge-coupled- device (CCD) video camera and lens, transfer optics, a panoramic imaging optic, a mounting cylinder, and an image-data-processing computer. The panoramic imaging optic is what makes it possible for the single video camera to image the complete cylindrical field of view; in order to image the same scene without the benefit of the panoramic imaging optic, it would be necessary to use multiple conventional video cameras, which have relatively narrow fields of view.

  1. INDUSTRIAL RADIOGRAPHY INSTRUCTOR'S GUIDE.

    ERIC Educational Resources Information Center

    Bureau of Adult, Vocational, and Technical Education (DHEW/OE), Washington, DC. Div. of Vocational and Technical Education.

    THIS LABORATORY GUIDE WAS DEVELOPED FOR AN 80-HOUR COURSE IN INDUSTRIAL RADIOGRAPHY FOR HIGH SCHOOL GRADUATES TRAINING TO BECOME BEGINNING RADIOGRAPHERS. IT IS USED IN CONJUNCTION WITH TWO OTHER VOLUMES--(1) INDUSTRIAL RADIOGRAPHY INSTRUCTOR'S GUIDE, AND (2) INUDSTRIAL RADIOGRAPHY MANUAL. THE PROGRAM WAS DEVELOPED BY A COMMITTEE OF REPRESENTATIVES…

  2. Increasing mobile radiography productivity.

    PubMed

    Wong, Edward; Lung, Ngan Tsz; Ng, Kris; Jeor, Patrick

    2013-01-01

    Mobile radiography using computed radiography (CR) cassettes is a common equipment combination with a workflow bottleneck limited by location of CR readers. Advent of direct digital radiography (DDR) mobile x-ray machines removes this limitation by immediate image review and quality control. Through the use of key performance indicators (KPIs), the increase in efficiency can be quantified.

  3. Dental radiology for children

    SciTech Connect

    Myers, D.R.

    1984-01-01

    The benefit for the child from the judicious use of diagnostic dental radiography is improved dental health. The risk to the child from dental diagnostic radiation exposure appears to be extremely low. Despite the low risk, the dentist must minimize the child's exposure to ionizing radiation by using sound clinical judgment to determine what radiographs are necessary and to provide children with optimal protection from ionizing radiation.

  4. [The role of panoramic radiography in assessing the risk of injury to the inferior alveolar nerve before the extraction of mandibular wisdom teeth. The effect of the extent of root curvature and inferior alveolar canal-root tip overlap on the risk assessment].

    PubMed

    Szalma, József; Lempel, Edina; Csuta, Tamás; Bártfai, Dóra; Jeges, Sára; Olasz, Lajos

    2010-06-01

    The aim of the present study was to determine on panoramic radiographic images the effect of the distance between the root curvatures and inferior alveolar canal (IAC) root tip overlap on the surgeon's risk assessment predicting inferior alveolar nerve (IAN) paresthesia after lower third molar removal. In this case-control study 41 cases with postoperative IAN paresthesia and 359 controls without any postoperative complications were involved. Demographic data, root curvatures and the extent of IAC-root tip overlap were registered. The cases of major curvature--larger than 90 degrees (P=0.015; odds ratio [OR]=2.65), the "deepest" superimposition (P<0.001; OR=1.96), female gender (P=0.020) and increased age (P=0.008) were significantly associated with IAN paresthesia. Assessing root curvatures and the extent of IAC-root tip overlap for predicting IAN paresthesia after mandibular third molar removal should help to improve risk assessment.

  5. Virtual environments from panoramic images

    NASA Astrophysics Data System (ADS)

    Chapman, David P.; Deacon, Andrew

    1998-12-01

    A number of recent projects have demonstrated the utility of Internet-enabled image databases for the documentation of complex, inaccessible and potentially hazardous environments typically encountered in the petrochemical and nuclear industries. Unfortunately machine vision and image processing techniques have not, to date, enabled the automatic extraction geometrical data from such images and thus 3D CAD modeling remains an expensive and laborious manual activity. Recent developments in panoramic image capture and presentation offer an alternative intermediate deliverable which, in turn, offers some of the benefits of a 3D model at a fraction of the cost. Panoramic image display tools such as Apple's QuickTime VR (QTVR) and Live Spaces RealVR provide compelling and accessible digital representations of the real world and justifiably claim to 'put the reality in Virtual Reality.' This paper will demonstrate how such technologies can be customized, extended and linked to facility management systems delivered over a corporate intra-net to enable end users to become familiar with remote sites and extract simple dimensional data. In addition strategies for the integration of such images with documents gathered from 2D or 3D CAD and Process and Instrumentation Diagrams (P&IDs) will be described as will techniques for precise 'As-Built' modeling using the calibrated images from which panoramas have been derived and the use of textures from these images to increase the realism of rendered scenes. A number of case studies relating to both nuclear and process engineering will demonstrate the extent to which such solution are scaleable in order to deal with the very large volumes of image data required to fully document the large, complex facilities typical of these industry sectors.

  6. Accuracy of cone beam dental CT, intraoral digital and conventional film radiography for the detection of periapical lesions. An ex vivo study in pig jaws.

    PubMed

    Stavropoulos, Andreas; Wenzel, Ann

    2007-03-01

    To compare the accuracy of cone beam CT scanning (NewTom 3G) with intraoral periapical radiography (Dixi2, Planmeca CCD sensor and Insight film) for the detection of periapical bone defects. Ten frozen pig mandibles were used. All soft tissues were removed and the jaws were sagittally sectioned to obtain three blocks from each side of the jaw containing the premolars and the molars with surrounding jaw bone. All teeth with intact roots were then "extracted". First, 15 blocks were used to define defect size and exposure parameters; then, the remaining 45 blocks were divided into three equal groups. In one group, cylindrical defects of 1 x 1 mm were prepared beyond the apices of the extraction sockets, in another group defects of 2 x 2 mm were similarly prepared, while no defects were prepared in the last group. The teeth were replaced into their sockets and digital and conventional radiographs of all blocks were taken under reproducible conditions. In addition, all blocks were CT scanned with the same volumetric data and then reconstructed to provide sagittal and coronal 2-D sections. Masked evaluation of the images (defect present vs no defect) was performed by four calibrated examiners. Statistical analysis was performed with ANOVA and the significance level was set to P < 0.05. NewTom 3G was statistically significantly better in terms of sensitivity (54%), positive (82.6%) and negative (44.5%) predictive values, and diagnostic accuracy (61%) when compared with digital radiographs (23%, 60%, 31%, 39%), and with conventional ones (28%, 70%, 35%, 44%)-except in the positive predictive value. Specificity was similar for all three methods. No difference was observed between the two periapical (digital vs conventional) radiographs. NewTom 3G may be useful in cases of immediate implants intended to replace teeth with suspicion for possible existing endodontic pathology, or in candidate implant sites neighboring such teeth.

  7. Modeling analysis metrics for panoramic sensors

    NASA Astrophysics Data System (ADS)

    Furxhi, Orges; Driggers, Ronald G.; Preece, Bradley; Krapels, Keith

    2015-05-01

    Panoramic infrared imaging is relatively new and has many applications to include tower mounted security systems, shipboard protection, and platform situational awareness. In this paper, we review metrics and methods that can be used for analysis of requirements for an infrared panoramic imaging system for military vehicles. We begin with a broad view of general military requirements organized into three categories, survivability, mobility, and lethality. A few requirements for the sensor modes of operation across all categories are selected so that panoramic system design can address as many needs as possible, but with affordability applied to system design. Metrics and associated methods that can translate military operational requirements into panoramic imager requirements are discussed in detail in this paper.

  8. Effectiveness of the thyroid shield in dental radiology

    SciTech Connect

    Sikorski, P.A.; Taylor, K.W.

    1984-08-01

    The effectiveness of the thyroid shield in reducing patient exposure during routine dental radiographic examinations was studied. A nonscreen film and two film-screen combinations were used as dosimeters and to show the spatial distribution of x-ray exposure. The error in the absolute accuracy of the film dosimeter and the error in the reproducibility of the film-screen combinations were less than +/- 10%. Measurements of thyroid exposure and exposure distribution, with and without the shield, were made on a Rando phantom and on patients. In the phantom study, the reduction by the shield of exposure to the thyroid from primary beam and from scatter was found to be highly dependent on the position of the primary beam relative to the thyroid gland but independent of kVp. Exposure reduction by the shield varied from 5% to 56% for a complete-mouth survey, 2% to 18% for a bitewing survey, and 10% to 79% for a panoramic survey. In the patient study, thyroid skin exposures measured on adults were 33% to 84% lower in offices in which the shield was used as compared to offices in which it was not used. Thyroid skin exposures measured on children were 63% to 92% lower. In accordance with the ALARA principle, these results support the routine use of the thyroid shield for all dental radiography.

  9. Panoramic lens designed with transformation optics

    NASA Astrophysics Data System (ADS)

    Wang, Huaping; Deng, Yangyang; Zheng, Bin; Li, Rujiang; Jiang, Yuyu; Dehdashti, Shahram; Xu, Zhiwei; Chen, Hongsheng

    2017-01-01

    The panoramic lens is a special kind of lens, which is applied to observe full view. In this letter, we theoretically present a panoramic lens (PL) using transformation optics method. The lens is designed with inhomogeneous and anisotropic constitutive parameters, which has the ability to gather light from all directions and confine light within the visual angle of observer. Simulation results validate our theoretical design.

  10. Endoscopic measurements using a panoramic annular lens

    NASA Technical Reports Server (NTRS)

    Gilbert, John A.; Matthys, Donald R.

    1992-01-01

    The objective of this project was to design, build, demonstrate, and deliver a prototype system for making measurements within cavities. The system was to utilize structured lighting as the means for making measurements and was to rely on a stationary probe, equipped with a unique panoramic annular lens, to capture a cylindrical view of the illuminated cavity. Panoramic images, acquired with a digitizing camera and stored in a desk top computer, were to be linearized and analyzed by mouse-driven interactive software.

  11. Panoramic lens designed with transformation optics

    PubMed Central

    Wang, Huaping; Deng, Yangyang; Zheng, Bin; Li, Rujiang; Jiang, Yuyu; Dehdashti, Shahram; Xu, Zhiwei; Chen, Hongsheng

    2017-01-01

    The panoramic lens is a special kind of lens, which is applied to observe full view. In this letter, we theoretically present a panoramic lens (PL) using transformation optics method. The lens is designed with inhomogeneous and anisotropic constitutive parameters, which has the ability to gather light from all directions and confine light within the visual angle of observer. Simulation results validate our theoretical design. PMID:28059142

  12. The implementation of digital sensors in maxillofacial radiography

    NASA Astrophysics Data System (ADS)

    van der Stelt, Paul F.

    2001-03-01

    Systems for intra-oral digital radiography in dentistry can be divided into two main groups: direct sensor systems and semi-direct or indirect sensor systems. Direct imaging is performed by a two-dimensional array of sensor elements. The size of a typical intra-oral CCD-sensor is approximately from 18 mm×24 mm to 30 mm×40 mm; the active area is somewhat smaller, because of the thickness of the packaging of the sensor. CCD-based imaging is now also available for panoramic and cephalometric radiography. Indirect (semi-direct) imaging is based on storage phosphor plates (SPP) imaging. The plate is positioned in the mouth of the patient behind the teeth, and exposed to radiation. The positioning of the sensor plate resembles very much the way conventional radiographic films are handled. SPP technology is also available for panoramic and cephalometric imaging. The purpose of radiography is to provide information to solve a particular diagnostic task. It is therefore very likely that the role of dedicated diagnostic software will become essential in the near future. The importance of dedicated software for diagnostic imaging will increase. As a result of worldwide research, more procedures will become available, for research as well as for use in general practice.

  13. Have panoramic indices the power to identify women with low BMD at the axial skeleton?

    PubMed

    Damilakis, John; Vlasiadis, Konstantinos

    2011-01-01

    The purpose of this study was to investigate whether panoramic mandibular indices i.e. mandibular cortical width (MCW), alveolar bone resorption degree (M/M ratio) and panoramic mandibular index (PMI) can be used as pre-selection tests to identify women with low bone mineral density (BMD) at the axial skeleton. MCW, PMI and M/M ratio were measured on dental panoramic radiographs in a group of 151 postmenopausal women aged 38-80 years. BMD at the lumbar spine and hip was measured by dual energy X-ray absorptiometry. BMD values were categorized as normal, osteopenic or osteoporotic according to the WHO classification. ROC analysis was used to determine cut-off values for MCW. MCW performed better than PMI and M/M ratio in its power to differentiate women with osteopenia or osteoporosis from healthy subjects. Cut-off values for the MCW estimated to detect women with T-score < -1 and those with T-score ≤ -2.5 identified a total of 45% and 34% of subjects respectively. Sensitivity and specificity was found to be low ranging between 55 and 70 for both cut-off values. Panoramic indices appear to have limited power in their ability to identify women with low BMD at the axial skeleton.

  14. Panoramic view from the intersection of Flower and Chapman looking ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Panoramic view from the intersection of Flower and Chapman looking west ( Views 11,12,13 complete 360 degree Panoramic) - National Home for Disabled Volunteer Soldiers, Marion Branch, 1700 East 38th Street, Marion, Grant County, IN

  15. Panoramic view from the intersection of Flower and Chapman looking ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Panoramic view from the intersection of Flower and Chapman looking southwest ( Views 11,12,13 complete 360 degree Panoramic) - National Home for Disabled Volunteer Soldiers, Marion Branch, 1700 East 38th Street, Marion, Grant County, IN

  16. Panoramic view from the intersection of Flower and Chapman looking ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Panoramic view from the intersection of Flower and Chapman looking northeast ( Views 11,12,13 complete 360 degree Panoramic) - National Home for Disabled Volunteer Soldiers, Marion Branch, 1700 East 38th Street, Marion, Grant County, IN

  17. Free-focus radiography using conventional films: Radiation exposures in a simulated clinical study

    SciTech Connect

    Jensen, T.W.; Randall, G.J.; Goldberg, A.J.

    1980-07-01

    This study compared air exposures during conventional dental and maxillofacial radiography and similar views using free-focus radiography with conventional image receptors. The results show that periapical type surveys on nonscreen film placed extraorally or in the buccal fold may be carried out with an exposure to the surface tissues, which is similar to or less than conventional dental radiography. Extraoral survey type radiographs of the jaws may be carried out with significantly less surface exposure than lateral oblique views of the jaws. The least exposure was required, when the film was placed in the buccla fold instead of against the face during free-focus radiography. The exposures with film screen combinations were reduced by an order of magnitude when compared to the nonscreen techniques. Proper filtration of the beam of the miniaturized x-ray machines radiography in dentistry may thus be desirable and applications in other parts of the body encouraged.

  18. Mobile Panoramic Video Applications for Learning

    ERIC Educational Resources Information Center

    Multisilta, Jari

    2014-01-01

    The use of videos on the internet has grown significantly in the last few years. For example, Khan Academy has a large collection of educational videos, especially on STEM subjects, available for free on the internet. Professional panoramic video cameras are expensive and usually not easy to carry because of the large size of the equipment.…

  19. Panoramic View of Lander During Turn

    NASA Technical Reports Server (NTRS)

    2004-01-01

    This 360-degree panoramic mosaic image composed of data from the hazard avoidance camera on the Mars Exploration Rover Spirit shows a view of the lander from under the rover deck. The images were taken as the rover turned from its landing position 95 degrees toward the northwest side of the lander.

  20. High energy neutron radiography

    SciTech Connect

    Gavron, A.; Morley, K.; Morris, C.; Seestrom, S.; Ullmann, J.; Yates, G.; Zumbro, J.

    1996-06-01

    High-energy spallation neutron sources are now being considered in the US and elsewhere as a replacement for neutron beams produced by reactors. High-energy and high intensity neutron beams, produced by unmoderated spallation sources, open potential new vistas of neutron radiography. The authors discuss the basic advantages and disadvantages of high-energy neutron radiography, and consider some experimental results obtained at the Weapons Neutron Research (WNR) facility at Los Alamos.

  1. [Dental pulp metastasis from oral squamous cell carcinoma: a case report and a review of the literature].

    PubMed

    Stefani, M; Angiero, F

    2006-02-01

    A 61-year-old man was seen in the Oral Pathology Department with a three-month history of right mandibular pain. Clinical examination revealed a 3 cm mass involving the body and the angle of the right site of the mandible and palpable masses in the neck. The dental panoramic radiography showed on the right a radiolucenT area surrounding the lower second molar, extending to the mandible angle. Additionally, chest radiograph and routine laboratory analysis results were unremarkable. An incisional biopsy of the area, revealed histologically a well differentiated squamous cell carcinoma and after few days, the patient received a right hemimandibulectomy with dissection of submandibular salivary gland and laterocervical lymph nodes on the same side. The histology of surgical material confirmed the diagnosis of a differentiated squamous cell carcinoma G1, homolateral diffusion in the mandible bone and metastasis to the dental pulp of the second lower molar tooth and to one of 18 lymph nodes dissected. In this report is described a very rare metastasis to the dental pulp and literature review, in which only fifteen other cases are reported.

  2. Phase-contrast radiography.

    PubMed

    Gao, D; Pogany, A; Stevenson, A W; Wilkins, S W

    1998-01-01

    For the past 100 years, the paradigm for radiography has been premised on absorption as the sole means of contrast formation and on ray optics as the basis for image interpretation. A new conceptual approach to radiography has been developed that includes phase (ie, refractive) contrast and requires wave optics for proper treatment. This new approach greatly increases the amount of information that can be obtained with radiographic techniques and is particularly well suited to the imaging of soft tissue and of very small features in biologic samples. A key feature of the present technique of phase-contrast radiography is the use of a microfocus x-ray source about an order of magnitude (< or = 20 microm) smaller than that used in conventional radiography. Phase-contrast radiography offers a number of improvements over conventional radiography in a clinical setting, especially in soft-tissue imaging. These improvements include increased contrast resulting in improved visualization of anatomic detail, reduced absorbed dose to the patient, inherent image magnification and high spatial resolution, use of harder x rays, and relative ease of implementation. More technologically advanced detectors are currently being developed and commercialized, which will help fully realize the considerable potential of phase-contrast imaging.

  3. Reliability of Panoramic Radiographs in the Localization of Mandibular Foramen

    PubMed Central

    Patil, Karthikeya; Guledgud, Mahima V

    2015-01-01

    Objective The present study evaluated the reliability and accuracy of panoramic radiographs in the localization of mandibular foramen. Materials and Methods Twenty five Indian dry human adult mandibles constituted the study material. Ten measurements were carried on each of them to evaluate the location of mandibular foramen with respect to adjacent anatomic landmarks. Panoramic radiographs were then made of the mandibles. Same distances were measured on the traced images of the radiographs. Paired t-test and Pearson’s correlation test were applied to evaluate the accuracy and reliability of panoramic radiographs in localization of mandibular foramen. Results The mean distances measured on dry mandibles and panoramic radiographs showed statistically significant difference (p<0.05). There was strong positive correlation between the measurements on dry mandible and panoramic radiographs. Conclusion The panoramic radiographs can serve as a guide in locating the anterosuperior point of mandibular foramen on panoramic radiographs. PMID:26155559

  4. Study of edge detection task in dental panoramic radiographs.

    PubMed

    Gráfová, L; Kasparová, M; Kakawand, S; Procházka, A; Dostálová, T

    2013-01-01

    The purpose of this study is (1) to introduce a new approach for edge detection in orthopantograms (OPGs) and an improved automatic parameter selector for common edge detectors, (2) to present a comparison between our novel approach with common edge detectors and (3) to provide faster outputs without compromising quality. A new approach for edge detection based on statistical measures was introduced: (1) a set of N edge detection results is calculated from a given input image and a selected type of edge detector, (2) N correspondence maps are constructed from N edge detection results, (3) probabilities and average probabilities are computed, (4) an overall correspondence is evaluated for each correspondence map and (5) the correspondence map providing the best overall correspondence is taken as the result of edge detection procedure. A comparison with common edge detectors (the Roberts, Prewitt, Sobel, Laplacian of the Gaussian and Canny methods) with various parameter settings (304 combinations for each test image) was carried out. The methods were assessed objectively [edge mismatch error (EME), modified Hausdorff distance (MHD) and principal component analysis] and subjectively by experts in dentistry and based on time demands. The suitability of the new approach for edge detection in OPGs was confirmed by experts. The current conventional methods in edge detection in OPGs are inadequate (none of the tested methods reach an EME value or MHD value below 0.1). Our proposed approach for edge detection shows promising potential for its implementation in clinical dentistry. It enhances the accuracy of OPG interpretation and advances diagnosis and treatment planning.

  5. 8. VIEW OF RADIOGRAPHY EQUIPMENT, TEST METHODS INCLUDED RADIOGRAPHY AND ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    8. VIEW OF RADIOGRAPHY EQUIPMENT, TEST METHODS INCLUDED RADIOGRAPHY AND BETA BACKSCATTERING. (7/13/56) - Rocky Flats Plant, Non-Nuclear Production Facility, South of Cottonwood Avenue, west of Seventh Avenue & east of Building 460, Golden, Jefferson County, CO

  6. Panoramic cockpit displays for tactical military cockpits

    NASA Astrophysics Data System (ADS)

    Fletcher, Mark; Huffman, David

    2010-04-01

    The F-35 Joint Strike Fighter (JSF) incorporates the latest technology for aerial warfighting. To support this aircraft's mission and to provide the pilot with the increased situational awareness needed in today's battlespace, a panoramic AMLCD was developed and is being deployed for the first time. This 20" by 8" display is the largest fielded to date in a tactical fighter. Key system innovations had to be employed to allow this technology to function in this demanding environment. Certain older generation aircraft are now considering incorporating a panoramic display to provide their crews with this level of increased capability. Key design issues that had to be overcome dealt with sunlight readability, vibration resistance, touchscreen operation, and reliability concerns to avoid single-point failures. A completely dual redundant system design had to be employed to ensure that the pilot would always have access to critical mission and flight data.

  7. Quality metric for spherical panoramic video

    NASA Astrophysics Data System (ADS)

    Zakharchenko, Vladyslav; Choi, Kwang Pyo; Park, Jeong Hoon

    2016-09-01

    Virtual reality (VR)/ augmented reality (AR) applications allow users to view artificial content of a surrounding space simulating presence effect with a help of special applications or devices. Synthetic contents production is well known process form computer graphics domain and pipeline has been already fixed in the industry. However emerging multimedia formats for immersive entertainment applications such as free-viewpoint television (FTV) or spherical panoramic video require different approaches in content management and quality assessment. The international standardization on FTV has been promoted by MPEG. This paper is dedicated to discussion of immersive media distribution format and quality estimation process. Accuracy and reliability of the proposed objective quality estimation method had been verified with spherical panoramic images demonstrating good correlation results with subjective quality estimation held by a group of experts.

  8. Real-time radiography

    SciTech Connect

    Bossi, R.H.; Oien, C.T.

    1981-02-26

    Real-time radiography is used for imaging both dynamic events and static objects. Fluorescent screens play an important role in converting radiation to light, which is then observed directly or intensified and detected. The radiographic parameters for real-time radiography are similar to conventional film radiography with special emphasis on statistics and magnification. Direct-viewing fluoroscopy uses the human eye as a detector of fluorescent screen light or the light from an intensifier. Remote-viewing systems replace the human observer with a television camera. The remote-viewing systems have many advantages over the direct-viewing conditions such as safety, image enhancement, and the capability to produce permanent records. This report reviews real-time imaging system parameters and components.

  9. Forensic dental identification of casualties during Operation Desert Storm.

    PubMed

    Kessler, H P; Pemble, C W

    1993-06-01

    Forensic dental identification of casualties during Operation Desert Storm was performed at the Dover Port Mortuary, Dover Air Force Base, under the auspices of the Office of the Armed Forces Medical Examiner. A total of 251 dental identifications were attempted and 244 individuals were positively identified by dental comparison. The panoramic radiographs on file at the Central Panograph Storage Facility were the primary antemortem records utilized in establishing the dental identification. The inability to establish a positive dental identification was most often the result of a lack of available antemortem dental records.

  10. Panoramic view of the Mexican Pacific Coastline

    NASA Technical Reports Server (NTRS)

    1993-01-01

    In this scenic panoramic view, the orbiter tail points toward the Mexican Pacific coastline (18.0N, 103.0W) near the international resort of Acapulco on the nearly cloud free eastern Pacific Ocean. Almost all of southern Mexico can be seen from Puerto Vallarta in the north to the Isthmus of Tehuantepec in the south. The cloud covered Gulf of Mexico at the horizon contrasts sharply with the blue Pacific.

  11. Phosphor plate radiography: an integral component of the filmless practice.

    PubMed

    Benjamin, Scott

    2010-11-01

    The federal government has mandated that all dental and medical patient records be electronic in 3 years. Practices using film radiography will be unable to comply with this mandate. PSP radiography is not only a surprisingly convenient way to transition from film to digital imaging, it can also greatly enhance the practice's productivity, profitability, and patient satisfaction. Modern, forward-thinking practices will want to take full advantage of PSP's superiority by making this transition now rather than waiting until they are forced to.

  12. Evaluation of Web-Based Interactive Instruction in Intraoral and Panoramic Radiographic Anatomy.

    PubMed

    Farkhondeh, Alireza; Geist, James R

    2015-07-01

    The objective was to evaluate the effectiveness of Web-based interactive modules in the instruction of dental hygiene students on intraoral and panoramic radiographic landmarks. The experimental group studied these landmarks as presented on interactive Web-based modules instead of in classroom presentations. The control group (the previous year's class) received instruction in the traditional classroom format. The outcomes measures included quizzes, examinations and an in-class project. Independent samples t-tests compared the scores of the two groups. A survey was administered to the experimental group to determine their perceptions of instruction with the modules. There was no significant difference in scores between the two groups on the project (p = .926) or the intraoral quiz and exam scores (p = .1 22), but the experimental group scored significantly lower on the panoramic outcomes (p = .039). Only 26% of the students preferred computer-assisted instruction to classroom instruction. The narration and interactive quizzes in the intraoral module may have contributed to the similar performance of the experimental and control groups, while their absence may have adversely affected the effectiveness of the panoramic module.

  13. Detecting ground moving objects using panoramic system

    NASA Astrophysics Data System (ADS)

    Xu, Fuyuan; Gu, Guohua; Wang, Jing

    2015-09-01

    The moving objects detection is an essential issue in many computer vision and video processing tasks. In this paper, a detecting moving objects method using a panoramic system is proposed. It can detect ground moving objects when the camera is rotated, so it can be called the moving objects detection in rotation (MODIR). The detection area and flexible of the panoramic system are be enhanced by MODIR. The background and moving objects are moving in image when the camera is rotated. Compare with the traditional methods, the aim of MODIR is to segment the isolated entities out according to the motions in the video whether imaging platform is moving or not. Firstly, the corresponding relations between the images captured from two different views is deduced from the multi-view geometric. The moving objects and stationary background in the images are distinguished by this corresponding relations. Secondly, the moving object detection framework base on multi-frame is established. This detection framework can reduce the impacts of the image matching error and cumulative error on the moving objects detection. In the experiment, an evaluation metrics method is used to compare the performance of MODIR with the traditional methods. And a lot of videos captured by the panoramic system are processed by MODIR to demonstrate its good performance in practice.

  14. Relationship between dental disease and radiation necrosis of the mandible

    SciTech Connect

    Murray, C.G.; Daly, T.E.; Zimmerman, S.O.

    1980-02-01

    Preirradiation panoramic radiographs of forty-six dentate patients were examined for the presence of significant dental disease. Evidence of a positive association between dental disease present before radiation therapy and subsequent necrosis of the mandible was found leading to a recommendation that significant disease be eradicated before irradiation of oral tissues. Considerable suffering results from bone necrosis, which can be reduced by careful and rational dental diagnosis and treatment.

  15. Correlation of the Radiographic and Morphological Features of the Dental Follicle of Third Molars with Incomplete Root Formation

    PubMed Central

    de OLIVEIRA, David Moraes; de Souza ANDRADE, Emanuel Sávio; da SILVEIRA, Márcia Maria Fonseca; CAMARGO, Igor Batista

    2008-01-01

    The objective of this study was to determine the correlation of the radiographic and morphological features of the dental follicle of unerupted third molars with incomplete root formation. A cross-sectional study was carried out with 56 patients (105 teeth) aged 13 to 24 years. Panoramic radiography was used to determine the stage of root formation to locate and measure pericoronal radiolucency. The width of the dental follicle ranged from 0.0 to 4.0 mm, the distal face being the one most frequently involved, and stage 7 of root formation showing the highest incidence. An inactive enamel reduced epithelium and inactive epithelium remnant also showed a high incidence. Dense connective tissue showed a high incidence, chronic inflammation was infrequent and calcification was a common finding. There was a significant association between the progression of the rhizogenesis and the transformation of the enamel reduced epithelium into a stratified squamous epithelium. No significant association was found between rhizogenesis and the other morphological findings or between the latter and the width of the pericoronal space. It was concluded that there was no clinically significant correlation between the radiographic and morphological features. Every asymptomatic unerupted third molar should be followed up and the follicular tissue analyzed. PMID:18311329

  16. Biomedical radiography: radiation protection and safety. (latest citations from the NTIS data base). Published Search

    SciTech Connect

    Not Available

    1992-04-01

    The bibliography contains citations concerning the safety of biomedical radiography. Radiation protection methods and techniques are described for both patients and operators. Safety techniques for dental radiology, routine x-rays, radiotherapy, thoracic radiography and other radiology procedures are included. Radiation exposure limits for patients and healthcare workers are defined. (Contains a minimum of 247 citations and includes a subject term index and title list.)

  17. Endoscopic inspection using a panoramic annular lens

    NASA Technical Reports Server (NTRS)

    Gilbert, John A.; Matthys, Donald R.

    1991-01-01

    The objective of this one year study was to design, build, and demonstrate a prototype system for cavity inspection. A cylindrical view of the cavity interior was captured in real time through a compound lens system consisting of a unique panoramic annular lens and a collector lens. Images, acquired with a digitizing camera and stored in a desktop computer, were manipulated using image processing software to aid in visual inspection and qualitative analysis. A detailed description of the lens and its applications is given.

  18. Apparatus for proton radiography

    DOEpatents

    Martin, Ronald L.

    1976-01-01

    An apparatus for effecting diagnostic proton radiography of patients in hospitals comprises a source of negative hydrogen ions, a synchrotron for accelerating the negative hydrogen ions to a predetermined energy, a plurality of stations for stripping extraction of a radiography beam of protons, means for sweeping the extracted beam to cover a target, and means for measuring the residual range, residual energy, or percentage transmission of protons that pass through the target. The combination of information identifying the position of the beam with information about particles traversing the subject and the back absorber is performed with the aid of a computer to provide a proton radiograph of the subject. In an alternate embodiment of the invention, a back absorber comprises a plurality of scintillators which are coupled to detectors.

  19. Forensic radiography: an overview.

    PubMed

    Reynolds, April

    2010-01-01

    Perhaps the first instance of forensic radiography occurred in the 1890s when Professor AW Wright of Yale University tested Wilhelm Roentgen's newly discovered x-ray photography on a deceased rabbit. Of interest were small, round objects inside the rabbit that appeared as dark spots on the positive film. The objects were extracted and identified as bullets, thereby helping to determine the cause of the rabbit's death. In the years since Roentgen's discovery, the use of radiography and other medical imaging specialties to aid in investigating civil and criminal matters has increased as investigators realize how radiologic technology can yield information that otherwise is unavailable. Radiologic technologists can play a key role in forensic investigations.

  20. Patient care in radiography

    SciTech Connect

    Ehrlich, R.A.; McCloskey, E.D.

    1989-01-01

    This book focuses on patient care procedures for radiographers. The authors focus on the role of the radiographer as a member of the health care team. The authors report on such topics as communication in patient care: safety, medico-legal considerations, transfer and positioning; physical needs; infection control; medication; CPR standards, acute situations; examination of the GI tract; contrast media; special imaging techniques and bedside radiography.

  1. Particle Beam Radiography

    NASA Astrophysics Data System (ADS)

    Peach, Ken; Ekdahl, Carl

    2014-02-01

    Particle beam radiography, which uses a variety of particle probes (neutrons, protons, electrons, gammas and potentially other particles) to study the structure of materials and objects noninvasively, is reviewed, largely from an accelerator perspective, although the use of cosmic rays (mainly muons but potentially also high-energy neutrinos) is briefly reviewed. Tomography is a form of radiography which uses multiple views to reconstruct a three-dimensional density map of an object. There is a very wide range of applications of radiography and tomography, from medicine to engineering and security, and advances in instrumentation, specifically the development of electronic detectors, allow rapid analysis of the resultant radiographs. Flash radiography is a diagnostic technique for large high-explosive-driven hydrodynamic experiments that is used at many laboratories. The bremsstrahlung radiation pulse from an intense relativistic electron beam incident onto a high-Z target is the source of these radiographs. The challenge is to provide radiation sources intense enough to penetrate hundreds of g/cm2 of material, in pulses short enough to stop the motion of high-speed hydrodynamic shocks, and with source spots small enough to resolve fine details. The challenge has been met with a wide variety of accelerator technologies, including pulsed-power-driven diodes, air-core pulsed betatrons and high-current linear induction accelerators. Accelerator technology has also evolved to accommodate the experimenters' continuing quest for multiple images in time and space. Linear induction accelerators have had a major role in these advances, especially in providing multiple-time radiographs of the largest hydrodynamic experiments.

  2. Comparative analysis of the gonial angle on lateral cephalometric radiographs and panoramic radiographs.

    PubMed

    Araki, Masao; Kiyosaki, Takeshi; Sato, Mai; Kohinata, Kiyomi; Matsumoto, Kunihito; Honda, Kazuya

    2015-01-01

    We measured the gonial angle (GA) on panoramic radiography (PR) and analyzed the correlation between the GA on PR and lateral cephalometric radiography (LCR). In total, 49 PR films and LCR films from dentate young adults were evaluated. Orthodontists plotted four points (articulare, menton, posterior gonion, and lower gonion) on the PR and carefully traced them. Using a protractor, two radiologists measured the GA on LCR images. A simultaneous experimental study of two dry skulls was performed to compare the GA on LCR and PR. The GA was slightly smaller on the PR of the dry mandible than on the LCR and tended to decrease continuously with magnitude toward the Frankfort horizontal plane. The mean GA was 115.1 ± 5.2° on PR and 122.2 ± 6.4° on the LCR. The values were highly correlated (Pearson product-moment correlation coefficient, 0.801). The GA on PR was nonsignificantly smaller than that measured on LCR. The difference may be due to head position, the inclination angle of the mandibular body, and/or the direction of the incident X-ray beam.

  3. Mars Cameras Make Panoramic Photography a Snap

    NASA Technical Reports Server (NTRS)

    2008-01-01

    If you wish to explore a Martian landscape without leaving your armchair, a few simple clicks around the NASA Web site will lead you to panoramic photographs taken from the Mars Exploration Rovers, Spirit and Opportunity. Many of the technologies that enable this spectacular Mars photography have also inspired advancements in photography here on Earth, including the panoramic camera (Pancam) and its housing assembly, designed by the Jet Propulsion Laboratory and Cornell University for the Mars missions. Mounted atop each rover, the Pancam mast assembly (PMA) can tilt a full 180 degrees and swivel 360 degrees, allowing for a complete, highly detailed view of the Martian landscape. The rover Pancams take small, 1 megapixel (1 million pixel) digital photographs, which are stitched together into large panoramas that sometimes measure 4 by 24 megapixels. The Pancam software performs some image correction and stitching after the photographs are transmitted back to Earth. Different lens filters and a spectrometer also assist scientists in their analyses of infrared radiation from the objects in the photographs. These photographs from Mars spurred developers to begin thinking in terms of larger and higher quality images: super-sized digital pictures, or gigapixels, which are images composed of 1 billion or more pixels. Gigapixel images are more than 200 times the size captured by today s standard 4 megapixel digital camera. Although originally created for the Mars missions, the detail provided by these large photographs allows for many purposes, not all of which are limited to extraterrestrial photography.

  4. [Metric and angular variables of the mandibular ramus on panoramic radiographs, as indicators for chronologic age].

    PubMed

    Espina-Fereira, Angela; Ortega, Ana Isabel; Barrios, Fernando Alonso; Maldonado, Yadelsy Jackelina; Fereira, José Luis

    2007-12-01

    This paper had as goals to identify the presence of age indicators in the mandibular ramus and to study their applicability in estimating the chronological age of children between the ages of 6 and 12 years. For this, a sample of 128 individuals (70 males and 58 females) was selected, all without chronic or acute sicknesses. An evaluation was made of the metric and angular variables of the mandibular ramus on panoramic radiographs of the oral cavity. The Greulich-Pyle method was applied to estimate the skeletal age, and the Demirjian et al. method was applied to estimate the dental age. A positive correlation, statistically significant, could be observed between the metric variables studied and the chronological age; nevertheless, the angular variables did not show correlation with the chronological age. Regression models were built using metric variables of the mandibular ramus in order to estimate the age, which made a significant contribution to the calculation of the age. A consistent subestimation of the skeletal age and an overestimation of the dental age were found in both sexes. It was evident that a combination of the dental age, the skeletal age and the metric variables obtained in the mandibular ramus, increases the precision for calculating the chronological age, when compared to separate-made estimations of the dental and skeletal age. The proposed regression models can be used for estimating the age of cadavers in advanced states of decomposition and in living individuals without valid identification documents.

  5. 19. PANORAMIC VIEW OF RADAR SITE, CONTROL ROOM, AND HELIPORT, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    19. PANORAMIC VIEW OF RADAR SITE, CONTROL ROOM, AND HELIPORT, LOOKING WEST-SOUTHWEST Everett Weinreb, photographer, March 1988 - Los Pinetos Nike Missile Site, Santa Clara Road, Los Angeles National Forest, Sylmar, Los Angeles County, CA

  6. 63. PANORAMIC VIEW OF HEADWORKS FROM WEST SIDE OF RIVER, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    63. PANORAMIC VIEW OF HEADWORKS FROM WEST SIDE OF RIVER, LOOKING UPSTREAM, Prints No. 173, 174 and 175, November 1903 - Electron Hydroelectric Project, Along Puyallup River, Electron, Pierce County, WA

  7. PANORAMIC VIEW OF SHIPYARD NO. 3, LOOKING SOUTHEAST. FIRST AID ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    PANORAMIC VIEW OF SHIPYARD NO. 3, LOOKING SOUTHEAST. FIRST AID STATION AT CENTER LEFT AND FORGE SHOP AT RIGHT - Rosie the Riveter National Historical Park, Richmond Shipyard No. 3, Point Potrero, Richmond, Contra Costa County, CA

  8. Dental Amalgam

    MedlinePlus

    ... Products and Medical Procedures Dental Devices Dental Amalgam Dental Amalgam Share Tweet Linkedin Pin it More sharing options Linkedin Pin it Email Print Dental amalgam is a dental filling material which is ...

  9. A comparison of Web page and slide/tape for instruction in periapical and panoramic radiographic anatomy.

    PubMed

    Ludlow, J B; Platin, E

    2000-04-01

    Self-guided slide/tape (ST) and web page (WP) instruction in normal radiographic anatomy of periapical and panoramic images is compared using objective test performance and subjective preference of freshman dental students. A class of seventy-four students was divided into a group studying anatomy in periapical images using WP and a group studying similar ST material. In a modified cross-over design the groups switched presentation technologies to learn anatomy in panoramic images. Students completed self-administered on-line quizzes covering WP materials and conventional quizzes for ST material. Students also completed a voluntary survey. Mean quiz performance identifying matched anatomic features in PA (n = 26) and panoramic images (n = 35) was excellent (96.9%) and not different between image types (p = 0.12) or presentation technologies (p = 0.81). Students preferred WP for accessibility, ease of use, freedom of navigation, and image quality (p < .01). Student comfort level with the quiz formats of the two technologies was not different (p = 0.11). Students experienced a higher rate of mechanical and logistical problems with ST than with WP technology. While 71 percent of the students preferred WP technology, this preference appears to be related to ease of use and facilitation of flexible learning styles rather than improved didactic performance.

  10. Survey of radiographic requirements and techniques in United States dental assisting programs, 1982

    SciTech Connect

    Farman, A.G.; Grammer, S.; Hunter, N.; Baker, C.

    1983-10-01

    A survey of dental assisting programs revealed little standardization of student requirements for dental radiography in the United States. Areas for concern were: the high proportion of programs in which classmates exposed one another to ionizing radiation for training purposes; and the continued use of closed cones in some cases. Preclinical laboratories in radiography were, on average, of considerably longer duration than those previously reported for dental students. Conversely, clinical requirements in intraoral techniques were less for dental assisting students than is the case for dental students. Available methods of reducing patient exposure to ionizing radiation are not being fully implemented.

  11. Rank distributions: A panoramic macroscopic outlook

    NASA Astrophysics Data System (ADS)

    Eliazar, Iddo I.; Cohen, Morrel H.

    2014-01-01

    This paper presents a panoramic macroscopic outlook of rank distributions. We establish a general framework for the analysis of rank distributions, which classifies them into five macroscopic "socioeconomic" states: monarchy, oligarchy-feudalism, criticality, socialism-capitalism, and communism. Oligarchy-feudalism is shown to be characterized by discrete macroscopic rank distributions, and socialism-capitalism is shown to be characterized by continuous macroscopic size distributions. Criticality is a transition state between oligarchy-feudalism and socialism-capitalism, which can manifest allometric scaling with multifractal spectra. Monarchy and communism are extreme forms of oligarchy-feudalism and socialism-capitalism, respectively, in which the intrinsic randomness vanishes. The general framework is applied to three different models of rank distributions—top-down, bottom-up, and global—and unveils each model's macroscopic universality and versatility. The global model yields a macroscopic classification of the generalized Zipf law, an omnipresent form of rank distributions observed across the sciences. An amalgamation of the three models establishes a universal rank-distribution explanation for the macroscopic emergence of a prevalent class of continuous size distributions, ones governed by unimodal densities with both Pareto and inverse-Pareto power-law tails.

  12. Rank distributions: a panoramic macroscopic outlook.

    PubMed

    Eliazar, Iddo I; Cohen, Morrel H

    2014-01-01

    This paper presents a panoramic macroscopic outlook of rank distributions. We establish a general framework for the analysis of rank distributions, which classifies them into five macroscopic "socioeconomic" states: monarchy, oligarchy-feudalism, criticality, socialism-capitalism, and communism. Oligarchy-feudalism is shown to be characterized by discrete macroscopic rank distributions, and socialism-capitalism is shown to be characterized by continuous macroscopic size distributions. Criticality is a transition state between oligarchy-feudalism and socialism-capitalism, which can manifest allometric scaling with multifractal spectra. Monarchy and communism are extreme forms of oligarchy-feudalism and socialism-capitalism, respectively, in which the intrinsic randomness vanishes. The general framework is applied to three different models of rank distributions-top-down, bottom-up, and global-and unveils each model's macroscopic universality and versatility. The global model yields a macroscopic classification of the generalized Zipf law, an omnipresent form of rank distributions observed across the sciences. An amalgamation of the three models establishes a universal rank-distribution explanation for the macroscopic emergence of a prevalent class of continuous size distributions, ones governed by unimodal densities with both Pareto and inverse-Pareto power-law tails.

