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Sample records for base lesions positioned

  1. Candidate lesion-based criteria for defining a positive sacroiliac joint MRI in two cohorts of patients with axial spondyloarthritis

    DEFF Research Database (Denmark)

    Weber, Ulrich; Østergaard, Mikkel; Lambert, Robert G W

    2015-01-01

    OBJECTIVE: To determine candidate lesion-based criteria for a positive sacroiliac joint (SIJ) MRI based on bone marrow oedema (BMO) and/or erosion in non-radiographic axial spondyloarthritis (nr-axSpA); to compare the performance of lesion-based criteria with global evaluation by expert readers....... METHODS: Two independent cohorts A/B of 69/88 consecutive patients with back pain aged ≤50 years, with median symptom duration 1.3/10.0 years, were referred for suspected SpA (A) or acute anterior uveitis plus back pain (B). Patients were classified according to rheumatologist expert opinion based...... on clinical examination, pelvic radiography and laboratory values as having nr-axSpA (n=51), ankylosing spondylitis (n=34) or non-specific back pain (n=72). Four blinded readers assessed SIJ MRI, recording the presence/absence of SpA by concomitant global evaluation of T1-weighted spin echo (T1SE) and short τ...

  2. The skull base: tumoral lesions

    International Nuclear Information System (INIS)

    Casselman, Jan W.

    2005-01-01

    Many lesions occur in the anterior, central and posterior skull base. In order to detect and characterise them, one has to apply the best imaging technique. Today MR is the preferred technique, and the use of CT is more and more restricted to evaluate the presence of calcifications and involvement of thin bony walls, foramina and fissures. However, MR is only superior when the right sequences and imaging planes are used. Many lesions can be characterised by their specific signal intensity on different sequences and by their location. Nevertheless some lesions can only be characterised after biopsy. The purpose of imaging in skull base tumours remains in the first place the evaluation of the exact tumour extent, and this is again best achieved with MR. In this paper the imaging technique and the most frequent skull base tumours are discussed. (orig.)

  3. Disseminated paracoccidioidomycosis diagnosis based on oral lesions

    Directory of Open Access Journals (Sweden)

    Liana Preto Webber

    2014-01-01

    Full Text Available Paracoccidioidomycosis (PCM is a deep mycosis with primary lung manifestations that may present cutaneous and oral lesions. Oral lesions mimic other infectious diseases or even squamous cell carcinoma, clinically and microscopically. Sometimes, the dentist is the first to detect the disease, because lung lesions are asymptomatic, or even misdiagnosed. An unusual case of PCM with 5 months of evolution presenting pulmonary, oral, and cutaneous lesions that was diagnosed by the dentist based on oral lesions is presented and discussed.

  4. Stereotactic biopsy of cerebellar lesions: straight versus oblique frame positioning.

    Science.gov (United States)

    Quick-Weller, Johanna; Brawanski, Nina; Dinc, Nazife; Behmanesh, Bedjahn; Kammerer, Sara; Dubinski, Daniel; Seifert, Volker; Marquardt, Gerhard; Weise, Lutz

    2017-10-26

    Biospies of brain lesions with unknown entity are an everyday procedure among many neurosurgical departments. Biopsies can be performed frame-guided or frameless. However, cerebellar lesions are a special entity with a more complex approach. All biopsies in this study were performed stereotactically frame guided. Therefore, only biopsies of cerebellar lesions were included in this study. We compared whether the frame was attached straight versus oblique and we focused on diagnostic yield and complication rate. We evaluated 20 patients who underwent the procedure between 2009 and 2017. Median age was 56.5 years. 12 (60%) Patients showed a left sided lesion, 6 (30%) showed a lesion in the right cerebellum and 2 (10%) patients showed a midline lesion. The stereotactic frame was mounted oblique in 12 (60%) patients and straight in 8 (40%) patients. Postoperative CT scan showed small, clinically silent blood collection in two (10%) of the patients, one (5%) patient showed haemorrhage, which caused a hydrocephalus. He received an external ventricular drain. In both patients with small haemorrhage the frame was positioned straight, while in the patient who showed a larger haemorrhage the frame was mounted oblique. In all patients a final histopathological diagnosis was established. Cerebellar lesions of unknown entity can be accessed transcerebellar either with the stereotactic frame mounted straight or oblique. Also for cerebellar lesions the procedure shows a high diagnostic yield with a low rate of severe complications, which need further treatment.