  13. Panoramic night vision goggle flight test results

    NASA Astrophysics Data System (ADS)

    Franck, Douglas L.; Geiselman, Eric E.; Craig, Jeffrey L.

    2000-06-01

    The Panoramic Night Vision Goggle (PNVG) has begun operational test and evaluation with its 100-degree horizontal by 40-degree vertical field of view (FOV) on different aircraft and at different locations. Two configurations of the PNVG are being evaluated. The first configuration design (PNVG I) is very low in profile and fits underneath a visor. PNVG I can be retained by the pilot during ejection. This configuration is interchangeable with a day helmet mounted tracker and display through a standard universal connector. The second configuration (PNVG II) resembles the currently fielded 40-degree circular FOV Aviator Night Vision Imaging Systems (ANVIS) and is designed for non-ejection seat aircraft and ground applications. Pilots completed subjective questionnaires after each flight to compare the capability of the 100-degree horizontal by 40-degree vertical PNVG to the 40-degree circular ANVIS across different operational tasks. This paper discusses current findings and pilot feedback from the flight trials objectives of the next phase of the PNVG program are also discussed.

  14. A Taxonomy of Functions of Dental X-Ray Technologists.

    ERIC Educational Resources Information Center

    Doty, Charles R.; And Others

    The taxonomy of the functions of dental x-ray technologists presented in this report resulted from a dental radiography curriculum development project undertaken at Middlesex County College (MCC) in 1981. After an introductory section citing arguments for creating taxonomies of objectives, the report explains the impetus for the curriculum…

  15. Accuracy of direct digital radiography for detecting occlusal caries in primary teeth compared with conventional radiography and visual inspection: an in vitro study

    PubMed Central

    Dias da Silva, P R; Martins Marques, M; Steagall, W; Medeiros Mendes, F; Lascala, C A

    2010-01-01

    Objectives The diagnosis of caries lesions is still a matter of concern in dentistry. The diagnosis of dental caries by digital radiography has a number of advantages over conventional radiography; however, this method has not been explored fully in the field of paediatric dentistry. This in vitro research evaluated the accuracy of direct digital radiography compared with visual inspection and conventional radiography in the diagnosis of occlusal caries lesions in primary molars. Methods 50 molars were selected and evaluated under standardized conditions by 2 previously calibrated examiners according to 3 diagnostic methods (visual inspection, conventional radiography and direct digital radiography). Direct digital radiographs were obtained with the Dixi3 system (Planmeca, Helsinki, Finland) and the conventional radiographs with InSight film (Kodak Eastman Co., Rochester, NY). The images were scored and a reference standard was obtained histologically. The interexaminer reliability was calculated using Cohen's kappa test and the specificity, sensitivity and accuracy of the methods were calculated. Results Examiner reliability was good. For lesions limited to the enamel, visual inspection showed significantly higher sensitivity and accuracy than both radiographic methods, but no significant difference was found in specificity. For teeth with dentinal caries, no significant differences were found for any parameter when comparing visual and radiographic evaluation. Conclusions Although less accurate than the visual method for detecting caries lesions confined to the enamel, the direct digital radiographic method is as effective as conventional radiographic examination and visual inspection of primary teeth with occlusal caries when the dentine is involved. PMID:20729186

  16. Electronic system for digital acquisition of rotational panoramic radiographs

    SciTech Connect

    McDavid, W.D.; Dove, S.B.; Welander, U.; Tronje, G. )

    1991-04-01

    A prototype system for digital panoramic imaging of the maxillofacial complex has been developed. In this system x-ray film is replaced by an electronic sensor that delivers the image information to a computer for storage in digital format. The images, which are similar to conventional panoramic radiographs, are displayed on a high-resolution video monitor and may be stored on optical disk for future use. Hard-copy output is also available. The present prototype system has been installed on an Orthopantomograph model OP10 panoramic x-ray machine is programmed for operation with this machine, but in principle the system can be installed on any such device. The system may be incorporated into the design of future panoramic x-ray systems or may be used to retrofit panoramic x-ray systems now using photographic film to record the radiographic image. Greater sensitivity of electronic sensors should make possible a reduction of x-ray dose to the patient, compared with film-based systems.

  17. Clinical Application of Cone Beam Computed Tomography of the Rabbit Head: Part 2—Dental Disease

    PubMed Central

    Riggs, G. G.; Cissell, Derek D.; Arzi, Boaz; Hatcher, David C.; Kass, Philip H.; Zhen, Amy; Verstraete, Frank J. M.

    2017-01-01

    Domestic rabbits are increasing in popularity as household pets; therefore, veterinarians need to be familiar with the most common diseases afflicting rabbits including dental disease. Current diagnostic approaches include gross oral examination, endoscopic oral examination, skull radiography, and computed tomography (CT). Cone beam computed tomography (CBCT), a new oral and maxillofacial imaging modality that has the capability to produce high-resolution images, has not yet been described for use in evaluating dental disease in rabbits. A total of 15 client-owned rabbits had CBCT, oral examination, dental charting, and dental treatment performed under general anesthesia. Images were evaluated using transverse and custom multiplanar (MPR), 3D, and panoramic reconstructed images. The CBCT findings were grouped into abnormalities that could be detected on conscious oral examination vs. abnormalities that could not be detected by conscious oral examination. Potential associations between the two categories were examined by pairwise Fisher’s exact test with statistical significance determined by P < 0.05. The most common findings identified on CBCT images were periodontal ligament space widening (14/15), premolar and molar malocclusion (13/15), apical elongation (13/15), coronal elongation (12/15), inflammatory tooth resorption (12/15), periapical lucency (11/15), moth-eaten pattern of osteolysis of the alveolar bone (9/15), ventral mandibular border contour changes (9/15), and missing teeth (8/15). Of the CBCT abnormalities likely to be observed on oral examination, coronal elongation (detectable on oral examination) was significantly associated with apical elongation (P = 0.029). There were no other significant associations between CBCT findings that are also clinically detectable and CBCT findings that are not be detectable on oral examination. This suggests that pathology often exists that is not apparent upon oral examination. This study establishes the

  18. Lower Gastrointestinal (GI) Tract X-Ray (Radiography)

    MedlinePlus

    ... Site Index A-Z X-ray (Radiography) - Lower GI Tract Lower gastrointestinal tract radiography or lower GI ... of Lower GI Tract Radiography? What is Lower GI Tract X-ray Radiography (Barium Enema)? Lower gastrointestinal ( ...

  19. Lasers In Dental Diagnosis

    NASA Astrophysics Data System (ADS)

    Everse, K. E.; Sinor, T. W.; Menzel, E. R.

    1987-01-01

    We have investigated the potential of lasers for real time in situ dental diagnosis via transillumination of teeth and gums and via fluorescence. Not surprisingly, absorption and/or scattering of light by teeth was found to be insensitive to light color. However, monochromatic transillumination revealed detail better than white light. Transillumination of gums was best performed with orange-red light because of tissue absorption. Illumination of oral structures by 488 nm Ar-laser light was effective in revealing diagnosis detail by fluorescence. Incipient caries and fine tooth fracture lines that are generally not revealed by radiography were observable by laser.

  20. Industrial Radiography | Radiation Protection | US EPA

    EPA Pesticide Factsheets

    2016-12-09

    Manufacturers use a method called industrial radiography to check for cracks or flaws in materials. Radiation is used in industrial radiography to show problems not visible from the outside without damaging the material.

  1. Accelerator system for neutron radiography

    SciTech Connect

    Rusnak, B; Hall, J

    2000-09-21

    The field of x-ray radiography is well established for doing non-destructive evaluation of a vast array of components, assemblies, and objects. While x-rays excel in many radiography applications, their effectiveness diminishes rapidly if the objects of interest are surrounded by thick, high-density materials that strongly attenuate photons. Due to the differences in interaction mechanisms, neutron radiography is highly effective in imaging details inside such objects. To obtain a high intensity neutron source suitable for neutron imaging a 9-MeV linear accelerator is being evaluated for putting a deuteron beam into a high-pressure deuterium gas cell. As a windowless aperture is needed to transport the beam into the gas cell, a low-emittance is needed to minimize losses along the high-energy beam transport (HEBT) and the end station. A description of the HEBT, the transport optics into the gas cell, and the requirements for the linac will be presented.

  2. Digital Radiography: A Technology Overview

    NASA Astrophysics Data System (ADS)

    Arnold, Ben A.

    1982-12-01

    Digital radiography, a term hardly recognized two years ago, has grown to become the talk of the radiology community and the excitement of many commercial companies. M2st of this attention has been directed toward digital subtraction intravenous angiography), although during this same time period, a variety of digital radiography apparatus and image processing techniques have been under development. In November of 1980 at the RSNA Conference in Chicago, three commercial digital angiography systems were announced by Philips, Technicare and ADAC Corporations. During this same time period, the University of Arizona was discussing the concept of a photo electronic radiology department2, the University of Pittsburg and Stanford University were investigating line scan radiography3,4 and approximately five laboratories were carrying out clinical IV angiography with digital video systems.5-9 These developments followed basic research programs in digital electronic and computerized imaging at various locations around the world. 10-18 In the spring of 1981 we attempted to review the state of digital radiography, focusing on the various detector systems and image acquisition approaches.19 Since that time, rapid advancements in digital radiography have occurred. A major conference was held on digital radiography at Stanford UniversityzO, a new area detector system for digital radiography was announced by Fuji Film Corporation, clinical testing began on the Picker line scan digital chest unit21, and improvements were made in selenium detectors for digital radiography. Several additional companies announced digital video angiography systems, bringing the total now to approximately 15 companies worldwide. Digital video subtraction angiography is now well established as an important clinical diagnostic procedure and a variety of improvements and extensions of digital angiography systems are now ongoing. Digital acquisition and storage systems are increasing in both speed and

  3. 9. PANORAMIC VIEW WEST, FERNOW EXPERIMENTAL FOREST RESIDENCE, CHEAT DISTRICT ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    9. PANORAMIC VIEW WEST, FERNOW EXPERIMENTAL FOREST RESIDENCE, CHEAT DISTRICT RANGER RESIDENCE AND GARAGE, IMPLEMENT BUILDING, SEED EXTRACTOR BUILDING, CONE DRYING SHED, PUMP HOUSE, OIL HOUSE, CHEAT DISTRICT RANGER OFFICE, WASH HOUSE, AND NURSERY MANAGER'S RESIDENCE. PLANTING BEDS IN BACKGROUND. - Parsons Nursery, South side of U.S. Route 219, Parsons, Tucker County, WV

  4. Design of a novel panoramic lens without central blindness

    NASA Astrophysics Data System (ADS)

    Gong, Chen; Cheng, Dewen; Xu, Chen; Wang, Yongtian

    2015-08-01

    The panoramic lenses are getting more and more popular in recent years. However, these lenses have the drawback of obscuring the rays of the coaxial fields, thus cause blind area in the center field of vision. We present a novel panoramic system consisting of two optical channels to overcome this issue, the system has a field of view (FOV) reaching 200 in vertical and 360 in horizontal direction without blindness area. The two channels have different focal lengths, providing design flexibility to meet application requirements where the center FOV or the marginal FOV is of more interest. The system has no half-reflecting surfaces to ensure high transmission ratio, but this feature greatly increase the design difficulty. The distortion of the novel lens is much smaller than traditional panoramic lenses since the distortion has two node points. Due to the ability of information acquisition in real-time and wide-angle, the novel panoramic lens would be very useful for a variety of real-world applications such as surveillance, short-throw projector and pilotless automobile.

  5. 2. Photocopy of section of panoramic map of 'Savannah, Georgia ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    2. Photocopy of section of panoramic map of 'Savannah, Georgia 1891' showing Savannah Repair Shops; drawn and published by Augustus Koch, Morning-News Lithograph, Savannah, GA. - Central of Georgia Railway, Savannah Repair Shops & Terminal Facilities, Bounded by West Broad, Jones, West Boundary & Hull Streets, Savannah, Chatham County, GA

  6. 18. PANORAMIC VIEW OF RADAR SITE, LOOKING WEST, SHOWING NORTHWEST ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    18. PANORAMIC VIEW OF RADAR SITE, LOOKING WEST, SHOWING NORTH-WEST HELIPAD AT UPPER LEFT AND CIRCLE BUILDING PAD Everett Weinreb, photographer, March 1988 - Los Pinetos Nike Missile Site, Santa Clara Road, Los Angeles National Forest, Sylmar, Los Angeles County, CA

  7. Designing 3 Dimensional Virtual Reality Using Panoramic Image

    NASA Astrophysics Data System (ADS)

    Wan Abd Arif, Wan Norazlinawati; Wan Ahmad, Wan Fatimah; Nordin, Shahrina Md.; Abdullah, Azrai; Sivapalan, Subarna

    The high demand to improve the quality of the presentation in the knowledge sharing field is to compete with rapidly growing technology. The needs for development of technology based learning and training lead to an idea to develop an Oil and Gas Plant Virtual Environment (OGPVE) for the benefit of our future. Panoramic Virtual Reality learning based environment is essential in order to help educators overcome the limitations in traditional technical writing lesson. Virtual reality will help users to understand better by providing the simulations of real-world and hard to reach environment with high degree of realistic experience and interactivity. Thus, in order to create a courseware which will achieve the objective, accurate images of intended scenarios must be acquired. The panorama shows the OGPVE and helps to generate ideas to users on what they have learnt. This paper discusses part of the development in panoramic virtual reality. The important phases for developing successful panoramic image are image acquisition and image stitching or mosaicing. In this paper, the combination of wide field-of-view (FOV) and close up image used in this panoramic development are also discussed.

  8. 60. PANORAMIC VIEW OF DOWNSTREAM FACE. No date, but believed ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    60. PANORAMIC VIEW OF DOWNSTREAM FACE. No date, but believed to be just subsequent to construction. Photograph by C.G. Duffey, Long Beach, California. (38' x 11' framed print). - Little Rock Creek Dam, Little Rock Creek, Littlerock, Los Angeles County, CA

  9. Left panel of panoramic overview of Beaver River Bridge and ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Left panel of panoramic overview of Beaver River Bridge and New Brighton, looking NE from Patterson Heights, abuts PA-511-2 - Pittsburgh, Fort Wayne & Chicago Railway, Beaver River Bridge, Spanning Beaver River along line of Second Avenue, New Brighton, Beaver County, PA

  10. Right panel of panoramic overview of Beaver River Bridge and ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Right panel of panoramic overview of Beaver River Bridge and New Brighton, looking SE from Patternson Heights, abuts PA-511-1. - Pittsburgh, Fort Wayne & Chicago Railway, Beaver River Bridge, Spanning Beaver River along line of Second Avenue, New Brighton, Beaver County, PA

  11. First of three panoramic views of North Base as seen ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    First of three panoramic views of North Base as seen from top of Building 4500, Control Tower. View looks southwest (220°) at taxiway, hangars, apron, and edge of Rogers Dry Lake. Buildings in distance in left of view are part of Edwards Air Force Base's Main Base. - Edwards Air Force Base, North Base, North Base Road, Boron, Kern County, CA

  12. 8. SECOND IMAGE OF THE PANORAMIC SERIES LOOKING WEST FROM ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    8. SECOND IMAGE OF THE PANORAMIC SERIES LOOKING WEST FROM THE UPHILL SIDE OF THE MILL. THE ORE RECEIVING HOUSE AND THE ORE DELIVERY TRESTLE IS IMAGE RIGHT, THE MILL BUILDING AND ANCILLARY STRUCTURE ARE IMAGE CENTER AND THE TOWN OF BODIE IS IMAGE BACKGROUND RIGHT. - Standard Gold Mill, East of Bodie Creek, Northeast of Bodie, Bodie, Mono County, CA

  13. New point matching algorithm for panoramic reflectance images

    NASA Astrophysics Data System (ADS)

    Kang, Zhizhong; Zlatanova, Sisi

    2007-11-01

    Much attention is paid to registration of terrestrial point clouds nowadays. Research is carried out towards improved efficiency and automation of the registration process. The most important part of registration is finding correspondence. The panoramic reflectance images are generated according to the angular coordinates and reflectance value of each 3D point of 360° full scans. Since it is similar to a black and white photo, it is possible to implement image matching on this kind of images. Therefore, this paper reports a new corresponding point matching algorithm for panoramic reflectance images. Firstly SIFT (Scale Invariant Feature Transform) method is employed for extracting distinctive invariant features from panoramic images that can be used to perform reliable matching between different views of an object or scene. The correspondences are identified by finding the nearest neighbors of each keypoint form the first image among those in the second image afterwards. The rigid geometric invariance derived from point cloud is used to prune false correspondences. Finally, an iterative process is employed to include more new matches for transformation parameters computation until the computation accuracy reaches predefined accuracy threshold. The approach is tested with panoramic reflectance images (indoor and outdoor scenes) acquired by the laser scanner FARO LS 880. 1

  14. Measurement accuracy and reliability of tooth length on conventional and CBCT reconstructed panoramic radiographs

    PubMed Central

    Flores-Mir, Carlos; Rosenblatt, Mark R; Major, Paul W.; Carey, Jason P.; Heo, Giseon

    2014-01-01

    INTRODUCTION: This in vivo study assessed accuracy and reliability of tooth length measurements obtained from conventional panoramic radiographs and CBCT panoramic reconstructions to that of a digital caliper (gold standard). METHODS: The sample consisted of subjects who had CBCT and conventional panoramic radiographic imaging and who required maxillary premolar extraction for routine orthodontic treatment. A total of 48 teeth extracted from 26 subjects were measured directly with digital calipers. Radiographic images were scanned and digitally measured in Dolphin 3D software. Accuracy of tooth length measurements made by CBCT panoramic reconstructions, conventional panoramic radiographs and digital caliper (gold standard) were compared to each other by repeated measures one-way ANOVA with Bonferroni correction and by single measures intraclass correlation coefficient. RESULTS: Repeated root length measures with digital calipers, panoramic radiographs and CBCT constructed panoramic-like images were all individually highly reliable. Compared to the caliper (gold standard), tooth measurements obtained from conventional panoramic radiographs were on average 6.3 mm (SD = 2.0 mm) longer, while tooth measurements from CBCT panoramic reconstructions were an average of 1.7 mm (SD = 1.2 mm) shorter. CONCLUSIONS: In comparison to actual tooth lengths, conventional panoramic radiographs were relatively inaccurate, overestimating the lengths by 29%, while CBCT panoramic reconstructions underestimated the lengths by 4%. PMID:25715716

  15. Radiographic signs and diagnosis of dental disease.

    PubMed

    Bellows, J

    1993-08-01

    Dental radiographs are critical for the complete assessment and treatment of dental diseases. Dental radiography is commonly used to evaluate congenital dental defects, periodontal disease, orthodontic manipulations, oral tumors, endodontic treatments, oral trauma, and any situation where an abnormality is suspected. Although standard radiographic equipment and film can be used to produce dental radiographs, dental X-ray equipment and film provide superior quality images and greater convenience of animal patient positioning. An understanding of normal dental radiographic anatomy is important when interpreting dental radiographs. Stage III periodontitis is the earliest stage of periodontal disease at which radiographic abnormalities become apparent. Bone loss associated with periodontal disease can be classified as either horizontal or vertical. Periapical radiolucencies can represent granulomas, cysts, or abscesses, whereas periapical radiodensities may represent sclerotic bone or condensing osteitis. Lytic lesions of the bone of the jaw often represent oral neoplasms. Neoplasms also can displace or disrupt teeth in the dental arch. Resorptive lesions can be external or internal and appear as radiolucent areas involving the external surface of the root or the pulp cavity, respectively. Feline dental resorptive lesions, also known as odontoclastic resorptions, are a specific form of dental resorptive lesions unique to cats.

  16. Dental implants in bilateral bifid canal and compromised interocclusal space using cone beam computerized tomography

    PubMed Central

    Ahmed, Nizar; Arunachalam, Lalitha Tanjore; Jacob, Caroline Annette; Kumar, Suresh Anand

    2016-01-01

    Knowledge of various anatomic landmarks is pivotal for important success. Bifid canals pose a challenge and can lead to difficulties while performing implant surgery in the mandible. Bifid canals can be diagnosed with panoramic radiography and more accurately with cone beam computerized tomography (CBCT). This case report details the placement of the implant in a patient with bilateral bifid canal and compromised interocclusal space, which was successfully treated using CBCT. PMID:27433073

  17. Neutron imaging and tomography with Medipix2 and dental micro-roentgenography

    NASA Astrophysics Data System (ADS)

    Jakubek, J.; Granja, C.; Holy, T.; Lehmann, E.; Linhart, V.; Pospisil, S.; Rypar, V.; Uher, J.; Vacik, J.; Vavrik, D.; Vykydal, Z.; Cevallos, M.

    2006-12-01

    The position-sensitive semiconductor Medipix2 detector has been adapted for high-resolution dental X-ray and neutron imaging. As a fully electronic, low-dose and high spatial resolution digital dental-imaging device the system aims to observe the bone-to-implant tissue of order of tens of microns. Neutron radiography is proposed as a complementary diagnostic method to standard X-ray radiography as it can produce contrast images of materials which are otherwise indistinguishable in X-ray images. Neutron radiography and tomography tests have been carried out. Results are compared with other techniques. A review of recent developments and current status is presented.

  18. Panoramic radiographic study of mental foramen in selected dravidians of south Indian population: A hospital based study

    PubMed Central

    Gupta, Vaibhav; Pitti, Parag

    2015-01-01

    Background This study aimed at documenting information on appearance, size, horizontal and vertical locations of Mental Foramen (MF) in Panoramic Radiograph. We also analyzed the age and gender differences with radiographic appearance and location of MF. We evaluated these findings in our population and co-relate with results of previous studies. Material and Methods 1662 panoramic radiographs were evaluated, of which 245 fulfilled the inclusion criteria. Each radiograph was traced to record the horizontal and vertical locations. The size of MF was recorded using digital caliper and its appearance was determined by visual examination. Chi-square and t-test were employed. Results The most common appearance of MF was continuous type and the tests showed significant difference with age and gender. The most frequent horizontal location of MF was “location c” with no statistical significant difference with age and gender. The MF was most commonly positioned mesially in relation to the apex of second premolar with no significant differences with gender. The vertical location of the foramen varied drastically with no statistical significant difference in both sides. The difference in dimensions on the left and right sides were not statistically significant. Conclusions Determining the morphological appearance and positional variation of MF is important for isolation of mental nerves and vessels when administering local anesthesia and performing surgeries. We therefore stress the importance of accurate radiographic identification of MF and interpretation. Our research findings can be used as reference material by the dental practitioners of South India while performing clinical procedures that involve MF. Key words:Mental foramen, mental nerve, panoramic radiograph, mandible. PMID:26535088

  19. Dental Procedures.

    PubMed

    Ramponi, Denise R

    2016-01-01

    Dental problems are a common complaint in emergency departments in the United States. There are a wide variety of dental issues addressed in emergency department visits such as dental caries, loose teeth, dental trauma, gingival infections, and dry socket syndrome. Review of the most common dental blocks and dental procedures will allow the practitioner the opportunity to make the patient more comfortable and reduce the amount of analgesia the patient will need upon discharge. Familiarity with the dental equipment, tooth, and mouth anatomy will help prepare the practitioner for to perform these dental procedures.

  20. Image post-processing in dental practice.

    PubMed

    Gormez, Ozlem; Yilmaz, Hasan Huseyin

    2009-10-01

    Image post-processing of dental digital radiographs, a function which used commonly in dental practice is presented in this article. Digital radiography has been available in dentistry for more than 25 years and its use by dental practitioners is steadily increasing. Digital acquisition of radiographs enables computer-based image post-processing to enhance image quality and increase the accuracy of interpretation. Image post-processing applications can easily be practiced in dental office by a computer and image processing programs. In this article, image post-processing operations such as image restoration, image enhancement, image analysis, image synthesis, and image compression, and their diagnostic efficacy is described. In addition this article provides general dental practitioners with a broad overview of the benefits of the different image post-processing operations to help them understand the role of that the technology can play in their practices.

  1. System for uncollimated digital radiography

    DOEpatents

    Wang, Han; Hall, James M.; McCarrick, James F.; Tang, Vincent

    2015-08-11

    The inversion algorithm based on the maximum entropy method (MEM) removes unwanted effects in high energy imaging resulting from an uncollimated source interacting with a finitely thick scintillator. The algorithm takes as input the image from the thick scintillator (TS) and the radiography setup geometry. The algorithm then outputs a restored image which appears as if taken with an infinitesimally thin scintillator (ITS). Inversion is accomplished by numerically generating a probabilistic model relating the ITS image to the TS image and then inverting this model on the TS image through MEM. This reconstruction technique can reduce the exposure time or the required source intensity without undesirable object blurring on the image by allowing the use of both thicker scintillators with higher efficiencies and closer source-to-detector distances to maximize incident radiation flux. The technique is applicable in radiographic applications including fast neutron, high-energy gamma and x-ray radiography using thick scintillators.

  2. Revealing of HII-regions in Galaxies with Panoramic Spectroscopy

    NASA Astrophysics Data System (ADS)

    Hakopian, S. A.; Balayan, S. K.

    2016-06-01

    Observations intended to investigation and revealing of nodes of processes of nuclear and starforming activity in galaxies were performed via panoramic spectroscopy. Data obtained on Mrk 1050 revealed evidence of starforming activity also outside the central engine of high surface brightness. Two small HII-regions, being likely a part of the chain, are located in the part of the spiral branch coming from the nucleus part.

  3. Photocopy of panoramic photograph entitled "Ground Breaking, April 27, 1918, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Photocopy of panoramic photograph entitled "Ground Breaking, April 27, 1918, U.S.A. General Hospital no. 21…". Photograph by Rocky Mountain photo and is in the Fitzsimons Army Medical Center Public Affairs Office, building 120. Photograph in public domain as it is not copyrighted. - Fitzsimons General Hospital, Bounded by East Colfax to south, Peoria Street to west, Denver City/County & Adams County Line to north, & U.S. Route 255 to east, Aurora, Adams County, CO

  4. Panoramic view of the electrical Department & Boiler House Complex, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Panoramic view of the electrical Department & Boiler House Complex, looking southwest from the roof of the lower shops. Originally constructed in 1888, only sections of original walls remain. In the right foreground is the no. 2 steel foundry, originally constructed in 1888 and converted many times as different furnaces were added. Behind the buildings (to the south and west) is the Stony Creek River. - Johnson Steel Street Rail Company, Electrical Department & Boiler House, 525 Central Avenue, Johnstown, Cambria County, PA

  5. Mercator - Independent rover localization using stereophotoclinometry and panoramic images

    NASA Astrophysics Data System (ADS)

    Palmer, Eric E.; Head, James N.; Gaskell, Robert W.; Sykes, Mark V.; McComas, Brian

    2016-12-01

    We present a navigation technique for a lunar vehicle based upon matching horizon imagery with a database of synthetic panoramas generated from ultrahigh-resolution topographic models created by stereophotoclinometry. We conducted two tests, one with lunar topography and fully synthetic panoramas, and another using Earth-based data and actual panoramic images. We have shown that the horizon-matching technique can search a wide area for a vehicle's location and determine that location to within 6 m using readily available imagery.

  6. Panomorph lenses: a low-cost solution for panoramic surveillance

    NASA Astrophysics Data System (ADS)

    Thibault, Simon; Artonne, Jean-Claude

    2006-05-01

    Historically, the US Army, border security agencies as well as in transportation security planner has recognized the advantages of panoramic imagers, increased areas coverage with fewer cameras, tracking of multiple target simultaneously and others. However, panoramic imager has blind zone when using catadioptric system and required high bandwidth and heavy installation with fisheye lens to get an interesting resolution. The novel Panomorph lens is the heart of the new surveillance and security system developed by ImmerVision. The Panomorph lens is anticipated to be a new generation of lenses that can be used with NTSC or PAL camera to provide equivalent resolution than a 2 MPixels system but at a fraction of the cost by using existing facilities (cable, camera...). By introducing at the optical design stage a proper angular to pixel function (distortion), the new lens can provide a higher resolution in a define zone of interest than a standard fisheye. To achieve a gain in resolution, a pixel size well corrected image spot size is required. Our development included a strong optical design effort that resulted in an all refractive anamorphic panoramic imager with uncompromised image resolution for longer range detection in the zone of interest. The paper describes the development and real performance status of the Panomorph lens. Other components of the ImmerVision system include image correction, image compression and data transferred to handle devices. The same approach can also be used with IR imager where the number of pixel is limited.

  7. MR360: Mixed Reality Rendering for 360° Panoramic Videos.

    PubMed

    Rhee, Taehyun; Petikam, Lohit; Allen, Benjamin; Chalmers, Andrew

    2017-04-01

    This paper presents a novel immersive system called MR360 that provides interactive mixed reality (MR) experiences using a conventional low dynamic range (LDR) 360° panoramic video (360-video) shown in head mounted displays (HMDs). MR360 seamlessly composites 3D virtual objects into a live 360-video using the input panoramic video as the lighting source to illuminate the virtual objects. Image based lighting (IBL) is perceptually optimized to provide fast and believable results using the LDR 360-video as the lighting source. Regions of most salient lights in the input panoramic video are detected to optimize the number of lights used to cast perceptible shadows. Then, the areas of the detected lights adjust the penumbra of the shadow to provide realistic soft shadows. Finally, our real-time differential rendering synthesizes illumination of the virtual 3D objects into the 360-video. MR360 provides the illusion of interacting with objects in a video, which are actually 3D virtual objects seamlessly composited into the background of the 360-video. MR360 was implemented in a commercial game engine and tested using various 360-videos. Since our MR360 pipeline does not require any pre-computation, it can synthesize an interactive MR scene using a live 360-video stream while providing realistic high performance rendering suitable for HMDs.

  8. Evaluation of two methods of tracings for implants in panoramic radiographs.

    PubMed

    Freitas, Deborah Queiroz de; Montebello Filho, Agenor

    2004-03-01

    In the last years, computer programs have appeared in order to help dental practitioners in implants planning. These programs aim to facilitate the acquisition of adequate measures in digitalized radiographs. The aims of this study were: to evaluate the intra-examiner agreement in the acquisition of measures using two methods (manual and computer program - Radioimp), comparing their performances. Three examiners analyzed twenty-one panoramic radiographs. They used the two methods in two occasions. In the manual method, the examiners made a tracing on a paper fixed to the images and measured nine regions with a caliper. The images were digitalized and showed in a computer screen to be analyzed in the computer program. The examiners acquired measures of the same regions by the manual method. Vertical measures of spheres in the images were acquired in order to discount the magnifying factor of the technique. Through statistics analysis (p=.05), it was possible to conclude that there were differences in intra-examiner agreement and the examiners had greater difficulty in reproducing the measures when they used the computer program; the measures acquired by the manual method were closer to the real ones.

  9. Panoramic Images Mapping Tools Integrated Within the ESRI ArcGIS Software

    NASA Astrophysics Data System (ADS)

    Guo, Jiao; Zhong, Ruofei; Zeng, Fanyang

    2014-03-01

    There is a general study on panoramic images which are presented along with appearance of the Google street map. Despite 360 degree viewing of street, we can realize more applications over panoramic images. This paper developed a toolkits plugged in ArcGIS, which can view panoramic photographs at street level directly from ArcMap and measure and capture all visible elements as frontages, trees and bridges. We use a series of panoramic images adjoined with absolute coordinate through GPS and IMU. There are two methods in this paper to measure object from these panoramic images: one is to intersect object position through a stereogram; the other one is multichip matching involved more than three images which all cover the object. While someone wants to measure objects from these panoramic images, each two panoramic images which both contain the object can be chosen to display on ArcMap. Then we calculate correlation coefficient of the two chosen panoramic images so as to calculate the coordinate of object. Our study test different patterns of panoramic pairs and compare the results of measurement to the real value of objects so as to offer the best choosing suggestion. The article has mainly elaborated the principles of calculating correlation coefficient and multichip matching.

  10. Lesion detectability in digital radiography

    NASA Astrophysics Data System (ADS)

    Gagne, Robert M.; Boswell, Jonathan S.; Myers, Kyle J.; Peter, Guillaume

    2001-06-01

    The usefulness of Fourier-based measures of imaging performance has come into question for the evaluation of digital imaging systems. Figures of merit such as detective quantum efficiency are relevant for linear, shift-invariant systems with stationary noise. However, no digital imaging system is shift invariant, and realistic images do not satisfy the stationarity condition. Our methods for task- based evaluation of imaging systems, based on lesion detectability, do not require such assumptions. We have computed the performance of Hotelling and nonprewhitening matched-filter observers for the task of lesion detection in digital radiography.

  11. Dental Hygienists

    MedlinePlus

    ... years to complete, and offer laboratory, clinical, and classroom instruction. Areas of study include anatomy, physiology, nutrition, radiography, pathology, medical ethics, head and neck anatomy, patient management, and periodontics, which is the study of gum ...

  12. ARG portable neutron radiography. Final report

    SciTech Connect

    Barton, J.P.

    1995-04-01

    In this report all available neutron radiographic data, including results of tests run at LANL, McClellan AFB, and University of Virginia, will be combined to outline specific transportable neutron radiography systems that could achieve the desired results as a complement to x-radiography capabilities for the Accident Response Group (ARG).

  13. Radiological protection in equine radiography and radiotherapy.

    PubMed

    Yoxall, A T

    1977-10-01

    The principles of radiological protection are summarised and consideration is then given to problems, which may confront the equine practitioner, in the fulfillment of these principles during diagnostic radiography of the limbs, head, and spine of the horse. The place of anaesthesia in such procedures is discussed and the special problems associated with therapeutic radiography of the horse are considered.

  14. INDUSTRIAL RADIOGRAPHY STUDENT GUIDE AND LABORATORY EXERCISES.

    ERIC Educational Resources Information Center

    Bureau of Adult, Vocational, and Technical Education (DHEW/OE), Washington, DC. Div. of Vocational and Technical Education.

    THIS INSTRUCTOR'S GUIDE TO AN 80-HOUR COURSE IN INDUSTRIAL RADIOGRAPHY IS COORDINATED WITH LESSONS IN THE STUDENT GUIDE AND LABORATORY EXERCISES AND IS BASED ON MATERIAL IN THE COURSE MANUAL, INDUSTRIAL RADIOGRAPHY. THE COURSE IS INTENDED TO TRAIN HIGH SCHOOL GRADUATES AS BEGINNING RADIOGRAPHERS WHO ARE EXPECTED TO BE ABLE TO EXTEND THEIR…

  15. PROTON RADIOGRAPHY FOR AN ADVANCED HYDROTEST FACILITY

    SciTech Connect

    C. MORRIS

    2000-11-01

    Analysis of data from BNL experiment 933 is presented. Results demonstrate that proton radiography can meet many of the requirements for an Advanced Hydrotest Facility (AHF). Results for background, position resolution, metrology, quantitative radiography, material identification, and edge resolution are presented.

  16. Process waste assessment for the Radiography Laboratory

    SciTech Connect

    Phillips, N.M.

    1994-07-01

    This Process Waste Assessment was conducted to evaluate the Radiography Laboratory, located in Building 923. It documents the processes, identifies the hazardous chemical waste streams generated by these processes, recommends possible ways to minimize waste, and serves as a reference for future assessments of this facility. The Radiography Laboratory provides film radiography or radioscopy (electronic imaging) of weapon and nonweapon components. The Radiography Laboratory has six x-ray machines and one gamma ray source. It also has several other sealed beta- and gamma-ray isotope sources of low microcurie ({mu}Ci) activity. The photochemical processes generate most of the Radiography Laboratory`s routinely generated hazardous waste, and most of that is generated by the DuPont film processor. Because the DuPont film processor generates the most photochemical waste, it was selected for an estimated material balance.

  17. Dose measurements in intraoral radiography using thermoluminescent dosimeters

    NASA Astrophysics Data System (ADS)

    Azorín, C.; Azorín, J.; Aguirre, F.; Rivera, T.

    2015-01-01

    The use of X-ray in medicine demands to expose the patient and the professional to the lowest radiation doses available in agreement with ALARA philosophy. The reference level for intraoral dental radiography is 7 mGy and, in Mexico, a number of examinations of this type are performed annually. It is considered that approximately 25% of all the X-rays examinations carried out in our country correspond to intraoral radiographies. In other hand, most of the intraoral X-ray equipment correspond to conventional radiological systems using film, which are developed as much manual as automatically. In this work the results of determining the doses received by the patients in intraoral radiological examinations made with different radiological systems using LiF:Mg,Cu,P+PTFE thermoluminescent dosimeters are presented. In some conventional radiological systems using film, when films are developed manual or automatically, incident kerma up to 10.61 ± 0.74 mGv were determined. These values exceed that reference level suggested by the IAEA and in the Mexican standards for intraoral examinations.

  18. Sex Determination of Adult Human Maxillary Sinuses on Panoramic Radiographs.

    PubMed

    Leao de Queiroz, Cristhiane; Terada, Andrea Sayuri Silveira Dias; Dezem, Thais Uenoyama; Gomes de Araújo, Lais; Galo, Rodrigo; Oliveira-Santos, Christiano; Alves da Silva, Ricardo Henrique

    2016-09-01

    The purpose of this study was to evaluate dimensions of adult human maxillary sinuses on panoramic radiographs and their possible application on the sex determination for forensic purposes. The sample comprised 64 database panoramic radiographs from individuals aged 20 years or older (32 male and 32 female subjects), with complete permanent dentition (or absence of third molars). One examiner measured the width and height of the right and left maxillary sinuses using the software Image J 1.47v (National Institutes of Health, Bethesda, USA). Measurements were repeated to calculate intra-observer agreement. Chi-Square test, Kappa, ANOVA and T-Student were used for results analysis for p≤ 0.05. Intra-observer agreement with correlation Kappa ranged between 0.38 and 0.96. For female subjects, the mean height and width of the left maxillary sinus were 28.7856mm and 44.6178mm, respectively. And right maxillary sinus was 27.7163mm for height and 45.1850mm for width. Male subjects were found to have the mean height and width of the left maxillary sinus 30.9981mm and 48.7753mm, respectively. And right maxillary sinus was 30.7403mm for height and 48.5753mm for width. There was a statistically significant difference in the height and width of maxillary sinuses between males and females. It can be concluded that maxillary sinuses height and width on panoramic radiographs can be used to determine the gender of adult human subjects.

  19. Sex Determination of Adult Human Maxillary Sinuses on Panoramic Radiographs

    PubMed Central

    Leao de Queiroz, Cristhiane; Terada, Andrea Sayuri Silveira Dias; Dezem, Thais Uenoyama; Gomes de Araújo, Lais; Galo, Rodrigo; Oliveira-Santos, Christiano

    2016-01-01

    Absract The purpose of this study was to evaluate dimensions of adult human maxillary sinuses on panoramic radiographs and their possible application on the sex determination for forensic purposes. The sample comprised 64 database panoramic radiographs from individuals aged 20 years or older (32 male and 32 female subjects), with complete permanent dentition (or absence of third molars). One examiner measured the width and height of the right and left maxillary sinuses using the software Image J 1.47v (National Institutes of Health, Bethesda, USA). Measurements were repeated to calculate intra-observer agreement. Chi-Square test, Kappa, ANOVA and T-Student were used for results analysis for p≤ 0.05. Intra-observer agreement with correlation Kappa ranged between 0.38 and 0.96. For female subjects, the mean height and width of the left maxillary sinus were 28.7856mm and 44.6178mm, respectively. And right maxillary sinus was 27.7163mm for height and 45.1850mm for width. Male subjects were found to have the mean height and width of the left maxillary sinus 30.9981mm and 48.7753mm, respectively. And right maxillary sinus was 30.7403mm for height and 48.5753mm for width. There was a statistically significant difference in the height and width of maxillary sinuses between males and females. It can be concluded that maxillary sinuses height and width on panoramic radiographs can be used to determine the gender of adult human subjects. PMID:27847394

  20. Quality assurance in film radiography

    SciTech Connect

    Van Bellegem, L.; Vaessen, B.

    1993-12-31

    The ISO 9000 standards were originally developed during the 1980`s to provide uniform, worldwide quality assurance requirements. The EC (European Communities) adopted these standards as part of their modular approach to ``conformity assessment`` procedures, for several product categories. This includes the development of standards (specifications) which define what the purchaser wants and what the supplier agrees to provide, as well as quality system registration (certification) which increases confidence in the supplier`s ability to produce consistently. The requirements are typically most rigorous for regulated products that have a major impact on health and safety i.e film radiographic systems. This is the main reason for making available the necessary Q.C. tools in film radiography to comply with Q.A. specifications and guarantee the required consistent performance. These tools can only give satisfying support if they are dedicated, easy to use, precise and cost effective at the user`s level. The main topics for such a Q.A. package are: (1) standard for Film System classification for industrial radiography; (2) film system certification; and (3) standard for control of film processing by means of reference values i.e. pre-exposed film wedges and archiving quality control method.