  5. INTRACRANIAL MASS LESIONS IN HIV-POSITIVE PATIENTS ...

    African Journals Online (AJOL)

    m. INTRACRANIAL MASS LESIONS IN. HIV-POSITIVE PATIENTS - THE. KwAZuLU/NATAL EXPERIENCE. A I Bhigjee, K Naidoo, V B Patel, D Govender, for the. Neuroscience AIDS Research Group. Background. Neurological disease heralds the develop1l).~tof. AIDS in 10 - 20% of HIV-seropositive individuals. In over half.

  6. Painful and multiple anogenital lesions are common in men with Treponema pallidum PCR-positive primary syphilis without herpes simplex virus coinfection: a cross-sectional clinic-based study.

    Science.gov (United States)

    Towns, Janet M; Leslie, David E; Denham, Ian; Azzato, Francesca; Fairley, Christopher K; Chen, Marcus

    2016-03-01

    Chancres, the hallmark of primary syphilis, are classically described as single, painless ulcers at the site of Treponema pallidum inoculation. We aimed to determine the frequency of painful or multiple anogenital lesions of primary syphilis among men, whether there was concurrent herpes simplex virus (HSV) infection and whether HIV status altered clinical presentations. This study was conducted among men with T. pallidum PCR-positive lesions, attending a clinic in Melbourne, Australia, between 2009 and 2014. Lesions were also tested with HSV PCR, and syphilis serology undertaken. 183 men with T. pallidum PCR-positive primary anogenital lesions were included. 89% were men who have sex with men, and 10.9% were heterosexual. 38 men (20.8%) were HIV positive. Anal lesions were more common in HIV-positive men (34.2%) than in HIV-negative men (11.6%). Primary lesions were frequently painful (49.2%) or multiple (37.7%), and infrequently associated with HSV (2.7%). Of 37 men with both painful and multiple primary lesions, only 8% had concurrent HSV. Presentation was not significantly altered by HIV status. Primary syphilis lesions are often painful and/or multiple in the absence of herpes coinfection, and may be clinically misdiagnosed. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

  7. Physical state and viral load as predictive biomarkersfor persistence and progression of HPV16-positive cervical lesions: results from a population based long-term prospective cohort study.

    Science.gov (United States)

    Manawapat, Anna; Stubenrauch, Frank; Russ, Rainer; Munk, Christian; Kjaer, Susanne Kruger; Iftner, Thomas

    2012-01-01

    Persistent infection with a high risk (hr) human papillomavirus (HPV) has been established as the main cause of cervical cancer and high-grade cervical intraepithelial neoplasia (CIN3). Because most infections are transient, testing for hrHPV lacks specificity and has a low positive predictive value. It has been suggested that additional parameters like viral load and physical status of the viral genome could improve the effectiveness of HPV-based screening. We investigated the association between HPV16 viral load and physical state with viral persistence or risk of incident CIN3 or worse in a population-based prospective cohort study comprising 8656 women (20-29 years). All participants had two gynecological examinations two years apart and were followed through the nationwide Danish Pathology Data Bank (median follow-up: 12.9 yrs). Seventynine cervical swabs from women with a persistent HPV16 infection were available for analysis. For comparison we selected a random age-matched sample of transiently HPV16 infected women (N=91). Persistently infected women with incident CIN3 or cancer (CIN3+; N=31) were compared to women with normal cytology during follow up (non-progressors; N=39). Quantitative real-time PCR for HPV16E6, E2 and IFNb1 was done to determine the HPV16 viral load and the E2/E6 ratio was used as a surrogate marker for integration. Women with normal cytology who became persistently HPV16 infected had a significantly lower HPV16 load at baseline than women who cleared the infection (median 4.72 copies/cell versus median 20.0 copies/cell, respectively; p=0.0003). There was no difference in viral load at enrollment between women who progressed to CIN3+ and women who stayed cytologically normal (p=0.85). At the second examination viral load tended to be higher in women who progressed, but the difference was not statistically significant (p=0.39). The E2/E6 ratio was shown to be lower in the persistently infected group (pload and integration of the viral

  8. Processing of Positive and Negative Feedback in Patients with Cerebellar Lesions.

    Science.gov (United States)

    Rustemeier, Martina; Koch, Benno; Schwarz, Michael; Bellebaum, Christian

    2016-08-01

    It is well accepted that the cerebellum plays a crucial role in the prediction of the sensory consequences of movements. Recent findings of altered error processing in patients with selective cerebellar lesions led to the hypothesis that feedback processing and feedback-based learning might be affected by cerebellar damage as well. Thus, the present study investigated learning from and processing of positive and negative feedback in 12 patients with selective cerebellar lesions and healthy control subjects. Participants performed a monetary feedback learning task. The processing of positive and negative feedback was assessed by means of event-related potentials (ERPs) during the learning task and during a separate task in which the frequencies of positive and negative feedback were balanced. Patients did not show a general learning deficit compared to controls. Relative to the control group, however, patients with cerebellar lesions showed significantly higher ERP difference wave amplitudes (rewards-losses) in a time window between 250 and 450 ms after feedback presentation, possibly indicating impaired outcome prediction. The analysis of the original waveforms suggested that patients and controls primarily differed in their pattern of feedback-related negativity and P300 amplitudes. Our results add to recent findings on altered performance monitoring associated with cerebellar damage and demonstrate, for the first time, alterations of feedback processing in patients with cerebellar damage. Unaffected learning performance appears to suggest that chronic cerebellar lesions can be compensated in behaviour.

  9. Quantitative study of neurofilament-positive fiber length in rat spinal cord lesions using isotropic virtual planes

    DEFF Research Database (Denmark)

    von Euler, Mia; Larsen, Jytte Overgaard; Janson, A M

    1998-01-01

    Spontaneous reocurrence of neurofilament (NF)-positive fibers has been described after spinal cord lesions in rats. However, previously introduced methods to evaluate the lesion and the regenerative fiber outgrowth suffer from several biases, why a new concept of quantitative, morphological...... analysis after spinal cord injury is needed. Length quantification of the putatively spontaneously regenerating fibers has been difficult until recently, when two length estimators based on sampling with isotropic virtual planes within thick physical sections were introduced. The applicability...

  10. Displaceability of SLAP lesion on shoulder MR arthrography with external rotation position

    Energy Technology Data Exchange (ETDEWEB)

    Jung, Jin Young; Ha, Doo Hoe; Lee, Sang Min [CHA University, Department of Radiology, CHA Bundang Medical Center, Gyeonggi-do (Korea, Republic of); Blacksin, Marcia F. [University of Medicine and Dentistry of New Jersey, Department of Radiology, New Jersey Medical School, Newark, NJ (United States); Kim, Kyung Ah [Inje University Ilsan-Paik Hospital, Department of Radiology, Gyeonggi-do (Korea, Republic of); Kim, Jae Wha [CHA University, Department of Orthopedics, CHA Bundang Medical Center, Gyeonggi-do (Korea, Republic of)