  1. Photocopy of left half of panoramic photograph marked "C 1928 ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Photocopy of left half of panoramic photograph marked "C 1928 Goldbeck". Photograph appears to have been taken from 1919 water tower, no longer extant, looking southwest with a rotating camera to encompass the entire installation. Photograph in the Fitzsimons Army Medical Center Directorate of Public Works conference room, building 118. This photograph is in the public domain as it was never actually registered with the Copyright Office. - Fitzsimons General Hospital, Bounded by East Colfax to south, Peoria Street to west, Denver City/County & Adams County Line to north, & U.S. Route 255 to east, Aurora, Adams County, CO

  2. 9. THIRD IMAGE OF THE PANORAMIC SERIES WITH CONSIDERABLE OVERLAP. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    9. THIRD IMAGE OF THE PANORAMIC SERIES WITH CONSIDERABLE OVERLAP. A SETTLING TANK, SMOKESTACK FROM THE MILL'S BOILER ROOM, MILL ANNEX AND OTHER MILL OUT BUILDINGS ARE IN THE MIDDLE RIGHT OF THE IMAGE THE SUPERINTENDENTS HOUSE IS IN THE MIDDLE LEFT OF THE IMAGE SPANNING FROM LEFT TO RIGHT IN THE BACKGROUND IS THE TOWN OF BODIE. IN THE FAR BACKGROUND LEFT IS THE ROAD THAT IS THE ACCESS PARK. - Standard Gold Mill, East of Bodie Creek, Northeast of Bodie, Bodie, Mono County, CA

  3. Second of three panoramic views of North Base as seen ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Second of three panoramic views of North Base as seen from top of Building 4500, Control Tower. View looks west (268°) at North Base complex. In foreground is taxiway, with Building 4456 (Fire House No. 4) at right. Building 4452 (Utility Vault) appears in extreme left foreground, with Building 4412 (Liquid Oxygen Repair Facility) and Building 4410 (Liquid Oxygen Storage) in extreme left background. In view over Building 4456 is the "loop" bound by Third, Fourth, A, and B Streets. Concrete slabs are all that remain of military housing constructed in the 1940s. - Edwards Air Force Base, North Base, North Base Road, Boron, Kern County, CA

  4. 7. THE BEGINNING OF A PANORAMIC SERIES VIEW LOOKING WEST ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    7. THE BEGINNING OF A PANORAMIC SERIES VIEW LOOKING WEST NORTHWEST FROM THE UPHILL SIDE OF THE MILL. THE ORE RECEIVING HOUSE IS IN THE IMAGE CENTER, THE ORE DELIVERY TRESTLE EXTENDS FROM THE RECEIVING HOUSE TO THE MILL BUILDING IN THE BACKGROUND LEFT. IN THE MID-GROUND LEFT IS A CYLINDRICAL STRUCTURE BELIEVE TO BE A SETTLING TANK FROM A LATER CHEMICAL RETREATMENT OF THE TAILINGS IN THE FOREGROUND RIGHT IS AN EXTANT ORE BUCKET. - Standard Gold Mill, East of Bodie Creek, Northeast of Bodie, Bodie, Mono County, CA

  5. Plasma-flash radiography utilizing a molybdenum target in dentistry

    NASA Astrophysics Data System (ADS)

    Yamamoto, Mariko; Takabe, Akihito; Sakamaki, Kimio; Sato, Eiichi; Takahashi, Kei; Sagae, Michiaki; Oizumi, Teiji; Hayasi, Yasuomi; Sasaki, Katsuaki; Tamakawa, Yoshiharu; Yanagisawa, Toru

    1995-09-01

    The construction and the radiographic characteristics of a plasma flash x-ray generator having a molybdenum-target (anode tip) triode are described. This generator was primarily designed in order to perform soft radiography in dental medicine and employed the following essential components: a high-voltage power supply, a low-impedance coaxial transmission line with a gap switch, a coaxial oil condenser of 0.2 (mu) F, a turbo-molecular pump, a Krytron pulser as a trigger device, and a flash x-ray tube. The high-voltage main condenser of 0.2 (mu) F was charged from 40 to 60 kV by the power supply, and the electric charges in the condenser were discharged to the tube after closing the gap switch. Because this tube employed a long target, the plasma x-ray source which consists of molybdenum ions and electrons was easily produced by the target evaporating. The maximum tube voltage was nearly equivalent to the initial charge voltage of the main condenser, and the maximum current had a value of about 25 kA with a charging voltage of 60 kV. The average width of flash x rays was less than 1 microsecond(s) , and the time-integrated x-ray intensity with a charging voltage of 60 kV was approximately 20 (mu) C/kg at 1.0 m per pulse. The characteristic K-series intensity substantially increased according to increases in the charged voltage. High-speed dental radiography was performed using a laser timing switch and a trigger-delay device.

  6. Plasma-flash radiography utilizing a molybdenum target in dentistry

    SciTech Connect

    Yamamoto, Mariko; Takabe, Akihito; Sakamaki, Kimio

    1995-12-31

    The construction and the radiographic characteristics of a plasma flash x-ray generator having a molybdenum-target (anode tip) triode are described. This generator was primarily designed in order to perform soft radiography in dental medicine and employed the following essential components: a high-voltage power supply, a low-impedance coaxial transmission line with a gap switch, a coaxial oil condenser of 0.2 {micro}F, a turbo-molecular pump, a Krytron pulser as a trigger device, and a flash x-ray tube. The high-voltage main condenser of 0.2 {micro}F was charged from 40 to 60 kV by the power supply, and the electric charges in the condenser were discharged to the tube after closing the gap switch. Because this tube employed a long target, the plasma x-ray source which consists of molybdenum ions and electrons was easily produced by the target evaporating. The maximum tube voltage was nearly equivalent to the initial charging voltage of the main condenser, and the maximum current had a value of about 25 kA with a charging voltage of 60 kV. The average width of flash x rays was less than 1 {micro}s, and the time-integrated x-ray intensity with a charging voltage of 60 kV was approximately 20 {micro}C/kg at 1.0 m per pulse. The characteristic K-series intensity substantially increased according to increases in the charging voltage. High-speed dental radiography was performed by using a laser timing switch and a trigger-delay device.

  7. Dental Assistants

    MedlinePlus

    ... help keep the dental office running smoothly. Important Qualities Detail oriented. Dental assistants must follow specific rules and protocols, such as infection control procedures, when helping dentists treat patients. Assistants also ...

  8. Analysis of Dental Maturation in Relation to Sagittal Jaw Relationships

    PubMed Central

    Durka-Zając, Magdalena; Derwich, Marcin; Mituś-Kenig, Maria; Łoboda, Magdalena; Pawłowska, Elżbieta

    2017-01-01

    Summary Background The degree of mineralization of permanent tooth germs in dental age assessment has been an area of interest among many authors for years. However, only recently have researchers attempted to determine the potential interdependencies between dental age and jaw relationships. The aim of this work was to compare dental maturation in patients with skeletal Class II to patients with skeletal Classes I and III. Material/Methods The study involved 150 patients who sought orthodontic treatment. Dental age was assessed from panoramic radiographs using the Demirjian’s method. Skeletal class was evaluated according to the value of the ANPg angle from the Björk’s analysis. We used the analysis of variance (ANOVA) and the Student’s t-test. Results The mean dental age in patients with skeletal Class III was significantly higher than the mean dental age in patients with skeletal Class II (p<0.0005). A correlation between the dental age and chronological age was established. The weakest correlation was seen between the dental age and skeletal Class II. Among patients with skeletal Class II, the strongest correlation was found between chronological age and the formation of the germ of the second lower premolar (r=0.67; p<0.001). Conclusions Dental age among patients with skeletal Class II was the lowest. PMID:28203310

  9. Image panoramic mosaicing with global and local registration

    NASA Astrophysics Data System (ADS)

    Li, Qi; Ji, Zhen; Zhang, Jihong

    2001-09-01

    This paper presents techniques for constructing full view panoramic mosaics from sequences of images. The goal of this work is to remove too many limitations for pure panning motion. The best reference block is critical for the block- matching method for improving the robustness and performance. It is automatically selected in the high- frequency image, which always contains the plenty visible features. In order to reduce accumulated registration errors, the global registration using the phase-correlation matching method with rotation adjustment is applied to the whole sequence of images, which results in an optimal image mosaic with resolving translational or rotational motion. The local registration using the Levenberg-Marquardt iterative non-linear minimization algorithm is applied to compensate for small amounts of motion parallax introduced by translations of the camera and other unmodeled distortions, when minimize the discrepancy after applying the global registration. The accumulated misregistration errors may cause a visible gap between the two images. A smoothing filter is introduced, derived from Marr's computer vision theory for removing the visible artifact. By combining both global and local registration, together with artifact smoothing, the quality of the image mosaics is significantly improved, thereby enabling the creation of full view panoramic mosaics with hand-held cameras.

  10. Using Vertical Panoramic Images to Record a Historic Cemetery

    NASA Astrophysics Data System (ADS)

    Tommaselli, A. M. G.; Polidori, L.; Hasegawa, J. K.; Camargo, P. O.; Hirao, H.; Moraes, M. V. A.; Rissate, E. A., Jr.; Henrique, G. R.; Abreu, P. A. G.; Berveglieri, A.; Marcato, J., Jr.

    2013-07-01

    In 1919, during colonization of the West Region of São Paulo State, Brazil, the Ogassawara family built a cemetery and a school with donations received from the newspaper Osaka Mainichi Shimbum, in Osaka, Japan. The cemetery was closed by President Getúlio Vargas in 1942, during the Second World War. The architecture of the Japanese cemetery is a unique feature in Latin America. Even considering its historical and cultural relevance, there is a lack of geometric documentation about the location and features of the tombs and other buildings within the cemetery. As an alternative to provide detailed and fast georeferenced information about the area, it is proposed to use near vertical panoramic images taken with a digital camera with fisheye lens as the primary data followed by bundle adjustment and photogrammetric restitution. The aim of this paper is to present a feasibility study on the proposed technique with the assessment of the results with a strip of five panoramic images, taken over some graves in the Japanese cemetery. The results showed that a plant in a scale of 1 : 200 can be produced with photogrammetric restitution at a very low cost, when compared to topographic surveying or laser scanning. The paper will address the main advantages of this technique as well as its drawbacks, with quantitative analysis of the results achieved in this experiment.

  11. Panoramic, large-screen, 3-D flight display system design

    NASA Technical Reports Server (NTRS)

    Franklin, Henry; Larson, Brent; Johnson, Michael; Droessler, Justin; Reinhart, William F.

    1995-01-01

    The report documents and summarizes the results of the required evaluations specified in the SOW and the design specifications for the selected display system hardware. Also included are the proposed development plan and schedule as well as the estimated rough order of magnitude (ROM) cost to design, fabricate, and demonstrate a flyable prototype research flight display system. The thrust of the effort was development of a complete understanding of the user/system requirements for a panoramic, collimated, 3-D flyable avionic display system and the translation of the requirements into an acceptable system design for fabrication and demonstration of a prototype display in the early 1997 time frame. Eleven display system design concepts were presented to NASA LaRC during the program, one of which was down-selected to a preferred display system concept. A set of preliminary display requirements was formulated. The state of the art in image source technology, 3-D methods, collimation methods, and interaction methods for a panoramic, 3-D flight display system were reviewed in depth and evaluated. Display technology improvements and risk reductions associated with maturity of the technologies for the preferred display system design concept were identified.

  12. Image enhancement for radiography inspection

    NASA Astrophysics Data System (ADS)

    Wang, Xin; Wong, Brian Stephen; Guan, Tui Chen

    2005-04-01

    The x-ray radiographic testing method is often used for detecting defects as a non-destructive testing method (NDT). In many cases, NDT is used for aircraft components, welds, etc. Hence, the backgrounds are always more complex than a piece of steel. Radiographic images are low contrast, dark and high noise image. It is difficult to detect defects directly. So, image enhancement is a significant part of automated radiography inspection system. Histogram equalization and median filter are the most frequently used techniques to enhance the radiographic images. In this paper, the adaptive histogram equalization and contrast limited histogram equalization are compared with histogram equalization. The adaptive wavelet thresholding is compared with median filter. Through comparative analysis, the contrast limited histogram equalization and adaptive wavelet thresholding can enhance perception of defects better.

  13. Dental OCT

    NASA Astrophysics Data System (ADS)

    Colston, Bill W.; Sathyam, Ujwal S.; Dasilva, Luiz B.; Everett, Matthew J.; Stroeve, Pieter; Otis, L. L.

    1998-09-01

    We present here the first in vivo optical coherence tomography (OCT) images of human dental tissue. A novel dental optical coherence tomography system has been developed. This system incorporates the interferometer sample arm and transverse scanning optics into a handpiece that can be used intraorally to image human dental tissues. The average imaging depth of this system varied from 3 mm in hard tissues to 1.5 mm in soft tissues. We discuss the application of this imaging system for dentistry and illustrate the potential of our dental OCT system for diagnosis of periodontal disease, detection of caries, and evaluation of dental restorations.

  14. Dental development in children with severe molar-incisor hypomineralization in Samsun, Turkey.

    PubMed

    Tunc, Emine S; Ulusoy, Ayca T; Bayrak, Sule; Cankaya, Soner

    2013-09-01

    Anomalies in amelogenesis may be due to developmental defects or abnormalities in different components of developing teeth and can affect dental development. We compared dental development in a group of children with molar-incisor hypomineralization (MIH) with that in age- and sex-matched controls. Dental age was determined using panoramic radiographs of 105 children (59 girls, 46 boys) aged 7-11 years with severe MIH, and the findings were compared with those from 105 healthy age- and sex-matched controls. Although accelerated dental development was noted in the MIH group, the difference between the MIH and control groups was not statistically significant (P < 0.05). Furthermore, no relationship was found between number of affected teeth and the difference between dental and chronological age. In conclusion, children with severe MIH had slightly accelerated dental development as compared with controls.

  15. Multi-purpose neutron radiography system

    SciTech Connect

    Barton, J.P.; Bryant, L.E.; Berry, P.

    1996-07-01

    A conceptual design is given for a low cost, multipurpose radiography system suited for the needs of the Los Alamos National Laboratory (LANL). The proposed neutron source is californium-252. One purpose is to provide an in-house capability for occasional, reactor quality, neutron radiography thus replacing the recently closed Omega-West Reactor. A second purpose is to provide a highly reliable standby transportable neutron radiography system. A third purpose is to provide for transportable neutron probe gamma spectroscopy techniques. The cost is minimized by shared use of an existing x-ray facility, and by use of an existing transport cask. The achievable neutron radiography and radioscopy performance characteristics have been verified. The demonstrated image qualities range from high resolution gadolinium - SR film, with L:D = 100:1, to radioscopy using a LIXI image with L:D = 30:1 and neutron fluence 3.4 x 10{sup 5} n/cm{sup 2}.

  16. Information extraction from muon radiography data

    SciTech Connect

    Borozdin, K. N.; Asaki, T. J.; Chartrand, R.; Hengartner, N. W.; Hogan, G. E.; Morris, C. L.; Priedhorsky, W. C.; Schirato, R.C.; Schultz, L. J.; Sottile, M. J.; Vixie, K. R.; Wohlberg, B. E.; Blanpied, G.

    2004-01-01

    Scattering muon radiography was proposed recently as a technique of detection and 3-d imaging for dense high-Z objects. High-energy cosmic ray muons are deflected in matter in the process of multiple Coulomb scattering. By measuring the deflection angles we are able to reconstruct the configuration of high-Z material in the object. We discuss the methods for information extraction from muon radiography data. Tomographic methods widely used in medical images have been applied to a specific muon radiography information source. Alternative simple technique based on the counting of high-scattered muons in the voxels seems to be efficient in many simulated scenes. SVM-based classifiers and clustering algorithms may allow detection of compact high-Z object without full image reconstruction. The efficiency of muon radiography can be increased using additional informational sources, such as momentum estimation, stopping power measurement, and detection of muonic atom emission.

  17. Corrosion Inhibitors as Penetrant Dyes for Radiography

    NASA Technical Reports Server (NTRS)

    Novak, Howard L.; Hall, Phillip B.

    2003-01-01

    Liquid/vapor-phase corrosion inhibitors (LVCIs) have been found to be additionally useful as penetrant dyes for neutron radiography (and perhaps also x-radiography). Enhancement of radiographic contrasts by use of LVCIs can reveal cracks, corrosion, and other defects that may be undetectable by ultrasonic inspection, that are hidden from direct optical inspection, and/or that are difficult or impossible to detect in radiographs made without dyes.

  18. Motivations for muon radiography of active volcanoes

    NASA Astrophysics Data System (ADS)

    Macedonio, G.; Martini, M.

    2010-02-01

    Muon radiography represents an innovative tool for investigating the interior of active volcanoes. This method integrates the conventional geophysical techniques and provides an independent way to estimate the density of the volcano structure and reveal the presence of magma conduits. The experience from the pioneer experiments performed at Mt. Asama, Mt. West Iwate, and Showa-Shinzan (Japan) are very encouraging. Muon radiography could be applied, in principle, at any stratovolcano. Here we focus our attention on Vesuvius and Stromboli (Italy).

  19. Validation of a computed radiography device to monitor the HIV-1 RNase H activity

    NASA Astrophysics Data System (ADS)

    Esposito, F.; Fanti, V.; Marzeddu, R.; Randaccio, P.; Tramontano, E.; Zinzula, L.

    2009-08-01

    A commercially available computed radiography (CR) system for dental radiography was used to produce images from radiolabeled polyacrilamide gel electrophoresis (PAGE) assays. Typically, similar investigations require specific and expensive autoradiography devices. The CR unit was characterized in terms of sensitivity and fading by means of a 90Sr source that well simulates the experimental conditions, and then used for quantitative analyses of the human immunodeficiency virus type 1 (HIV-1) reverse transcriptase (RT) polymerase-independent ribonuclease H (RNase H) activity monitored by PAGE analysis. The results showed that the present methodology allows quantifying effectively the RNase H catalyses and that the obtained data are in good agreement with previous reference works. Finally, in order to further validate the present method in terms of relationship between enzyme activity, the rate of products formation and signal intensity, a PAGE analyses of the HIV-1 RNase H inhibition by the known diketo acid derivative RDS1643 was carried out.

  20. a Method of Generating Panoramic Street Strip Image Map with Mobile Mapping System

    NASA Astrophysics Data System (ADS)

    Tianen, Chen; Yamamoto, Kohei; Tachibana, Kikuo

    2016-06-01

    This paper explores a method of generating panoramic street strip image map which is called as "Pano-Street" here and contains both sides, ground surface and overhead part of a street with a sequence of 360° panoramic images captured with Point Grey's Ladybug3 mounted on the top of Mitsubishi MMS-X 220 at 2m intervals along the streets in urban environment. On-board GPS/IMU, speedometer and post sequence image analysis technology such as bundle adjustment provided much more accuracy level position and attitude data for these panoramic images, and laser data. The principle for generating panoramic street strip image map is similar to that of the traditional aero ortho-images. A special 3D DEM(3D-Mesh called here) was firstly generated with laser data, the depth map generated from dense image matching with the sequence of 360° panoramic images, or the existing GIS spatial data along the MMS trajectory, then all 360° panoramic images were projected and stitched on the 3D-Mesh with the position and attitude data. This makes it possible to make large scale panoramic street strip image maps for most types of cities, and provides another kind of street view way to view the 360° scene along the street by avoiding the switch of image bubbles like Google Street View and Bing Maps Streetside.

  1. Panoramic camera on the Yutu lunar rover of the Chang'e-3 mission

    NASA Astrophysics Data System (ADS)

    Yang, Jian-Feng; Li, Chun-Lai; Xue, Bin; Ruan, Ping; Gao, Wei; Qiao, Wei-Dong; Lu, Di; Ma, Xiao-Long; Li, Fu; He, Ying-Hong; Li, Ting; Ren, Xin; Yan, Xing-Tao

    2015-11-01

    The Chang'e-3 panoramic camera, which is composed of two cameras with identical functions, performances and interfaces, is installed on the lunar rover mast. It can acquire 3D images of the lunar surface based on the principle of binocular stereo vision. By rotating and pitching the mast, it can take several photographs of the patrol area. After stitching these images, panoramic images of the scenes will be obtained. Thus the topography and geomorphology of the patrol area and the impact crater, as well as the geological structure of the lunar surface, will be analyzed and studied. In addition, it can take color photographs of the lander using the Bayer color coding principle. It can observe the working status of the lander by switching between static image mode and dynamic video mode with automatic exposure time. The focal length of the lens on the panoramic camera is 50 mm and the field of view is 19.7° × 14.5°. Under the best illumination and viewing conditions, the largest signal-to-noise ratio of the panoramic camera is 44 dB. Its static modulation transfer function is 0.33. A large number of ground testing experiments and on-orbit imaging results show that the functional interface of the panoramic camera works normally. The image quality of the panoramic camera is satisfactory. All the performance parameters of the panoramic camera satisfy the design requirements.

  2. Comparison of the diagnostic performance of panoramic and occlusal radiographs in detecting submandibular sialoliths

    PubMed Central

    Kim, Jun Ho; Aoki, Eduardo Massaharu; Abdala-Júnior, Reinaldo; Asaumi, Junichi; Arita, Emiko Saito

    2016-01-01

    Purpose The aim of this study was to assess and compare the diagnostic performance of panoramic and occlusal radiographs in detecting submandibular sialoliths. Materials and Methods A total of 40 patients (20 cases and 20 controls) were included in this retrospective study. Cases were defined as subjects with a submandibular sialolith confirmed by computed tomography (CT), whereas controls did not have any submandibular calcifications. Three observers with different expertise levels assessed panoramic and occlusal radiographs of all subjects for the presence of sialoliths. Intraobserver and interobserver agreement were assessed using the kappa test. Sensitivity, specificity, accuracy, positive and negative predictive values, and the diagnostic odds ratio of panoramic and occlusal radiographs in screening for submandibular sialoliths were calculated for each observer. Results The sensitivity and specificity values for occlusal and panoramic radiographs all ranged from 80% to 100%. The lowest values of sensitivity and specificity observed among the observers were 82.6% and 80%, respectively (P=0.001). Intraobserver and interobserver agreement were higher for occlusal radiographs than for panoramic radiographs, although panoramic radiographs demonstrated a higher overall accuracy. Conclusion Both panoramic and occlusal radiographic techniques displayed satisfactory diagnostic performance and should be considered before using a CT scan to detect submandibular sialoliths. PMID:27358815

  3. Biometric Analysis – A Reliable Indicator for Diagnosing Taurodontism using Panoramic Radiographs

    PubMed Central

    Hegde, Veda; Anegundi, Rajesh Trayambhak; Pravinchandra, K.R.

    2013-01-01

    Background: Taurodontism is a clinical entity with a morpho–anatomical change in the shape of the tooth, which was thought to be absent in modern man. Taurodontism is mostly observed as an isolated trait or a component of a syndrome. Various techniques have been devised to diagnose taurodontism. Aim: The aim of this study was to analyze whether a biometric analysis was useful in diagnosing taurodontism, in radiographs which appeared to be normal on cursory observations. Setting and Design: This study was carried out in our institution by using radiographs which were taken for routine procedures. Material and Methods: In this retrospective study, panoramic radiographs were obtained from dental records of children who were aged between 9–14 years, who did not have any abnormality on cursory observations. Biometric analyses were carried out on permanent mandibular first molar(s) by using a novel biometric method. The values were tabulated and analysed. Statistics: Fischer exact probability test, Chi square test and Chi-square test with Yates correction were used for statistical analysis of the data. Results: Cursory observation did not yield us any case of taurodontism. In contrast, the biometric analysis yielded us a statistically significant number of cases of taurodontism. However, there was no statistically significant difference in the number of cases with taurodontism, which was obtained between the genders and the age group which was considered. Conclusion: Thus, taurodontism was diagnosed on a biometric analysis, which was otherwise missed on a cursory observation. It is therefore necessary from the clinical point of view, to diagnose even the mildest form of taurodontism by using metric analysis rather than just relying on a visual radiographic assessment, as its occurrence has many clinical implications and a diagnostic importance. PMID:24086912

  4. Accuracy of dental age estimation in Venezuelan children: comparison of Demirjian and Willems methods.

    PubMed

    Medina, Aída C; Blanco, Lucila

    2014-01-01

    Dental age is a somatic maturity indicator with importance in clinical and forensic dentistry. The purpose of this study is to compare the applicability of the Demirjian and Willems methods for dental age estimation in a group of Venezuelan children. Panoramic radiographs of 238 Venezuelan children aged 5-13 years were used to assess dental age using the methods described by Demirjian and Willems. Children with unclear panoramic radiographs, dental agenesis, and premature loss of primary teeth were excluded. Mean differences between dental age and chronological age by gender and age groups were estimated (ANOVA, Student tests p = 0.05). For the Demirjian method, the mean difference between dental age and chronological age was 0.62 +/- 0.93 years, statistically significant. The mean overestimation was lower for females than for males (females 0.56 +/- 0.96 years, males 0.67 +/- 0.93 years). For the Willems method, the mean difference between dental age and chronological age was 0.15 +/- 0.97 years, not statistically significant. Accuracy was significantly different between genders, performing best for females (females 0.01 +/- 0.96 years, males 0.29 +/- 0.96 years). The Willems method for age estimation was found to be more accurate than the Demirjian method in this sample of Venezuelan children.

  5. An innovative algorithm for panoramic representation in observation systems

    NASA Astrophysics Data System (ADS)

    Luison, Cristian; Aquilanti, Valeria; Riccobono, Aldo; Liberace, Claudio

    2013-06-01

    This document presents the study and test carried out for the development of an innovative algorithm designed to create a panoramic representation of the scene scanned by observation systems operating with passive sensors. The purpose of the algorithm is to represent 360° of scene using staring sensors mounted on stabilized or semi-stabilized platforms, without requirements on video output, both in terms of the transmission format and in terms of frame rate. The algorithm is real-time and does not require step-and-stare technique or special systems to scan the scene. The architecture of the algorithm requires a very low computational cost for the electronics contained in a Multi-Functional Display (MDP) used in defense applications. The algorithm has been implemented and tested on the JANUS NAVAL system, where the results were very satisfactory. Today, a patent is pendent.

  6. The development of a learning management system for dental radiology education: A technical report

    PubMed Central

    Chang, Hee-Jin; Symkhampha, Khanthaly; Huh, Kyung-Hoe; Yi, Won-Jin; Lee, Sam-Sun; Choi, Soon-Chul

    2017-01-01

    Purpose This study was conducted to suggest the development of a learning management system for dental radiology education using the Modular Object-Oriented Dynamic Learning Environment (Moodle). Materials and Methods Moodle is a well-known and verified open-source software-learning management system (OSS-LMS). The Moodle software was installed on a server computer and customized for dental radiology education. The system was implemented for teaching undergraduate students to diagnose dental caries in panoramic images. Questions were chosen that could assess students' diagnosis ability. Students were given several questions corre-sponding to each of 100 panoramic images. Results The installation and customization of Moodle was feasible, cost-effective, and time-saving. By having students answer questions repeatedly, it was possible to train them to examine panoramic images sequentially and thoroughly. Conclusion Based on its educational efficiency and efficacy, the adaptation of an OSS-LMS in dental school may be highly recommended. The system could be extended to continuing education for dentists. Further studies on the objective evaluation of knowledge acquisition and retention are needed. PMID:28361030

  7. [Panoramic radiograph in edentulous and partially edentulous patients].

    PubMed

    Angulo, F

    1989-01-01

    A group of two hundred patients from the School of Dentistry, UCV were study using panoramic RX, in order to determined the incidence of impacted roots, impacted teeth, radiographic feature (radiolucent and radiopaque) and foreign body. From the 200 patient 118 (59%) were edentulous and 82 (415) partially edentulous, from of clinically point of view; 40 (20%) were male and 160 (80%) female. From the total sample only 77 (38.5%) showed radiographic feature meanwhile 123 (61.5%) had not any present. Only the patients with radiographic feature were considered and the result according the age were the following: 18 patients 20-40 years old (23.4%); 41 patients 41-60 years old (53.2%) and 18 patients 61-80 years old (23.4%). The higher numbers of feature were observed in the range of age 41-60 years old. In relation to the form there was a predominance of diffuse form (53.3%). However, the size was greater of 5 mm. (43.3%). On the other hand, the higher numbers of feature were observed in the area 456 in the mandible (50%). This findings are in agreement with the result found by Jones & et al (1985) (J. Prosthet Dent 53:535-539). This values are in the same range 20-60% founded in other countries. No significant difference were founded between the partially or totally edentulous patients. This work suggest the important of the panoramic RX as a diagnostic aid before a prosthetic treatment.

  8. The algorithm for generation of panoramic images for omnidirectional cameras

    NASA Astrophysics Data System (ADS)

    Lazarenko, Vasiliy P.; Yarishev, Sergey; Korotaev, Valeriy

    2015-05-01

    The omnidirectional cameras are used in areas where large field-of-view is important. Omnidirectional cameras can give a complete view of 360° along one of direction. But the distortion of omnidirectional cameras is great, which makes omnidirectional image unreadable. One way to view omnidirectional images in a readable form is the generation of panoramic images from omnidirectional images. At the same time panorama keeps the main advantage of the omnidirectional image - a large field of view. The algorithm for generation panoramas from omnidirectional images consists of several steps. Panoramas can be described as projections onto cylinders, spheres, cubes, or other surfaces that surround a viewing point. In practice, the most commonly used cylindrical, spherical and cubic panoramas. So at the first step we describe panoramas field-of-view by creating virtual surface (cylinder, sphere or cube) from matrix of 3d points in virtual object space. Then we create mapping table by finding coordinates of image points for those 3d points on omnidirectional image by using projection function. At the last step we generate panorama pixel-by-pixel image from original omnidirectional image by using of mapping table. In order to find the projection function of omnidirectional camera we used the calibration procedure, developed by Davide Scaramuzza - Omnidirectional Camera Calibration Toolbox for Matlab. After the calibration, the toolbox provides two functions which express the relation between a given pixel point and its projection onto the unit sphere. After first run of the algorithm we obtain mapping table. This mapping table can be used for real time generation of panoramic images with minimal cost of CPU time.

  9. Panoramic 3d Vision on the ExoMars Rover

    NASA Astrophysics Data System (ADS)

    Paar, G.; Griffiths, A. D.; Barnes, D. P.; Coates, A. J.; Jaumann, R.; Oberst, J.; Gao, Y.; Ellery, A.; Li, R.

    The Pasteur payload on the ESA ExoMars Rover 2011/2013 is designed to search for evidence of extant or extinct life either on or up to ˜2 m below the surface of Mars. The rover will be equipped by a panoramic imaging system to be developed by a UK, German, Austrian, Swiss, Italian and French team for visual characterization of the rover's surroundings and (in conjunction with an infrared imaging spectrometer) remote detection of potential sample sites. The Panoramic Camera system consists of a wide angle multispectral stereo pair with 65° field-of-view (WAC; 1.1 mrad/pixel) and a high resolution monoscopic camera (HRC; current design having 59.7 µrad/pixel with 3.5° field-of-view) . Its scientific goals and operational requirements can be summarized as follows: • Determination of objects to be investigated in situ by other instruments for operations planning • Backup and Support for the rover visual navigation system (path planning, determination of subsequent rover positions and orientation/tilt within the 3d environment), and localization of the landing site (by stellar navigation or by combination of orbiter and ground panoramic images) • Geological characterization (using narrow band geology filters) and cartography of the local environments (local Digital Terrain Model or DTM). • Study of atmospheric properties and variable phenomena near the Martian surface (e.g. aerosol opacity, water vapour column density, clouds, dust devils, meteors, surface frosts,) 1 • Geodetic studies (observations of Sun, bright stars, Phobos/Deimos). The performance of 3d data processing is a key element of mission planning and scientific data analysis. The 3d Vision Team within the Panoramic Camera development Consortium reports on the current status of development, consisting of the following items: • Hardware Layout & Engineering: The geometric setup of the system (location on the mast & viewing angles, mutual mounting between WAC and HRC) needs to be optimized w

  10. Dose distribution and mapping with 3D imaging presentation in intraoral and panoramic examinations

    NASA Astrophysics Data System (ADS)

    Chen, Hsiu-Ling; Huang, Yung-Hui; Wu, Tung-Hsin; Wang, Shih-Yuan; Lee, Jason J. S.

    2011-10-01

    In current medical imaging applications, high quality images not only provide more diagnostic value for anatomic delineation but also offer functional information for treatment direction. However, this approach would potentially subscribe higher radiation dose in dental radiographies, which has been putatively associated with low-birth-weight during pregnancy, which affects the hypothalamus-pituitary-thyroid axis or thereby directly affects the reproductive organs. The aim of this study was to apply the high resolution 3-D image mapping technique to evaluate radiation doses from the following aspects: (1) verifying operating parameters of dental X-ray units, (2) measuring the leakage radiations and (3) mapping dose with 3-D radiographic imaging to evaluate dose distribution in head and neck regions. From the study results, we found that (1) leakage radiation from X-ray units was about 21.31±15.24 mR/h (<100 mR/h), (2) error of actual tube voltage for 60 kVp setting was from 0.2% to 6.5%, with an average of 2.5% (<7%) and (3) the error of exposure time for a 0.5-1.5 s setting was within 0.7-8.5%, with an average of 7.3% (<10%) error as well. Our 3-D dose mapping demonstrated that dose values were relatively lower in soft tissues and higher in bone surfaces compared with other investigations. Multiple causes could contribute to these variations, including irradiation geometry, image equipment and type of technique applied, etc. From the results, we also observed that larger accumulated doses were presented in certain critical organs, such as salivary gland, thyroid gland and bone marrow. Potential biological affects associated with these findings warrant further investigation.

  11. Radiobiologic risk estimation from dental radiology. Part II. Cancer incidence and fatality

    SciTech Connect

    Underhill, T.E.; Kimura, K.; Chilvarquer, I.; McDavid, W.D.; Langlais, R.P.; Preece, J.W.; Barnwell, G.

    1988-08-01

    With the use of the measured absorbed doses from part I of this article, the specific radiobiologic risk to the patient from (1) five different panoramic machines with rare-earth screens, (2) a 20-film complete-mouth survey with E-speed film, long round cone, (3) a 20-film complete-mouth survey with E-speed film, long rectangular cone, (4) a 4-film interproximal survey with E-speed film, long round cone, and (5) a 4-film interproximal survey with E-speed film, long rectangular cone, was calculated. The estimated risks are expressed in two ways: the probability of radiation-induced cancer in specific organs per million examinations and the probability of expression of a fatal cancer per million examinations. The highest risks calculated were from the complete-mouth survey with the use of round collimation. The lowest risks calculated were from panoramic radiography and four interproximal radiographs with rectangular collimation.

  12. Proton radiography for clinical applications

    NASA Astrophysics Data System (ADS)

    Talamonti, C.; Reggioli, V.; Bruzzi, M.; Bucciolini, M.; Civinini, C.; Marrazzo, L.; Menichelli, D.; Pallotta, S.; Randazzo, N.; Sipala, V.; Cirrone, G. A. P.; Petterson, M.; Blumenkrantz, N.; Feldt, J.; Heimann, J.; Lucia, D.; Seiden, A.; Williams, D. C.; Sadrozinski, H. F.-W.; Bashkirov, V.; Schulte, R.

    2010-01-01

    Proton imaging is not yet applied as a clinical routine, although its advantages have been demonstrated. In the context of quality assurance in proton therapy, proton images can be used to verify the correct positioning of the patient and to control the range of protons. Proton computed tomography (pCT) is a 3D imaging method appropriate for planning and verification of proton radiation treatments, because it allows evaluating the distributions of proton stopping power within the tissues and can be directly utilized when the patient is in the actual treatment position. The aim of the PRoton IMAging experiment, supported by INFN, and the PRIN 2006 project, supported by MIUR, is to realize a proton computed radiography (pCR) prototype for reconstruction of proton images from a single projection in order to validate the technique with pre-clinical studies and, eventually, to conceive the configuration of a complete pCT system. A preliminary experiment performed at the 250 MeV proton synchrotron of Loma Linda University Medical Center (LLUMC) allowed acquisition of experimental data before the completion of PRIMA project's prototype. In this paper, the results of the LLUMC experiment are reported and the reconstruction of proton images of two phantoms is discussed.

  13. Mobile real time radiography system

    SciTech Connect

    Vigil, J.; Taggart, D.; Betts, S.

    1997-11-01

    A 450-keV Mobile Real Time Radiography (RTR) System was delivered to Los Alamos National Laboratory (LANL) in January 1996. It was purchased to inspect containers of radioactive waste produced at (LANL). Since its delivery it has been used to radiograph more than 600 drums of radioactive waste at various LANL sites. It has the capability of inspecting waste containers of various sizes from <1-gal. buckets up to standard waste boxes (SWB, dimensions 54.5 in. x 71 in. x 37 in.). It has three independent x-ray acquisition formats. The primary system used is a 12- in. image intensifier, the second is a 36-in. linear diode array (LDA) and the last is an open system. It is fully self contained with on board generator, HVAC, and a fire suppression system. It is on a 53-ft long x 8-ft. wide x 14-ft. high trailer that can be moved over any highway requiring only an easily obtainable overweight permit because it weights {approximately}38 tons. It was built to conform to industry standards for a cabinet system which does not require an exclusion zone. The fact that this unit is mobile has allowed us to operate where the waste is stored, rather than having to move the waste to a fixed facility.

  14. Thorium-uranium fission radiography

    NASA Technical Reports Server (NTRS)

    Haines, E. L.; Weiss, J. R.; Burnett, D. S.; Woolum, D. S.

    1976-01-01

    Results are described for studies designed to develop routine methods for in-situ measurement of the abundance of Th and U on a microscale in heterogeneous samples, especially rocks, using the secondary high-energy neutron flux developed when the 650 MeV proton beam of an accelerator is stopped in a 42 x 42 cm diam Cu cylinder. Irradiations were performed at three different locations in a rabbit tube in the beam stop area, and thick metal foils of Bi, Th, and natural U as well as polished silicate glasses of known U and Th contents were used as targets and were placed in contact with mica which served as a fission track detector. In many cases both bare and Cd-covered detectors were exposed. The exposed mica samples were etched in 48% HF and the fission tracks counted by conventional transmitted light microscopy. Relative fission cross sections are examined, along with absolute Th track production rates, interaction tracks, and a comparison of measured and calculated fission rates. The practicality of fast neutron radiography revealed by experiments to data is discussed primarily for Th/U measurements, and mixtures of other fissionable nuclei are briefly considered.

  15. Dental sepsis.

    PubMed

    Mueller, P O; Lowder, M Q

    1998-08-01

    Dental sepsis or periapical abscess formation constitutes a large percentage of dental conditions that afflict horses. Dental sepsis occurs when the pulp chamber of the tooth is exposed to the oral cavity or external environment, allowing bacterial localization with resulting infection. Although acute, primary, septic pulpitis in horses is rare, dental sepsis often results from colonization of the pulp chamber with pathogenic bacteria secondary to maleruption or impaction of teeth with secondary alveolar bone lysis, primary fractures of the tooth, mandible, or maxilla, periodontal disease, or infundibular necrosis. The sequela to pulpal infection are extensions into the periradicular tissues and mandibular or maxillary periapical abscess formation.

  16. Microbiological contamination in digital radiography: evaluation at the radiology clinic of an educational institution.

    PubMed

    Malta, Cristiana P; Damasceno, Naiana Nl; Ribeiro, Rosangela A; Silva, Carolina Sf; Devito, Karina L

    2016-12-01

    The aim of this study was to evaluate the contamination rate of intra and extraoral digital X ray equipment in a dental radiology clinic at a public educational institution. Samples were collected on three different days, at two times in the day: in the morning, before attending patients, and at the end of the day, after appointment hours and before cleaning and disinfection procedures. Samples were collected from the periapical X-ray machine (tube head, positioning device, control panel and activator button), the panoramic X- ray machine (temporal support, bite block, control panel and activator button), the intraoral digital system (sensor), and the digital system computers (keyboard and mouse). The samples were seeded in different culture media, incubated, and colony forming units (CFU/mL) counted. Biochemical tests were performed for suspected colonies of Staphylococcus, Streptococcus and Gramnegative bacilli (GNB). Fungi were visually differentiated into filamentous fungi and yeasts. The results indicated the growth of fungi and Staphylococcus fromall sampling locations. GNB growth was observed from all sites sampled from the intraoral X-ray equipment. On the panoramic unit, GNB growth was observed in samples from activator button, keyboard and mouse. In general, a higher number of CFU/mL was present before use. It can be concluded that more stringent protocols are needed to control infection and prevent X-ray exams from acting as vehicle for cross contamination.

  17. Photographic technology development project: Timber typing in the Tahoe Basin using high altitude panoramic photography

    NASA Technical Reports Server (NTRS)

    Ward, J. F.

    1981-01-01

    Procedures were developed and tested for using KA-80A optical bar camera panoramic photography for timber typing forest land and classifying nonforest land. The study area was the south half of the Lake Tahoe Basin Management Unit. Final products from this study include four timber type map overlays on 1:24,000 orthophoto maps. The following conclusions can be drawn from this study: (1) established conventional timber typing procedures can be used on panoramic photography if the necessary equipment is available, (2) The classification and consistency results warrant further study in using panoramic photography for timber typing; and (3) timber type mapping can be done as fast or faster with panoramic photography than with resource photography while maintaining comparable accuracy.

  18. Muon radiography for exploration of Mars geology

    NASA Astrophysics Data System (ADS)

    Kedar, S.; Tanaka, H. K. M.; Naudet, C. J.; Jones, C. E.; Plaut, J. P.; Webb, F. H.

    2013-06-01

    Muon radiography is a technique that uses naturally occurring showers of muons (penetrating particles generated by cosmic rays) to image the interior of large-scale geological structures in much the same way as standard X-ray radiography is used to image the interior of smaller objects. Recent developments and application of the technique to terrestrial volcanoes have demonstrated that a low-power, passive muon detector can peer deep into geological structures up to several kilometers in size, and provide crisp density profile images of their interior at ten meter scale resolution. Preliminary estimates of muon production on Mars indicate that the near horizontal Martian muon flux, which could be used for muon radiography, is as strong or stronger than that on Earth, making the technique suitable for exploration of numerous high priority geological targets on Mars. The high spatial resolution of muon radiography also makes the technique particularly suited for the discovery and delineation of Martian caverns, the most likely planetary environment for biological activity. As a passive imaging technique, muon radiography uses the perpetually present background cosmic ray radiation as the energy source for probing the interior of structures from the surface of the planet. The passive nature of the measurements provides an opportunity for a low power and low data rate instrument for planetary exploration that could operate as a scientifically valuable primary or secondary instrument in a variety of settings, with minimal impact on the mission's other instruments and operation.

  19. Muon radiography for exploration of Mars geology

    NASA Astrophysics Data System (ADS)

    Kedar, S.; Tanaka, H. K. M.; Naudet, C. J.; Jones, C. E.; Plaut, J. P.; Webb, F. H.

    2012-10-01

    Muon radiography is a technique that uses naturally occurring showers of muons (penetrating particles generated by cosmic rays) to image the interior of large scale geological structures in much the same way as standard X-ray radiography is used to image the interior of smaller objects. Recent developments and application of the technique to terrestrial volcanoes have demonstrated that a low-power, passive muon detector can peer deep into geological structures up to several kilometers in size, and provide crisp density profile images of their interior at ten meter scale resolution. Preliminary estimates of muon production on Mars indicate that the near horizontal Martian muon flux, which could be used for muon radiography, is as strong or stronger than that on Earth, making the technique suitable for exploration of numerous high priority geological targets on Mars. The high spatial resolution of muon radiography also makes the technique particularly suited for the discovery and delineation of Martian caverns, the most likely planetary environment for biological activity. As a passive imaging technique, muon radiography uses the perpetually present background cosmic ray radiation as the energy source for probing the interior of structures from the surface of the planet. The passive nature of the measurements provides an opportunity for a low power and low data rate instrument for planetary exploration that could operate as a scientifically valuable primary or secondary instrument in a variety of settings, with minimal impact on the mission's other instruments and operation.

  20. Dental Hygienist.

    ERIC Educational Resources Information Center

    Ohio State Univ., Columbus. Center on Education and Training for Employment.

    This document, which is designed for use in developing a tech prep competency profile for the occupation of dental hygienist, lists technical competencies and competency builders for 13 units pertinent to the health technologies cluster in general and 9 units specific to the occupation of dental hygienist. The following skill areas are covered in…

  1. Dental Implants.

    PubMed

    Zohrabian, Vahe M; Sonick, Michael; Hwang, Debby; Abrahams, James J

    2015-10-01

    Dental implants restore function to near normal in partially or completely edentulous patients. A root-form implant is the most frequently used type of dental implant today. The basis for dental implants is osseointegration, in which osteoblasts grow and directly integrate with the surface of titanium posts surgically embedded into the jaw. Radiologic assessment is critical in the preoperative evaluation of the dental implant patient, as the exact height, width, and contour of the alveolar ridge must be determined. Moreover, the precise locations of the maxillary sinuses and mandibular canals, as well as their relationships to the site of implant surgery must be ascertained. As such, radiologists must be familiar with implant design and surgical placement, as well as augmentation procedures utilized in those patients with insufficient bone in the maxilla and mandible to support dental implants.