    2011-08-15

    To investigate the usefulness of the external rotation (ER) position on magnetic resonance (MR) arthrography for the diagnosis of superior labral anterior to posterior (SLAP) lesion. Approval of institutional review board was obtained, and informed consent was waived. The MR arthrograms of 210 shoulders that were arthroscopically confirmed as SLAP lesion in 163 shoulders and intact superior labrum in 47 shoulders were retrospectively reviewed in each neutral and ER position for the diagnosis of SLAP lesion, the extent of distraction of the torn labrum, and the external rotation angle. The sensitivity, specificity, and diagnostic accuracy of MR arthrograms for determining SLAP lesion were assessed in each position. For the arthroscopically confirmed group, the diagnosis of SLAP lesion and the extent of distraction about the tear were compared between neutral and ER positions by Fisher's exact test and the paired t-test. The correlation between the external rotation angle and the diagnosis of SLAP lesion, and between the external rotation angle and the differences in the extent of distraction were evaluated in the ER position using the ANOVA test. Sensitivity and diagnostic accuracy of MR arthrography for SLAP lesion increased from 64.4% and 71.0% in the neutral position to 78.5% and 81.9% in the ER position, respectively, without change of specificity, which was 93.6% in both positions. The diagnosis of SLAP lesion was changed from negative to SLAP lesion in 16.0% of the arthroscopically confirmed group. Mean difference in the extent of distraction about the tear was 0.69 mm (range -1.40 {proportional_to} 6.67 mm), which was statistically significant. There was no relationship between the external rotation angle and the diagnosis of SLAP lesion, and between the external rotation angle and the differences in the extent of distraction. Shoulder MR arthrography with additional ER positioning helps in the diagnosis of SLAP lesion and provides information about the

  11. Discrimination and anatomical mapping of PET-positive lesions: comparison of CT attenuation-corrected PET images with coregistered MR and CT images in the abdomen

    Energy Technology Data Exchange (ETDEWEB)

    Kuhn, Felix P.; Crook, David W.; Mader, Caecilia E.; Appenzeller, Philippe; Schulthess, G.K. von; Schmid, Daniel T. [University Hospital Zurich, Department of Medical Radiology, Zurich (Switzerland)

    2013-01-15

    PET/MR has the potential to become a powerful tool in clinical oncological imaging. The purpose of this prospective study was to evaluate the performance of a single T1-weighted (T1w) fat-suppressed unenhanced MR pulse sequence of the abdomen in comparison with unenhanced low-dose CT images to characterize PET-positive lesions. A total of 100 oncological patients underwent sequential whole-body {sup 18}F-FDG PET with CT-based attenuation correction (AC), 40 mAs low-dose CT and two-point Dixon-based T1w 3D MRI of the abdomen in a trimodality PET/CT-MR system. PET-positive lesions were assessed by CT and MRI with regard to their anatomical location, conspicuity and additional relevant information for characterization. From among 66 patients with at least one PET-positive lesion, 147 lesions were evaluated. No significant difference between MRI and CT was found regarding anatomical lesion localization. The MR pulse sequence used performed significantly better than CT regarding conspicuity of liver lesions (p < 0.001, Wilcoxon signed ranks test), whereas no difference was noted for extrahepatic lesions. For overall lesion characterization, MRI was considered superior to CT in 40 % of lesions, equal to CT in 49 %, and inferior to CT in 11 %. Fast Dixon-based T1w MRI outperformed low-dose CT in terms of conspicuity and characterization of PET-positive liver lesions and performed similarly in extrahepatic tumour manifestations. Hence, under the assumption that the technical issue of MR AC for whole-body PET examinations is solved, in abdominal PET/MR imaging the replacement of low-dose CT by a single Dixon-based MR pulse sequence for anatomical lesion correlation appears to be valid and robust. (orig.)

  12. An ensemble deep learning based approach for red lesion detection in fundus images.

    Science.gov (United States)

    Orlando, José Ignacio; Prokofyeva, Elena; Del Fresno, Mariana; Blaschko, Matthew B

    2018-01-01

    Diabetic retinopathy (DR) is one of the leading causes of preventable blindness in the world. Its earliest sign are red lesions, a general term that groups both microaneurysms (MAs) and hemorrhages (HEs). In daily clinical practice, these lesions are manually detected by physicians using fundus photographs. However, this task is tedious and time consuming, and requires an intensive effort due to the small size of the lesions and their lack of contrast. Computer-assisted diagnosis of DR based on red lesion detection is being actively explored due to its improvement effects both in clinicians consistency and accuracy. Moreover, it provides comprehensive feedback that is easy to assess by the physicians. Several methods for detecting red lesions have been proposed in the literature, most of them based on characterizing lesion candidates using hand crafted features, and classifying them into true or false positive detections. Deep learning based approaches, by contrast, are scarce in this domain due to the high expense of annotating the lesions manually. In this paper we propose a novel method for red lesion detection based on combining both deep learned and domain knowledge. Features learned by a convolutional neural network (CNN) are augmented by incorporating hand crafted features. Such ensemble vector of descriptors is used afterwards to identify true lesion candidates using a Random Forest classifier. We empirically observed that combining both sources of information significantly improve results with respect to using each approach separately. Furthermore, our method reported the highest performance on a per-lesion basis on DIARETDB1 and e-ophtha, and for screening and need for referral on MESSIDOR compared to a second human expert. Results highlight the fact that integrating manually engineered approaches with deep learned features is relevant to improve results when the networks are trained from lesion-level annotated data. An open source implementation of our

  13. Intracranial mass lesions in HIV-positive patients – the Kwazulu ...

    African Journals Online (AJOL)

    Background. Neurological disease heralds the development of AIDS in 10 - 20% of HIV-seropositive individuals. In over half of these cases the presentation will be that of an intracranial mass lesion (IML). In developed countries toxoplasmosis is the most frequent cause of IML in a positive patient, followed by primary central ...

  14. Voxel-based lesion-symptom mapping of stroke lesions underlying somatosensory deficits

    Science.gov (United States)

    Meyer, Sarah; Kessner, Simon S.; Cheng, Bastian; Bönstrup, Marlene; Schulz, Robert; Hummel, Friedhelm C.; De Bruyn, Nele; Peeters, Andre; Van Pesch, Vincent; Duprez, Thierry; Sunaert, Stefan; Schrooten, Maarten; Feys, Hilde; Gerloff, Christian; Thomalla, Götz; Thijs, Vincent; Verheyden, Geert

    2015-01-01

    The aim of this study was to investigate the relationship between stroke lesion location and the resulting somatosensory deficit. We studied exteroceptive and proprioceptive somatosensory symptoms and stroke lesions in 38 patients with first-ever acute stroke. The Erasmus modified Nottingham Sensory Assessment was used to clinically evaluate somatosensory functioning in the arm and hand within the first week after stroke onset. Additionally, more objective measures such as the perceptual threshold of touch and somatosensory evoked potentials were recorded. Non-parametric voxel-based lesion-symptom mapping was performed to investigate lesion contribution to different somatosensory deficits in the upper limb. Additionally, structural connectivity of brain areas that demonstrated the strongest association with somatosensory symptoms was determined, using probabilistic fiber tracking based on diffusion tensor imaging data from a healthy age-matched sample. Voxels with a significant association to somatosensory deficits were clustered in two core brain regions: the central parietal white matter, also referred to as the sensory component of the superior thalamic radiation, and the parietal operculum close to the insular cortex, representing the secondary somatosensory cortex. Our objective recordings confirmed findings from clinical assessments. Probabilistic tracking connected the first region to thalamus, internal capsule, brain stem, postcentral gyrus, cerebellum, and frontal pathways, while the second region demonstrated structural connections to thalamus, insular and primary somatosensory cortex. This study reveals that stroke lesions in the sensory fibers of the superior thalamocortical radiation and the parietal operculum are significantly associated with multiple exteroceptive and proprioceptive deficits in the arm and hand. PMID:26900565

  15. Risk factors for anal high-grade squamous intraepithelial lesions in HIV-positive MSM: is targeted screening possible?