  2. Dental MRI using wireless intraoral coils

    PubMed Central

    Ludwig, Ute; Eisenbeiss, Anne-Katrin; Scheifele, Christian; Nelson, Katja; Bock, Michael; Hennig, Jürgen; von Elverfeldt, Dominik; Herdt, Olga; Flügge, Tabea; Hövener, Jan-Bernd

    2016-01-01

    Currently, the gold standard for dental imaging is projection radiography or cone-beam computed tomography (CBCT). These methods are fast and cost-efficient, but exhibit poor soft tissue contrast and expose the patient to ionizing radiation (X-rays). The need for an alternative imaging modality e.g. for soft tissue management has stimulated a rising interest in dental magnetic resonance imaging (MRI) which provides superior soft tissue contrast. Compared to X-ray imaging, however, so far the spatial resolution of MRI is lower and the scan time is longer. In this contribution, we describe wireless, inductively-coupled intraoral coils whose local sensitivity enables high resolution MRI of dental soft tissue. In comparison to CBCT, a similar image quality with complementary contrast was obtained ex vivo. In-vivo, a voxel size of the order of 250∙250∙500 μm3 was achieved in 4 min only. Compared to dental MRI acquired with clinical equipment, the quality of the images was superior in the sensitive volume of the coils and is expected to improve the planning of interventions and monitoring thereafter. This method may enable a more accurate dental diagnosis and avoid unnecessary interventions, improving patient welfare and bringing MRI a step closer to becoming a radiation-free alternative for dental imaging. PMID:27021387

  3. Dental MRI using wireless intraoral coils

    NASA Astrophysics Data System (ADS)

    Ludwig, Ute; Eisenbeiss, Anne-Katrin; Scheifele, Christian; Nelson, Katja; Bock, Michael; Hennig, Jürgen; von Elverfeldt, Dominik; Herdt, Olga; Flügge, Tabea; Hövener, Jan-Bernd

    2016-03-01

    Currently, the gold standard for dental imaging is projection radiography or cone-beam computed tomography (CBCT). These methods are fast and cost-efficient, but exhibit poor soft tissue contrast and expose the patient to ionizing radiation (X-rays). The need for an alternative imaging modality e.g. for soft tissue management has stimulated a rising interest in dental magnetic resonance imaging (MRI) which provides superior soft tissue contrast. Compared to X-ray imaging, however, so far the spatial resolution of MRI is lower and the scan time is longer. In this contribution, we describe wireless, inductively-coupled intraoral coils whose local sensitivity enables high resolution MRI of dental soft tissue. In comparison to CBCT, a similar image quality with complementary contrast was obtained ex vivo. In-vivo, a voxel size of the order of 250•250•500 μm3 was achieved in 4 min only. Compared to dental MRI acquired with clinical equipment, the quality of the images was superior in the sensitive volume of the coils and is expected to improve the planning of interventions and monitoring thereafter. This method may enable a more accurate dental diagnosis and avoid unnecessary interventions, improving patient welfare and bringing MRI a step closer to becoming a radiation-free alternative for dental imaging.

  4. Using Google Streetview Panoramic Imagery for Geoscience Education

    NASA Astrophysics Data System (ADS)

    De Paor, D. G.; Dordevic, M. M.

    2014-12-01

    Google Streetview is a feature of Google Maps and Google Earth that allows viewers to switch from map or satellite view to 360° panoramic imagery recorded close to the ground. Most panoramas are recorded by Google engineers using special cameras mounted on the roofs of cars. Bicycles, snowmobiles, and boats have also been used and sometimes the camera has been mounted on a backpack for off-road use by hikers and skiers or attached to scuba-diving gear for "Underwater Streetview (sic)." Streetview panoramas are linked together so that the viewer can change viewpoint by clicking forward and reverse buttons. They therefore create a 4-D touring effect. As part of the GEODE project ("Google Earth for Onsite and Distance Education"), we are experimenting with the use of Streetview imagery for geoscience education. Our web-based test application allows instructors to select locations for students to study. Students are presented with a set of questions or tasks that they must address by studying the panoramic imagery. Questions include identification of rock types, structures such as faults, and general geological setting. The student view is locked into Streetview mode until they submit their answers, whereupon the map and satellite views become available, allowing students to zoom out and verify their location on Earth. Student learning is scaffolded by automatic computerized feedback. There are lots of existing Streetview panoramas with rich geological content. Additionally, instructors and members of the general public can create panoramas, including 360° Photo Spheres, by stitching images taken with their mobiles devices and submitting them to Google for evaluation and hosting. A multi-thousand-dollar, multi-directional camera and mount can be purchased from DIY-streetview.com. This allows power users to generate their own high-resolution panoramas. A cheaper, 360° video camera is soon to be released according to geonaute.com. Thus there are opportunities for

  5. Mars Exploration Rover Athena Panoramic Camera (Pancam) investigation

    USGS Publications Warehouse

    Bell, J.F.; Squyres, S. W.; Herkenhoff, K. E.; Maki, J.N.; Arneson, H.M.; Brown, D.; Collins, S.A.; Dingizian, A.; Elliot, S.T.; Hagerott, E.C.; Hayes, A.G.; Johnson, M.J.; Johnson, J. R.; Joseph, J.; Kinch, K.; Lemmon, M.T.; Morris, R.V.; Scherr, L.; Schwochert, M.; Shepard, M.K.; Smith, G.H.; Sohl-Dickstein, J. N.; Sullivan, R.J.; Sullivan, W.T.; Wadsworth, M.

    2003-01-01

    The Panoramic Camera (Pancam) investigation is part of the Athena science payload launched to Mars in 2003 on NASA's twin Mars Exploration Rover (MER) missions. The scientific goals of the Pancam investigation are to assess the high-resolution morphology, topography, and geologic context of each MER landing site, to obtain color images to constrain the mineralogic, photometric, and physical properties of surface materials, and to determine dust and aerosol opacity and physical properties from direct imaging of the Sun and sky. Pancam also provides mission support measurements for the rovers, including Sun-finding for rover navigation, hazard identification and digital terrain modeling to help guide long-term rover traverse decisions, high-resolution imaging to help guide the selection of in situ sampling targets, and acquisition of education and public outreach products. The Pancam optical, mechanical, and electronics design were optimized to achieve these science and mission support goals. Pancam is a multispectral, stereoscopic, panoramic imaging system consisting of two digital cameras mounted on a mast 1.5 m above the Martian surface. The mast allows Pancam to image the full 360?? in azimuth and ??90?? in elevation. Each Pancam camera utilizes a 1024 ?? 1024 active imaging area frame transfer CCD detector array. The Pancam optics have an effective focal length of 43 mm and a focal ratio f/20, yielding an instantaneous field of view of 0.27 mrad/pixel and a field of view of 16?? ?? 16??. Each rover's two Pancam "eyes" are separated by 30 cm and have a 1?? toe-in to provide adequate stereo parallax. Each eye also includes a small eight position filter wheel to allow surface mineralogic studies, multispectral sky imaging, and direct Sun imaging in the 400-1100 nm wavelength region. Pancam was designed and calibrated to operate within specifications on Mars at temperatures from -55?? to +5??C. An onboard calibration target and fiducial marks provide the capability

  6. Mars Exploration Rover Athena Panoramic Camera (Pancam) investigation

    NASA Astrophysics Data System (ADS)

    Bell, J. F.; Squyres, S. W.; Herkenhoff, K. E.; Maki, J. N.; Arneson, H. M.; Brown, D.; Collins, S. A.; Dingizian, A.; Elliot, S. T.; Hagerott, E. C.; Hayes, A. G.; Johnson, M. J.; Johnson, J. R.; Joseph, J.; Kinch, K.; Lemmon, M. T.; Morris, R. V.; Scherr, L.; Schwochert, M.; Shepard, M. K.; Smith, G. H.; Sohl-Dickstein, J. N.; Sullivan, R. J.; Sullivan, W. T.; Wadsworth, M.

    2003-11-01

    The Panoramic Camera (Pancam) investigation is part of the Athena science payload launched to Mars in 2003 on NASA's twin Mars Exploration Rover (MER) missions. The scientific goals of the Pancam investigation are to assess the high-resolution morphology, topography, and geologic context of each MER landing site, to obtain color images to constrain the mineralogic, photometric, and physical properties of surface materials, and to determine dust and aerosol opacity and physical properties from direct imaging of the Sun and sky. Pancam also provides mission support measurements for the rovers, including Sun-finding for rover navigation, hazard identification and digital terrain modeling to help guide long-term rover traverse decisions, high-resolution imaging to help guide the selection of in situ sampling targets, and acquisition of education and public outreach products. The Pancam optical, mechanical, and electronics design were optimized to achieve these science and mission support goals. Pancam is a multispectral, stereoscopic, panoramic imaging system consisting of two digital cameras mounted on a mast 1.5 m above the Martian surface. The mast allows Pancam to image the full 360° in azimuth and +/-90° in elevation. Each Pancam camera utilizes a 1024 × 1024 active imaging area frame transfer CCD detector array. The Pancam optics have an effective focal length of 43 mm and a focal ratio of f/20, yielding an instantaneous field of view of 0.27 mrad/pixel and a field of view of 16° × 16°. Each rover's two Pancam ``eyes'' are separated by 30 cm and have a 1° toe-in to provide adequate stereo parallax. Each eye also includes a small eight position filter wheel to allow surface mineralogic studies, multispectral sky imaging, and direct Sun imaging in the 400-1100 nm wavelength region. Pancam was designed and calibrated to operate within specifications on Mars at temperatures from -55° to +5°C. An onboard calibration target and fiducial marks provide the

  7. Mosquitoes, flies and dental cavities: Dr. Howard Riley Raper's public campaign to prevent toothache.

    PubMed

    Christen, Arden G; Christen, Joan A

    2010-01-01

    Dr. Howard Riley Raper (1886-1978) was an early oral health pioneer and dental roentgenology faculty member of the Indiana Dental College (IDC) who single-handedly introduced key concepts in radiology to dentistry. Due to his efforts, IDC became in 1910-11 the first dental school to have a regular course in dental radiology. Virtually all American dental schools soon added this subject to their regular curriculum. Raper's text, Elementary and Dental Radiography (1913) became the first comprehensive student textbook of dental X-ray diagnosis. In his 1933 Blue Book entitled, The New Aim in the Care of the Teeth, Raper elaborated upon his mission to prevent caries, by comparing the insidious damages of tooth decay with the threat of insect-borne disease.

  8. Mobile waste inspection real time radiography system

    SciTech Connect

    Vigil, J.; Taggart, D.; Betts, S.; Rael, C.; Martinez, F.; Mendez, J.

    1995-10-01

    The 450-KeV Mobile Real Time Radiography System was designed and purchased to inspect containers of radioactive waste produced at Los Alamos National Laboratory (LANL). The Mobile Real Time Radiography System has the capability of inspecting waste containers of various sizes from 5-gal. buckets to standard waste boxes (SWB, dimensions 54.5 in. x 71 in. x 37 in.). The fact that this unit is mobile makes it an attractive alternative to the costly road closures associated with moving waste from the waste generator to storage or disposal facilities.

  9. Proton Radiography: Its uses and Resolution Scaling

    SciTech Connect

    Mariam, Fesseha G.

    2012-08-09

    Los Alamos National Laboratory has used high energy protons as a probe in flash radiography for over a decade. In this time the proton radiography project has used 800 MeV protons, provided by the LANSCE accelerator facility at LANL, to diagnose over five-hundred dynamic experiments in support of stockpile stewardship programs as well as basic materials science. Through this effort significant experience has been gained in using charged particles as direct radiographic probes to diagnose transient systems. The results of this experience will be discussed through the presentation of data from experiments recently performed at the LANL pRad.

  10. An investigation of potential applications of intensifying screens in intraoral radiography

    SciTech Connect

    Stephens, R.G.; Kogon, S.L.; Reid, J.A.

    1982-11-01

    In medicine, the somewhat degraded image from the screen/film system is accepted for most diagnostic purposes in the interest of radiation thrift. In dentistry, however, the superb image resolution and sharpness of the radiation-intensive, direct-exposure film is the standard for intraoral radiography. There may be occasions in dental practice where such quality is not necessary, thus making the high level of exposure difficult to justify. In a laboratory study, screen-type radiographs were effectively substituted for ultraspeed film in the monitoring stages of endodontic therapy and as posttreatment films in operative dentistry. Even with a slow system, the radiation exposure was one sixteenth of the usual periapical dose. If clinical trials support these conclusions, only the lack of a practical periapical cassette limits the application of this significant method of radiation reduction to dental practice.

  11. Fraudulent use of digital radiography: methods to detect and protect digital radiographs.

    PubMed

    Calberson, Filip L G; Hommez, Geert M; De Moor, Roeland J

    2008-05-01

    Digital radiography has become an indispensable diagnostic tool in dentistry today. To improve vision and diagnosis, dental x-ray software allows image enhancement (eg, adjusting color, density, sharpness, brightness, or contrast). Exporting digital radiographs to a file format compatible with commercial graphic software increases chances that information can be altered, added, or removed in an unethical manner. Dental radiographs are easily duplicated, stored, or distributed in digital format. It is difficult to guarantee the authenticity of digital images, which is especially important in insurance or juridic cases. Image-enhancement features applied to digital radiographs allow mishandling or potential abuse. This has been illustrated by several recently published studies. A standard authentication procedure for digital radiographs is needed. A number of manipulated radiographic images are presented to show concerns about security, reliability, and the potential for fraud. Antitampering techniques and methods of detecting manipulations in digital medical images are discussed.

  12. Californium-252: A New Isotopic Source for Neutron Radiography

    SciTech Connect

    Reinig, W.C.

    2001-08-29

    This report discusses a new isotopic source for neutron radiography, Californium-252. Nuclear reactors are the usual source of neutrons for radiography, primarily because of their intense neutron beams. If neutron radiography is to have widespread use, intense transportable neutron sources are required that can be used in plants, in laboratories and in the field.

  13. Digital radiography. A comparison with modern conventional imaging

    PubMed Central

    Bansal, G J

    2006-01-01

    The development of computed radiography over the past two decades has transformed radiological imaging. The radiology departments in the 21st century will look very different from those in the preceding period. In this review, the development of digital radiography is presented with a description of its various forms and a comparison with screen film radiography. PMID:16822918

  14. Real-time panoramic infrared imaging system based on FPGA

    NASA Astrophysics Data System (ADS)

    Zhang, Hao-Jun; Shen, Yong-Ge

    2010-11-01

    During the past decades, signal processing architecture, which is based on FPGA, conventional DSP processor and host computer, is popular for infrared or other electro-optical systems. With the increasing processing requirement, the former architecture starts to show its limitation in several respects. This paper elaborates a solution based on FPGA for panoramic imaging system as our first step of upgrading the processing module to System-on-Chip (SoC) solution. Firstly, we compare this new architecture with the traditional to show its superiority mainly in the video processing ability, reduction in the development workload and miniaturization of the system architecture. Afterwards, this paper provides in-depth description of this imaging system, including the system architecture and its function, and addresses several related issues followed by the future development. FPGA has developed so rapidly during the past years, not only in silicon device but also in the design flow and tools. In the end, we briefly present our future system development and introduce those new design tools to make up the limitation of the traditional FPGA design methodology. The advanced design flow through Simulink and Xilinx System Generator (Sysgen) has been elaborated, which enables engineers to develop sophisticated DSP algorithms and implement them in FPGA more efficiently. It is believed that this new design approach can shorten system design cycle by allowing rapid prototyping and refining design process.

  15. Visually Coupled Systems (VCS): The Virtual Panoramic Display (VPD) System

    NASA Technical Reports Server (NTRS)

    Kocian, Dean F.

    1992-01-01

    The development and impact is described of new visually coupled system (VCS) equipment designed to support engineering and human factors research in the military aircraft cockpit environment. VCS represents an advanced man-machine interface (MMI). Its potential to improve aircrew situational awareness seems enormous, but its superiority over the conventional cockpit MMI has not been established in a conclusive and rigorous fashion. What has been missing is a 'systems' approach to technology advancement that is comprehensive enough to produce conclusive results concerning the operational viability of the VCS concept and verify any risk factors that might be involved with its general use in the cockpit. The advanced VCS configuration described here, was ruggedized for use in military aircraft environments and was dubbed the Virtual Panoramic Display (VPD). It was designed to answer the VCS portion of the systems problem, and is implemented as a modular system whose performance can be tailored to specific application requirements. The overall system concept and the design of the two most important electronic subsystems that support the helmet mounted parts, a new militarized version of the magnetic helmet mounted sight and correspondingly similar helmet display electronics, are discussed in detail. Significant emphasis is given to illustrating how particular design features in the hardware improve overall system performance and support research activities.

  16. Assessment of panoramic and conventional night vision goggles

    NASA Astrophysics Data System (ADS)

    Thorndycraft, David

    2003-09-01

    This paper presents results obtained during a flight evaluation of Night Vision Devices (NVDs) equipped with a symbology injection capability. The NVDs used represented both conventional and wide (Panoramic) Field of View Night Vision Goggle (PNVG) systems. The evaluation was conducted at the National Research Council of Canada Bell 205 Flying Simulator under the auspices of the Technical Co-operation Programme. 6 Pilots from 4 nations participated in the trial and some 36 hours of flight data and pilot performance were recorded. The metrics used to evaluate Pilot performance included conventional Visual Cue Ratings, estimates of workload, and objective measures obtained through advanced data-analysis techniques. The trial used both conventional ADS-33D manoeuvres and a novel 'Racetrack" course. The paper concludes that although PNVG compare favourably with NVGs the clarity of image currently available in standard NVGs surpasses that of the PNVG and negates some of the advantages gained by the wider Field of View. The manoeuvres favoured by the NVG include those where a high degree of foveal attention demanding processing is being performed, for example navigation tasks. The manoeuvres favoured by the PNVG include those where a more automatic peripheral processing is being performed, for example in reducing drift in the hover.

  17. Third of three panoramic views of North Base as seen ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Third of three panoramic views of North Base as seen from top of Building 4500, Control Tower. View looks west (268°) at ancillary structures surrounding Building 4505. In immediate foreground is Building 4499 Loading Ramp. To the far upper left is Building 4497 Guard House, adjacent to Building 4496 Security Facility. At the extreme right of the view is the chimney and western corner of Building 4505 to which is attached a large light-colored wing used as offices and workspaces; to the immediate southwest of this wing stands Building 4498 Supply Warehouse. In the background, just above Building 4498 in view, stands Building 4494 Cafeteria. The round drum to the right of Building 4494 is Building 4503, a 500,000 gallon water tank which supplies the firefighting system; to the immediate right of the tank is Building 4504 Deluge Water Pumping Station which contains large pumps for firefighting. Just visible above the water tank is Building 4493 Gymnasium. - Edwards Air Force Base, North Base, North Base Road, Boron, Kern County, CA

  18. Sensitometric characteristics of dental xeroradiography

    SciTech Connect

    Gratt, B.M.; Sickles, E.A.

    1983-11-01

    Dental xeroradiography is a high-quality intraoral imaging system which provides a potentially convenient, rapid, low-dose alternative to conventional film radiography. In this study the sensitometric properties of dental xeroradiography were investigated via assessment of high- and low-contrast xeroradiographic processor settings, transmission versus reflection densitometry, reciprocity-law failure, and kVp (tube voltage) plate dependence. Findings of the study indicated that imaging at high-contrast processor settings results in greater dynamic range but less exposure latitude than imaging at low-contrast processor settings. Determination of characteristic curves demonstrated greater contrast in reflection mode than imaging by transillumination for all but the very densest of images (greater than 1.6 O.D.). There was also little difference in characteristic curves produced from 50 to 90 kVp, indicating that the xeroradiographic plate exhibits a relatively constant sensitivity over the tube voltages tested if exposure is expressed in roentgens. Finally, no substantial reciprocity-law failure was observed for dental xeroradiography over a clinically relevant range of exposure times.

  19. Dental OCT

    NASA Astrophysics Data System (ADS)

    Wilder-Smith, Petra; Otis, Linda; Zhang, Jun; Chen, Zhongping

    This chapter describes the applications of OCT for imaging in vivo dental and oral tissue. The oral cavity is a diverse environment that includes oral mucosa, gingival tissues, teeth and their supporting structures. Because OCT can image both hard and soft tissues of the oral cavity at high resolution, it offers the unique capacity to identity dental disease before destructive changes have progressed. OCT images depict clinically important anatomical features such as the location of soft tissue attachments, morphological changes in gingival tissue, tooth decay, enamel thickness and decay, as well as the structural integrity of dental restorations. OCT imaging allows for earlier intervention than is possible with current diagnostic modalities.

  20. The significance of cone beam computed tomography for the visualization of anatomical variations and lesions in the maxillary sinus for patients hoping to have dental implant-supported maxillary restorations in a private dental office in Japan

    PubMed Central

    2014-01-01

    Objectives The purpose of the present study was to elucidate the significance of cone bean computed tomography (CBCT) for patients hoping to undergo implant-supported restorations of the maxilla. Therefore, two studies were planned. One was to compare the prevalence of anatomic variations and lesions in the maxillary sinus on CBCT of patients hoping to undergo implant-supported restorations of the maxilla with that in patients with other chief complaints in a private dental office in Japan. The other study was to elucidate the limitations of panoramic radiographs in the detection of anatomic variations and lesions in the maxillary sinus. Study design Sixty-one pairs of panoramic radiographs and CBCT were retrospectively analyzed in two groups of patients, those who hoped to undergo implant-supported restorations in the maxilla (Implant group) and those who did not (Non-implant group). The presence of anatomic variations and lesions in the maxillary sinus were analyzed. Results The detection rate of mucosal thickening was significantly higher in the Implant group than in the Non-implant group. The detection rates for the features analyzed were significantly lower on panoramic radiographs. In particular, the detection rates of internal and anterior locations of some features were noticeably lower on panoramic radiographs. A significant relationship was found between the change in the detection rate on panoramic radiographs and the widths of mucosal thickening or the lengths of the major axis of SOLs in the maxillary sinus. If the width of mucosal thickening or the length of the major axis of SOLs was <3 mm or <4 mm, respectively, the detection rate on panoramic radiographs was significantly decreased. Conclusion CBCT is important for patients hoping to undergo implant-supported restorations of the maxilla because of the mucosal thickening in the maxillary sinus in such patients and their lower detection rates on panoramic radiographs. PMID:24884983

  1. Retromolar Canal Associated with Age, Side, Sex, Bifid Mandibular Canal, and Accessory Mental Foramen in Panoramic Radiographs of Brazilians

    PubMed Central

    Capote, Ticiana Sidorenko de O.; Gonçalves, Marcela de Almeida; Campos, Juliana Álvares Duarte Bonini

    2015-01-01

    Background. The retromolar canal (RMC) is an anatomical variation that can cause complications in dental procedures. Method. The RMC was evaluated according to age, sex, and presence of accessory mandibular canal and accessory mental foramen, on both sides in 500 panoramic radiographs, belonging to individuals at the age of 7 to 20 years. The associations of interest were studied through Fisher's Exact Test and Pearson's Chi-Square Test, and the correlation was studied through Pearson's Correlation Coefficient (r). The significance level used was 5%. Results. The RMC was observed in 44 radiographs (8.8%), and out of those 24 were females. There was no statistically significant association between the RMC and age (p > 0.05; Fisher's Exact Test), sex (p = 0.787; Pearson's Chi-Square Test), amount of mandibular canals and mental foramina, on both sides (p > 0.05; Pearson's Chi-Square Test). There was a significant association between RMC and side, the higher frequency of the canal being on the right side (p < 0.05; Fisher's Exact Test). Conclusions. Despite the low occurrence of the RMC, its identification and the verification of its dimensions and path are relevant, mainly in cases when anesthetic and surgical procedures can present failures or difficulties. PMID:26366300

  2. Retromolar Canal Associated with Age, Side, Sex, Bifid Mandibular Canal, and Accessory Mental Foramen in Panoramic Radiographs of Brazilians.

    PubMed

    Capote, Ticiana Sidorenko de O; Gonçalves, Marcela de Almeida; Campos, Juliana Álvares Duarte Bonini

    2015-01-01

    Background. The retromolar canal (RMC) is an anatomical variation that can cause complications in dental procedures. Method. The RMC was evaluated according to age, sex, and presence of accessory mandibular canal and accessory mental foramen, on both sides in 500 panoramic radiographs, belonging to individuals at the age of 7 to 20 years. The associations of interest were studied through Fisher's Exact Test and Pearson's Chi-Square Test, and the correlation was studied through Pearson's Correlation Coefficient (r). The significance level used was 5%. Results. The RMC was observed in 44 radiographs (8.8%), and out of those 24 were females. There was no statistically significant association between the RMC and age (p > 0.05; Fisher's Exact Test), sex (p = 0.787; Pearson's Chi-Square Test), amount of mandibular canals and mental foramina, on both sides (p > 0.05; Pearson's Chi-Square Test). There was a significant association between RMC and side, the higher frequency of the canal being on the right side (p < 0.05; Fisher's Exact Test). Conclusions. Despite the low occurrence of the RMC, its identification and the verification of its dimensions and path are relevant, mainly in cases when anesthetic and surgical procedures can present failures or difficulties.

  3. 2D and 3D visualization methods of endoscopic panoramic bladder images

    NASA Astrophysics Data System (ADS)

    Behrens, Alexander; Heisterklaus, Iris; Müller, Yannick; Stehle, Thomas; Gross, Sebastian; Aach, Til

    2011-03-01

    While several mosaicking algorithms have been developed to compose endoscopic images of the internal urinary bladder wall into panoramic images, the quantitative evaluation of these output images in terms of geometrical distortions have often not been discussed. However, the visualization of the distortion level is highly desired for an objective image-based medical diagnosis. Thus, we present in this paper a method to create quality maps from the characteristics of transformation parameters, which were applied to the endoscopic images during the registration process of the mosaicking algorithm. For a global first view impression, the quality maps are laid over the panoramic image and highlight image regions in pseudo-colors according to their local distortions. This illustration supports then surgeons to identify geometrically distorted structures easily in the panoramic image, which allow more objective medical interpretations of tumor tissue in shape and size. Aside from introducing quality maps in 2-D, we also discuss a visualization method to map panoramic images onto a 3-D spherical bladder model. Reference points are manually selected by the surgeon in the panoramic image and the 3-D model. Then the panoramic image is mapped by the Hammer-Aitoff equal-area projection onto the 3-D surface using texture mapping. Finally the textured bladder model can be freely moved in a virtual environment for inspection. Using a two-hemisphere bladder representation, references between panoramic image regions and their corresponding space coordinates within the bladder model are reconstructed. This additional spatial 3-D information thus assists the surgeon in navigation, documentation, as well as surgical planning.

  4. Registered Dental Hygienists as Dental Students.

    ERIC Educational Resources Information Center

    Arnold, Janet; Shugars, Daniel A.

    1985-01-01

    Surveys conducted to (1) investigate why dental hygienists choose to become dentists, (2) evaluate their success in dental school, (3) assess the experience of those who had entered dental school, and (4) gauge the level of interest among dental hygienists in applying to dental school are discussed. (Author/MLW)

  5. Dental sealants

    MedlinePlus

    ... few quick steps. There is no drilling or scraping of the molars. Your dentist will: Clean the ... Dental sealants. Updated October 19, 2016. ADA.org Web site. www.ada.org/en/member-center/oral- ...

  6. Dental Sealants

    MedlinePlus

    ... form does not collect any actual information. External Web Site Policy This graphic notice ( ) means that you are ... the link. Home Contact Us Viewers and Players Site Map FOIA Web Policies Privacy Policy National Institute of Dental and ...

  7. 75 FR 16511 - Pentron Clinical Technologies, a Wholly-Owned Subsidiary of Kerr Dental/Sybron Dental...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-04-01

    ... such as dental prosthetics, dental composites, dental impressions, dental adhesives, and other dental... prosthetics, dental composites, dental impressions, dental adhesives, and other dental materials to...

  8. Safety Testing of Industrial Radiography Devices

    SciTech Connect

    Trapp, D.J.

    1999-09-29

    The Nuclear Regulatory Commission contracted the Savannah River Technology Center to verify the relevancy of the 10 CFR Part 34 requirements for the normal use of portable gamma radiography systems and to propose recommendations for changes or modifications to the requirements.

  9. INDUSTRIAL RADIOGRAPHY COURSE, INSTRUCTORS' GUIDE. VOLUME 2.

    ERIC Educational Resources Information Center

    Texas A and M Univ., College Station. Engineering Extension Service.

    INFORMATION RELATIVE TO THE LESSON PLANS IN "INDUSTRIAL RADIOGRAPHY COURSE, INSTRUCTOR'S GUIDE, VOLUME I" (VT 003 565) IS PRESENTED ON 52 INFORMATION SHEETS INCLUDING THE SUBJECTS SHIELDING EQUATIONS AND LOGARITHMS, METAL PROPERTIES, FIELD TRIP INSTRUCTIONS FOR STUDENTS, WELDING SYMBOLS AND SIZES, SAMPLE REPORT FORMS, AND TYPICAL SHIPPING…

  10. Film radiography -- The lone star of quality

    SciTech Connect

    Kochakian, R.

    1995-12-31

    In this year of 1995, 100 years of x-ray photography are being celebrated. The reason film radiography is still the number one NDT technique is because of its quality. In this paper the author discusses: (1) fundamentals of image quality and (2) status of new draft ASRM film system classification standard.

  11. Advances in diagnostic imaging for pathologic conditions of the jaws.

    PubMed

    Benson, Byron W; Flint, Diane J; Liang, Hui; Opatowsky, Michael J

    2014-12-01

    Advances in dental and maxillofacial imaging are delineated along with the advantages and disadvantages of each imaging modality. The imaging modalities that are included are intraoral radiography, panoramic radiography, cone-beam computed tomography, multidetector computed tomography, magnetic resonance imaging, nuclear medicine, and ultrasound.

  12. Dental Emergencies

    PubMed Central

    Symington, J.M.

    1988-01-01

    Patients with dental emergencies sometimes present to their physician. This article outlines the role of the physician in the management of dental patients who have suffered traumatic injuries, postoperative hemorrhage, pain, and infection. It deals with those difficulties for which the physician may easily prescribe treatment and outlines the treatment that would be undertaken by a dentist who receives such a patient on referral. PMID:21253249

  13. Panoramic Views of the Landing site from Sagan Memorial Station

    NASA Technical Reports Server (NTRS)

    1997-01-01

    Each of these panoramic views is a controlled mosaic of approximately 300 IMP images covering 360 degrees of azimuth and elevations from approximately 4 degrees above the horizon to 45 degrees below it. Simultaneous adjustment of orientations of all images has been performed to minimize discontinuities between images. Mosaics have been highpass-filtered and contrast-enhanced to improve discrimination of details without distorting relative colors overall.

    TOP IMAGE: Enhanced true-color image created from the 'Gallery Pan' sequence, acquired on sols 8-10 so that local solar time increases nearly continuously from about 10:00 at the right edge to about 12:00 at the left. Mosaics of images obtained by the right camera through 670 nm, 530 nm, and 440 nm filters were used as red, green and blue channels. Grid ticks indicate azimuth clockwise from north in 30 degree increments and elevation in 15 degree increments.

    BOTTOM IMAGE: Anaglyphic stereoimage created from the 'monster pan' sequence, acquired in four sections between about 8:30 and 15:00 local solar time on sol 3. Mosaics of images obtained through the 670 nm filter (left camera) and 530 and 440 nm filters (right camera) were used where available. At the top and bottom, left- and right-camera 670 nm images were used. Part of the northern horizon was not imaged because of the tilt of the lander. This image may be viewed stereoscopically through glasses with a red filter for the left eye and a cyan filter for the right eye.

    NOTE: original caption as published in Science Magazine

    Mars Pathfinder is the second in NASA's Discovery program of low-cost spacecraft with highly focused science goals. The Jet Propulsion Laboratory, Pasadena, CA, developed and manages the Mars Pathfinder mission for NASA's Office of Space Science, Washington, D.C. JPL is a division of the California Institute of Technology (Caltech).

  14. Line-Based Registration of Panoramic Images and LiDAR Point Clouds for Mobile Mapping

    PubMed Central

    Cui, Tingting; Ji, Shunping; Shan, Jie; Gong, Jianya; Liu, Kejian

    2016-01-01

    For multi-sensor integrated systems, such as the mobile mapping system (MMS), data fusion at sensor-level, i.e., the 2D-3D registration between an optical camera and LiDAR, is a prerequisite for higher level fusion and further applications. This paper proposes a line-based registration method for panoramic images and a LiDAR point cloud collected by a MMS. We first introduce the system configuration and specification, including the coordinate systems of the MMS, the 3D LiDAR scanners, and the two panoramic camera models. We then establish the line-based transformation model for the panoramic camera. Finally, the proposed registration method is evaluated for two types of camera models by visual inspection and quantitative comparison. The results demonstrate that the line-based registration method can significantly improve the alignment of the panoramic image and the LiDAR datasets under either the ideal spherical or the rigorous panoramic camera model, with the latter being more reliable. PMID:28042855

  15. Study on image processing of panoramic X-ray using deviation improvement software.

    PubMed

    Kim, Tae-Gon; Lee, Yang-Sun; Kim, Young-Pyo; Park, Yong-Pil; Cheon, Min-Woo

    2014-01-01

    Utilization of panoramic X-ray device is getting wider. Panoramic X-ray has low resolution than general X-ray device and it occurs to distortion by deviation of image synthesis. Due to structural problems, it has been used restrictively to identify of tooth structure, not for whole head. Therefore, it designed and produced panoramic X-ray device which is possible to diagnostic coverage can be extended and had to be adjusted interval control between X-ray generator and image processing for whole of Maxillofacia's diagnosis. Produced panoramic X-ray device is composed basically of short image synthesis. In addition, it was confirmed the results by used the device which was applied deviation of the brightness of the image, filter to improve the location of the deviation and interpolation method. In this study, it was used 13 images including the front. It occurs to brightness deviation, position deviation, and geometric correction when synthesis of image, but it had been solved by deviation improvement software and a change of CCD camera's scan line which is used for image acquisition. Therefore, it confirmed expansion possibility of utilization range to commonly used panoramic X-ray device.

  16. Line-Based Registration of Panoramic Images and LiDAR Point Clouds for Mobile Mapping.

    PubMed

    Cui, Tingting; Ji, Shunping; Shan, Jie; Gong, Jianya; Liu, Kejian

    2016-12-31

    For multi-sensor integrated systems, such as the mobile mapping system (MMS), data fusion at sensor-level, i.e., the 2D-3D registration between an optical camera and LiDAR, is a prerequisite for higher level fusion and further applications. This paper proposes a line-based registration method for panoramic images and a LiDAR point cloud collected by a MMS. We first introduce the system configuration and specification, including the coordinate systems of the MMS, the 3D LiDAR scanners, and the two panoramic camera models. We then establish the line-based transformation model for the panoramic camera. Finally, the proposed registration method is evaluated for two types of camera models by visual inspection and quantitative comparison. The results demonstrate that the line-based registration method can significantly improve the alignment of the panoramic image and the LiDAR datasets under either the ideal spherical or the rigorous panoramic camera model, with the latter being more reliable.

  17. Oral and dental imaging equipment and techniques for small animals.

    PubMed

    Coffman, Curt R; Brigden, Glenn M

    2013-05-01

    In the diagnosis and treatment of oral and dental diseases in dogs and cats, digital intraoral radiography offers many advantages over the use of standard dental radiographic film, including rapid image generation, easier exposure correction, enhancement, and paperless storage. Digital image receptors can be divided into 2 main types, direct digital systems using charged coupled devices and complementary metal oxide semiconductor sensors, and indirect digital systems using phosphor plates with a computerized scanner. Each system is paired with a computer software system to allow handling, visualization, enhancement, sharing, and archiving of the images.

  18. Acquired Wharton's duct stenosis after dental radiographs treated with sialendoscopy.

    PubMed

    Kieliszak, Christopher R; Shokri, Tom; Joshi, Arjun S

    2015-04-26

    Salivary gland trauma may result in ductal stenosis and chronic sialadenitis. We describe a case of an 81-year-old woman with a history of intermittent left submandibular swelling that began after recent dental examination and radiographs. Diagnostic sialendoscopy was performed and demonstrated a near complete distal stenosis. It was determined that trauma experienced during dental radiography may have resulted in the patient's ductal obstruction and subsequent sialadenitis. This case illustrates an unusual presentation of non-sialolith-related ductal obstruction in the submandibular gland, treated with sialendoscopic-assisted sialodochoplasty.

  19. Use of Digital Technology and Support Software Programs in the Private Dental Offices in Nevada

    ERIC Educational Resources Information Center

    Fattore-Bruno, LaDeane

    2009-01-01

    The purpose of this survey research was to determine the diffusion of digital radiography, the electronic oral health record (EOHR), digital intraoral photography, and diagnosis and clinical decision-making support software into the dental offices of Nevada. A cross-sectional survey design was utilized with a random sample of 600 Nevada dentists.…

  20. [Absorbed doses in dental radiology].

    PubMed

    Bianchi, S D; Roccuzzo, M; Albrito, F; Ragona, R; Anglesio, S

    1996-01-01

    The growing use of dento-maxillo-facial radiographic examinations has been accompanied by the publication of a large number of studies on dosimetry. A thorough review of the literature is presented in this article. Most studies were carried out on tissue equivalent skull phantoms, while only a few were in vivo. The aim of the present study was to evaluate in vivo absorbed doses during Orthopantomography (OPT). Full Mouth Periapical Examination (FMPE) and Intraoral Tube Panoramic Radiography (ITPR). Measurements were made on 30 patients, reproducing clinical conditions, in 46 anatomical sites, with 24 intra- and 22 extra-oral thermoluminiscent dosimeters (TLDS). The highest doses were measured, in orthopantomography, at the right mandibular angle (1899 mu Gy) in FMPE on the right naso-labial fold (5640 mu Gy and in ITPR on the palatal surface of the left second upper molar (1936 mu Gy). Intraoral doses ranged from 21 mu Gy, in orthopantomography, to 4494 mu Gy in FMPE. Standard errors ranged from 142% in ITPR to 5% in orthopantomography. The highest rate of standard errors was found in FMPE and ITPR. The data collected in this trial are in agreement with others in major literature reports. Disagreements are probably due to different exam acquisition and data collections. Such differences, presented comparison in several sites, justify lower doses in FMPE and ITPR. Advantages and disadvantages of in vivo dosimetry of the maxillary region are discussed, the former being a close resemblance to clinical conditions of examination and the latter the impossibility of collecting values in depth of tissues. Finally, both ITPR and FMPE required lower doses than expected, and can be therefore reconsidered relative to their radiation risk.

  1. Biologically Motivated Novel Localization Paradigm by High-Level Multiple Object Recognition in Panoramic Images

    PubMed Central

    Kim, Sungho; Shim, Min-Sheob

    2015-01-01

    This paper presents the novel paradigm of a global localization method motivated by human visual systems (HVSs). HVSs actively use the information of the object recognition results for self-position localization and for viewing direction. The proposed localization paradigm consisted of three parts: panoramic image acquisition, multiple object recognition, and grid-based localization. Multiple object recognition information from panoramic images is utilized in the localization part. High-level object information was useful not only for global localization, but also for robot-object interactions. The metric global localization (position, viewing direction) was conducted based on the bearing information of recognized objects from just one panoramic image. The feasibility of the novel localization paradigm was validated experimentally. PMID:26457323

  2. Assessing the current state of dental informatics in saudi arabia: the new frontier.

    PubMed

    Al-Nasser, Lubna; Al-Ehaideb, Ali; Househ, Mowafa

    2014-01-01

    Dental informatics is an emerging field that has the potential to transform the dental profession. This study aims to summarize the current applications of dental informatics in Saudi Arabia and to identify the challenges facing expansion of dental informatics in the Saudi context. Search for published articles and specialized forum entries was conducted, as well as interviews with dental professionals familiar with the topic. Results indicated that digital radiography/analysis and administrative management of dental practice are the commonest applications used. Applications in Saudi dental education included: web-based learning systems, computer-based assessments and virtual technology for clinical skills' teaching. Patients' education software, electronic dental/oral health records and the potential of dental research output from electronic databases are yet to be achieved in Saudi Arabia. Challenges facing Saudi dental informatics include: lack of IT infrastructure/support, social acceptability and financial cost. Several initiatives are taken towards the research in dental informatics. Still, more investments are needed to fully achieve the potential of various application of informatics in dental education, practice and research.

  3. Does cone-beam CT alter treatment plans? Comparison of preoperative implant planning using panoramic versus cone-beam CT images

    PubMed Central

    Guerrero, Maria Eugenia; Noriega, Jorge; Castro, Carmen

    2014-01-01

    Purpose The present study was performed to compare the planning of implant placement based on panoramic radiography (PAN) and cone-beam computed tomography (CBCT) images, and to study the impact of the image dataset on the treatment planning. Materials and Methods One hundred five partially edentulous patients (77 males, 28 females, mean age: 46 years, range: 26-67 years) seeking oral implant rehabilitation were referred for presurgical imaging. Imaging consisted of PAN and CBCT imaging. Four observers planned implant treatment based on the two-dimensional (2D) image datasets and at least one month later on the three-dimensional (3D) image dataset. Apart from presurgical diagnostic and dimensional measurement tasks, the observers needed to indicate the surgical confidence levels and assess the image quality in relation to the presurgical needs. Results All observers confirmed that both imaging modalities (PAN and CBCT) gave similar values when planning implant diameter. Also, the results showed no differences between both imaging modalities for the length of implants with an anterior location. However, significant differences were found in the length of implants with a posterior location. For implant dimensions, longer lengths of the implants were planned with PAN, as confirmed by two observers. CBCT provided images with improved scores for subjective image quality and surgical confidence levels. Conclusion Within the limitations of this study, there was a trend toward PAN-based preoperative planning of implant placement leading towards the use of longer implants within the posterior jaw bone. PMID:24944961

  4. Evaluation by dental cone-beam computed tomography of the incidence and sites of branches of the inferior dental canal that supply mandibular third molars.