    NARCIS (Netherlands)

    Siegenbeek van Heukelom, Matthijs L.; Marra, Elske; de Vries, Henry J. C.; Schim van der Loeff, Maarten F.; Prins, Jan M.

    2017-01-01

    HIV-positive MSM are at increased risk for developing anal squamous cell carcinoma. Detection of precursor lesions of anal cancer [anal high-grade squamous intraepithelial lesions (HSIL)] is cumbersome and expensive. Our objective was to identify potential risk factors for anal HSIL in HIV-positive

  16. Papulonodular Secondary Syphilis Presenting as Multiple Distinct Cutaneous Lesions in an HIV-Positive Transgender Woman

    Directory of Open Access Journals (Sweden)

    Kristina Navrazhina

    2017-03-01

    Full Text Available We present the first reported case of papulonodular secondary syphilis in an HIV-positive transgender female. Syphilis is classified into primary, secondary, latent, and tertiary stages, with secondary syphilis having notably diverse cutaneous manifestations. Our patient presented with diverse lesions throughout her body, all pathologically consistent with papulonodular secondary syphilis. Proper identification of the multiple presentations of syphilis is crucial to early diagnosis and treatment. This report seeks to broaden the scope of dermatological manifestations that arise secondary to papulonodular syphilis in HIV-positive patients.

  17. Pedunculopontine tegmental nucleus lesions impair probabilistic reversal learning by reducing sensitivity to positive reward feedback.

    Science.gov (United States)

    Syed, Anam; Baker, Phillip M; Ragozzino, Michael E

    2016-05-01

    Recent findings indicate that pedunculopontine tegmental nucleus (PPTg) neurons encode reward-related information that is context-dependent. This information is critical for behavioral flexibility when reward outcomes change signaling a shift in response patterns should occur. The present experiment investigated whether NMDA lesions of the PPTg affects the acquisition and/or reversal learning of a spatial discrimination using probabilistic reinforcement. Male Long-Evans rats received a bilateral infusion of NMDA (30nmoles/side) or saline into the PPTg. Subsequently, rats were tested in a spatial discrimination test using a probabilistic learning procedure. One spatial location was rewarded with an 80% probability and the other spatial location rewarded with a 20% probability. After reaching acquisition criterion of 10 consecutive correct trials, the spatial location - reward contingencies were reversed in the following test session. Bilateral and unilateral PPTg-lesioned rats acquired the spatial discrimination test comparable to that as sham controls. In contrast, bilateral PPTg lesions, but not unilateral PPTg lesions, impaired reversal learning. The reversal learning deficit occurred because of increased regressions to the previously 'correct' spatial location after initially selecting the new, 'correct' choice. PPTg lesions also reduced the frequency of win-stay behavior early in the reversal learning session, but did not modify the frequency of lose-shift behavior during reversal learning. The present results suggest that the PPTg contributes to behavioral flexibility under conditions in which outcomes are uncertain, e.g. probabilistic reinforcement, by facilitating sensitivity to positive reward outcomes that allows the reliable execution of a new choice pattern. Copyright © 2016 Elsevier Inc. All rights reserved.

  18. Medical Imaging Lesion Detection Based on Unified Gravitational Fuzzy Clustering

    Directory of Open Access Journals (Sweden)