    PubMed

    Ogawa, A; Fukuta, Y; Nakasato, H; Nakasato, S

    2016-12-01

    Our aim was to assess the incidence and anatomical site of branches of the inferior dental canal that supply mandibular third molars using dental cone-beam computed tomography (CT). We evaluated the incidence and diameter of branches of the inferior dental canal using 272 cone-beam CT mandibular scans from 172 patients referred for imaging before the extraction of impacted mandibular third molars. We found three typical branching patterns from the inferior dental canal in the third molar region: the retromolar canal (in the retromolar triangle), the dental canal (that courses directly beneath the socket of the third molar), and the accessory canal (that courses through the socket and leads from the inferior dental canal to a bony ridge). The incidences of retromolar, dental, and accessory canals were 75 (28%), 223 (82%), and 21 (8%), respectively, with mean diameters of 0.9 (0.4), 0.7 (0.5), and 1.1 (0.4) mm, respectively. Operative injury to the neurovascular contents within the branches of the inferior dental canal can lead to excessive bleeding and postoperative paraesthesia, so identification of its branches on preoperative cone-beam CT images may prove useful during extraction of impacted mandibular third molars or when harvesting bone blocks from the region of mandibular third molars. We also describe two cases of branches detected on panoramic and cone-beam CT images that prompted this research.

  5. Registration of Vehicle-Borne Point Clouds and Panoramic Images Based on Sensor Constellations.

    PubMed

    Yao, Lianbi; Wu, Hangbin; Li, Yayun; Meng, Bin; Qian, Jinfei; Liu, Chun; Fan, Hongchao

    2017-04-11

    A mobile mapping system (MMS) is usually utilized to collect environmental data on and around urban roads. Laser scanners and panoramic cameras are the main sensors of an MMS. This paper presents a new method for the registration of the point clouds and panoramic images based on sensor constellation. After the sensor constellation was analyzed, a feature point, the intersection of the connecting line between the global positioning system (GPS) antenna and the panoramic camera with a horizontal plane, was utilized to separate the point clouds into blocks. The blocks for the central and sideward laser scanners were extracted with the segmentation feature points. Then, the point clouds located in the blocks were separated from the original point clouds. Each point in the blocks was used to find the accurate corresponding pixel in the relative panoramic images via a collinear function, and the position and orientation relationship amongst different sensors. A search strategy is proposed for the correspondence of laser scanners and lenses of panoramic cameras to reduce calculation complexity and improve efficiency. Four cases of different urban road types were selected to verify the efficiency and accuracy of the proposed method. Results indicate that most of the point clouds (with an average of 99.7%) were successfully registered with the panoramic images with great efficiency. Geometric evaluation results indicate that horizontal accuracy was approximately 0.10-0.20 m, and vertical accuracy was approximately 0.01-0.02 m for all cases. Finally, the main factors that affect registration accuracy, including time synchronization amongst different sensors, system positioning and vehicle speed, are discussed.

  6. Handling qualities comparison of panoramic night vision goggles and 46-deg. night vision goggles

    NASA Astrophysics Data System (ADS)

    Craig, Gregory; Jennings, Sion; Thorndycraft, David

    2003-09-01

    Night Vision Goggles allow the user to see in extremely low illumination levels but the visual information provided by Night Vision Goggles has a limited field-of-view that diminishes handling-qualities in the night flying environment. Panoramic Night Vision Goggles were designed to correct this problem by providing a 100° horizontal field-of-view which is larger than currently used Night Vision Goggles. However, in the first generation Panoramic Night Vision Goggle, the improved field of view came at the cost of diminished resolution, contrast and central overlap area when compared to conventional Night Vision Goggles. This paper describes an evaluation that was conducted in the variable stability NRC Bell-205 helicopter to examine the influence on system handling qualities of the Panoramic Night Vision Goggles and a 46° field-of-view UK Night Vision Goggle. Five pilots flew the ADS-33D hover, sidestep and pirouette manoeuvres in simulated night conditions with the UK Night Vision Goggle and the Panoramic Night Vision Goggle. Both subjective and objective measures of task performance were obtained. Handling-qualities ratings showed the pirouette was performed better with the Panoramic Night Vision Goggles. This was the only manoeuvre where there was a clear-cut handling qualities improvement when using the Panoramic Night Vision Goggles. Other manoeuvres such as the sidestep and hover did not show definitive handling qualities rating differences between the two Night Vision Goggle types. The flight test results were interpreted in terms of the design trade-offs of the two night vision systems, with regard to the different acuity, binocular overlaps and fields-of-view.

  7. Quantitative studies on inner interfaces in conical metal joints using hard x-ray inline phase contrast radiography

    NASA Astrophysics Data System (ADS)

    Zabler, S.; Rack, T.; Rack, A.; Nelson, K.

    2010-10-01

    Quantitative investigation of micrometer and submicrometer gaps between joining metal surfaces is applied to conical plug-socket connections in dental titanium implants. Microgaps of widths well beyond the resolving power of industrial x-ray systems are imaged by synchrotron phase contrast radiography. Furthermore, by using an analytical model for the relatively simple sample geometry and applying it to numerical forward simulations of the optical Fresnel propagation, we show that quantitative measurements of the microgap width down to 0.1 μm are possible. Image data recorded at the BAMline (BESSY-II light source, Germany) are presented, with the resolving power of the imaging system being 4 μm in absorption mode and ˜14 μm in phase contrast mode (z2=0.74 m). Thus, phase contrast radiography, combined with numerical forward simulations, is capable of measuring the widths of gaps that are two orders of magnitude thinner than the conventional detection limit.

  8. Dental Calculus Arrest of Dental Caries

    PubMed Central

    Keyes, Paul H.; Rams, Thomas E.

    2016-01-01

    Background An inverse relationship between dental calculus mineralization and dental caries demineralization on teeth has been noted in some studies. Dental calculus may even form superficial layers over existing dental caries and arrest their progression, but this phenomenon has been only rarely documented and infrequently considered in the field of Cariology. To further assess the occurrence of dental calculus arrest of dental caries, this study evaluated a large number of extracted human teeth for the presence and location of dental caries, dental calculus, and dental plaque biofilms. Materials and methods A total of 1,200 teeth were preserved in 10% buffered formal saline, and viewed while moist by a single experienced examiner using a research stereomicroscope at 15-25× magnification. Representative teeth were sectioned and photographed, and their dental plaque biofilms subjected to gram-stain examination with light microscopy at 100× magnification. Results Dental calculus was observed on 1,140 (95%) of the extracted human teeth, and no dental carious lesions were found underlying dental calculus-covered surfaces on 1,139 of these teeth. However, dental calculus arrest of dental caries was found on one (0.54%) of 187 evaluated teeth that presented with unrestored proximal enamel caries. On the distal surface of a maxillary premolar tooth, dental calculus mineralization filled the outer surface cavitation of an incipient dental caries lesion. The dental calculus-covered carious lesion extended only slightly into enamel, and exhibited a brown pigmentation characteristic of inactive or arrested dental caries. In contrast, the tooth's mesial surface, without a superficial layer of dental calculus, had a large carious lesion going through enamel and deep into dentin. Conclusions These observations further document the potential protective effects of dental calculus mineralization against dental caries. PMID:27446993

  9. Spectral Skyline Separation: Extended Landmark Databases and Panoramic Imaging

    PubMed Central

    Differt, Dario; Möller, Ralf

    2016-01-01

    databases, increasing, due to the increased variety of ground objects, the validity of our findings for novel environments. Third, we collected omnidirectional images, as often used for visual navigation tasks, of skylines using an UV-reflective hyperbolic mirror. We could show that “local” separation techniques can be adapted to the use of panoramic images by splitting the image into segments and finding individual thresholds for each segment. Contrarily, this is not possible for ‘global’ separation techniques. PMID:27690053

  10. Spectral Skyline Separation: Extended Landmark Databases and Panoramic Imaging.

    PubMed

    Differt, Dario; Möller, Ralf

    2016-09-29

    , increasing, due to the increased variety of ground objects, the validity of our findings for novel environments. Third, we collected omnidirectional images, as often used for visual navigation tasks, of skylines using an UV-reflective hyperbolic mirror. We could show that "local" separation techniques can be adapted to the use of panoramic images by splitting the image into segments and finding individual thresholds for each segment. Contrarily, this is not possible for 'global' separation techniques.

  11. Monte Carlo calculation for microplanar beam radiography.

    PubMed

    Company, F Z; Allen, B J; Mino, C

    2000-09-01

    In radiography the scattered radiation from the off-target region decreases the contrast of the target image. We propose that a bundle of collimated, closely spaced, microplanar beams can reduce the scattered radiation and eliminate the effect of secondary electron dose, thus increasing the image dose contrast in the detector. The lateral and depth dose distributions of 20-200 keV microplanar beams are investigated using the EGS4 Monte Carlo code to calculate the depth doses and dose profiles in a 6 cm x 6 cm x 6 cm tissue phantom. The maximum dose on the primary beam axis (peak) and the minimum inter-beam scattered dose (valley) are compared at different photon energies and the optimum energy range for microbeam radiography is found. Results show that a bundle of closely spaced microplanar beams can give superior contrast imaging to a single macrobeam of the same overall area.

  12. Contrast enhancement in microplanar beam radiography.

    PubMed

    Company, F Z; Allen, B J; Mino, C

    1999-12-01

    In x-ray radiography, the target produces a useful shadow from absorption of the primary beam, while the scattered radiation into the off-target region decreases the contrast of the target image. A bundle of closely spaced microplanar beams can reduce the scattered radiation and give superior image contrast compared with a single macrobeam of the same dimensions. To further reduce the scattered radiation and increase the image contrast, we place an air gap between the tissue phantom and the detector. The primary and scattered photon flux of a single microplanar beam is measured as a function of thickness inside the phantom and in the air gap. Results show that a bundle of closely spaced, microplanar beams increase the image contrast by 22% and a 2 cm air gap decreases the scattered photon flux by about half, improving the contrast by an additional 16%. Thus an overall improvement of 41% in contrast can be achieved with microplanar beam radiography.

  13. A system for fast neutron radiography

    SciTech Connect

    Klann, R.T.

    1996-05-01

    A system has been designed and a neutron generator installed to perform fast neutron radiography. With this sytem, objects as small as a coin or as large as a waste drum can be radiographed. The neutron source is an MF Physics A-711 neutron generator which produces 3x10{sup 10} neutrons/second with an average energy of 14.5 MeV. The radiography system uses x-ray scintillation screens and film in commercially available cassettes. The cassettes have been modified to include a thin sheet of plastic to convert neutrons to protons through elastic scattering from hydrogen and other low Z materials in the plastic. For film densities from 1.8 to 3.0, exposures range from 1.9x10{sup 7} to 3.8x10{sup 8} n/cm{sup 2} depending on the type of screen and film.

  14. A Comparison of the AVS-9 and the Panoramic Night Vision Goggles During Rotorcraft Hover and Landing

    NASA Technical Reports Server (NTRS)

    Szoboszlay, Zoltan; Haworth, Loran; Simpson, Carol

    2000-01-01

    A flight test was conducted to assess any differences in pilot-vehicle performance and pilot opinion between the use of a current generation night vision goggle (the AVS-9) and one variant of the prototype panoramic night vision goggle (the PNVGII). The panoramic goggle has more than double the horizontal field-of-view of the AVS-9, but reduced image quality. Overall the panoramic goggles compared well to the AVS-9 goggles. However, pilot comment and data are consistent with the assertion that some of the benefits of additional field-of-view with the panoramic goggles were negated by the reduced image quality of the particular variant of the panoramic goggles tested.

  15. Dental Caries

    PubMed Central

    Burgess, Ralph C.

    1988-01-01

    Dental caries is one of the most prevalent diseases afflicting mankind. It reached a peak in the 1950s but has been declining drastically in recent years in children and young adults. This article describes the three contributing factors in dental caries: microbial plaque, tooth susceptibility, and diet, and discusses practical preventive measures which help to reduce caries incidence. Some of these, such as vaccines and antimicrobial varnishes, are still in the research stages, while others, such as sucrose substitutes, low-calorie sweeteners, and limitation of frequency of sugar snacks are well established and can be promoted by family physicians. PMID:21253193

  16. Digital radiography: Present detectors and future developments

    SciTech Connect

    Perez-Mendez, V.

    1990-08-01

    Present detectors for digital radiography are of two classes: real time detectors and storage (non real time) types. Present real time detectors consist of image intensifier tubes with an internal cesium iodide layer x-ray converter. Non real time detectors involve linear sweep arrays or storage detectors such as film. Future detectors discussed here can be of both types utilizing new technologies such as hydrogenated amorphous silicon photodiode arrays coupled to thin film transistor arrays. 17 refs., 10 figs.

  17. Proton Radiography Peers into Metal Solidification

    DOE PAGES

    Clarke, Amy J.; Imhoff, Seth D.; Gibbs, Paul J.; ...

    2013-06-19

    Historically, metals are cut up and polished to see the structure and to infer how processing influences the evolution. We can now peer into a metal during processing without destroying it using proton radiography. Understanding the link between processing and structure is important because structure profoundly affects the properties of engineering materials. Synchrotron x-ray radiography has enabled real-time glimpses into metal solidification. However, x-ray energies favor the examination of small volumes and low density metals. In this study, we use high energy proton radiography for the first time to image a large metal volume (>10,000 mm3) during melting and solidification.more » We also show complementary x-ray results from a small volume (<1mm3), bridging four orders of magnitude. In conclusion, real-time imaging will enable efficient process development and the control of the structure evolution to make materials with intended properties; it will also permit the development of experimentally informed, predictive structure and process models.« less

  18. Newer imaging methods in chest radiography.

    PubMed

    Wandtke, J C

    1990-01-01

    In recent years the application of computers to chest radiography has resulted in a wide variety of innovative research. Major research efforts have resulted in the development of new types of x-ray detectors, such as storage phosphor technology, for use with computers. Storage phosphor imaging is one of the most promising new techniques, and almost 100 systems have been installed worldwide. Radiologists are quickly evaluating the image quality provided by this new detector system, which has the potential to improve image quality. It has wide latitude and is coupled with a computer to perform image processing. Another promising technology, originally studied in the form of scan equalization radiography, is now commercially available in the form of advanced multiple-beam equalization radiography. This film technique uses computers to modulate the x-ray exposure to take maximum advantage of the imaging capabilities of radiographic film. Digital solid-state detectors have been studied in conjunction with computerized image enhancement systems. These currently show improvement in nodule detection and quantification of the calcium content of a lesion. Application of large image intensifiers to a digital image system is being studied, but there are currently limitations on spatial resolution.

  19. Proton Radiography Peers into Metal Solidification

    SciTech Connect

    Clarke, Amy J.; Imhoff, Seth D.; Gibbs, Paul J.; Cooley, Jason C.; Morris, Christopher; Merrill, Frank E.; Hollander, Brian J.; Mariam, Fesseha G.; Ott, Thomas J.; Barker, Martha R.; Tucker, Tim J.; Lee, Wah-Keat; Fezzaa, Kamel; Deriy, Alex; Patterson, Brian M.; Clarke, Kester D.; Montalvo, Joel D.; Field, Robert D.; Thoma, Dan J.; Smith, James L.; Teter, David F.

    2013-06-19

    Historically, metals are cut up and polished to see the structure and to infer how processing influences the evolution. We can now peer into a metal during processing without destroying it using proton radiography. Understanding the link between processing and structure is important because structure profoundly affects the properties of engineering materials. Synchrotron x-ray radiography has enabled real-time glimpses into metal solidification. However, x-ray energies favor the examination of small volumes and low density metals. In this study, we use high energy proton radiography for the first time to image a large metal volume (>10,000 mm3) during melting and solidification. We also show complementary x-ray results from a small volume (<1mm3), bridging four orders of magnitude. In conclusion, real-time imaging will enable efficient process development and the control of the structure evolution to make materials with intended properties; it will also permit the development of experimentally informed, predictive structure and process models.

  20. Dual energy scanning beam X-radiography

    NASA Astrophysics Data System (ADS)

    Wojcik, Randolph Frank

    Dual energy X-radiography is a method first developed in the mid-1970's by which one uses the information contained in the energy spectrum of the transmitted X-ray flux through an object. With this information one can distinguish the types of materials present in a radiograph and thus allow a computer to subtract them from the image enhancing the contrast of the remaining materials. Using this method, one can see details, which would have been hidden by overlying structures of other materials such as seen in radiographs of parts, made up of mixtures of metals and composites. There is also great interest in this technique for medical imaging of the chest where images of the organs are significantly improved by subtracting the bones. However, even with the enhanced capabilities realized with this technique, the majority of X-radiography systems only measures the bulk transmitted X-ray intensity and ignores the information contained in the energy spectrum. This is due to the added expense, time requirements, and registration problems incurred using standard radiographic methods to obtain dual energy radiographs. This dissertation describes a novel method which overcomes these problems and allows one to perform inexpensive, near real time, single shot dual energy X-radiography. The work of this thesis resulted in US patent #5,742,660.

  1. Impact of digital radiography on clinical workflow.

    PubMed

    May, G A; Deer, D D; Dackiewicz, D

    2000-05-01

    It is commonly accepted that digital radiography (DR) improves workflow and patient throughput compared with traditional film radiography or computed radiography (CR). DR eliminates the film development step and the time to acquire the image from a CR reader. In addition, the wide dynamic range of DR is such that the technologist can perform the quality-control (QC) step directly at the modality in a few seconds, rather than having to transport the newly acquired image to a centralized QC station for review. Furthermore, additional workflow efficiencies can be achieved with DR by employing tight radiology information system (RIS) integration. In the DR imaging environment, this provides for patient demographic information to be automatically downloaded from the RIS to populate the DR Digital Imaging and Communications in Medicine (DICOM) image header. To learn more about this workflow efficiency improvement, we performed a comparative study of workflow steps under three different conditions: traditional film/screen x-ray, DR without RIS integration (ie, manual entry of patient demographics), and DR with RIS integration. This study was performed at the Cleveland Clinic Foundation (Cleveland, OH) using a newly acquired amorphous silicon flat-panel DR system from Canon Medical Systems (Irvine, CA). Our data show that DR without RIS results in substantial workflow savings over traditional film/screen practice. There is an additional 30% reduction in total examination time using DR with RIS integration.

  2. Emergency skull radiography: the effect of restrictive criteria on skull radiography and CT use

    SciTech Connect

    Baker, S.R.; Gaylord, G.M.; Lantos, G.; Tabaddor, K.; Gallagher, E.J.

    1985-08-01

    A prospective study was performed to determine the effect of restrictive criteria on the use of emergency skull radiography and computed tomography (CT) of the head. Emergency skull radiography required the completion of a special requisition form. Emergency CT of the head was done at the request of senior consultants and was available on a full-time basis. Over 1 year, 2758 skull studies were performed, a decrease of 39.1% when compared with the year before restrictive criteria were instituted, during which 4587 skull examinations were done. In the same period, the number of emergency CT scans of the head increased by 45.7%, from 471 in the control year to 686 in the experimental year. With the use of restrictive criteria, a net savings of $164,000 was achieved. Our results suggest that the use of restrictive criteria is a cost-effective means of limiting skull radiography when CT of the head is readily available.

  3. An automatic and effective tooth isolation method for dental radiographs

    NASA Astrophysics Data System (ADS)

    Lin, P.-L.; Huang, P.-W.; Cho, Y. S.; Kuo, C.-H.

    2013-03-01

    Tooth isolation is a very important step for both computer-aided dental diagnosis and automatic dental identification systems, because it will directly affect the accuracy of feature extraction and, thereby, the final results of both types of systems. This paper presents an effective and fully automatic tooth isolation method for dental X-ray images, which contains up-per-lower jaw separation, single tooth isolation, over-segmentation verification, and under-segmentation detection. The upper-lower jaw separation mechanism is based on a gray-scale integral projection to avoid possible information loss and incorporates with the angle adjustment to handle skewed images. In a single tooth isolation, an adaptive windowing scheme for locating gap valleys is proposed to improve the accuracy. In over-segmentation, an isolation-curve verification scheme is proposed to remove excessive curves; and in under-segmentation, a missing-teeth detection scheme is proposed. The experimental results demonstrate that our method achieves the accuracy rates of 95.63% and 98.71% for the upper and lower jaw images, respectively, from the test database of 60 bitewing dental radiographs, and performs better for images with severe teeth occlusion, excessive dental works, and uneven illumination than that of Nomir and Abdel-Mottaleb's method. The method without upper-lower jaw separation step also works well for panoramic and periapical images.

  4. Chondrosarcoma of the maxilla: panoramic radiographic and computed tomographic with multiplanar reconstruction findings.

    PubMed

    Hayt, M W; Becker, L; Katz, D S

    1998-03-01

    Chondrosarcomas are extremely rare tumors of which approximately 10% are found in the maxillofacial region. In this report, we present the imaging findings of a maxillary chondrosarcoma on a panoramic radiograph of the jaws and computed tomography with multiplanar reconstructions. We recommend the latter as an excellent way to image evolving or suspected lesions of the maxilla, particularly for surgical treatment planning.

  5. 75 FR 76444 - Environmental Impact Statement (EIS) for Construction and Operation of a Panoramic Survey...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-12-08

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF DEFENSE Department of the Air Force Environmental Impact Statement (EIS) for Construction and Operation of a Panoramic Survey Telescope and Rapid Response System (Pan-STARRS) at the Summit of Mauna Kea, HI...

  6. Panoramic optical annular staring inspection system for evaluating the inner surface of a pipe

    NASA Astrophysics Data System (ADS)

    Zhao, Liefeng; Feng, Huajun; Bai, Jian; Jin, Hao

    2008-01-01

    There should be flaws and defects on the inner surface during the producing period of a pipe, as well as contaminations and corrosions during the using period of it. A corresponding panoramic optical annular staring inspection system has been developed. It requires no rotating mechanism to exam the whole circumference of a cross section of the inner pipe surface at once, which results high speed inspection. There are two main subsystems in this inspection system, the panoramic optical annular staring imaging subsystem and driving robot subsystem. The Flat Cylinder Perspective (FCP) is the principle to image a panoramic annular view to a flat imagery, i.e. a cylinder of vision imaged is flat. Our imaging subsystem includes a panoramic annular lens (PAL), which is critical and used to implement the FCP, a series of image rotation lenses, a charge-coupled device (CCD) camera, and an illuminating light-emitting diode (LED) ring. The CCD camera sending the signal to a personal computer (PC) via VGA signal results a real time inspection. The driving robot subsystem is a fine designed complicated mechanism including a subassembly of stepper motor. It can drive the inspection system forward and backward continuously in the pipe along the axial direction. The experimental system reported in this paper has the following specifications: average detection resolution of 0.5 mm at the circumference direction and 1.0 mm at the axial direction of a pipe, and inspection speed of 15 mm/s.

  7. DIAGNOSTIC AGREEMENT BETWEEN PANORAMIC RADIOGRAPHS AND COLOR DOPPLER IMAGES OF CAROTID ATHEROMA

    PubMed Central

    Romano-Sousa, Claudia Maria; Krejci, Laís; Medeiros, Flavilene Marchioro Martins; Graciosa, Ricardo Gomes; Martins, Maria Fernanda Fonseca; Guedes, Vanessa Novaes; Fenyo-Pereira, Marlene

    2009-01-01

    The aim of this study was to investigate the agreement between diagnoses of calcified atheroma seen on panoramic radiographs and color Doppler images. Our interest stems from the fact that panoramic images can show the presence of atheroma regardless of the level of obstruction detected by color Doppler images. Panoramic and color Doppler images of 16 patients obtained from the archives of the Health Department of the city of Valença, RJ, Brazil, were analyzed in this study. Both sides of each patient were observed on the images, with a total of 32 analyzed cervical regions. The level of agreement between diagnoses was analyzed using the Kappa statistics. There was a high level of agreement, with a Kappa value of 0.78. In conclusion, panoramic radiographs can help detecting calcifications in the cervical region of patients susceptible to vascular diseases predisposing to myocardial infarction and cerebrovascular accidents. If properly trained and informed, dentists can refer their patients to a physician for a cardiovascular evaluation in order to receive proper and timely medical treatment. PMID:19148405

  8. Achieving real-time capsule endoscopy (CE) video visualization through panoramic imaging

    NASA Astrophysics Data System (ADS)

    Yi, Steven; Xie, Jean; Mui, Peter; Leighton, Jonathan A.

    2013-02-01

    In this paper, we mainly present a novel and real-time capsule endoscopy (CE) video visualization concept based on panoramic imaging. Typical CE videos run about 8 hours and are manually reviewed by physicians to locate diseases such as bleedings and polyps. To date, there is no commercially available tool capable of providing stabilized and processed CE video that is easy to analyze in real time. The burden on physicians' disease finding efforts is thus big. In fact, since the CE camera sensor has a limited forward looking view and low image frame rate (typical 2 frames per second), and captures very close range imaging on the GI tract surface, it is no surprise that traditional visualization method based on tracking and registration often fails to work. This paper presents a novel concept for real-time CE video stabilization and display. Instead of directly working on traditional forward looking FOV (field of view) images, we work on panoramic images to bypass many problems facing traditional imaging modalities. Methods on panoramic image generation based on optical lens principle leading to real-time data visualization will be presented. In addition, non-rigid panoramic image registration methods will be discussed.

  9. Panoramic imaging is not suitable for quantitative evaluation, classification, and follow up in unilateral condylar hyperplasia.

    PubMed

    Nolte, J W; Karssemakers, L H E; Grootendorst, D C; Tuinzing, D B; Becking, A G

    2015-05-01

    Patients with suspected unilateral condylar hyperplasia are often screened radiologically with a panoramic radiograph, but this is not sufficient for routine diagnosis and follow up. We have therefore made a quantitative analysis and evaluation of panoramic radiographs in a large group of patients with the condition. During the period 1994-2011, 132 patients with 113 panoramic radiographs were analysed using a validated method. There was good reproducibility between observers, but the condylar neck and head were the regions reported with least reliability. Although in most patients asymmetry of the condylar head, neck, and ramus was confirmed, the kappa coefficient as an indicator of agreement between two observers was poor (-0.040 to 0.504). Hardly any difference between sides was measured at the gonion angle, and the body appeared to be higher on the affected side in 80% of patients. Panoramic radiographs might be suitable for screening, but are not suitable for the quantitative evaluation, classification, and follow up of patients with unilateral condylar hyperplasia.

  10. AMOLED image source for use in integrated panoramic night vision goggle (IPNVG)

    NASA Astrophysics Data System (ADS)

    Ross, Jeff A.; Parisi, Vince

    2004-09-01

    The objective of this paper is to present an overview of the active matrix organic light emitting diode (OLED) microdisplay used in the integrated panoramic night vision goggle (IPNVG). These devices will be used to insert independent and overlaid video imagery into the IPNVG. Interface and operational details of the microdisplay relative to the IPNVG implementation in military aircraft will be discussed.

  11. Dental Training Films.

    ERIC Educational Resources Information Center

    Veterans Administration Medical Center, Washington, DC.

    This dental training films catalog is organized into two sections. Section I is a category listing of the films by number and title, indexed according to generalized headings; categories are as follow: anatomy, articulator systems, complete dentures, dental assisting, dental laboratory technology, dental materials, dental office emergencies,…

  12. Finding Dental Care

    MedlinePlus

    ... Finding Dental Care Where can I find low-cost dental care? Dental schools often have clinics that allow dental ... can I find more information? See Finding Low Cost Dental Care . ​​​​ WWNRightboxRadEditor2 Contact Us 1-866-232-4528 nidcrinfo@ ...

  13. Dental pathology in conventionally fed and pasture managed dairy cattle.

    PubMed

    Fadden, A N; Poulsen, K P; Vanegas, J; Mecham, J; Bildfell, R; Stieger-Vanegas, S M

    2016-01-02

    Healthy teeth are important in the first stages of digestion for dairy cattle, yet little is known about bovine dental disease. This study aimed to investigate dental pathology of dairy cattle in two parts. First dairy cattle cadaver heads (n=11) were examined at the time of culling. Second, the authors performed oral exams in cattle fed a total mixed ration (TMR) (n=200) and pasture-based (n=71) grazing cattle. Cadaver heads were imaged using radiography and computed tomography before gross dissection to study dental anatomy and pathology. The most prevalent dental abnormalities were excessive transverse ridging of the occlusal surface, the presence of diastemas and third molar dental overgrowths (M3DO) in cadaver heads. Average thickness of subocclusal dentine ranged from 3.5 mm to 5.8 mm in cheek teeth but was >10 mm in maxillary teeth with M3DO. Radiographic findings were compared with oral examinations in live cattle. Prevalence of M3DO upon oral examination was 19 per cent and 28 per cent in herds of cattle fed a TMR diet and 0 per cent in a herd of grazing cattle. Dental abnormalities are prevalent in dairy cattle but due to thin subocclusal dentine in the cheek teeth, established equine dental treatment methodology is not appropriate for bovine cheek teeth with the exception of those that have developed M3DO.

  14. Applications of Panoramic Images: from 720° Panorama to Interior 3d Models of Augmented Reality

    NASA Astrophysics Data System (ADS)

    Lee, I.-C.; Tsai, F.

    2015-05-01

    A series of panoramic images are usually used to generate a 720° panorama image. Although panoramic images are typically used for establishing tour guiding systems, in this research, we demonstrate the potential of using panoramic images acquired from multiple sites to create not only 720° panorama, but also three-dimensional (3D) point clouds and 3D indoor models. Since 3D modeling is one of the goals of this research, the location of the panoramic sites needed to be carefully planned in order to maintain a robust result for close-range photogrammetry. After the images are acquired, panoramic images are processed into 720° panoramas, and these panoramas which can be used directly as panorama guiding systems or other applications. In addition to these straightforward applications, interior orientation parameters can also be estimated while generating 720° panorama. These parameters are focal length, principle point, and lens radial distortion. The panoramic images can then be processed with closerange photogrammetry procedures to extract the exterior orientation parameters and generate 3D point clouds. In this research, VisaulSFM, a structure from motion software is used to estimate the exterior orientation, and CMVS toolkit is used to generate 3D point clouds. Next, the 3D point clouds are used as references to create building interior models. In this research, Trimble Sketchup was used to build the model, and the 3D point cloud was added to the determining of locations of building objects using plane finding procedure. In the texturing process, the panorama images are used as the data source for creating model textures. This 3D indoor model was used as an Augmented Reality model replacing a guide map or a floor plan commonly used in an on-line touring guide system. The 3D indoor model generating procedure has been utilized in two research projects: a cultural heritage site at Kinmen, and Taipei Main Station pedestrian zone guidance and navigation system. The

  15. Dental education and dental practice.

    PubMed Central

    Moore, J R

    1984-01-01

    This paper relates recent modes of dental practice to changes that the public and government are likely to ask the health care professions to make in the future. As usual they are asking for the best of all worlds. First, that we maintain the clinical model to the highest standards of personal dental care based and tested against the best research at our disposal, whilst we ensure there is no reduction in the high technical standards for which british dentists have a reputation. Second, that the profession is required to consider ways of providing care on the medicosocial model for the whole community at an economic level the country will afford. The broad changes in dental education have been reviewed, from the technical apprenticeship to the establishment of strong university departments in teaching hospitals. The importance of a sound biomedical foundation and of research both to education and the credibility of dental practice as a primary health care profession is stressed if the profession is to retain its position as a sister to medicine and not slide down to that of a technical ancillary. PMID:6374141

  16. Dental Implant Surgery

    MedlinePlus

    Dental implant surgery Overview By Mayo Clinic Staff Dental implant surgery is a procedure that replaces tooth roots with ... look and function much like real ones. Dental implant surgery can offer a welcome alternative to dentures ...

  17. Axial Tomography from Digitized Real Time Radiography

    DOE R&D Accomplishments Database

    Zolnay, A. S.; McDonald, W. M.; Doupont, P. A.; McKinney, R. L.; Lee, M. M.

    1985-01-18

    Axial tomography from digitized real time radiographs provides a useful tool for industrial radiography and tomography. The components of this system are: x-ray source, image intensifier, video camera, video line extractor and digitizer, data storage and reconstruction computers. With this system it is possible to view a two dimensional x-ray image in real time at each angle of rotation and select the tomography plane of interest by choosing which video line to digitize. The digitization of a video line requires less than a second making data acquisition relatively short. Further improvements on this system are planned and initial results are reported.

  18. Digital Radiography Qualification of Tube Welding

    NASA Technical Reports Server (NTRS)

    Carl, Chad

    2012-01-01

    The Orion Project will be directing Lockheed Martin to perform orbital arc welding on commodities metallic tubing as part of the Multi Purpose Crew Vehicle assembly and integration process in the Operations and Checkout High bay at Kennedy Space Center. The current method of nondestructive evaluation is utilizing traditional film based x-rays. Due to the high number of welds that are necessary to join the commodities tubing (approx 470), a more efficient and expeditious method of nondestructive evaluation is desired. Digital radiography will be qualified as part of a broader NNWG project scope.

  19. Axial tomography from digitized real time radiography

    SciTech Connect

    Zolnay, A.S.; McDonald, W.M.; Doupont, P.A.; McKinney, R.L.; Lee, M.M.

    1985-01-18

    Axial tomography from digitized real time radiographs provides a useful tool for industrial radiography and tomography. The components of this system are: x-ray source, image intensifier, video camera, video line extractor and digitizer, data storage and reconstruction computers. With this system it is possible to view a two dimensional x-ray image in real time at each angle of rotation and select the tomography plane of interest by choosing which video line to digitize. The digitization of a video line requires less than a second making data acquisition relatively short. Further improvements on this system are planned and initial results are reported.

  20. Dental Holography

    NASA Astrophysics Data System (ADS)

    Dirtoft, Ingegerd

    1983-12-01

    Ten years have passed since the first articles appeared in this new field. The qualities of the laser light together with the need of contactless 3-D measurements for different dental purposes seemed to be extremely promising, but still just a few scientists have used the method and mostly for laboratory studies. For some reason there has been a preponderance for orthodontic measurements. This seems to be a bit peculiar from holographic view compared with measurements for engineering purposes, which usually are made on metals. So naturally holography can become a clinical tool for measurements in the field of fixed bridges, removable partial dentures and implants. One of the problems is that the need for holography in dental research must be fulfilled in collaboration with physicists. Only a two-way communication during an entire experiment can balance both technical and odontological demands and thus give practical and clinical important results. The need for an easy way of handling the evaluation to get all required information is another problem and of course the holographic equipment must be converted to a box easy to handle for everyone. At last the position of dental holography today is going to be carefully examined together with an attempt to look into the hopefully exciting and not to utopic future for this research field.

  1. Diagnostics of coated fuel particles by neutron and synchrotron radiography

    SciTech Connect

    Momot, G. V.; Podurets, K. M.; Pogorelyi, D. K.; Somenkov, V. A.; Yakovenko, E. V.

    2011-12-15

    The nondestructive monitoring of coated fuel particles has been performed using contact neutron radiography and refraction radiography based on synchrotron radiation. It is shown that these methods supplement each other and have a high potential for determining the sizes, densities, and isotopic composition of the particle components.

  2. HUBBLE'S PANORAMIC PORTRAIT OF A VAST STAR-FORMING REGION

    NASA Technical Reports Server (NTRS)

    2002-01-01

    NASA's Hubble Space Telescope has snapped a panoramic portrait of a vast, sculpted landscape of gas and dust where thousands of stars are being born. This fertile star-forming region, called the 30 Doradus Nebula, has a sparkling stellar centerpiece: the most spectacular cluster of massive stars in our cosmic neighborhood of about 25 galaxies. The mosaic picture shows that ultraviolet radiation and high-speed material unleashed by the stars in the cluster, called R136 [the large blue blob left of center], are weaving a tapestry of creation and destruction, triggering the collapse of looming gas and dust clouds and forming pillar-like structures that are incubators for nascent stars. The photo offers an unprecedented, detailed view of the entire inner region of 30 Doradus, measuring 200 light-years wide by 150 light-years high. The nebula resides in the Large Magellanic Cloud (a satellite galaxy of the Milky Way), 170,000 light-years from Earth. Nebulas like 30 Doradus are the 'signposts' of recent star birth. High-energy ultraviolet radiation from the young, hot, massive stars in R136 causes the surrounding gaseous material to glow. Previous Hubble telescope observations showed that R136 contains several dozen of the most massive stars known, each about 100 times the mass of the Sun and about 10 times as hot. These stellar behemoths all formed at the same time about 2 million years ago. The stars in R136 are producing intense 'stellar winds' (streams of material traveling at several million miles an hour), which are wreaking havoc on the gas and dust in the surrounding neighborhood. The winds are pushing the gas away from the cluster and compressing the inner regions of the surrounding gas and dust clouds [the pinkish material]. The intense pressure is triggering the collapse of parts of the clouds, producing a new generation of star formation around the central cluster. The new stellar nursery is about 30 to 50 light-years from R136. Most of the stars in the

  3. Advances in digital radiography: physical principles and system overview.

    PubMed

    Körner, Markus; Weber, Christof H; Wirth, Stefan; Pfeifer, Klaus-Jürgen; Reiser, Maximilian F; Treitl, Marcus

    2007-01-01

    During the past two decades, digital radiography has supplanted screen-film radiography in many radiology departments. Today, manufacturers provide a variety of digital imaging solutions based on various detector and readout technologies. Digital detectors allow implementation of a fully digital picture archiving and communication system, in which images are stored digitally and are available anytime. Image distribution in hospitals can now be achieved electronically by means of web-based technology with no risk of losing images. Other advantages of digital radiography include higher patient throughput, increased dose efficiency, and the greater dynamic range of digital detectors with possible reduction of radiation exposure to the patient. The future of radiography will be digital, and it behooves radiologists to be familiar with the technical principles, image quality criteria, and radiation exposure issues associated with the various digital radiography systems that are currently available.

  4. Using ytterbium-169 for safe and economical industrial radiography

    SciTech Connect

    Dowalo, J.A.

    1994-01-01

    Safety has become an issue of paramount importance for industrial radiography. Many NDE facilities and suppliers are finding the cost of performing radiography Prohibitive due to heightened safety concerns for radiation area protection. The most common sources used in radiography, Iridium-192 and Cobalt-60, result in high radiation fields over a large area. Even when collimators are used large radiation fields can result from multicurie source radiography. Radiographic operations are being forced to find alternative test methods and techniques to the use of the old stand-by sources. These alternate methods are not always as comprehensive a test as full volumetric examination with radiography. Since Iridium and Cobalt are in such wide spread use, they are sometimes called upon to perform test of materials which are not in their optimum sensitivity range.

  5. Simulation of computed radiography with imaging plate detectors

    SciTech Connect

    Tisseur, D.; Costin, M.; Mathy, F.; Schumm, A.

    2014-02-18

    Computed radiography (CR) using phosphor imaging plate detectors is taking an increasing place in Radiography Testing. CR uses similar equipment as conventional radiography except that the classical X-ray film is replaced by a numerical detector, called image plate (IP), which is made of a photostimulable layer and which is read by a scanning device through photostimulated luminescence. Such digital radiography has already demonstrated important benefits in terms of exposure time, decrease of source energies and thus reduction of radioprotection area besides being a solution without effluents. This paper presents a model for the simulation of radiography with image plate detectors in CIVA together with examples of validation of the model. The study consists in a cross comparison between experimental and simulation results obtained on a step wedge with a classical X-ray tube. Results are proposed in particular with wire Image quality Indicator (IQI) and duplex IQI.

  6. Neutron radiography of irradiated nuclear fuel at Idaho National Laboratory

    SciTech Connect

    Craft, Aaron E.; Wachs, Daniel M.; Okuniewski, Maria A.; Chichester, David L.; Williams, Walter J.; Papaioannou, Glen C.; Smolinski, Andrew T.

    2015-09-10

    Neutron radiography of irradiated nuclear fuel provides more comprehensive information about the internal condition of irradiated nuclear fuel than any other non-destructive technique to date. Idaho National Laboratory (INL) has multiple nuclear fuels research and development programs that routinely evaluate irradiated fuels using neutron radiography. The Neutron Radiography reactor (NRAD) sits beneath a shielded hot cell facility where neutron radiography and other evaluation techniques are performed on these highly radioactive objects. The NRAD currently uses the foil-film transfer technique for imaging fuel that is time consuming but provides high spatial resolution. This study describes the NRAD and hot cell facilities, the current neutron radiography capabilities available at INL, planned upgrades to the neutron imaging systems, and new facilities being brought online at INL related to neutron imaging.

  7. Neutron Radiography of Irradiated Nuclear Fuel at Idaho National Laboratory

    NASA Astrophysics Data System (ADS)

    Craft, Aaron E.; Wachs, Daniel M.; Okuniewski, Maria A.; Chichester, David L.; Williams, Walter J.; Papaioannou, Glen C.; Smolinski, Andrew T.

    Neutron radiography of irradiated nuclear fuel provides more comprehensive information about the internal condition of irradiated nuclear fuel than any other non-destructive technique to date. Idaho National Laboratory (INL) has multiple nuclear fuels research and development programs that routinely evaluate irradiated fuels using neutron radiography. The Neutron Radiography reactor (NRAD) sits beneath a shielded hot cell facility where neutron radiography and other evaluation techniques are performed on these highly radioactive objects. The NRAD currently uses the foil-film transfer technique for imaging fuel that is time consuming but provides high spatial resolution. This paper describes the NRAD and hot cell facilities, the current neutron radiography capabilities available at INL, planned upgrades to the neutron imaging systems, and new facilities being brought online at INL related to neutron imaging.

  8. Neutron radiography of irradiated nuclear fuel at Idaho National Laboratory

    DOE PAGES

    Craft, Aaron E.; Wachs, Daniel M.; Okuniewski, Maria A.; ...

    2015-09-10

    Neutron radiography of irradiated nuclear fuel provides more comprehensive information about the internal condition of irradiated nuclear fuel than any other non-destructive technique to date. Idaho National Laboratory (INL) has multiple nuclear fuels research and development programs that routinely evaluate irradiated fuels using neutron radiography. The Neutron Radiography reactor (NRAD) sits beneath a shielded hot cell facility where neutron radiography and other evaluation techniques are performed on these highly radioactive objects. The NRAD currently uses the foil-film transfer technique for imaging fuel that is time consuming but provides high spatial resolution. This study describes the NRAD and hot cell facilities,more » the current neutron radiography capabilities available at INL, planned upgrades to the neutron imaging systems, and new facilities being brought online at INL related to neutron imaging.« less

  9. Radiography and computed tomography in the diagnosis of nonneoplastic equine mandibular disease.

    PubMed

    Huggons, Nick A; Bell, Robin J W; Puchalski, Sarah M

    2011-01-01

    We compared the information gained from computed tomography (CT) vs. radiography in horses with nonneoplastic disease of the mandible. We hypothesized that CT would provide additional diagnostic information. Medical records, radiographs, and CT images of horses with nonneoplastic mandibular disease evaluated between 1994 and 2008 were reviewed. Nineteen horses were identified; 11 had a tooth root abscess and related disease, four had a fracture of the teeth and/or mandible, and four had a nonneoplastic mass. Both CT images and radiographs allowed identification of diseased teeth that appeared clinically normal otherwise. CT allowed identification of teeth that were clinically affected but appeared normal radiographically. Parameters such as tooth pulp involvement, lamina dura destruction, presence of bone fragments, lingual and buccal mandibular bone periosteal reaction, and cortical bone destruction were more conspicuous with CT. Performing radiography and CT in horses with nonneoplastic mandibular disease provides a more complete evaluation than either technique alone. CT contributes additional information that could otherwise be overlooked with radiographs alone in horses with a mandibular fracture. CT provides ancillary information to radiographs in horses with dental infection or a nonneoplastic mass of the mandible.

  10. Accuracy of digital periapical radiography and cone-beam computed tomography in detecting external root resorption

    PubMed Central

    Geha, Hassem; Sankar, Vidya; Teixeira, Fabricio B.; McMahan, Clyde Alex; Noujeim, Marcel

    2015-01-01

    Purpose The purpose of this study was to evaluate and compare the efficacy of cone-beam computed tomography (CBCT) and digital intraoral radiography in diagnosing simulated small external root resorption cavities. Materials and Methods Cavities were drilled in 159 roots using a small spherical bur at different root levels and on all surfaces. The teeth were imaged both with intraoral digital radiography using image plates and with CBCT. Two sets of intraoral images were acquired per tooth: orthogonal (PA) which was the conventional periapical radiograph and mesioangulated (SET). Four readers were asked to rate their confidence level in detecting and locating the lesions. Receiver operating characteristic (ROC) analysis was performed to assess the accuracy of each modality in detecting the presence of lesions, the affected surface, and the affected level. Analysis of variation was used to compare the results and kappa analysis was used to evaluate interobserver agreement. Results A significant difference in the area under the ROC curves was found among the three modalities (P=0.0002), with CBCT (0.81) having a significantly higher value than PA (0.71) or SET (0.71). PA was slightly more accurate than SET, but the difference was not statistically significant. CBCT was also superior in locating the affected surface and level. Conclusion CBCT has already proven its superiority in detecting multiple dental conditions, and this study shows it to likewise be superior in detecting and locating incipient external root resorption. PMID:26389057

  11. Beam characterization at the Neutron Radiography Reactor

    SciTech Connect

    Sarah W. Morgan; Jeffrey C. King; Chad L. Pope

    2013-12-01

    The quality of a neutron-imaging beam directly impacts the quality of radiographic images produced using that beam. Fully characterizing a neutron beam, including determination of the beam's effective length-to-diameter ratio, neutron flux profile, energy spectrum, potential image quality, and beam divergence, is vital for producing quality radiographic images. This paper provides a characterization of the east neutron imaging beamline at the Idaho National Laboratory Neutron Radiography Reactor (NRAD). The experiments which measured the beam's effective length-to-diameter ratio and potential image quality are based on American Society for Testing and Materials (ASTM) standards. An analysis of the image produced by a calibrated phantom measured the beam divergence. The energy spectrum measurements consist of a series of foil irradiations using a selection of activation foils, compared to the results produced by a Monte Carlo n-Particle (MCNP) model of the beamline. The NRAD has an effective collimation ratio greater than 125, a beam divergence of 0.3 +_ 0.1 degrees, and a gold foil cadmium ratio of 2.7. The flux profile has been quantified and the facility is an ASTM Category 1 radiographic facility. Based on bare and cadmium covered foil activation results, the neutron energy spectrum used in the current MCNP model of the radiography beamline over-samples the thermal region of the neutron energy spectrum.

  12. Utility of thyroid collars in cephalometric radiography

    PubMed Central

    Sansare, KP; Khanna, V; Karjodkar, F

    2011-01-01

    Objective A study was carried out to investigate the rationale that use of a thyroid collar (TC) in cephalometric radiography hampers the diagnostic and descriptive quality of lateral cephalogram. Methods A randomized observer blinded study was designed. The study consisted of two groups. The first group data were retrieved from the oral radiology archival system having lateral cephalogram without a TC. The second group was selected from the oral radiology department of patients where lateral cephalogram was taken using a TC. Lateral cephalogram was taken on direct digital system, the Kodak 9000 unit (Eastman Kodak, Rochester, NY). 2 observers blinded about the aim of the study were appointed to identify 15 sets of landmarks on the lateral cephalogram. Interobserver variance was also analysed for the study. Results 50 lateral cephalograms in each group were studied. Out of 15 sets of landmarks, 12 were identified consistent with the TC group. Three landmarks, namely the hyoid bone, second cervical vertebra and third cervical vertebra could not be identified on the TC group. There was no significant difference in the interobserver markings on lateral cephalogram. Conclusions TCs do mask a few landmarks on the lateral cephalogram. These landmarks are mainly used for analysis of skeletal maturity index (SMI). Lead TCs are probably the most convenient and easily available means to protect the thyroid from unwanted radiation while taking lateral cephalogram. It is therefore encouraged to use a TC during routine cephalometric radiography where SMI information is not needed. PMID:22065795

  13. A system for fast neutron radiography

    SciTech Connect

    Klann, R.T.

    1997-04-01

    A system has been designed and a neutron generator installed to perform fast neutron radiography. With this system, objects as small as a coin and as large as a 19 liter container have been radiographed. The neutron source is an MF Physics A-711 neutron generator which produces 3 x 10[sup 10] neutrons/second with an average energy of 14. 5 MeV. The radiography system uses x-ray scintillation screens and film in commercially available light-tight cassettes. The cassettes have been modified to include a thin sheet of plastic to produce protons from the neutron beam through elastic scattering from hydrogen and other low Z materials in the plastic. For film densities from 1.8 to 3.0, exposures range from 1.9 x 10[sup 7] n/cm[sup 2] to 3.8 x 10[sup 8] n/cm[sup 2] depending on the type of screen and film. The optimum source-to-film distance was found to be 150 cm. At this distance, the geometric unsharpness was determined to be approximately 2.2-2.3 mm and the smallest hole that could be resolved in a 1.25 cm thick sample had a diameter of 0.079 cm.

  14. Positioning long lines: contrast versus plain radiography

    PubMed Central

    Reece, A; Ubhi, T; Craig, A; Newell, S

    2001-01-01

    AIM—To assess the value of contrast versus plain radiography in determining radio-opaque long line tip position in neonates.
METHODS—In a prospective study, plain radiography was performed after insertion of radio-opaque long lines. If the line tip was not visible on the plain film, a second film with contrast was obtained in an attempt to visualise the tip.
RESULTS—Sixty eight lines were inserted during the study period, 62 of which were included in the study. In 31, a second radiographic examination with contrast was necessary to determine position of the tip. In 29 of these, the line tip was clearly visualised with contrast. On two occasions, the line tip could not be seen because the contrast had filled the vein and obscured the tip from view. Eight of the lines that required a second radiograph with contrast were repositioned.
CONCLUSION—Intravenous contrast should be routinely used in the assessment of long line position in the neonate.

 PMID:11207231

  15. Neutron Radiography Reactor Reactivity -- Focused Lessons Learned

    SciTech Connect

    Eric Woolstenhulme; Randal Damiana; Kenneth Schreck; Ann Marie Phillips; Dana Hewit

    2010-11-01

    As part of the Global Threat Reduction Initiative, the Neutron Radiography Reactor (NRAD) at the Idaho National Laboratory (INL) was converted from using highly enriched uranium (HEU) to low enriched uranium (LEU) fuel. After the conversion, NRAD resumed operations and is meeting operational requirements. Radiography image quality and the number of images that can be produced in a given time frame match pre-conversion capabilities. However, following the conversion, NRAD’s excess reactivity with the LEU fuel was less than it had been with the HEU fuel. Although some differences between model predictions and actual performance are to be expected, the lack of flexibility in NRAD’s safety documentation prevented adjusting the reactivity by adding more fuel, until the safety documentation could be modified. To aid future reactor conversions, a reactivity-focused Lessons Learned meeting was held. This report summarizes the findings of the lessons learned meeting and addresses specific questions posed by DOE regarding NRAD’s conversion and reactivity.

  16. Imaging properties of digital magnification radiography.

    PubMed

    Boyce, Sarah J; Samei, Ehsan

    2006-04-01

    Flat panel detectors exhibit improved signal-to-noise ratio (SNR) and display capabilities compared to film. This improvement necessitates a new evaluation of optimal geometry for conventional projection imaging applications such as digital projection mammography as well as for advanced x-ray imaging applications including cone-beam computed tomography (CT), tomosynthesis, and mammotomography. Such an evaluation was undertaken in this study to examine the effects of x-ray source distribution, inherent detector resolution, magnification, scatter rejection, and noise characteristics including noise aliasing. A model for x-ray image acquisition was used to develop generic results applicable to flat panel detectors with similar x-ray absorption characteristics. The model assumed a Gaussian distribution for the focal spot and a rectangular distribution for a pixel. A generic model for the modulated transfer function (MTF) of indirect flat panel detectors was derived by a nonlinear fit of empirical receptor data to the Burgess model for phosphor MTFs. Noise characteristics were investigated using a generic noise power spectrum (NPS) model for indirect phosphor-based detectors. The detective quantum efficiency (DQE) was then calculated from the MTF and NPS models. The results were examined as a function of focal spot size (0.1, 0.3, and 0.6 mm) and pixel size (50, 100, 150, and 200 microm) for magnification ranges 1 to 3. Mammography, general radiography (also applicable to mammotomography), and chest radiography applications were explored using x-ray energies of 28, 74, and 120 kVp, respectively. Nodule detection was examined using the effective point source scatter model, effective DQE, and the Hotelling SNR2 efficiency. Results indicate that magnification can potentially improve the signal and noise performance of digital images. Results also show that a cross over point occurs in the spatial frequency above and below which the effects of magnification differ

  17. High Brightness Neutron Source for Radiography

    SciTech Connect

    Cremer, J. T.; Piestrup, Melvin, A.; Gary, Charles, K.; Harris, Jack, L. Williams, David, J.; Jones, Glenn, E.; Vainionpaa, J. , H.; Fuller, Michael, J.; Rothbart, George, H.; Kwan, J., W.; Ludewigt, B., A.; Gough, R.., A..; Reijonen, Jani; Leung, Ka-Ngo

    2008-12-08

    This research and development program was designed to improve nondestructive evaluation of large mechanical objects by providing both fast and thermal neutron sources for radiography. Neutron radiography permits inspection inside objects that x-rays cannot penetrate and permits imaging of corrosion and cracks in low-density materials. Discovering of fatigue cracks and corrosion in piping without the necessity of insulation removal is possible. Neutron radiography sources can provide for the nondestructive testing interests of commercial and military aircraft, public utilities and petrochemical organizations. Three neutron prototype neutron generators were designed and fabricated based on original research done at the Lawrence Berkeley National Laboratory (LBNL). The research and development of these generators was successfully continued by LBNL and Adelphi Technology Inc. under this STTR. The original design goals of high neutron yield and generator robustness have been achieved, using new technology developed under this grant. In one prototype generator, the fast neutron yield and brightness was roughly 10 times larger than previously marketed neutron generators using the same deuterium-deuterium reaction. In another generator, we integrate a moderator with a fast neutron source, resulting in a high brightness thermal neutron generator. The moderator acts as both conventional moderator and mechanical and electrical support structure for the generator and effectively mimics a nuclear reactor. In addition to the new prototype generators, an entirely new plasma ion source for neutron production was developed. First developed by LBNL, this source uses a spiral antenna to more efficiently couple the RF radiation into the plasma, reducing the required gas pressure so that the generator head can be completely sealed, permitting the possible use of tritium gas. This also permits the generator to use the deuterium-tritium reaction to produce 14-MeV neutrons with increases

  18. Dental anomalies in an orthodontic patient population with maxillary lateral incisor agenesis

    PubMed Central

    Citak, Mehmet; Cakici, Elif Bahar; Benkli, Yasin Atakan; Cakici, Fatih; Bektas, Bircan; Buyuk, Suleyman Kutalmış

    2016-01-01

    ABSTRACT Introduction: The purpose of this study was to evaluate the prevalence of dental anomalies in a subpopulation of orthodontic patients with agenesis of maxillary lateral incisors (MLI). Methods: The material of the present study included the records of the 1964 orthodontic patients. Panoramic radiographs and dental casts were used to analyze other associated eight dental anomalies, including agenesis of other teeth, dens invaginatus, dens evaginatus, peg shaped MLI, taurodontism, pulp stone, root dilaceration and maxillary canine impaction. Results: Out of the 1964 patients examined, 90 were found to have agenesis of MLI, representing a prevalence of 4.6%. The most commonly found associated-anomalies were agenesis of other teeth (23.3%), peg-shaped MLIs (15.6%), taurodontism (42.2%), and dilacerated teeth (18.9%). Conclusion: Permanent tooth agenesis, taurodontism, peg-shaped maxillary lateral incisor, and root dilacerations are frequently associated with maxillary lateral incisor agenesis. PMID:28125145

  19. A distortion correction algorithm for fish-eye panoramic image of master-slave visual surveillance system

    NASA Astrophysics Data System (ADS)

    Zuo, Chenglin; Liu, Yu; Li, Yongle; Xu, Wei; Zhang, Maojun

    2013-09-01

    A master-slave visual surveillance system is composed of one fish-eye panoramic camera and one dynamic pan-tilt-zoom (PTZ) dome camera. In order to make PTZ dome camera zoom into all targets of interest in panoramic image, the fish-eye panoramic camera is fixed inclining towards the gravity direction, which may cause more obvious distortion. This paper proposed a novel method for the distortion correction of captured panoramic image based on the midpoint circle algorithm (MCA). The method uses incremental calculation of decision parameters to determine the pixel positions along a circle circumference, and both of the vertical and horizontal are rectilinearised. Experimental results show that our correction method based on MCA is efficient and effective. In particular, due to its low computational cost, our method can be applied on embedded camera platform without any extra hardware resources.

  20. Prevalence of Dental Anomalies in Permanent Dentition of Brazilian Individuals with Down Syndrome

    PubMed Central

    Cuoghi, Osmar Aparecido; Topolski, Francielle; Perciliano de Faria, Lorraine; Occhiena, Carla Machado; Ferreira, Nancy dos Santos Pinto; Ferlin, Camila Ribeiro; Rogério de Mendonça, Marcos

    2016-01-01

    Objective: The aim of this study was to evaluate the incidence of dental anomalies in the permanent dentition of individuals with Down Syndrome (DS) to increase the knowledge on the dental issues in this syndrome. Method: One hundred and five panoramic X-rays of patients with DS (61 males and 44 females), aged 7 to 42 years were used. The data were statistically analyzed using bivariate analyses test (p <0.05). Results: Dental anomalies were observed in 50.47% of the sample. More than one anomaly was observed in 9.52% of the individuals. The most frequent dental anomalies were hypodontia and microdontia (16.19%), followed by retained tooth (10.47%), taurodontism (9.52%), supernumerary teeth (5.71%), macrodontia (2.85%) and root dilaceration (0.95%). There was no statistically significant difference between genders for any of the anomalies. Conclusion: A high prevalence of dental anomalies was observed in individuals with DS. The results of the present study reinforce the importance of good dental care, offering a greater basis for professionals who provide dental service to these patients. PMID:27733874

  1. Dental age assessment among Tunisian children using the Demirjian method

    PubMed Central

    Aissaoui, Abir; Salem, Nidhal Haj; Mougou, Meryam; Maatouk, Fethi; Chadly, Ali

    2016-01-01

    Context: Since Demirjian system of estimating dental maturity was first described, many researchers from different countries have tested its accuracy among diverse populations. Some of these studies have pointed out a need to determine population-specific standards. Aim: The aim of this study is to evaluate the suitability of the Demirjian's method for dental age assessment in Tunisian children. Materials and Methods: This is a prospective study previously approved by the Research Ethics Local Committee of the University Hospital Fattouma Bourguiba of Monastir (Tunisia). Panoramic radiographs of 280 healthy Tunisian children of age 2.8–16.5 years were examined with Demirjian method and scored by three trained observers. Statistical Analysis Used: Dental age was compared to chronological age by using the analysis of variance (ANOVA) test. Cohen's Kappa test was performed to calculate the intra- and inter-examiner agreements. Results: Underestimation was seen in children aged between 9 and 16 years and the range of accuracy varied from −0.02 to 3 years. The advancement in dental age as determined by Demirjian system when compared to chronological age ranged from 0.3 to 1.32 year for young males and from 0.26 to 1.37 year for young females (age ranged from 3 to 8 years). Conclusions: The standards provided by Demirjian for French-Canadian children may not be suitable for Tunisian children. Each population of children may need their own specific standard for an accurate estimation of chronological age. PMID:27051223

  2. Common Errors in Digital Panoramic Radiographs of Patients with Mixed Dentition and Patients with Permanent Dentition

    PubMed Central

    Peretz, Benjamin; Gotler, Maya; Kaffe, Israel

    2012-01-01

    Purpose. To compare errors in digital panoramic radiographs of permanent and mixed dentitions. Methods. 143 and 146 digital radiographs of mixed and permanent dentitions were examined. Results. Significantly fewer errors presented in the mixed dentition. Positioning too forward significantly prevalent in the mixed dentition; slumped position and nonpositioning of chin properly were significantly prevailed in the permanent dentition. Blurred or shortened upper incisors were significantly more prevalent in the mixed dentition. Diagnostic ability could be improved by manipulating the brightness or contrast in nearly 45% of all radiographs. In the mixed dentition, tilting the chin down and a slumped position made the lower incisors significantly nondiagnostic. In the permanent dentition, tilting the chin down made the lower incisors to be significantly nondiagnostic. Conclusions. More errors were prevalent in panoramic radiographs of permanent dentitions. Properly positioning the patient is the most important factor in preventing a cascade of errors. PMID:22505905

  3. CNN-coupled Humanoid Panoramic Annular Lens (PAL)-Optical System for Military Applications (Feasibility Study)

    NASA Astrophysics Data System (ADS)

    Greguss, Pal

    2002-01-01

    This report results from a contract tasking OPTOPAL Panoramic Metrology Consulting as follows: This investigation will consist of adaptation of a Hungarian-developed single-piece imaging block, the Panoramic Annular Lens (PAL) and the CNN chip for a few military applications. A polar beam splitter will be placed immediately after the relay lens to obtain two image planes, one will be used by the existing 64X64 CNN-UM focal plane array processor chip. The other image plane will be projected on the space-variant CMOS retina-like digital camera GIOTTO. Using this configuration enables us to compensate for the relatively low pixel number of the CNN-UM array processor; further it will allow a real time switching from log-polar imaging to regular imaging and allow for the design of the humanoid PAL optical system.

  4. Mandibular Inferior Cortical Bone Thickness on Panoramic Radiographs in Patients using Bisphosphonates

    PubMed Central

    Torres, Sandra R.; Chen, Curtis S. K.; Leroux, Brian G.; Lee, Peggy P.; Hollender, Lars G.; Lloid, Michelle; Drew, Shane Patrick; Schubert, Mark M.

    2015-01-01

    Objective To detect dimensional changes in the mandibular cortical bone associated with bisphosphonate (BP) use and to correlate the measurements of the cortical bone with the cumulative dose of BP therapy. Methods Mandibular inferior cortical bone thickness (MICBT) was measured under the mental foramen from panoramic radiographs of subjects using BP with and without bisphosphonate related osteonecrosis of the jaws (BRONJ) and controls. Results The highest mean MICBT was observed in BRONJ subjects 6.81 (± 1.35 mm), when compared to subjects using BP 5.44 (± 1.09 mm) and controls 4.79 (± 0.85 mm; p<0.01). The mean MICBT of BRONJ subjects was significantly higher than that of subjects using BP without BRONJ. There was a correlation between MICBT and cumulative dose of zolendronate. Conclusion The MICBT on panoramic radiograph is a potentially useful tool for the detection of dimensional changes associated with BP therapy. PMID:25864820

  5. Panoramic-image-based rendering solutions for visualizing remote locations via the web

    NASA Astrophysics Data System (ADS)

    Obeysekare, Upul R.; Egts, David; Bethmann, John

    2000-05-01

    With advances in panoramic image-based rendering techniques and the rapid expansion of web advertising, new techniques are emerging for visualizing remote locations on the WWW. Success of these techniques depends on how easy and inexpensive it is to develop a new type of web content that provides pseudo 3D visualization at home, 24-hours a day. Furthermore, the acceptance of this new visualization medium depends on the effectiveness of the familiarization tools by a segment of the population that was never exposed to this type of visualization. This paper addresses various hardware and software solutions available to collect, produce, and view panoramic content. While cost and effectiveness of building the content is being addressed using a few commercial hardware solutions, effectiveness of familiarization tools is evaluated using a few sample data sets.

  6. Child Indicators: Dental Health.

    ERIC Educational Resources Information Center

    Lewit, Eugene M.; Kerrebrock, Nancy

    1998-01-01

    Reviews measures of dental health in children and the evidence on child dental health. Although children's dental health has improved over the past two decades, many poor children do not receive necessary dental health services, and reasons for this failure are summarized. (SLD)

  7. Design and implementation of segment oriented spatio-temporal model in urban panoramic maps

    NASA Astrophysics Data System (ADS)

    Li, Haiting; Fei, Lifan; Peng, Qingshan; Li, Yanhong

    2009-10-01

    Object-oriented spatio-temporal model is directed by human cognition that each object has what/where/when attributes. The precise and flexible structure of such models supports multi-semantics of space and time. This paper reviews current research of spatio-temporal models using object-oriented approach and proposed a new spatio-temporal model based on segmentation in order to resolve the updating problem of some special GIS system by taking advantages of object-oriented spatio-temporal model and adopting category theory. Category theory can be used as a unifying framework for specifying complex systems and it provides rules on how objects may be joined. It characterizes the segments of object through mappings between them. The segment-oriented spatio-temporal model designed for urban panoramic maps is described and implemented. We take points and polylines as objects in this model in the management of panoramic map data. For the randomness of routes which transportation vehicle adopts each time, road objects in this model are split into some segments by crossing points. The segments still remains polyline type, but the splitting makes it easier to update the panoramic data when new photos are captured. This model is capable of eliminating redundant data and accelerating data access when panoramas are unchanged. For evaluation purpose, the data types and operations are designed and implemented in PostgreSQL and the results of experiments come out to prove that this model is efficient and expedient in the application of urban panoramic maps.

  8. Weaker dental enamel explains dental decay.

    PubMed

    Vieira, Alexandre R; Gibson, Carolyn W; Deeley, Kathleen; Xue, Hui; Li, Yong

    2015-01-01

    Dental caries continues to be the most prevalent bacteria-mediated non-contagious disease of humankind. Dental professionals assert the disease can be explained by poor oral hygiene and a diet rich in sugars but this does not account for caries free individuals exposed to the same risk factors. In order to test the hypothesis that amount of amelogenin during enamel development can influence caries susceptibility, we generated multiple strains of mice with varying levels of available amelogenin during dental development. Mechanical tests showed that dental enamel developed with less amelogenin is "weaker" while the dental enamel of animals over-expressing amelogenin appears to be more resistant to acid dissolution.

  9. Efficient panoramic sampling of real-world environments for image-based stereoscopic telepresence

    NASA Astrophysics Data System (ADS)

    Gurrieri, Luis E.; Dubois, Eric

    2012-03-01

    A key problem in telepresence systems is how to effectively emulate the subjective experience of being there delivered by our visual system. A step toward visual realism can be achieved by using high-quality panoramic snapshots instead of computer-based models of the scene. Furthermore, a better immersive illusion can be created by enabling the free viewpoint stereoscopic navigation of the scene, i.e. using omnistereoscopic imaging. However, commonly found implementation constraints of telepresence systems such as acquisition time, rendering complexity, and storage capacity, make the idea of using stereoscopic panoramas challenging. Having these constraints in mind, we developed a technique for the efficient acquisition and rendering of omnistereoscopic images based on sampling the scene with clusters of three panoramic images arranged in a controlled geometric pattern. Our technique can be implemented with any off-the-shelf panoramic cameras. Furthermore, it does not require neither the acquisition of additional depth information of the scene nor the estimation of camera parameters. The low the computational complexity and reduced data overhead of our rendering process make it attractive for the large scale stereoscopic sampling in a variety of scenarios.

  10. Panoramic radiographs underestimate extensions of the anterior loop and mandibular incisive canal

    PubMed Central

    Nejaim, Yuri; de Freitas, Deborah Queiroz; de Oliveira Santos, Christiano

    2016-01-01

    Purpose The purpose of this study was to detect the anterior loop of the mental nerve and the mandibular incisive canal in panoramic radiographs (PAN) and cone-beam computed tomography (CBCT) images, as well as to determine the anterior/mesial extension of these structures in panoramic and cross-sectional reconstructions using PAN and CBCT images. Materials and Methods Images (both PAN and CBCT) from 90 patients were evaluated by 2 independent observers. Detection of the anterior loop and the incisive canal were compared between PAN and CBCT. The anterior/mesial extension of these structures was compared between PAN and both cross-sectional and panoramic CBCT reconstructions. Results In CBCT, the anterior loop and the incisive canal were observed in 7.7% and 24.4% of the hemimandibles, respectively. In PAN, the anterior loop and the incisive canal were detected in 15% and 5.5% of cases, respectively. PAN presented more difficulties in the visualization of structures. The anterior/mesial extensions ranged from 0.0 mm to 19.0 mm on CBCT. PAN underestimated the measurements by approximately 2.0 mm. Conclusion CBCT appears to be a more reliable imaging modality than PAN for preoperative workups of the anterior mandible. Individual variations in the anterior/mesial extensions of the anterior loop of the mental nerve and the mandibular incisive canal mean that is not prudent to rely on a general safe zone for implant placement or bone surgery in the interforaminal region. PMID:27672611

  11. Computer-aided system for measuring the mandibular cortical width on panoramic radiographs in osteoporosis diagnosis

    NASA Astrophysics Data System (ADS)

    Arifin, Agus Zainal; Asano, Akira; Taguchi, Akira; Nakamoto, Takashi; Ohtsuka, Masahiko; Tanimoto, Keiji

    2005-04-01

    Osteoporotic fractures are associated with substantial morbidity, increased medical cost and high mortality risk. Several equipments of bone assessment have been developed to identify individuals, especially postmenopausal women, with high risk of osteoporotic fracture; however, a large segment of women with low skeletal bone mineral density (BMD), namely women with high risk of osteoporotic fractures, cannot be identified sufficiently because osteoporosis is asymptomatic. Recent studies have been demonstrating that mandibular inferior cortical width manually measured on panoramic radiographs may be useful for the identification of women with low BMD. Automatic measurement of cortical width may enable us to identify a large number of asymptomatic women with low BMD. The purpose of this study was to develop a computer-aided system for measuring the mandibular cortical width on panoramic radiographs. Initially, oral radiologists determined the region of interest based on the position of mental foramen. Some enhancing image techniques were applied so as to measure the cortical width at the best point. Panoramic radiographs of 100 women who had BMD assessments of the lumbar spine and femoral neck were used to confirm the efficacy of our new system. Cortical width measured with our system was compared with skeletal BMD. There were significant correlation between cortical width measured with our system and skeletal BMD. These correlations were similar with those between cortical width manually measured by the dentist and skeletal BMD. Our results suggest that our new system may be useful for mass screening of osteoporosis.

  12. Elongated styloid process evaluation on digital panoramic radiograph in a North Italian population

    PubMed Central

    Gracco, Antonio; De Stefani, Alberto; Balasso, Paolo; Alessandri-Bonetti, Giulio; Stellini, Edoardo

    2017-01-01

    Background The aim of this study is to evaluate the prevalence of elongated styloid process in digital panoramic radiographs in a North Italian population in relation to age, gender and side. Material and Methods This study was performed as a retrospective analysis on digital panoramic radiographs of 600 (271 males and 329 females) Italian patients between 6 and 87 years old. The styloid process length were measured using the measuring tool of Sidexis Software. It was measured from the point where it left the temporal bone plate to its tip. Styloid processes measuring more than 30 mm were considered elongated. Chi-squared and Fisher tests were used and the test is considered significant if the p-value is lower or equal to 0.05. Results Thirty-three per cent of the patients showed an elongated styloid process. Seventeen per cent were elongated on both right and left side, fifteen point nine per cent were elongated only in one side. Conclusions The prevalence of elongated styloid process was high and a progressive increase of the elongation prevalence was found in older groups. Key words:Elongated styloid process, Eagle’s syndrome, panoramic radiograph. PMID:28298982

  13. Correlation of Condylar Guidance Determined by Panoramic Radiographs to One Determined by Conventional Methods

    PubMed Central

    Godavarthi, A Sowjanya; Sajjan, M C Suresh; Raju, A V Rama; Rajeshkumar, P; Premalatha, Averneni; Chava, Narayana

    2015-01-01

    Background: To evaluate the feasibility of using panoramic radiographs as an alternative to an interocclusal recording method for determining the condylar guidance in dentate and edentulous conditions. Materials and Methods: 20 dentulous individuals with an age range of 20-30 years and 20 edentulous patients of 40-65 years were selected. An interocclusal bite registration was done in protrusive position for all the subjects. Orthopantomographs were made for all patients in open mouth position. Hanau articulator was modified to record the angulations to the accuracy of 1°. Tracing of glenoid fossa on radiograph was done to measure the condylar guidance angles. Readings were recorded and analyzed by Freidman’s test and t-test. Results: Condylar guidance values obtained by the interocclusal method and radiographic method in dentate individuals on the right side and left side 40.55°, and 37.1°, and 40.15°, and 34.75°, respectively. In the edentulous individuals, the values on the right side and left side was 36.7° and 36.1° and 35.95° and 33.6,° respectively. The difference was statistically significant (P = < 0.001) in dentate group and was not statistically significant (P = 0.6493) in edentulous group. Conclusion: Panoramic radiograph can be used as an alternative to interocclusal technique only in edentulous patients. Further studies comparing panoramic radiograph to jaw tracking devices would substantiate the results of this study. PMID:26464554

  14. Dental education in Colombia

    PubMed Central

    Jaramillo, Jorge A.; Pulido, Jairo H. Ternera; Núñez, Jaime A. Castro; Bird, William F.; Komabayashi, Takashi

    2014-01-01

    This article describes Colombia's development of formal dentistry, its dental school system, curriculum, and dental licensure, and current issues in oral health care. In 1969, there were only 4 dental schools in Colombia; at this writing there are 21. Five dental schools are public and the other 16 are private. Nearly all classes are conducted in Spanish. Undergraduate pre-dental coursework is not a prerequisite for dental school in Colombia. To obtain licensure, Colombian dental students must complete 5 years of study in dental school, earn a diploma, and work for the government for 1 year. There are approximately 41,400 dentists in Colombia, and the number is increasing quickly. However, the unemployment rate among dentists is very high, even though graduation from dental school is extremely difficult. Although the 1,100:1 ratio of citizens to dentists is considered satisfactory, access to dental care is limited due to the high rate of poverty. PMID:20339245

  15. Digital mammography performed with computed radiography technology.

    PubMed

    Jouan, B

    1999-07-01

    Introduced by Fuji Photo Film Japan in the early 1980s, computed radiography (CR) technology has developed considerably since then to become the mature widely installed technology it is today (about 7500 systems worldwide). Various mammographic examinations require high performance results to which CR complies on demand or following some procedures such as geometrical magnification carried out during the examination. The basic CR principles and digital image processing as well as technical improvements are detailed in this study, which also includes a synthesis of the articles on CR mammographic applications referenced in the bibliography, focusing on strong points, limits and current methods of surpassing these limits. New CR technology development perspectives in mammography and computed assisted diagnosis (CAD) algorithms will allow wider use of this method in the near future.

  16. Measuring microfocus focal spots using digital radiography

    SciTech Connect

    Fry, David A

    2009-01-01

    Measurement of microfocus spot size can be important for several reasons: (1) Quality assurance during manufacture of microfocus tubes; (2) Tracking performance and stability of microfocus tubes; (3) Determining magnification (especially important for digital radiography where the native spatial resolution of the digital system is not adequate for the application); (4) Knowledge of unsharpness from the focal spot alone. The European Standard EN 12543-5 is based on a simple geometrical method of calculating focal spot size from unsharpness of high magnification film radiographs. When determining microfocus focal spot dimensions using unsharpness measurements both signal-to-noise (SNR) and magnification can be important. There is a maximum accuracy that is a function of SNR and therefore an optimal magnification. Greater than optimal magnification can be used but it will not increase accuracy.

  17. Polarized neutron radiography with a periscope

    NASA Astrophysics Data System (ADS)

    Schulz, Michael; Neubauer, Andreas; Mühlbauer, Martin; Calzada, Elbio; Schillinger, Burkhard; Pfleiderer, Christian; Böni, Peter

    2010-01-01

    The interaction of the magnetic moment of the neutron with magnetic fields provides a powerful probe for spatially resolved magnetisation measurements in magnetic materials. We have tested a periscope as a new type of polarizer providing neutron beams with a high polarization and a low divergence. The observed inhomogeneity of the beam caused by the waviness of the glass substrates was quantified by means of Monte-Carlo simulations using the software package McStas. The results show that beams of high homogeneity can be produced if the waviness is reduced to below 1.0·10-5 rad. Finally, it is shown that radiography with polarized neutrons is a powerful method for measuring the spatially resolved magnetisation in optically float-zoned samples of the weak itinerant ferromagnet Ni3Al, thereby aiding the identification of the appropriate growth parameters.

  18. Direct magnification radiography of the newborn infant

    SciTech Connect

    Brasch, R.C.; Gould, R.G.

    1982-03-01

    Recent advances in technology have made direct radiographic magnification of the newborn infant clinically feasible. A microfocus radiographic tube and a rare-earth, high-speed recording system were combined to obtain more than 2,000 radiographs at magnifications of 2-2.5. Special positioning devices permitted imaging of even those infants confined to incubators and connected to life-supporting systems. When quantitatively compared with three conventional contact radiographic systems with respect to resolution, contrast, and noise, magnification radiography showed overall superiority of image characteristics. Definition of subtle abnormalities and anatomically small structures permitted diagnoses which could not be made from conventional images. Furthermore, infant radiation exposure was markedly less (15 mR (3.9 mC/kg) maximum skin exposure) as compared with conventional contact radiographic systems (24 mR (6.1 mC/kg) to 45 mR (11.6 mC/kg)).

  19. Direct magnification radiography of the newborn infant

    SciTech Connect

    Brasch, R.C.; Gould, R.G.

    1982-03-01

    Recent advances in technology have made direct radiographic magnification of the newborn infant clinically feasible. A microfocus radiographic tube and a rare-earth, high-speed recording system were combined to obtain more than 2,000 radiographs at magnifications of 2 to 2.5. Special positioning devices permitted imaging of even those infants confined to incubators and connected to life-supporting systems. When quantitatively compared with three conventional contact radiographic systems with respect to resolution, contrast, and noise, magnification radiography showed overall superiority of image characteristics. Definition of subtle abnormalities and anatomically small structures permitted diagnoses which could not be made from conventional images. Furthermore, infant radiation exposure was markedly less (15 mR (3.9 mC/kg) maximum skin exposure) as compared with conventional contact radiographic systems (24 mR(6.1 mC/kg) to 45 mR (11.6 mC/kg)).

  20. Digital radiography exposure indices: A review

    SciTech Connect

    Mothiram, Ursula; Brennan, Patrick C; Lewis, Sarah J; Moran, Bernadette; Robinson, John

    2014-06-15

    Digital radiography (DR) technologies have the advantage of a wide dynamic range compared to their film-screen predecessors, however, this poses a potential for increased patient exposure if left unchecked. Manufacturers have developed the exposure index (EI) to counter this, which provides radiographers with feedback on the exposure reaching the detector. As these EIs were manufacturer-specific, a wide variety of EIs existed. To offset this, the international standardised EI has been developed by the International Electrotechnical Commission (IEC) and the American Association of Physicists in Medicine (AAPM). The purpose of this article is to explore the current literature relating to EIs, beginning with the historical development of the EI, the development of the standardised EI and an exploration of common themes and studies as evidenced in the research literature. It is anticipated that this review will provide radiographers with a useful guide to understanding EIs, their application in clinical practice, limitations and suggestions for further research.

  1. Atypical Forensic Dental Identifications.

    PubMed

    Cardoza, Anthony R; Wood, James D

    2015-06-01

    Forensic dental identification specialists are typically the last conventional option for postmortem identification. Forensic dental identification is most often accomplished by comparing radiographs of the decedent's teeth with the dental radiographs obtained from the dentist of the suspected victim. Unfortunately, antemortem dental radiographs are not always available. When presented with this challenge, the authors of this article have been successful in completing identifications using means other than dental radiographic comparison.

  2. Dental cone beam computed tomography: justification for use in planning oral implant placement.

    PubMed

    Jacobs, Reinhilde; Quirynen, Marc

    2014-10-01

    Intra-oral and panoramic radiographs are most frequently used in oral health care. Yet, the inherent nature of jaws and teeth renders three-dimensional diagnosis essential, especially in relation to oral surgery. Nowadays, this can be accomplished by dental cone beam computed tomography, which provides high-quality images at low radiation doses and low costs. Nonetheless, the effective dose ranges of cone beam computed tomography machines may easily vary from 10 to 1000 μSv, this being equivalent to two to 200 panoramic radiographs, even for similar presurgical indications. Moreover, the diagnostic image quality varies massively among available machines and parameter settings. Apart from the radiodiagnostic possibilities, dental cone beam computed tomography may offer a vast therapeutic potential, including opportunities for surgical guidance and further prosthetic rehabilitation via computer-aided design/computer-aided manufacturing solutions. These additional options may definitely explain part of the success of cone beam computed tomography for oral implant placement. In conclusion, dental cone beam computed tomography imaging could be justified for oral implant-related diagnosis, planning and transfer to surgical and further prosthetic treatment, but guidelines for justification and cone beam computed tomography optimization remain mandatory.

  3. Muscle parameters estimation based on biplanar radiography.

    PubMed

    Dubois, G; Rouch, P; Bonneau, D; Gennisson, J L; Skalli, W

    2016-11-01

    The evaluation of muscle and joint forces in vivo is still a challenge. Musculo-Skeletal (musculo-skeletal) models are used to compute forces based on movement analysis. Most of them are built from a scaled-generic model based on cadaver measurements, which provides a low level of personalization, or from Magnetic Resonance Images, which provide a personalized model in lying position. This study proposed an original two steps method to access a subject-specific musculo-skeletal model in 30 min, which is based solely on biplanar X-Rays. First, the subject-specific 3D geometry of bones and skin envelopes were reconstructed from biplanar X-Rays radiography. Then, 2200 corresponding control points were identified between a reference model and the subject-specific X-Rays model. Finally, the shape of 21 lower limb muscles was estimated using a non-linear transformation between the control points in order to fit the muscle shape of the reference model to the X-Rays model. Twelfth musculo-skeletal models were reconstructed and compared to their reference. The muscle volume was not accurately estimated with a standard deviation (SD) ranging from 10 to 68%. However, this method provided an accurate estimation the muscle line of action with a SD of the length difference lower than 2% and a positioning error lower than 20 mm. The moment arm was also well estimated with SD lower than 15% for most muscle, which was significantly better than scaled-generic model for most muscle. This method open the way to a quick modeling method for gait analysis based on biplanar radiography.

  4. Dental Age in Orthodontic Patients with Different Skeletal Patterns.

    PubMed

    Lauc, Tomislav; Nakaš, Enita; Latić-Dautović, Melina; Džemidžić, Vildana; Tiro, Alisa; Rupić, Ivana; Kostić, Mirjana; Galić, Ivan

    2017-01-01

    Objective. To evaluate the difference between chronological and dental age, calculated by Willems and Cameriere methods, in various skeletal patterns according to Steiner's ANB Classification. Methods. This retrospective cross-sectional study comprised the sample of 776 participants aged between 7 and 15 years (368 males and 408 females). For each participant, panoramic images (OPT) and laterolateral cephalograms (LC) were collected from the medical database. On LC ANB angle was measured; on OPT dental age (DA) was calculated while chronological age (CA) and sex were recorded. The sample was divided into three subgroups (Class I, Class II, and Class III) with similar distribution based on the chronological age and ANB angle. CA was calculated as the difference between the date of OPT imaging and the date of birth, while DA was evaluated using Willems and Cameriere methods. ANB angle was measured on LC by two independent investigators using the cephalometric software. Differences between sexes and the difference between dental and chronological age were tested by independent and paired samples t-test, respectively; one-way ANOVA was used to test differences among ANB classes with Tukey post hoc test to compare specific pairs of ANB classes. Results. The significant difference was found between Class III and other two skeletal classes in males using both dental age estimation methods. In Class III males dental age was ahead averagely by 0.41 years when using Willems method, while Cameriere method overestimated CA for 0.22 years. Conclusion. In males with Class III skeletal pattern, dental development is faster than in Classes I and II skeletal pattern. This faster development is not present in females.

  5. Dental Age in Orthodontic Patients with Different Skeletal Patterns

    PubMed Central

    Lauc, Tomislav; Nakaš, Enita; Latić-Dautović, Melina; Džemidžić, Vildana; Tiro, Alisa; Rupić, Ivana; Kostić, Mirjana

    2017-01-01

    Objective. To evaluate the difference between chronological and dental age, calculated by Willems and Cameriere methods, in various skeletal patterns according to Steiner's ANB Classification. Methods. This retrospective cross-sectional study comprised the sample of 776 participants aged between 7 and 15 years (368 males and 408 females). For each participant, panoramic images (OPT) and laterolateral cephalograms (LC) were collected from the medical database. On LC ANB angle was measured; on OPT dental age (DA) was calculated while chronological age (CA) and sex were recorded. The sample was divided into three subgroups (Class I, Class II, and Class III) with similar distribution based on the chronological age and ANB angle. CA was calculated as the difference between the date of OPT imaging and the date of birth, while DA was evaluated using Willems and Cameriere methods. ANB angle was measured on LC by two independent investigators using the cephalometric software. Differences between sexes and the difference between dental and chronological age were tested by independent and paired samples t-test, respectively; one-way ANOVA was used to test differences among ANB classes with Tukey post hoc test to compare specific pairs of ANB classes. Results. The significant difference was found between Class III and other two skeletal classes in males using both dental age estimation methods. In Class III males dental age was ahead averagely by 0.41 years when using Willems method, while Cameriere method overestimated CA for 0.22 years. Conclusion. In males with Class III skeletal pattern, dental development is faster than in Classes I and II skeletal pattern. This faster development is not present in females.