    Jean Marie Vianney Kinani

    2017-01-01

    Full Text Available We develop a swift, robust, and practical tool for detecting brain lesions with minimal user intervention to assist clinicians and researchers in the diagnosis process, radiosurgery planning, and assessment of the patient’s response to the therapy. We propose a unified gravitational fuzzy clustering-based segmentation algorithm, which integrates the Newtonian concept of gravity into fuzzy clustering. We first perform fuzzy rule-based image enhancement on our database which is comprised of T1/T2 weighted magnetic resonance (MR and fluid-attenuated inversion recovery (FLAIR images to facilitate a smoother segmentation. The scalar output obtained is fed into a gravitational fuzzy clustering algorithm, which separates healthy structures from the unhealthy. Finally, the lesion contour is automatically outlined through the initialization-free level set evolution method. An advantage of this lesion detection algorithm is its precision and its simultaneous use of features computed from the intensity properties of the MR scan in a cascading pattern, which makes the computation fast, robust, and self-contained. Furthermore, we validate our algorithm with large-scale experiments using clinical and synthetic brain lesion datasets. As a result, an 84%–93% overlap performance is obtained, with an emphasis on robustness with respect to different and heterogeneous types of lesion and a swift computation time.

  19. STEREOLOGIC ESTIMATION OF KI-67, CASPASE 3 AND GSTP1 POSITIVE CELLS IN PROSTATE LESIONS

    Directory of Open Access Journals (Sweden)

    Luis Santamaría

    2011-05-01

    Full Text Available Cell proliferation, caspase 3 and pi-form of glutathione S transferase (GSTP1 were evaluated in prostate carcinoma (PCA, proliferative inflammatory atrophy (PIA and prostate intraepithelial neoplasia (PIN. Forty biopsies were classified as: without morphological lesions (controls: CTR, PIA, PIN and PCA. Ki67, caspase3 and GSTP1 were immunostained. The following estimates were performed: Numerical densities of Ki67+ cells (NVEPKi67, of all epithelial cells (NVEPtotal and of GSTP1+ cells (NVEPGSTP1; labelling index for Ki67 (LIKi67; volume fraction to caspase 3 positive tissue (VVcaspase 3 and of GSTP1 positive tissue (VVGSTP1. ANOVA was performed to compare the groups. NVEPtotal and NVEPKi67 were increased in PIA. LIKi67 was only increased in PCA. VVcaspase 3 was decreased in PIN and PCA. VVEGSTP1 was decreased in PCA. In our results PIA lacks the characteristics of a premalignant lesion. The result may be explained by the use of unbiased quantitative methods, the inadequate definition of PIA and the scarce inflammation observed in the samples with PIA included in this study.

  20. Analysis of false positive and false negative cytological diagnosis of breast lesions

    International Nuclear Information System (INIS)

    Jamal, Awtif A.; Mansoor, I.

    2001-01-01

    To study the reasons for interpretive errors in false negative and false positive diagnosis of breast carcinoma on fine needle aspiration cytology material. We reviewed only those cases in which cytohistological discrepancies were found, where the cytologic material was abnormal and to some extent misinterpreted or both. There was only one false negative case (false negative fraction 0.32%) proved histologically as ductal carcinoma and four false positive cases (false positive fraction 1.2%); 2 fibroadenoma; 1 fibrocystic disease; and 1 stromal fibrosis. Smears of the two false positive fibroadenoma cases showed very high cellularity, overcrowded clusters and frequent stripped nuclei. The fibrocystic case showed tight clusters of apocrine cells and sheets of loosely aggregated macrophages that were over interpreted. Smears of the false negative ductal carcinoma was hypocellular overall, and the cells showed minimal nuclear pleomorphism. Overcrowded clusters and hypercellular smears should be carefully assessed for uniformity of cells and detailed nuclear and cytomorphological features. If the full-blown malignant cytomorphological changes are not visible, a diagnosis of suspicious or inconclusive should be made and frozen section recommended before surgery. Hypocellularity and relatively nuclear monomorphism are the reasons for failure to diagnose malignant breast lesions. Careful attention should be paid to extreme nuclear monomorphism and absence of naked bipolar cells. A cytologically atypical or suspicious diagnosis together with positive radiological and clinical findings should suggest a diagnosis of malignancy. (author)