  6. Ex vivo evaluation of new 2D and 3D dental radiographic technology for detecting caries

    PubMed Central

    Tyndall, Donald; Mol, André; Everett, Eric T; Bangdiwala, Ananta

    2016-01-01

    Objectives: Proximal dental caries remains a prevalent disease with only modest detection rates by current diagnostic systems. Many new systems are available without controlled validation of diagnostic efficacy. The objective of this study was to evaluate the diagnostic efficacy of three potentially promising new imaging systems. Methods: This study evaluated the caries detection efficacy of Schick 33 (Sirona Dental, Salzburg, Austria) intraoral digital detector images employing an advanced sharpening filter, Planmeca ProMax® (Planmeca Inc., Helsinki, Finland) extraoral “panoramic bitewing” images and Sirona Orthophos XG3D (Sirona Dental) CBCT images with advanced artefact reduction. Conventional photostimulable phosphor images served as the control modality. An ex vivo study design using extracted human teeth, ten expert observers and micro-CT ground truth was employed. Results: Receiver operating characteristic analysis indicated similar diagnostic efficacy of all systems (ANOVA p > 0.05). The sensitivity of the Schick 33 images (0.48) was significantly lower than the other modalities (0.53–0.62). The specificity of the Planmeca images (0.86) was significantly lower than Schick 33 (0.96) and XG3D (0.97). The XG3D showed significantly better cavitation detection sensitivity (0.62) than the other modalities (0.48–0.57). Conclusions: The Schick 33 images demonstrated reduced caries sensitivity, whereas the Planmeca panoramic bitewing images demonstrated reduced specificity. XG3D with artefact reduction demonstrated elevated sensitivity and specificity for caries detection, improved depth accuracy and substantially improved cavitation detection. Care must be taken to recognize potential false-positive caries lesions with Planmeca panoramic bitewing images. Use of CBCT for caries detection must be carefully balanced with the presence of metal artefacts, time commitment, financial cost and radiation dose. PMID:26670605

  7. The Enhanced Workflow and Efficiency of the Wireless Local Area Network (WLAN)-Based Direct Digital Radiography (DDR) Portable Radiography.

    PubMed

    Ngan, Tsz-Lung; Wong, Edward Ting-Hei; Ng, Kris Lap-Shun; Jeor, Patrick Kwok-Shing; Lo, Gladys Goh

    2015-06-01

    With the implementation of the PACS in the hospital, there is an increasing demand from the clinicians for immediate access and display of radiological images. Recently, our hospital has installed the first wireless local area network (WLAN)-based direct digital radiography (DDR) portable radiography system. The DDR portable radiography system allows wireless retrieval of modality worklist and wireless transmission of portable X-ray image on the console to the Picture Archiving and Communication System (PACS), via WLAN connection of wireless fidelity (Wi-Fi). The aim of this study was to analyze the workflow and performance between the WLAN-based DDR portable radiography system and the old practice using conventional portable X-ray machine with computed radiography (CR) system. A total of 190 portable chest X-ray examinations were evaluated and timed, using the conventional portable X-ray machine with CR from March to April of 2012 and using the new DDR portable radiography system on December of 2012 (n = 97 for old system and n = 93 for DDR portable system). The time interval of image becoming available to the PACS using the WLAN-based DDR portable radiography system was significantly shorter than that of the old practice using the conventional portable X-ray machine with CR (6.8 ± 2.6 min for DDR portable system; 23 ± 10.2 min for old system; p < 0.0001), with the efficiency improved by 70 %. The implementation of the WLAN-based DDR portable radiography system can enhance the workflow of portable radiography by reduction of procedural steps.

  8. Hygiene implications associated with x-ray exposures to dental patients

    SciTech Connect

    McKlveen, J.W.

    1980-12-01

    An elastic mask worn by patients, then a skeleton encased in plastic, was instrumented with LiF thermoluminescent dosimeters to quantify radiation exposures delivered from full-face diagnostic dental x-rays. Locations of interest included skin surface, eyes, upper and lower teeth and thyroid. Exposures in the 100 mR range were common and a maximum of over 6000 mR was measured in the teeth region during a full-face examination with a periapical unit. In general, exposures received from periapical equipment were several times those obtained from panoramic devices.

  9. Bilateral dentigerous cysts that involve all four dental quadrants: a case report and literature review

    PubMed Central

    2016-01-01

    Dentigerous cysts are common odontogenic cysts that are associated with the crown of the tooth and typically develop from single lesions. Bilateral and multiple dentigerous cysts are very rare and occur in patients with syndromic conditions. This paper presents a case report of a 15-year-old male patient that experienced non-syndromic bilateral dentigerous cysts that simultaneously occurred in all four dental quadrants around the unerupted third molars. Clinicians should confirm the extent of cystic lesions using a panoramic view and computed tomography, and should keep the possibility of bilateral dentigerous cysts in mind as a potential diagnosis, even in a non-syndromic patient. PMID:27162755

  10. 5. INTERIOR VIEW, SHOWING A CONTROL ROOM INSIDE THE RADIOGRAPHY ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    5. INTERIOR VIEW, SHOWING A CONTROL ROOM INSIDE THE RADIOGRAPHY ROOM; PASS-THROUGH FOR EXPOSED FILM ON RIGHT - Fort McCoy, Building No. T-1031, North side of South Tenth Avenue, Block 10, Sparta, Monroe County, WI

  11. Radiography with the Fission Neutrons from Californium-252

    DTIC Science & Technology

    1977-07-01

    iftD-Ao45 3^ m-77-B1i2i TECHNICAL 7󈧖 LIBRARY lADfto^^^ RADIOGRAPHY WITH THE FISSION NEUTRONS FROM CALIFORNIUM -252 JOHN J. ANTAL and...TITLE C«id Sub(l(/«J RADIOGRAPHY WITH THE FISSION NEUTRONS FROM CALIFORNIUM -252 5. TYPE OF REPORT it PERIOD COVERED Final Report 6...Cellulose nitrate Californium -252 20. ABSTRACT (Continue on reverse aide 11 necessary and identity by block number) (SEE REVERSE SIDE) DD 1

  12. The prevalence of specific dental anomalies in a group of Saudi cleft lip and palate patients

    PubMed Central

    Al-Kharboush, Ghada H.; Al-Balkhi, Khalid M.; Al-Moammar, Khalid

    2015-01-01

    Objective The aims of this study were to investigate the prevalence and distribution of dental anomalies in a group of Saudi subjects with cleft lip and palate (CLP), to examine potential sex-based associations of these anomalies, and to compare dental anomalies in Saudi subjects with CLP with published data from other population groups. Design This retrospective study involved the examination of pre-treatment records obtained from three CLP centers in Riyadh, Saudi Arabia, in February and March 2010. The pre-treatment records of 184 subjects with cleft lip and palate were identified and included in this study. Pre-treatment maxillary occlusal radiographs of the cleft region, panoramic radiographs, and orthodontic study models of subjects with CLP were analyzed for dental anomalies. Results Orthopantomographs and occlusal radiographs may not be reliable for the accurate evaluation of root malformation anomalies. A total of 265 dental anomalies were observed in the 184 study subjects. Hypodontia was observed most commonly (66.8%), followed by microdontia (45.6%), intra-oral ectopic eruption (12.5%), supernumerary teeth (12.5%), intra-nasal ectopic eruption (3.2), and macrodontia (3.2%). No gender difference in the prevalence of these anomalies was observed. Conclusions Dental anomalies were common in Saudi subjects with CLP type. This will complicate the health care required for the CL/P subjects. This study was conducted to epidemiologically explore the prevalence of dental anomalies among Saudi Arabian subjects with CLP. PMID:26082573

  13. Diagnostic Imaging of Dental Disease in Pet Rabbits and Rodents.

    PubMed

    Capello, Vittorio

    2016-09-01

    Diagnostic imaging techniques are of paramount importance for dentistry and oral disorders of rabbits, rodents, and other exotic companion mammals. Aside from standard radiography, stomatoscopy is a complementary tool allowing a thorough and detailed inspection of the oral cavity. Computed tomography (CT) generates multiple 2-dimensional views and 3-dimensional reconstructions providing superior diagnostic accuracy also useful for prognosis and treatment of advanced dental disease and its related complications. MRI is a diagnostic imaging technique additional to CT used primarily to enhance soft tissues, including complex odontogenic abscesses.

  14. Electronic intraoral dental x-ray imaging system employing a direct sensing CCD array

    SciTech Connect

    Cox, J.D.; Langford, D.S.; Williams, D.W.

    1993-12-31

    A commercial prototype intraoral radiography system has been developed that can provide digital x-ray images for diagnosis. The system consists of an intraoral detector head, an intermediate drive electronics package, a main drive electronics package and a PC-based digital image management system. The system has the potential to replace the use of dental film in intraoral radiographic examinations. High-resolution images are acquired, then displayed on a CRT within seconds of image acquisition.

  15. Bilateral tonsillolithiasis: a case report.

    PubMed

    Ozcan, Emel; Ural, Ahmet; Oktemer, Tuğba Koçak; Alpaslan, Gökhan

    2006-09-01

    Although tonsilloliths are reported to be fairly common, florid cases casting distinct radiopaque shadows on panoramic radiographs are not often reported. This report illustrates such a case as an incidental finding in an asymptomatic 38-year-old female dental patient. Panoramic radiography revealed distinct radiopaque shadows over the ascending rami of the mandible bilaterally. These radiopacities were localized to the palatine tonsils by computerized tomographic inspection. Tonsillectomy was performed and tonsillolithiasis was confirmed by histopathologic examination.

  16. Neutron radiography inspection of investment castings.

    PubMed

    Richards, W J; Barrett, J R; Springgate, M E; Shields, K C

    2004-10-01

    Investment casting, also known as the lost wax process, is a manufacturing method employed to produce near net shape metal articles. Traditionally, investment casting has been used to produce structural titanium castings for aero-engine applications with wall thickness less than 1 in (2.54 cm). Recently, airframe manufacturers have been exploring the use of titanium investment casting to replace components traditionally produced from forgings. Use of titanium investment castings for these applications reduces weight, cost, lead time, and part count. Recently, the investment casting process has been selected to produce fracture critical structural titanium airframe components. These airframe components have pushed the traditional inspection techniques to their physical limits due to cross sections on the order of 3 in (7.6 cm). To overcome these inspection limitations, a process incorporating neutron radiography (n-ray) has been developed. In this process, the facecoat of the investment casting mold material contains a cocalcined mixture of yttrium oxide and gadolinium oxide. The presence of the gadolinium oxide, allows for neutron radiographic imaging (and eventual removal and repair) of mold facecoat inclusions that remain within these thick cross sectional castings. Probability of detection (POD) studies have shown a 3 x improvement of detecting a 0.050 x 0.007 in2 (1.270 x 0.178 mm2) inclusion of this cocalcined material using n-ray techniques when compared to the POD using traditional X-ray techniques. Further, it has been shown that this n-ray compatible mold facecoat material produces titanium castings of equal metallurgical quality when compared to the traditional materials. Since investment castings can be very large and heavy, the neutron radiography facilities at the University of California, Davis McClellan Nuclear Radiation Center (UCD/MNRC) were used to develop the inspection techniques. The UCD/MNRC has very unique facilities that can handle large

  17. Dental Auxiliary Occupations. Interim Report.

    ERIC Educational Resources Information Center

    Kingston, Richard D.

    As part of a dental auxiliaries project, a Dental Auxiliary National Technical Advisory Committee was established, and its major undertaking was to assist in the development of a functional inventory for each of the three dental auxiliary occupations (dental assisting, dental hygiene, and dental laboratory technology). The analysis consisted of…

  18. Toward panoramic in situ mapping of action potential propagation in transgenic hearts to investigate initiation and therapeutic control of arrhythmias

    PubMed Central

    Dura, Miroslav; Schröder-Schetelig, Johannes; Luther, Stefan; Lehnart, Stephan E.

    2014-01-01

    To investigate the dynamics and propensity for arrhythmias in intact transgenic hearts comprehensively, optical strategies for panoramic fluorescence imaging of action potential (AP) propagation are essential. In particular, mechanism-oriented molecular studies usually depend on transgenic mouse hearts of only a few millimeters in size. Furthermore, the temporal scales of the mouse heart remain a challenge for panoramic fluorescence imaging with heart rates ranging from 200 min−1 (e.g., depressed sinus node function) to over 1200 min−1 during fast arrhythmias. To meet these challenging demands, we and others developed physiologically relevant mouse models and characterized their hearts with planar AP mapping. Here, we summarize the progress toward panoramic fluorescence imaging and its prospects for the mouse heart. In general, several high-resolution cameras are synchronized and geometrically arranged for panoramic voltage mapping and the surface and blood vessel anatomy documented through image segmentation and heart surface reconstruction. We expect that panoramic voltage imaging will lead to novel insights about molecular arrhythmia mechanisms through quantitative strategies and organ-representative analysis of intact mouse hearts. PMID:25249982

  19. The usefulness of dental and cervical maturation stages in New Zealand children for Disaster Victim Identification.

    PubMed

    Timmins, Kimberley; Liversidge, Helen; Farella, Mauro; Herbison, Peter; Kieser, Jules

    2012-06-01

    Age estimation of young victims of natural and un-natural disasters remains a crucial and challenging task during the process of Disaster Victim Identification (DVI). The purpose of this study was to compare dental maturity using the Demirjian and Cameriere methods and to explore the relationship between dental age and cervical vertebral maturity (CVM) using the Hassel and Farman method for a group of New Zealand children. The study used lateral cephalometric and panoramic radiographs of 200 orthodontic patients aged 7-17 years. Dental age was calculated from mandibular tooth formation stages using the Demirjian and Cameriere methods by calculating the ratio of tooth length to apex width for these teeth. CVM was assessed using stages from Hassel and Farman. Reliability of maturity from reassessment of 20 radiographs showed good agreement for the three methods. Chronological and dental ages were compared using a mixed model. Descriptive statistics of dental ages by CVM stage were calculated. The results show that both dental methods were similar in assessing maturity. A disadvantage of using the Cameriere method was that all seven teeth reached maturity at 13.69 and 14.06 years in females and males respectively, compared to age 16 using the Dermijian method. Females reached CVM stages at earlier chronological and dental ages than males. Mean chronological age for CVM stages 2-5 is about 1 year earlier in females than males. The Demirjian and Cameriere methods of dental maturity and CVM are reliable and useful in assessing dental and skeletal maturity. Ideally in a DVI situation, both the methods of Demirjian and Cameriere, together with CVM, should be employed in the ageing of individuals suspected of being between 7 and 16 years.

  20. Association between dental anomalies and malocclusion in Brazilian orthodontic patients.

    PubMed

    Pedreira, Fernanda R de O; de Carli, Marina L; Pedreira, Renato do P G; Ramos, Patrícia de S; Pedreira, Marcelo R; Robazza, Carlos Roberto C; Hanemann, João Adolfo C

    2016-01-01

    Developmental dental anomalies have been associated with different malocclusions in various populations. This study verified this association in Brazilian non-syndromic orthodontic patients. The prevalence of dental anomalies was evaluated by examining 2,052 pretreatment records of orthodontic patients. Panoramic radiographs, study designs, intraoral photographs and medical history were collected in order to identify hypodontia, hyperdontia, microdontia, macrodontia, taurodontism, transposition, impaction, and ectopia. Epidemiological data and classification of malocclusion were also obtained. Data were analyzed using chi-square and Fisher's exact test (P < 0.05), and the prevalence ratio was obtained from cases that had a significant association between anomaly and malocclusion. The results showed that 27.4% of the patients evaluated had some dental anomaly, and most of them were white women aged 11-20 years. Ectopia, microdontia, impaction, and hypodontia were more prevalent in patients with Class I malocclusion. Macrodontia was the only anomaly associated with Class II division 1. Impaction was associated with Class III malocclusion, at a 1.84-times higher prevalence. In conclusion, impaction was correlated with Class I malocclusion; macrodontia showed association with Class II division 1; and impaction and ectopia were associated with Class III malocclusion in Brazilian orthodontic patients. (J Oral Sci 58, 75-81, 2016).

  1. Evaluation of panoramic digital images using Panoptiq for frozen section diagnosis

    PubMed Central

    Pradhan, Dinesh; Monaco, Sara E.; Parwani, Anil V.; Ahmed, Ishtiaque; Duboy, Jon; Pantanowitz, Liron

    2016-01-01

    Introduction: Whole slide imaging (WSI) permits intraoperative consultations (frozen sections) to be performed remotely. However, WSI files are large and can be problematic if there are tissue artifacts (e.g., tissue folds) or when slides are scanned without multiplanes (Z-stacks) to permit focusing. The Panoptiq dynamic imaging system allows users to create their own digital files that combine low power panoramic digital images with regions of interest that can be imaged using high power Z-stacks. The aim of this study was to determine the utility of the Panoptiq dynamic imaging system for frozen section telepathology. Materials and Methods: Twenty archival randomly selected genitourinary surgical pathology frozen sectional cases were evaluated using conventional light microscopy (glass slides), panoramic images, and whole slide images. To create panoramic images glass slides were digitized using a Prosilica GT camera (model GT1920C, Allied Vision Technologies) attached to an Olympus B × 45 microscope and Dell Precision Tower 810 computer (Dell). Panoptiq 3 version 3.1.2 software was used for image acquisition and Panoptiq View version 3.1.2 to view images (ViewsIQ, Richmond, BC, Canada). Image acquisition using Panoptiq software involved a pathology resident, who manually created digital maps (×4 objective) and then selected representative regions of interest to generate Z-stacks at higher magnification (×40 objective). Whole slide images were generated using an Aperio XT Scanscope (Leica) and viewed using ImageScope Software (Aperio ePathology, Leica). Three pathologists were asked to render diagnoses and rate image quality (1–10) and their diagnostic confidence (1–10) for each modality. Results: The diagnostic concordance with glass slides was 98.3% for panoramic images and 100% for WSI. Panoptiq images were comparable to the glass slide viewing experience in terms of image quality and diagnostic confidence. Complaints regarding WSI included poor focus

  2. Patient information extraction in digitized radiography.

    PubMed

    Wu, Hsien-Huang P

    2002-03-01

    Digital imagery is gradually replacing the traditional radiograph with the development of digital radiography and film scanner. This report presents a new method to extract the patient information number (PIN) field automatically from the film-scanned image using image analysis technique. To evaluate the PIN field extraction algorithm, 2 formats of label acquired from 2 different hospitals are tested. Given the available films with no constraints on the way the labels are written and positioned, the correct extraction rates are 73% and 84%, respectively. This extracted PIN information can link with Radiology Information System (RIS) or Hospital Information System (HIS), and the image scanned from the film then can be filed into the database automatically. The efficiency this method offers can simplify greatly the image filing process and improve the user friendliness of the overall image digitization system. Moreover, compared with the bar code reader, it solves the automatic information input problem in a very economical way. The authors believe the success of this technique will benefit the development of the PACS (Picture Archiving and Communication System) and teleradiology.

  3. Developments in digital radiography: an equipment update.

    PubMed

    James, J J; Davies, A G; Cowen, A R; O'Connor, P J

    2001-01-01

    Digital X-ray imaging technology has advanced rapidly over the past few years. This review, particularly aimed at those involved in using and purchasing such technology, is an attempt to unravel some of the complexities of this potentially confusing subject. The main groups of X-ray imaging devices that are considered are digitisers of conventional radiographs, image-intensifier-based fluorography systems, photostimulable phosphor computed radiography, amorphous selenium-based technology for thorax imaging and flat-panel systems. As well as describing these different systems, we look at ways of objectively assessing their image quality. Concepts that are used and explained include spatial resolution, grey-scale bit resolution, signal-to-noise ratio and detective quantum efficiency. An understanding of these basic parameters is vital in making a scientific assessment of a system's performance. Image processing and techniques are also briefly discussed, particularly with reference to their potential effects on image quality. This review aims to provide a basic understanding of digital X-ray imaging technology and enables the reader to make an independent and educated assessment of the relative merits of each system.

  4. Applications of Cosmic Ray Muon Radiography

    NASA Astrophysics Data System (ADS)

    Guardincerri, E.; Durham, J. M.; Morris, C. L.; Rowe, C. A.; Poulson, D. C.; Bacon, J. D.; Plaud-Ramos, K.; Morley, D. J.

    2015-12-01

    The Dome of Santa Maria del Fiore, Florence Cathedral, was built between 1420 and 1436 by architect Filippo Brunelleschi and it is now cracking under its own weight. Engineering efforts are underway to model the dome's structure and reinforce it against further deterioration. According to some scholars, Brunelleschi might have built reinforcement structures into the dome itself; however, the only confirmed known subsurface reinforcement is a chain of iron and stone around the dome's base. Tomography with cosmic ray muons is a non-destructive imaging method that can be used to image the interior of the wall and therefore ascertain the layout and status of any iron substructure in the dome. We will show the results from a muon tomography measurement of iron hidden in a mockup of the dome's wall performed at Los Alamos National Lab in 2015. The sensitivity of this technique, and the status of this project will be also discussed. At last, we will show results on muon attenuation radiography of larger shallow targets.

  5. Portable Digital Radiography and Computed Tomography Manual

    SciTech Connect

    Not Available

    2007-11-01

    This user manual describes the function and use of the portable digital radiography and computed tomography (DRCT) scanner. The manual gives a general overview of x-ray imaging systems along with a description of the DRCT system. An inventory of the all the system components, organized by shipping container, is also included. In addition, detailed, step-by-step procedures are provided for all of the exercises necessary for a novice user to successfully collect digital radiographs and tomographic images of an object, including instructions on system assembly and detector calibration and system alignment. There is also a short section covering the limited system care and maintenance needs. Descriptions of the included software packages, the DRCT Digital Imager used for system operation, and the DRCT Image Processing Interface used for image viewing and tomographic data reconstruction are given in the appendixes. The appendixes also include a cheat sheet for more experienced users, a listing of known system problems and how to mitigate them, and an inventory check-off sheet suitable for copying and including with the machine for shipment purposes.

  6. Beam Characterization at the Neutron Radiography Facility

    SciTech Connect

    Sarah Morgan; Jeffrey King

    2013-01-01

    The quality of a neutron imaging beam directly impacts the quality of radiographic images produced using that beam. Fully characterizing a neutron beam, including determination of the beam’s effective length-to-diameter ratio, neutron flux profile, energy spectrum, image quality, and beam divergence, is vital for producing quality radiographic images. This project characterized the east neutron imaging beamline at the Idaho National Laboratory Neutron Radiography Reactor (NRAD). The experiments which measured the beam’s effective length-to-diameter ratio and image quality are based on American Society for Testing and Materials (ASTM) standards. An analysis of the image produced by a calibrated phantom measured the beam divergence. The energy spectrum measurements consist of a series of foil irradiations using a selection of activation foils, compared to the results produced by a Monte Carlo n-Particle (MCNP) model of the beamline. Improvement of the existing NRAD MCNP beamline model includes validation of the model’s energy spectrum and the development of enhanced image simulation methods. The image simulation methods predict the radiographic image of an object based on the foil reaction rate data obtained by placing a model of the object in front of the image plane in an MCNP beamline model.

  7. Dental Exam for Children

    MedlinePlus

    ... and thumb sucking Toddlers, school-age children and adolescents During each regular checkup, the dentist or hygienist ... dental hygienist about proper oral health care for adolescents. American Dental Hygienists' Association. http://www.adha.org/ ...

  8. About Dental Amalgam Fillings

    MedlinePlus

    ... documents in the Related Resources section. Why is mercury used in dental amalgam? Approximately half of a ... about bioaccumulation, please see Related Resources. Is the mercury in dental amalgam the same as the mercury ...

  9. Analysis of the imaging performance of panoramic annular lens with conic conformal dome

    NASA Astrophysics Data System (ADS)

    Huang, Xiao; Bai, Jian

    2015-10-01

    Panoramic annular lens (PAL) is a kind of the specific wide angle lenses which is widely applied in panoramic imaging especially in aerospace field. As we known, to improve the aerodynamic performance of the aircraft, conformal dome, which notably reduces the drag of an aircraft, is also functioning as an optical window for the inbuilt optical system. However, there is still no report of the specific analysis of the imaging performance of PAL with conformal dome, which is imperative in its aerospace-related applications. In this paper, we propose an analysis of the imaging performance of a certain PAL with various conic conformal domes. Working in visible wavelength, the PAL in our work observes 360° surroundings with a large field of view (FOV) ranging from 30° ~105° . Meanwhile, various thicknesses, half-vertex angles, materials of the conic dome and the central distances between the dome and PAL are considered. The imaging performances, mainly indicated by modulation transfer function (MTF) as well as RMS radius of the spot diagram, are systematically compared. It is proved that, on the contrary to the general cases, the dome partly contributes to the imaging performance of the inbuilt PAL. In particular, with a conic conformal dome in material of K9 glass with a half-vertex angle of 25° and a thickness of 6mm, the maximum MTF at 100lp/mm could be improved by 6.68% with nearly no degeneration of the minimum MTF, and the RMS radius could be improved by 14.76% to 19.46% in different FOV. It is worth to note that the PAL is adaptive to panoramic aerospace applications with conic or quasi-conic conformal dome and the co-design of both PAL and the dome is very important.

  10. 75 FR 33169 - Dental Devices: Classification of Dental Amalgam, Reclassification of Dental Mercury, Designation...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-06-11

    ...-AG21 Dental Devices: Classification of Dental Amalgam, Reclassification of Dental Mercury, Designation of Special Controls for Dental Amalgam, Mercury, and Amalgam Alloy; Technical Amendment AGENCY: Food... classified dental amalgam as a class II device, reclassified dental mercury from class I to class II,...

  11. DENTAL MATURITY AS AN INDICATOR OF CHRONOLOGICAL AGE: RADIOGRAPHIC ASSESSMENT OF DENTAL AGE IN A BRAZILIAN POPULATION

    PubMed Central

    Kurita, Lucio Mitsuo; Menezes, Alynne Vieira; Casanova, Marcia Spinelli; Haiter-Neto, Francisco

    2007-01-01

    Objective: The purpose of this investigation was to evaluate the applicability of the methods proposed by Nolla and by Nicodemo and colleagues for assessing dental age and its correlation to chronological age. Methods: Panoramic radiographs of 360 patients from the city of Fortaleza (CE, Brazil) aged 7-15 years were used to assess the associations between dental and chronological age. Data were submitted to statistical analysis using the BioEstat 2.0 (2000) software. Student-Neuman-Keuls test was performed and Pearson's correlation coefficients were calculated at 5% significance level. Results: When the Nolla method was applied, the mean difference between true and estimated age for males and females was underestimated. The use of the method proposed by Nicodemo and colleagues also resulted in underestimation, although it was more evident in male subjects. The correlation coefficients between chronological age and estimated dental age were high, with mean values ranging between 0.87 and 0.91 for males and between 0.84 and 0.93 for females. Conclusion: Although both methods proved to be reliable in estimating age, the use of correction factors is recommended. PMID:19089110

  12. A method to optimize the processing algorithm of a computed radiography system for chest radiography.

    PubMed

    Moore, C S; Liney, G P; Beavis, A W; Saunderson, J R

    2007-09-01

    A test methodology using an anthropomorphic-equivalent chest phantom is described for the optimization of the Agfa computed radiography "MUSICA" processing algorithm for chest radiography. The contrast-to-noise ratio (CNR) in the lung, heart and diaphragm regions of the phantom, and the "system modulation transfer function" (sMTF) in the lung region, were measured using test tools embedded in the phantom. Using these parameters the MUSICA processing algorithm was optimized with respect to low-contrast detectability and spatial resolution. Two optimum "MUSICA parameter sets" were derived respectively for maximizing the CNR and sMTF in each region of the phantom. Further work is required to find the relative importance of low-contrast detectability and spatial resolution in chest images, from which the definitive optimum MUSICA parameter set can then be derived. Prior to this further work, a compromised optimum MUSICA parameter set was applied to a range of clinical images. A group of experienced image evaluators scored these images alongside images produced from the same radiographs using the MUSICA parameter set in clinical use at the time. The compromised optimum MUSICA parameter set was shown to produce measurably better images.

  13. Accreditation in Dental Hygiene.

    ERIC Educational Resources Information Center

    National Commission on Accrediting, Washington, DC.

    The Council on Dental Education cooperates with the American Dental Hygienists' Association in developing educational requirements for schools of dental hygiene. To be eligible for accreditation, schools must operate on a non-profit basis. A school applying for accreditation completes a previsitation questionnaire concerning its program. The…

  14. Dental Manpower Fact Book.

    ERIC Educational Resources Information Center

    Ake, James N.; Johnson, Donald W.

    Statistical data on many aspects of dental and allied dental personnel supply, distribution, characteristics, and education and on certain other aspects of dental services are presented and discussed. The data on dentist supply show the national trend in the supply of active dentists since 1950 and the concurrent changes in dentist-to-population…

  15. Dental Laboratory Technology.

    ERIC Educational Resources Information Center

    Department of the Air Force, Washington, DC.

    The Air Force dental laboratory technology manual is designed as a basic training text as well as a reference source for dental laboratory technicians, a specialty occupation concerned with the design, fabrication, and repair of dental prostheses. Numerous instructive diagrams and photographs are included throughout the manual. The comprehensive…

  16. DENTAL SCHOOL PLANNING.

    ERIC Educational Resources Information Center

    GALAGAN, DONALD J.

    THIS DISCUSSION PRESENTS A COMPLETE PICTURE OF THE CURRENT STATE OF DENTAL EDUCATION WITH SUGGESTIONS FOR MEETING THE DEMANDS FOR DENTAL STAFF AND FACILITIES. THE AREAS INVESTIGATED ARE (1) OBJECTIVES IN DENTAL EDUCATION--COURSES, TEACHING MODES, INNOVATIONS IN CURRICULUM, COORDINATION OF BASIC AND CLINICAL INSTRUCTION, (2) FACILITY…

  17. Dental Assisting Laboratory Manual.

    ERIC Educational Resources Information Center

    Thiel, Sandra J.

    Compiled to introduce the dental assisting student to various techniques used in the dental office and to present theoretical information essential for the student's professional development, this laboratory guide consists of three units of instruction. The first unit is an introduction to dental assisting and contains five topics of study. The…

  18. Perspectives from Dental Research.

    ERIC Educational Resources Information Center

    Baum, Bruce J.

    1996-01-01

    This paper responds to the Institute of Medicine's 1995 report concerning the present status and future needs of dental education in the United States. It examines whether real reform is occurring at the National Institute of Dental Research, within the academic dental community, and within the practicing profession. It concludes that very little…

  19. Is there a relation between local bone quality as assessed on panoramic radiographs and alveolar bone level?

    PubMed

    Nackaerts, Olivia; Gijbels, Frieda; Sanna, Anna-Maria; Jacobs, Reinhilde

    2008-03-01

    The aim was to explore the relation between radiographic bone quality on panoramic radiographs and relative alveolar bone level. Digital panoramic radiographs of 94 female patients were analysed (mean age, 44.5; range, 35-74). Radiographic density of the alveolar bone in the premolar region was determined using Agfa Musica software. Alveolar bone level and bone quality index (BQI) were also assessed. Relationships between bone density and BQI on one hand and the relative loss of alveolar bone level on the other were assessed. Mandibular bone density and loss of alveolar bone level were weakly but significantly negatively correlated for the lower premolar area (r = -.27). The BQI did not show a statistically significant relation to alveolar bone level. Radiographic mandibular bone density on panoramic radiographs shows a weak but significant relation to alveolar bone level, with more periodontal breakdown for less dense alveolar bone.

  20. Xeroradiography for intraoral dental radiology. A process description.

    PubMed

    Jeromin, L S; Geddes, G F; White, S C; Gratt, B M

    1980-02-01

    A novel x-ray imaging system for intraoral dental radiography is described. The imaging process is based on xeroradiographic principles. The surface of a small selenium photoreceptor is electrically charged. After insertion into a light-tight cassette, the photoreceptor is placed intraorally and x-ray exposed like film. The resultant electrostatic charge image is developed in a processor using liquid toner. The toner image is then transferred from the photoreceptor and fixed to a white plastic substrate for viewing. After cleaning, the photoreceptor is available for reuse. In contrast to film images, xeroradiographic images are exposed and processed sequentially. Processing time is approximately 20 seconds. Two image characteristics--edge enhancement and deletion--are primarily responsible for many advantageous qualities of xeroradiographic images over film images. An experimental processor was tested successfully at two dental schools.

  1. Weaker Dental Enamel Explains Dental Decay

    PubMed Central

    Vieira, Alexandre R.; Gibson, Carolyn W.; Deeley, Kathleen; Xue, Hui; Li, Yong

    2015-01-01

    Dental caries continues to be the most prevalent bacteria-mediated non-contagious disease of humankind. Dental professionals assert the disease can be explained by poor oral hygiene and a diet rich in sugars but this does not account for caries free individuals exposed to the same risk factors. In order to test the hypothesis that amount of amelogenin during enamel development can influence caries susceptibility, we generated multiple strains of mice with varying levels of available amelogenin during dental development. Mechanical tests showed that dental enamel developed with less amelogenin is “weaker” while the dental enamel of animals over-expressing amelogenin appears to be more resistant to acid dissolution. PMID:25885796

  2. Design and implementation of three-dimension texture mapping algorithm for panoramic system based on smart platform

    NASA Astrophysics Data System (ADS)

    Liu, Zhi; Zhou, Baotong; Zhang, Changnian

    2017-03-01

    Vehicle-mounted panoramic system is important safety assistant equipment for driving. However, traditional systems only render fixed top-down perspective view of limited view field, which may have potential safety hazard. In this paper, a texture mapping algorithm for 3D vehicle-mounted panoramic system is introduced, and an implementation of the algorithm utilizing OpenGL ES library based on Android smart platform is presented. Initial experiment results show that the proposed algorithm can render a good 3D panorama, and has the ability to change view point freely.

  3. Recent advances in fast neutron radiography for cargo inspection

    NASA Astrophysics Data System (ADS)

    Sowerby, B. D.; Tickner, J. R.

    2007-09-01

    Fast neutron radiography techniques are attractive for screening cargo for contraband such as narcotics and explosives. Neutrons have the required penetration, they interact with matter in a manner complementary to X-rays and they can be used to determine elemental composition. Compared to neutron interrogation techniques that measure secondary radiation (neutron or gamma-rays), neutron radiography systems are much more efficient and rapid and they are much more amenable to imaging. However, for neutron techniques to be successfully applied to cargo screening, they must demonstrate significant advantages over well-established X-ray techniques. This paper reviews recent developments and applications of fast neutron radiography for cargo inspection. These developments include a fast neutron and gamma-ray radiography system that utilizes a 14 MeV neutron generator as well as fast neutron resonance radiography systems that use variable energy quasi-monoenergetic neutrons and pulsed broad energy neutron beams. These systems will be discussed and compared with particular emphasis on user requirements, sources, detector systems, imaging ability and performance.

  4. Evaluation of a Noise Reduction Procedure for Chest Radiography

    PubMed Central

    Fukui, Ryohei; Ishii, Rie; Kodani, Kazuhiko; Kanasaki, Yoshiko; Suyama, Hisashi; Watanabe, Masanari; Nakamoto, Masaki; Fukuoka, Yasushi

    2013-01-01

    Background The aim of this study was to evaluate the usefulness of noise reduction procedure (NRP), a function in the new image processing for chest radiography. Methods A CXDI-50G Portable Digital Radiography System (Canon) was used for X-ray detection. Image noise was analyzed with a noise power spectrum (NPS) and a burger phantom was used for evaluation of density resolution. The usefulness of NRP was evaluated by chest phantom images and clinical chest radiography. We employed the Bureau of Radiological Health Method for scoring chest images while carrying out our observations. Results NPS through the use of NRP was improved compared with conventional image processing (CIP). The results in image quality showed high-density resolution through the use of NRP, so that chest radiography examination can be performed with a low dose of radiation. Scores were significantly higher than for CIP. Conclusion In this study, use of NRP led to a high evaluation in these so we are able to confirm the usefulness of NRP for clinical chest radiography. PMID:24574577

  5. Small-scale anomaly detection in panoramic imaging using neural models of low-level vision

    NASA Astrophysics Data System (ADS)

    Casey, Matthew C.; Hickman, Duncan L.; Pavlou, Athanasios; Sadler, James R. E.

    2011-06-01

    Our understanding of sensory processing in animals has reached the stage where we can exploit neurobiological principles in commercial systems. In human vision, one brain structure that offers insight into how we might detect anomalies in real-time imaging is the superior colliculus (SC). The SC is a small structure that rapidly orients our eyes to a movement, sound or touch that it detects, even when the stimulus may be on a small-scale; think of a camouflaged movement or the rustle of leaves. This automatic orientation allows us to prioritize the use of our eyes to raise awareness of a potential threat, such as a predator approaching stealthily. In this paper we describe the application of a neural network model of the SC to the detection of anomalies in panoramic imaging. The neural approach consists of a mosaic of topographic maps that are each trained using competitive Hebbian learning to rapidly detect image features of a pre-defined shape and scale. What makes this approach interesting is the ability of the competition between neurons to automatically filter noise, yet with the capability of generalizing the desired shape and scale. We will present the results of this technique applied to the real-time detection of obscured targets in visible-band panoramic CCTV images. Using background subtraction to highlight potential movement, the technique is able to correctly identify targets which span as little as 3 pixels wide while filtering small-scale noise.

  6. Italian panoramic monochromator for the THEMIS telescope: the first results and instrument evaluation

    NASA Astrophysics Data System (ADS)

    Cavallini, Fabio; Berrilli, Francesco; Caccin, Bruno; Cantarano, Sergio; Ceppatelli, Guido; Egidi, Alberto; Righini, Alberto

    1998-07-01

    We briefly describe the design and the characteristics of the Italian Panoramic Monochromator installed at the focal plane of the THEMIS telescope built in Izana by a joint venture of the French and Italian National Research Councils. The Panoramic Monochromator substantially is a narrow band filter (approximately equals 22 mAngstrom bandwidth) tunable on the visible spectrum for quasi simultaneous bidimensional spectrometry of the solar atmosphere. The narrow bandwidth is obtained by using a non standard birefringent filter and a Fabry Perot interferometer mounted in series. This assembly has the advantage of the spectral purity of one channel of the Fabry Perot interferometer and a very large free spectral range. Moreover the spectral stability depends on the interferometer, the environment of which may be carefully controlled. The design of this instrument is not really new, but, only now it has been possible to build it thanks to the development of servo controlled Fabry Perot interferometers, which are stable in time and may easily be tuned. The system seems to perform well. It is stable in wavelength and the spectral pass band and stray light are within the expected values, as it may be deduced by very preliminary tests performed at the THEMIS Telescope and in Arcetri (Firenze) at the 'G. B. Donati' solar tower.

  7. Determination of sexual dimorphism in humans by measurements of mandible on digital panoramic radiograph

    PubMed Central

    Sairam, V.; Geethamalika, M. V.; Kumar, Praveen B.; Naresh, G.; Raju, Gareema P.

    2016-01-01

    Background: Identification of sex is the first step in forensic science obtained from skeletal remains. Mandible, being a strong bone that is difficult to damage and disintegrate, is an important tool in sex determination. The present study is aimed to assess, compare, and evaluate the mandibular measurements as seen on digital panoramic radiographs to analyze their use in sexual dimorphism assessment. Materials and Methods: This retrospective study was conducted using digital panoramic images of 100 each in both genders. Mandibular measurements were carried out utilizing RadiAnt DICOM Viewer 2.2.9 (32 bit) software (Medixant Company, Poland) and subjected to statistical analysis. Results: Descriptive statistics for all the parameters on the right and left sides of mandible in both males and females were analyzed. Inferential statistics were performed using t-test to compare males and females with different variables. A statistical significance of P < 0.001 has been demonstrated for all the variables (except linear measurement of mandibular foramen). All variables showed increased measurements in males than in females. The accuracy of sex determination in mandibular ramus measurements is 79.5% on right side and 77% on left side, where as, in linear mandibular measurements it is 76% on right side and 79.5% on left side. Conclusion: Mandibular measurements on digital radiograph are useful in sex determination, and this study can be compared with other similar studies. PMID:27994407

  8. Exposure reduction of 96% in intraoral radiography

    SciTech Connect

    Kircos, L.T.; Vandre, R.H.; Lorton, L.

    1986-11-01

    This study compared the diagnostic quality of E-speed film, xeroradiographic cassettes, and a screen-film imaging system used in medical radiology. The surfaces of defects simulating caries were scored for the presence and depth of the defects under ideal viewing conditions by independent observers. Receiver Operator Characteristics analysis of the data showed no significant differences regarding diagnostic potential among the three systems. The true-positive fraction was 1.00 for all systems and all operators, and the false-positive fraction was .011, .011, and .007, respectively. An exposure of 5.5 mR was used to produce images with the screen-film combination, and 150 mR was used for standard dental systems. This study showed that an exposure reduction of 96% is possible while maintaining high-quality radiographs for the diagnosis of caries.

  9. 42 CFR Appendix C to Part 75 - Standards for Accreditation of Dental Radiography Training for Dental Assistants

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... areas: radiation physics; radiation biology; radiation health, safety, and protection; X-ray films and...-radiation; and X-radiation units, detection and monitoring devices. —Radiation Biology. Curriculum...

  10. 42 CFR Appendix C to Part 75 - Standards for Accreditation of Dental Radiography Training for Dental Assistants

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... areas: radiation physics; radiation biology; radiation health, safety, and protection; X-ray films and...-radiation; and X-radiation units, detection and monitoring devices. —Radiation Biology. Curriculum...

  11. 42 CFR Appendix B to Part 75 - Standards for Accreditation of Dental Radiography Training for Dental Hygienists

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... must include content in seven areas: radiation physics; radiation biology; radiation health, safety... devices. —Radiation Biology. Curriculum content should include: Interaction of ionizing radiation...

  12. 42 CFR Appendix B to Part 75 - Standards for Accreditation of Dental Radiography Training for Dental Hygienists

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... must include content in seven areas: radiation physics; radiation biology; radiation health, safety... devices. —Radiation Biology. Curriculum content should include: Interaction of ionizing radiation...

  13. 42 CFR Appendix C to Part 75 - Standards for Accreditation of Dental Radiography Training for Dental Assistants

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... areas: radiation physics; radiation biology; radiation health, safety, and protection; X-ray films and...-radiation; and X-radiation units, detection and monitoring devices. —Radiation Biology. Curriculum...

  14. 42 CFR Appendix B to Part 75 - Standards for Accreditation of Dental Radiography Training for Dental Hygienists

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... must include content in seven areas: radiation physics; radiation biology; radiation health, safety... devices. —Radiation Biology. Curriculum content should include: Interaction of ionizing radiation...

  15. 42 CFR Appendix B to Part 75 - Standards for Accreditation of Dental Radiography Training for Dental Hygienists

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... must include content in seven areas: radiation physics; radiation biology; radiation health, safety... devices. —Radiation Biology. Curriculum content should include: Interaction of ionizing radiation...

  16. 42 CFR Appendix C to Part 75 - Standards for Accreditation of Dental Radiography Training for Dental Assistants

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... areas: radiation physics; radiation biology; radiation health, safety, and protection; X-ray films and...-radiation; and X-radiation units, detection and monitoring devices. —Radiation Biology. Curriculum...

  17. 42 CFR Appendix C to Part 75 - Standards for Accreditation of Dental Radiography Training for Dental Assistants

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... areas: radiation physics; radiation biology; radiation health, safety, and protection; X-ray films and...-radiation; and X-radiation units, detection and monitoring devices. —Radiation Biology. Curriculum...

  18. 42 CFR Appendix B to Part 75 - Standards for Accreditation of Dental Radiography Training for Dental Hygienists

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... must include content in seven areas: radiation physics; radiation biology; radiation health, safety... devices. —Radiation Biology. Curriculum content should include: Interaction of ionizing radiation...

  19. Prevalence and distribution of selected dental anomalies among saudi children in Abha, Saudi Arabia

    PubMed Central

    2016-01-01

    Background Dental anomalies are not an unusual finding in routine dental examination. The effect of dental anomalies can lead to functional, esthetic and occlusal problems. The Purpose of the study was to determine the prevalence and distribution of selected developmental dental anomalies in Saudi children. Material and Methods The study was based on clinical examination and Panoramic radiographs of children who visited the Pediatric dentistry clinics at King Khalid University College of Dentistry, Saudi Arabia. These patients were examined for dental anomalies in size, shape, number, structure and position. Data collected were entered and analyzed using statistical package for social sciences version. Results Of the 1252 children (638 Boys, 614 girls) examined, 318 subjects (25.39%) presented with selected dental anomalies. The distribution by gender was 175 boys (27.42%) and 143 girls (23.28%). On intergroup comparison, number anomalies was the most common anomaly with Hypodontia (9.7%) being the most common anomaly in Saudi children, followed by hyperdontia (3.5%). The Prevalence of size anomalies were Microdontia (2.6%) and Macrodontia (1.8%). The prevalence of Shape anomalies were Talon cusp (1.4%), Taurodontism (1.4%), Fusion (0.8%).The prevalence of Positional anomalies were Ectopic eruption (2.3%) and Rotation (0.4%). The prevalence of structural anomalies were Amelogenesis imperfecta (0.3%) Dentinogenesis imperfecta (0.1%). Conclusions A significant number of children had dental anomaly with Hypodontia being the most common anomaly and Dentinogenesis imperfecta being the rare anomaly in the study. Early detection and management of these anomalies can avoid potential orthodontic and esthetic problems in a child. Key words:Dental anomalies, children, Saudi Arabia. PMID:27957258

  20. NEUTRON RADIOGRAPHY (NRAD) REACTOR 64-ELEMENT CORE UPGRADE

    SciTech Connect

    John D. Bess

    2014-03-01

    The neutron radiography (NRAD) reactor is a 250 kW TRIGA (registered) (Training, Research, Isotopes, General Atomics) Mark II , tank-type research reactor currently located in the basement, below the main hot cell, of the Hot Fuel Examination Facility (HFEF) at the Idaho National Laboratory (INL). It is equipped with two beam tubes with separate radiography stations for the performance of neutron radiography irradiation on small test components. The interim critical configuration developed during the core upgrade, which contains only 62 fuel elements, has been evaluated as an acceptable benchmark experiment. The final 64-fuel-element operational core configuration of the NRAD LEU TRIGA reactor has also been evaluated as an acceptable benchmark experiment. Calculated eigenvalues differ significantly (approximately +/-1%) from the benchmark eigenvalue and have demonstrated sensitivity to the thermal scattering treatment of hydrogen in the U-Er-Zr-H fuel.

  1. Limiting the use of routine radiography for acute ankle injuries.

    PubMed Central

    Cockshott, W. P.; Jenkin, J. K.; Pui, M.

    1983-01-01

    In the diagnosis of ankle injuries routine radiography is often productive. An international survey of the average number of radiographs made of injured ankles suggested that two projections are adequate to detect fractures. This was confirmed in a prospective study of 242 patients coming to a hospital emergency department with recent ankle injuries. All the fractures could be identified on an anteroposterior or a lateral projection, although some were more obvious on an oblique view. As well, all the fractures were associated with malleolar soft-tissue swelling. Thus, radiography for acute ankle injuries could safely be restricted to patients with soft-tissue swelling, and fractures could be diagnosed using only two routine projections, though for management purposes additional projections might be needed. With a policy of limiting the use of radiography substantial cost reductions are possible. Images FIG. 1 PMID:6407744

  2. Studies of solid propellant combustion with pulsed radiography

    NASA Technical Reports Server (NTRS)

    Godai, T.; Tanemura, T.; Fujiwara, T.; Shimizu, M.

    1987-01-01

    Pulsed radiography was applied to observe solid propellant surface regression during rocket motor operation. Using a 150 KV flash X-ray system manufactured by the Field Emission Corporation and two kinds of film suppliers, images of the propellant surface of a 5 cm diameter end burning rocket motor were recorded on film. The repetition frame rate of 8 pulses per second and the pulse train length of 10 pulses are limited by the capability of the power supply and the heat build up within the X-ray tube, respectively. The experiment demonstrated the effectiveness of pulsed radiography for observing solid propellant surface regression. Measuring the position of burning surface images on film with a microdensitometer, quasi-instantaneous burning rate as a function of pressure and the variation of characteristic velocity with pressure and gas stay time were obtained. Other research items to which pulsed radiography can be applied are also suggested.

  3. [Significance of plain radiography in shoulder pain diagnosis].

    PubMed

    Botser, Itamar Busheri; Shapira, Shachar; Oran, Ariel; Avivi, Eran; Pritsch, Moshe

    2011-09-01

    Shoulder pain is a common complaint--almost 20% of the population will suffer shoulder pain during their life time. Despite the availability of newer imaging techniques for evaluation of the shoulder, the first imaging study should be radiography. Recently, ultrasonography of the shoulder has become one of the first studies performed. Sometimes, ultrasonography is conducted before radiography; moreover, many patients are being referred to a shoulder specialist without performing an X-ray. There is a plethora of pathologies that can cause shoulder pain--rotator cuff tears, impingement syndrome, calcified tendinitis, osteoarthritis, rheumatoid arthritis, neoplasms and more. This review aims to show the significance of plain radiography in the diagnosis of shoulder pathologies, in order to encourage the use of this modality. In this paper we shall review the different causes of shoulder pain and their radiographic characteristics.

  4. Pressure Indication of 3013 Inner Containers Using Digital Radiography

    SciTech Connect

    HENSEL, SJ

    2004-04-15

    Plutonium bearing materials packaged for long term storage per the Department of Energy Standard 3013 (DOE-STD-3013) are required to be examined periodically in a non-destructive manner (i.e. without compromising the storage containers) for pressure buildup. Radiography is the preferred technology for performing the examinations. The concept is to measure and record the container lid position. As a can pressurizes the lid will deflect outward and thus provide an indication of the internal pressure. A radiograph generated within 30 days of creation of each storage container serves as the baseline from which future surveillance examinations will be compared. A problem with measuring the lid position was discovered during testing of a digital radiography system. The solution was to provide a distinct feature upon the lower surface of the container lid from which the digital radiography system could easily track the lid position.

  5. The use of low-level laser therapy for controlling the gag reflex in children during intraoral radiography.

    PubMed

    Elbay, Mesut; Tak, Önjen; Şermet Elbay, Ülkü; Kaya, Can; Eryılmaz, Kubilay

    2016-02-01

    The current literature suggests that low-level laser stimulation of the PC 6 acupuncture points may prevent gagging. This study aimed to determine if low-level laser therapy (LLLT) can reduce the gag reflex in children undergoing intraoral maxillary radiography. This randomized, controlled, double-blind clinical trial was conducted with 25 children with moderate-to-very severe gag reflexes who required bilateral periapical radiographic examination of the maxillary molar region. Children's anxiety levels were initially evaluated using Corah's Dental Anxiety Scale (DAS) to identify any possible relationship between gagging and anxiety. A control radiograph was taken of one randomly selected side in each patient after simulated laser application so that the patient was blinded to the experimental conditions (control group). Laser stimulation was then performed for the experimental side. A laser probe was placed on the Pericardium 6 (PC 6) acupuncture point on each wrist, and laser energy was delivered for 14 s (300 mW, energy density 4 J/cm(2)) at a distance of 1 cm from the target tissue. Following laser stimulation, the experimental radiograph was taken (experimental group). Gagging responses were measured using the Gagging Severity Criteria for each group. Data were analyzed using Spearman's rho correlations and Mann-Whitney U tests. Both mean and median gagging scores were higher in the control group than in the experimental group. Patients who were unable to tolerate the intraoral control radiography were able to tolerate the procedure after LLLT. Differences between gagging scores of the control and experimental groups were statistically significant (P = .000). There was no significant correlation between gagging severity and anxiety score (P > .05). A negative correlation was found between age and gagging score in the control group (P ˂ .05). Within the limitations of this study, LLLT of the PC 6 acupuncture points appears to be a useful technique

  6. Dental anomalies inside the cleft region in individuals with nonsyndromic cleft lip with or without cleft palate

    PubMed Central

    Sá, Jamile; Araújo, Luana; Guimarães, Laís; Maranhão, Samário; Lopes, Gabriela; Medrado, Alena; Coletta, Ricardo

    2016-01-01

    Background Individuals with non syndromic cleft lip with or without cleft palate (NSCL±P) present high frequency of dental anomalies, which may represent complicating factors for dental treatment. The aim of this study was to investigate the prevalence of dental anomalies inside cleft area in a group of Brazilians with NSCL±P. Material and Methods Retrospective analysis of 178 panoramic radiographs of patients aged from 12 to 45 years old and without history of tooth extraction or orthodontic treatment was performed. Association between cleft type and the prevalence of dental anomalies was assessed by chi-square test with a significance level set at p≤ 0.05. Results Dental anomalies were found in 88.2% (n=157) of the patients. Tooth agenesis (47.1%), giroversion (20%) and microdontia (15.5%) were the most common anomalies. Individuals with unilateral complete cleft lip and palate (CLP, p<0.0001), bilateral complete CLP (p=0.0002) and bilateral incomplete CLP (p< 0.0001) were more affected by tooth agenesis than individuals with other cleft types. The maxillary lateral incisors were the most affected teeth (p<0.0001). Conclusions The present study revealed a high frequency of dental anomalies inside cleft region in NSCL±P patients, and further demonstrated that patients with unilateral complete CLP and bilateral incomplete CLP were frequently more affected by dental anomalies. Moreover, our results demonstrate that dental anomalies should be considered during dental treatment planning of individuals affected by NSCL±P. Key words:Nonsyndromic cleft lip with or without palate, dental anomaly, tooth agenesis, microdontia. PMID:26615505

  7. Pilot study of bovine interdigital cassetteless computed radiography.

    PubMed

    El-Shafaey, El-Sayed Ahmed Awad; Aoki, Takahiro; Ishii, Mitsuo; Yamada, Kazutaka

    2013-11-01

    Twenty-one limbs of bovine cadavers (42 digits) were exposed to interdigital cassetteless imaging plate using computed radiography. The radiographic findings included exostosis, a rough planta surface, osteolysis of the apex of the distal phalanx and widening of the laminar zone between the distal phalanx and the hoof wall. All these findings were confirmed by computed tomography. The hindlimbs (19 digits) showed more changes than the forelimbs (10 digits), particularly in the lateral distal phalanx. The cassetteless computed radiography technique is expected to be an easily applicable method for the distal phalanx rather than a conventional cassette-plate and/or the film-screen cassetteless methods.

  8. Californium Multiplier Part I: design for neutron radiography

    SciTech Connect

    Crosbie, K.L.; Preskitt, C.A.; John, J.; Hastings, J.D.

    1982-01-01

    The Californium Multiplier (CFX) is a subcritical assembly of enriched uranium surrounding a californium-252 neutron source. The function of the CFX is to multiply the neutrons emitted by the source to a number sufficient for neutron radiography. The CFX is designed to provide a collimated beam of thermal neutrons from which the gamma radiation is filtered, and the scattered neutrons are reduced to make it suitable for high resolution radiography. The entire system has inherent safety features, which provide for system and personnel safety, and it operates at moderate cost. In Part I, the CFX and the theory of its operation are described in detail.

  9. Proton radiography, nuclear cross sections and multiple Coulomb scattering

    SciTech Connect

    Sjue, Sky K.

    2015-11-04

    The principles behind proton radiography including multiple Coulomb scattering are discussed for a purely imaginary square well nucleus in the eikonal approximation. It is found that a very crude model can reproduce the angular dependence of the cross sections measured at 24 GeV/c. The largest differences are ~3% for the 4.56 mrad data, and ~4% for the 6.68 mrad data. The prospect of understanding how to model deterministically high-energy proton radiography over a very large range of energies is promising, but it should be tested more thoroughly.

  10. Quantitative studies on inner interfaces in conical metal joints using hard x-ray inline phase contrast radiography

    SciTech Connect

    Zabler, S.; Rack, T.; Nelson, K.; Rack, A.

    2010-10-15

    Quantitative investigation of micrometer and submicrometer gaps between joining metal surfaces is applied to conical plug-socket connections in dental titanium implants. Microgaps of widths well beyond the resolving power of industrial x-ray systems are imaged by synchrotron phase contrast radiography. Furthermore, by using an analytical model for the relatively simple sample geometry and applying it to numerical forward simulations of the optical Fresnel propagation, we show that quantitative measurements of the microgap width down to 0.1 {mu}m are possible. Image data recorded at the BAMline (BESSY-II light source, Germany) are presented, with the resolving power of the imaging system being 4 {mu}m in absorption mode and {approx}14 {mu}m in phase contrast mode (z{sub 2}=0.74 m). Thus, phase contrast radiography, combined with numerical forward simulations, is capable of measuring the widths of gaps that are two orders of magnitude thinner than the conventional detection limit.

  11. Measuring microfocal spots using digital radiography

    SciTech Connect

    Fry, David A; Ewert, Uwe

    2009-01-01

    Measurement of microfocus spot size can be important for several reasons: (1) Quality assurance during manufacture of microfocus tubes; (2) Tracking performance and stability of microfocus tubes; (3) Determining magnification is especially important for digital radiography where the native spatial resolution of the digital system is not adequate for the application; and (4) Knowledge of unsharpness from the focal spot alone. The European Standard EN 12543-5 is based on a simple geometrical method of calculating focal spot size from unsharpness of high magnification film radiographs. The following equations are used for the focal spot size measurement: By similar triangles the following equations are presupposed: f/a = U/b and M = (a+b)/a. These equations can be combined to yield the well known expression: U = f(M - 1). Solving for f, f = U/(M-1). Therefore, the focal spot size, f, can be calculated by measuring the radiographic unsharpness and magnification of a known object. This is the basis for these tests. The European standard actually uses one-half of the unsharpness (which are then added together) from both sides of the object to avoid additional unsharpness contributions due to edge transmission unsharpness of the round test object (the outside of the object is measured). So the equation becomes f = (1/2 U{sub 1} + 1/2 U{sub 2})/(M-1). In practice 1/2 U is measured from the 50% to the 90% signal points on the transition profile from ''black'' to ''white,'' (positive image) or attenuated to unattenuated portion of the image. The 50% to 90% points are chosen as a best fit to an assumed Gaussian radiation distribution from the focal spot and to avoid edge transmission effects. 1/2 U{sub 1} + 1/2 U{sub 2} corresponds about to the full width at half height of a Gaussian focal spot. A highly absorbing material (Tungsten, Tungsten Alloy, or Platinum) is used for the object. Either wires or a sphere are used as the object to eliminate alignment issues. One

  12. 42 CFR 37.51 - Interpreting and classifying chest radiographs-digital radiography systems.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...-digital radiography systems. 37.51 Section 37.51 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH... of Chest Radiographs § 37.51 Interpreting and classifying chest radiographs—digital radiography systems. (a) For each chest radiograph obtained at an approved facility using a digital radiography...

  13. What is dental ecology?

    PubMed

    Cuozzo, Frank P; Sauther, Michelle L

    2012-06-01

    Teeth have long been used as indicators of primate ecology. Early work focused on the links between dental morphology, diet, and behavior, with more recent years emphasizing dental wear, microstructure, development, and biogeochemistry, to understand primate ecology. Our study of Lemur catta at the Beza Mahafaly Special Reserve, Madagascar, has revealed an unusual pattern of severe tooth wear and frequent tooth loss, primarily the result of consuming a fallback food for which these primates are not dentally adapted. Interpreting these data was only possible by combining our areas of expertise (dental anatomy [FC] and primate ecology [MS]). By integrating theoretical, methodological, and applied aspects of both areas of research, we adopted the term "dental ecology"-defined as the broad study of how teeth respond to the environment. Specifically, we view dental ecology as an interpretive framework using teeth as a vehicle for understanding an organism's ecology, which builds upon earlier work, but creates a new synthesis of anatomy and ecology that is only possible with detailed knowledge of living primates. This framework includes (1) identifying patterns of dental pathology and tooth use-wear, within the context of feeding ecology, behavior, habitat variation, and anthropogenic change, (2) assessing ways in which dental development and biogeochemical signals can reflect habitat, environmental change and/or stress, and (3) how dental microstructure and macro-morphology are adapted to, and reflect feeding ecology. Here we define dental ecology, provide a short summary of the development of this perspective, and place our new work into this context.

  14. Dental hygiene in Slovakia.

    PubMed

    Luciak-Donsberger, C; Krizanová, M

    2004-08-01

    This article reports on the development of the dental hygiene profession in Slovakia from a global perspective. The aim is to inform about current developments and to examine, how access to qualified dental hygiene care might be improved and how professional challenges might be met. For an international study on dental hygiene, secondary source data were obtained from members of the House of Delegates of the International Federation of Dental Hygienists (IFDH) or by fax and e-mail from experts involved in the national professional and educational organization of dental hygiene in non-IFDH member countries, such as Slovakia. Responses were followed-up by interviews, e-mail correspondence, visits to international universities, and a review of supporting studies and reference literature. Results show that the introduction of dental hygiene in Slovakia in 1992 was inspired by the delivery of preventive care in Switzerland. Initiating local dentists and dental hygienists strive to attain a high educational level, equitable to that of countries in which dental hygiene has an established tradition of high quality care. Low access to qualified dental hygiene care may be a result of insufficient funding for preventive services, social and cultural lack of awareness of the benefits of preventive care, and of limitations inherent in the legal constraints preventing unsupervised dental hygiene practice. These may be a result of gender politics affecting a female-dominated profession and of a perception that dental hygiene is auxiliary to dental care. International comparison show that of all Eastern European countries, the dental hygiene profession appears most advanced in Slovakia. This is expressed in high evidence-based academic goals, in extensive work with international consultants from the Netherlands and Switzerland, in annual congresses of high professional quality, and in the establishment of a profession, which has not been introduced in all Western EU countries.

  15. The algorithm to generate color point-cloud with the registration between panoramic image and laser point-cloud

    NASA Astrophysics Data System (ADS)

    Zeng, Fanyang; Zhong, Ruofei

    2014-03-01

    Laser point cloud contains only intensity information and it is necessary for visual interpretation to obtain color information from other sensor. Cameras can provide texture, color, and other information of the corresponding object. Points with color information of corresponding pixels in digital images can be used to generate color point-cloud and is conducive to the visualization, classification and modeling of point-cloud. Different types of digital cameras are used in different Mobile Measurement Systems (MMS).the principles and processes for generating color point-cloud in different systems are not the same. The most prominent feature of the panoramic images is the field of 360 degrees view angle in the horizontal direction, to obtain the image information around the camera as much as possible. In this paper, we introduce a method to generate color point-cloud with panoramic image and laser point-cloud, and deduce the equation of the correspondence between points in panoramic images and laser point-clouds. The fusion of panoramic image and laser point-cloud is according to the collinear principle of three points (the center of the omnidirectional multi-camera system, the image point on the sphere, the object point). The experimental results show that the proposed algorithm and formulae in this paper are correct.

  16. Test-retest reliability and the minimal detectable change for achilles tendon length: a panoramic ultrasound assessment.

    PubMed

    Ryan, Eric D; Rosenberg, Joseph G; Scharville, Michael J; Sobolewski, Eric J; Thompson, Brennan J; King, Gilbert E

    2013-12-01

    The purpose of the present study was to examine test-retest reliability and minimal detectable change (MDC) values for Achilles tendon (AT) length determined using panoramic ultrasound (US) imaging. Seventeen men (age = 21.0 ± 2.3 y) visited the laboratory on two separate days, where AT length was examined along the mid-longitudinal axis of the right lower leg with a portable B-mode panoramic US device. These measures were found to have acceptable reliability with intra-class correlation coefficient (ICC) and standard error of measurement (SEM) values of 0.954 and 4.43 mm (SEM% of the mean = 2.37%), respectively. In addition, the MDC for the panoramic US assessment of AT length was 12.27 mm (MDC% of the mean = 6.57%). These findings suggest that panoramic US imaging is a reliable technique for detection of clinically relevant changes in AT length and may therefore be a practical and time-efficient clinical tool for future studies examining AT length in vivo.

  17. Employment of Dental Hygienists as Dental Educators.

    ERIC Educational Resources Information Center

    Fong, Cynthia; Odrich, Johanna

    1987-01-01

    A study of the use of dental hygienists to teach periodontics, preventive dentistry, community dentistry, and public health courses looked at employment patterns and practices and the qualifications of the teachers. (MSE)

  18. On dental wear, dental work, and oral health in the type specimen (LB1) of Homo floresiensis.

    PubMed

    Jungers, William L; Kaifu, Yousuke

    2011-06-01

    The claim that the lower left first mandibular molar of LB1, the type specimen of Homo floresiensis, displays endodontic work, and a filling is assessed by digital radiography and micro-CT scanning. The M(1) tooth crown is heavily worn and exhibits extensive dentine exposure that is stained white, but there is no trace of endodontic treatment or a dental filling in this Indonesian fossil dated to 17.1-19.0 kya. Dental calculus (commonly observed in foragers) is present on the teeth of LB1, but there are no observable caries. The pattern of dental attrition in the mandibles of both LB1/2 and LB6/1 (moderate to extensive flat wear across the entire arch) is consistent with that seen in Plio-Pleistocene Homo fossils and in modern hunter-gatherers, and is not typical of most agriculturalists. We conclude that the dental-work and farming hypotheses are falsified and therefore irrelevant to the debate over the taxonomy and phylogeny of H. floresiensis.

  19. The optimum circular field size for dental radiography with intraoral films

    SciTech Connect

    van Straaten, F.J.; van Aken, J.

    1982-09-01

    Intraoral radiographs are often made with circular fields to irradiate the film, and in many instances these fields are much larger than the film. The feasibility of reducing a circular radiation field without increasing the probability of excessive cone cutting was evaluated clinically, and an optimum field size was determined. A circular radiation field 4.5 cm. at the tube end was found to minimize cone cutting and reduce the area of tissue irradiated by at least 44 percent. Findings suggest that current I.C.R.P. recommendations for a 6 to 7.5 cm. diameter circular field may be too liberal.

  20. Pathways in dental public health.

    PubMed

    Silverstein, Steven J

    2005-07-01

    Dental public health is one of the nine specialties of dentistry recognized by the American Dental Association Commission on Dental Accreditation. Dental public health has been defined as the "science and art of preventing and controlling dental diseases and promoting dental health through organized community efforts. It is that form of dental practice which serves the community as a patient rather than as an individual. It is concerned with the dental health education of the public, with applied dental research, and with the administration of group dental care programs as well as the prevention and control of dental diseases on a community basis." This article will describe the many career and educational pathways dentists may follow to become irvolved in the practice of dental public health.

  1. International dental standards.

    PubMed

    Jones, Derek W

    2007-09-22

    International dental standards are vital in maintaining the safety and quality of both the products and materials used by dental professionals and the many oral health products used by members of the general public, yet many dentists will be unaware of the role standards play in their daily practice. In this article, Derek W. Jones outlines the vital work of the International Standards Organization and highlights how standards pervade nearly every dental procedure.

  2. Trichobezoars Detected and Treated Based on Plain Radiography.

    PubMed

    Barrows, Amy; Vachon, Tyler; Campin, Richard C; Ignacio, Romeo C

    2015-10-01

    Bezoars are conglomerations of indigestible material that become trapped in the gastrointestinal tract. We present a case of an 8-year-old female child diagnosed with a gastric bezoar solely on plain radiography and treated with abdominal surgical exploration and removal. In addition, traditional characteristic radiographic findings and treatment options for bezoars found in the current literature are reviewed.

  3. 10 CFR 34.13 - Specific license for industrial radiography.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 34.13 Energy NUCLEAR REGULATORY COMMISSION LICENSES FOR INDUSTRIAL RADIOGRAPHY AND RADIATION SAFETY... may affirm that all individuals acting as industrial radiographers will be certified in radiation... submits a description of the applicant's overall organizational structure as it applies to the...

  4. 10 CFR 34.13 - Specific license for industrial radiography.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 34.13 Energy NUCLEAR REGULATORY COMMISSION LICENSES FOR INDUSTRIAL RADIOGRAPHY AND RADIATION SAFETY... may affirm that all individuals acting as industrial radiographers will be certified in radiation... submits a description of the applicant's overall organizational structure as it applies to the...

  5. 10 CFR 34.13 - Specific license for industrial radiography.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 34.13 Energy NUCLEAR REGULATORY COMMISSION LICENSES FOR INDUSTRIAL RADIOGRAPHY AND RADIATION SAFETY... may affirm that all individuals acting as industrial radiographers will be certified in radiation... submits a description of the applicant's overall organizational structure as it applies to the...

  6. Beam Physics in X-Ray Radiography Facilities

    SciTech Connect

    Chen, Y J; Caporaso, G J; Chambers, F W; Falabella, S; Goldin, F J; Guethlein, G; Lauer, E L; McCarrick, J F; Neurath, R; Richardson, R A; Sampayan, S; Weir, J T

    2002-12-02

    Performance of x-ray radiography facilities requires focusing the electron beams to sub-millimeter spots on the x-ray converters. Ions extracted from a converter by impact of a high intensity beam can partially neutralize the beam space charge and change the final focusing system. We will discuss these ion effects and mitigation.

  7. Method and Apparatus for Computed Imaging Backscatter Radiography

    NASA Technical Reports Server (NTRS)

    Shedlock, Daniel (Inventor); Meng, Christopher (Inventor); Sabri, Nissia (Inventor); Dugan, Edward T. (Inventor); Jacobs, Alan M. (Inventor)

    2013-01-01

    Systems and methods of x-ray backscatter radiography are provided. A single-sided, non-destructive imaging technique utilizing x-ray radiation to image subsurface features is disclosed, capable of scanning a region using a fan beam aperture and gathering data using rotational motion.

  8. Radiography Capabilities for Matter-Radiation Interactions in Extremes

    SciTech Connect

    Walstrom, Peter Lowell; Garnett, Robert William; Chapman, Catherine A. B; Salazar, Harry Richard; Otoole, Joseph Alfred; Barber, Ronald L.; Gomez, Tony Simon

    2015-04-28

    The Matter-Radiation Interactions in Extremes (MaRIE) experimental facility will be used to discover and design the advanced materials needed to meet 21st century national security and energy security challenges. This new facility will provide the new tools scientists need to develop next-generation materials that will perform predictably and on-demand for currently unattainable lifetimes in extreme environments. The MaRIE facility is based on upgrades to the existing LANSCE 800-MeV proton linac and a new 12-GeV electron linac and associated X-ray FEL to provide simultaneous multiple probe beams, and new experimental areas. In addition to the high-energy photon probe beam, both electron and proton radiography capabilities will be available at the MaRIE facility. Recently, detailed radiography system studies have been performed to develop conceptual layouts of high-magnification electron and proton radiography systems that can meet the experimental requirements for the expected first experiments to be performed at the facility. A description of the radiography systems, their performance requirements, and a proposed facility layout are presented.

  9. Point Scattered Function (PScF) for fast neutron radiography

    NASA Astrophysics Data System (ADS)

    Hassan, Mohamed H.

    2009-08-01

    Fast neutron radiography opened up a new range of possibilities to image extremely dense objects. The removal of the scattering effect is one of the most challenging problems in neutron imaging. Neutron scattering in fast neutron radiography did not receive much attention compared with X-ray and thermal neutron radiography. The purpose of this work is to investigate the behavior of the Point Scattered Function (PScF) as applied in fast neutron radiography. The PScF was calculated using MCNP as a spatial distribution of scattered neutrons over the detector surface for one emitting source element. Armament and explosives materials, namely, Rifle steel, brass, aluminum and trinitrotoluene (TNT) were simulated. Effect of various sample thickness and sample-to-detector distance were considered. Simulated sample geometries included a slab with varying thickness, a sphere with varying radii, and a cylinder with varying base radii. Different neutron sources, namely, Cf-252, DT as well as DD neutron sources were considered. Neutron beams with zero degree divergence angle; and beams with varying angles related to the normal to the source plane were simulated. Curve fitting of the obtained PScF, in the form of Gaussian function, were given to be used in future work using image restoration codes. Analytical representation of the height as well as the Full Width at Half Maximum (FWHM) of the obtained Gaussian functions eliminates the need to calculate the PScF for sample parameters that were not investigated in this study.

  10. Panoramic Measurement and Analysis of Strain Distribution in the Human ACL Using a Photoelastic Coating Method

    NASA Astrophysics Data System (ADS)

    Hirokawa, Shunji; Yamamoto, Kouji; Kawada, Takashi

    Large and highly variable deformations of the ACL cannot be adequately quantified by one-dimensional and/or localized measurements. Since the complex anatomy of the ACL makes uniform loading of all fiber bundles almost impossible, strains on specific portions being tested are considerably altered during knee movement. To observe the ACL's entire surface, we propose a photoelastic coating method. A simulator jig was used to allow a natural motion of the knee whose medial and lateral femoral bone parts were removed in order to expose the ACL for observation. The simulator jig with the knee was mounted on a universal stand which allows tilt and swivel rotations, so that the exposed ACL might be viewed from any direction. Measurements were performed on the strain distributions over the ACL at various knee angles. The panoramic images of the photoelastic fringe patterns yielded significant results. Special attention was paid for insight into the relation between strain distribution and the directions of fiber run.

  11. A panoramic view of the Space Station Processing Facility with Unity connecting module

    NASA Technical Reports Server (NTRS)

    1998-01-01

    In this panoramic view of the Space Station Processing Facility (SSPF) can be seen (left to right) Unity connecting module, the Rack Insertion Device and the first Multi-Purpose Launch Module, the Leonardo. Windows at the right above Leonardo allow visitors on tour to watch the activities in the SSPF. The Unity, scheduled to be launched on STS-88 in December 1998, will be mated to the Russian-built Zarya control module which will already be in orbit. STS-88 will be the first Space Shuttle launch for the International Space Station. The Italian-built MPLM, scheduled to be launched on STS-100 on Dec. 2, 1999, will be carried in the payload bay of the Shuttle orbiter, and will provide storage and additional work space for up to two astronauts when docked to the International Space Station.

  12. Verification of source and collimator configuration for Gamma Knife Perfexion using panoramic imaging

    SciTech Connect

    Cho, Young-Bin; Prooijen, Monique van; Jaffray, David A.; Islam, Mohammad K.

    2010-03-15

    Purpose: The new model of stereotactic radiosurgery system, Gamma Knife Perfexion, allows automatic selection of built-in collimation, eliminating the need for the time consuming manual collimator installation required with previous models. However, the configuration of sources and collimators inside the system does not permit easy access for the verification of the selected collimation. While the conventional method of exposing a film at the isocenter is useful for obtaining composite dose information, it is difficult to interpret the data in terms of the integrity of each individual source and corresponding collimation. The primary aim of this study was to develop a method of verifying the geometric configuration of the sources and collimator modules of the Gamma Knife Perfexion. In addition, the method was extended to make dose measurements and verify the accuracy of dose distributions calculated by the mathematical formalism used in the treatment planning system, Leksell Gamma Plan. Methods: A panoramic view of all of 192 cobalt sources was simultaneously acquired by exposing a radiochromic film wrapped around the surface of a cylindrical phantom. The center of the phantom was mounted at the isocenter with its axis aligned along the longitudinal axis of the couch. The sizes and shapes of the source images projected on the phantom surface were compared to those calculated based on the manufacturer's design specifications. The measured dose at various points on the film was also compared to calculations using the algorithm of the planning system. Results: The panoramic images allowed clear identification of each of the 192 sources, verifying source integrity and selected collimator sizes. Dose on the film surface is due to the primary beam as well as phantom scatter and leakage contributions. Therefore, the dose at a point away from the isocenter cannot be determined simply based on the proportionality of collimator output factors; the use of a dose computation

  13. Power-law and exponential rank distributions: A panoramic Gibbsian perspective

    SciTech Connect

    Eliazar, Iddo

    2015-04-15

    Rank distributions are collections of positive sizes ordered either increasingly or decreasingly. Many decreasing rank distributions, formed by the collective collaboration of human actions, follow an inverse power-law relation between ranks and sizes. This remarkable empirical fact is termed Zipf’s law, and one of its quintessential manifestations is the demography of human settlements — which exhibits a harmonic relation between ranks and sizes. In this paper we present a comprehensive statistical-physics analysis of rank distributions, establish that power-law and exponential rank distributions stand out as optimal in various entropy-based senses, and unveil the special role of the harmonic relation between ranks and sizes. Our results extend the contemporary entropy-maximization view of Zipf’s law to a broader, panoramic, Gibbsian perspective of increasing and decreasing power-law and exponential rank distributions — of which Zipf’s law is one out of four pillars.

  14. Dental erosion, summary.

    PubMed

    ten Cate, J M; Imfeld, T

    1996-04-01

    Although reports on dental erosion have always appeared in the dental literature, there is currently a growing interest among researchers and clinicians. Potential risk factors for dental erosion are changed lifestyle and eating patterns, with increased consumption of acidic foods and beverages. Various gastrointestinal and eating disorders expose the dentition to frequent contacts with very acidic gastric content, which may lead to erosion. Whether these factors indeed lead, on a population scale, to a higher prevalence and incidence of erosion is yet to be established. This article summarizes the different aspects of the prevalence, pathology, etiology, assessment, prevention and treatment of dental erosion, and concludes with recommendations for future research.

  15. Dental Implant Systems

    PubMed Central

    Oshida, Yoshiki; Tuna, Elif B.; Aktören, Oya; Gençay, Koray

    2010-01-01

    Among various dental materials and their successful applications, a dental implant is a good example of the integrated system of science and technology involved in multiple disciplines including surface chemistry and physics, biomechanics, from macro-scale to nano-scale manufacturing technologies and surface engineering. As many other dental materials and devices, there are crucial requirements taken upon on dental implants systems, since surface of dental implants is directly in contact with vital hard/soft tissue and is subjected to chemical as well as mechanical bio-environments. Such requirements should, at least, include biological compatibility, mechanical compatibility, and morphological compatibility to surrounding vital tissues. In this review, based on carefully selected about 500 published articles, these requirements plus MRI compatibility are firstly reviewed, followed by surface texturing methods in details. Normally dental implants are placed to lost tooth/teeth location(s) in adult patients whose skeleton and bony growth have already completed. However, there are some controversial issues for placing dental implants in growing patients. This point has been, in most of dental articles, overlooked. This review, therefore, throws a deliberate sight on this point. Concluding this review, we are proposing a novel implant system that integrates materials science and up-dated surface technology to improve dental implant systems exhibiting bio- and mechano-functionalities. PMID:20480036

  16. Immersive Virtual Moon Scene System Based on Panoramic Camera Data of Chang'E-3

    NASA Astrophysics Data System (ADS)

    Gao, X.; Liu, J.; Mu, L.; Yan, W.; Zeng, X.; Zhang, X.; Li, C.

    2014-12-01

    The system "Immersive Virtual Moon Scene" is used to show the virtual environment of Moon surface in immersive environment. Utilizing stereo 360-degree imagery from panoramic camera of Yutu rover, the system enables the operator to visualize the terrain and the celestial background from the rover's point of view in 3D. To avoid image distortion, stereo 360-degree panorama stitched by 112 images is projected onto inside surface of sphere according to panorama orientation coordinates and camera parameters to build the virtual scene. Stars can be seen from the Moon at any time. So we render the sun, planets and stars according to time and rover's location based on Hipparcos catalogue as the background on the sphere. Immersing in the stereo virtual environment created by this imaged-based rendering technique, the operator can zoom, pan to interact with the virtual Moon scene and mark interesting objects. Hardware of the immersive virtual Moon system is made up of four high lumen projectors and a huge curve screen which is 31 meters long and 5.5 meters high. This system which take all panoramic camera data available and use it to create an immersive environment, enable operator to interact with the environment and mark interesting objects contributed heavily to establishment of science mission goals in Chang'E-3 mission. After Chang'E-3 mission, the lab with this system will be open to public. Besides this application, Moon terrain stereo animations based on Chang'E-1 and Chang'E-2 data will be showed to public on the huge screen in the lab. Based on the data of lunar exploration,we will made more immersive virtual moon scenes and animations to help the public understand more about the Moon in the future.

  17. Measurement methods and accuracy analysis of Chang'E-5 Panoramic Camera installation parameters

    NASA Astrophysics Data System (ADS)

    Yan, Wei; Ren, Xin; Liu, Jianjun; Tan, Xu; Wang, Wenrui; Chen, Wangli; Zhang, Xiaoxia; Li, Chunlai

    2016-04-01

    Chang'E-5 (CE-5) is a lunar probe for the third phase of China Lunar Exploration Project (CLEP), whose main scientific objectives are to implement lunar surface sampling and to return the samples back to the Earth. To achieve these goals, investigation of lunar surface topography and geological structure within sampling area seems to be extremely important. The Panoramic Camera (PCAM) is one of the payloads mounted on CE-5 lander. It consists of two optical systems which installed on a camera rotating platform. Optical images of sampling area can be obtained by PCAM in the form of a two-dimensional image and a stereo images pair can be formed by left and right PCAM images. Then lunar terrain can be reconstructed based on photogrammetry. Installation parameters of PCAM with respect to CE-5 lander are critical for the calculation of exterior orientation elements (EO) of PCAM images, which is used for lunar terrain reconstruction. In this paper, types of PCAM installation parameters and coordinate systems involved are defined. Measurement methods combining camera images and optical coordinate observations are studied for this work. Then research contents such as observation program and specific solution methods of installation parameters are introduced. Parametric solution accuracy is analyzed according to observations obtained by PCAM scientifically validated experiment, which is used to test the authenticity of PCAM detection process, ground data processing methods, product quality and so on. Analysis results show that the accuracy of the installation parameters affects the positional accuracy of corresponding image points of PCAM stereo images within 1 pixel. So the measurement methods and parameter accuracy studied in this paper meet the needs of engineering and scientific applications. Keywords: Chang'E-5 Mission; Panoramic Camera; Installation Parameters; Total Station; Coordinate Conversion

  18. Prevalence of dental anomalies in patients with cleft lip and palate.

    PubMed

    Eslami, Neda; Majidi, Mohammad Reza; Aliakbarian, Majid; Hasanzadeh, Nadia

    2013-09-01

    The aim of the present study was to investigate the prevalence of dental anomalies in a group of patients with cleft lip and palate (CL/P) in the northeast of Iran. Ninety-one patients referring to the Cleft Lip and Palate Clinic of Mashhad Dental School were enrolled and classified into right CL/P, left CL/P, and bilateral CL/P groups. Photographs, dental casts, and panoramic and periapical radiographs were retrieved, and dental anomalies were recorded. χ test was used to analyze the frequency of dental anomalies according to type of cleft and sex. Missing maxillary lateral incisors was the most frequent dental anomaly, which was slightly higher in the bilateral group (61.1%). There were significantly more cases of missing lateral incisors outside the cleft area in right CL/P (P = 0.015). Peg lateral incisors were observed in 33.3% of bilateral CL/P compared with 28% of right and 23.3% of left unilateral cases. The sample presented rotations of central incisors in the cleft area in 33.3% of bilateral clefts. In unilateral clefts, it occurred more frequently in the right side (48%). Sexual dimorphism appeared only for maxillary central incisor rotation in the cleft area, which showed significantly greater frequency in females (P = 0.025). Transposition of maxillary canine and first premolars was found in 5.5% of bilateral, 8% of right, and 3.3% of left unilateral clefts. The prevalence of dental anomalies in the studied sample seems to be higher than that reported in the normal population. More anomalies were observed at the cleft side. The frequency of most anomalies was not significantly different between the 2 sexes.

  19. Is dosimetry still a necessity in current dental practice?

    PubMed

    Reddy, S S; Rakesh, N; Chauhan, Pallavi; Clint, Joseph Ben; Sharma, Shivani

    2015-12-01

    Today, dentists have a wide range of imaging modalities to choose from, the film based techniques, digital techniques, and the recent introduction of 3D volumetric or cone beam computed tomography (CBCT). The inherent design features of the new generation dental x-ray equipment has significantly improved over the years with no evidence of substandard x-ray units in operation. In dental facilities radiological workload is comparatively low, newer radiation equipments and accessories follow safety guidelines and employ better radiation protection measures for the patient and the operator. Dentists' knowledge and expertise in radiation protection measures is good, enabling them to carry out riskfree radiation procedures in their practice. Therefore, the present study is aimed at assessing the need for dosimeters in current dental scenario. 'Is there currently a significant risk from dental radiography to merit the use of personal dosimetery in dental practice. 'Dental health professionals (Oral radiologists) and radiographic assistants of fourteen dental colleges in Karnataka state participated in this questionnaire study. The questionnaire consisted of the following questions--the make, type, year of manufacture of radiographic machines used in their setup, number of radiographs made per day in the institution, type of receptors used, number of personnel at risk for radiation exposure, radiation protection measures used, regular monitoring by personal dosimeters, equivalent dosage readings for the past 12 months and whether the reading of thermoluminescent dosimeters (TLD) for any personnel had exceeded the recommended exposure value in the last 3 years. Dosimetry records of the radiology staff in the last three years shows doses no more than 1.50 mSv per year. The various institutions' dose (person mSv) was in the range of 3.70 mSv-3.90 mSv. Personal monitoring for Dentists can be omitted in the dental colleges since the estimated dose of oral radiologists

  20. Education About Dental Hygienists' Roles in Public Dental Prevention Programs: Dental and Dental Hygiene Students' and Faculty Members' and Dental Hygienists' Perspectives.

    PubMed

    Pervez, Anushey; Kinney, Janet S; Gwozdek, Anne; Farrell, Christine M; Inglehart, Marita R

    2016-09-01

    In 2005, Public Act No. 161 (PA 161) was passed in Michigan, allowing dental hygienists to practice in approved public dental prevention programs to provide services for underserved populations while utilizing a collaborative agreement with a supervising dentist. The aims of this study were to assess how well dental and dental hygiene students and faculty members and practicing dental hygienists have been educated about PA 161, what attitudes and knowledge about the act they have, and how interested they are in additional education about it. University of Michigan dental and dental hygiene students and faculty members, students in other Michigan dental hygiene programs, and dental hygienists in the state were surveyed. Respondents (response rate) were 160 dental students (50%), 63 dental hygiene students (82%), 30 dental faculty members (26%), and 12 dental hygiene faculty members (52%) at the University of Michigan; 143 dental hygiene students in other programs (20%); and 95 members of the Michigan Dental Hygienists' Association (10%). The results showed that the dental students were less educated about PA 161 than the dental hygiene students, and the dental faculty members were less informed than the dental hygiene faculty members and dental hygienists. Responding dental hygiene faculty members and dental hygienists had more positive attitudes about PA 161 than did the students and dental faculty members. Most of the dental hygiene faculty members and dental hygienists knew a person providing services in a PA 161 program. Most dental hygiene students, faculty members, and dental hygienists wanted more education about PA 161. Overall, the better educated about the program the respondents were, the more positive their attitudes, and the more interested they were in learning more.