  1. MR-DWI-positive lesions and symptomatic ischemic complications after coiling of unruptured intracranial aneurysms.

    Science.gov (United States)

    Kang, Dong-Hun; Kim, Byung Moon; Kim, Dong Joon; Suh, Sang Hyun; Kim, Dong Ik; Kim, Yong-Sun; Huh, Seung Kon; Park, Jaechan; Lee, Jae Whan; Kim, Yong Bae

    2013-03-01

    The aims of this study are to evaluate the risk factors for symptomatic ischemic complication (symptomatic ischemic complication [SIC], transient ischemic attack, or stroke) and microembolisms detected as MR diffusion-weighted imaging (MR-DWI)-positive (DWI(+)) lesions, and the relationship between DWI(+) and SIC after coiling of unruptured intracranial aneurysm. Between March 2009 and November 2011, 382 unruptured intracranial aneurysms in 343 patients underwent both coiling and posttreatment MR-DWI. The incidence of and risk factors for SIC and DWI(+), and the relationship between DWI(+) and SIC were retrospectively analyzed. The incidence of SIC was 4.1%. The incidence of DWI(+) was 54.5%. The number of DWI(+) lesions was significantly larger in the SIC group, than in the asymptomatic one (12.1±10.4 versus 5.0±8.7, P<0.00). The cutoff value of DWI(+) for predicting SIC was ≥6 (sensitivity 85.7%, specificity 70.7%). The patients with DWI(+) ≥6 was 28.6%. Of the patients with SIC, the patients with DWI(+) ≥6 was 78.6%. Patients aged≥65 years had a trend for SIC, and it was the only independent risk factor for DWI(+) ≥cutoff (n=6; 95%CI, 1.167-3.083). The number of DWI(+) lesions was significantly larger in the SIC group than in the asymptomatic one after coiling of unruptured intracranial aneurysm. Patients aged≥65 had a trend for SIC, and it was the only independent risk factor for the number of DWI(+) ≥cutoff value (n=6) for predicting SIC.

  2. Usefulness and limits of ultrasound guided hook-wire positioning for localisation of soft tissue lesions prior to surgery

    International Nuclear Information System (INIS)

    Trenaghi, Alberto; Dal Bosco, Chiara; Talenti, Enrico; Rubaltelli, Enrico; Borsato, Simonetta; Rossi, Carlo Riccardo; Lumachi, Franco

    2005-01-01

    Purpose. The aim of our study was to assess the usefulness of positioning metal wires under ultrasound guidance for localising soft tissue lesions in the preoperative phase. Materials and methods. We studied superficial soft-tissue lesions in 12 patients, using hooked mammographic wires of different lengths. One patient had a multifocal growth of disease which required a double localisation procedure. Correct positioning of the wire was confirmed by ultrasonography. All patients underwent surgery within five hours of hook-wire positioning. Results. Correct wire position was confirmed at surgery in 12 out of 13 procedures. In one case the hook-wire reached the margin of the lesion. In all cases, the preoperative localisation procedure facilitated identification and resection of the masses. Conclusions. In our experience, the main indications for hook-wire positioning before surgery are: marking of small lesions, localisation of lesions in anatomic areas structurally subverted by previous surgery and consequently difficult to detect, guidance for surgical sectioning in order to safeguard the noble structures dose to the lesions [it

  3. Benign thyroid and neck lesions mimicking malignancy with false positive findings on positron emission tomography-computed tomography

    Energy Technology Data Exchange (ETDEWEB)

    Yoon, Ye Ri; Kim, Shin Young; Lee, Sang Mi [Soonchunhyang University Cheonan Hospital, Cheonan (Korea, Republic of); Lee, Deuk Young [Dept. of Surgery, Younsei Angelot Women' s Clinic, Cheonan (Korea, Republic of)

    2017-02-15

    The increasing use of positron emission tomography-computed tomography (PET/CT) has led to the frequent detection of incidental thyroid and neck lesions with increased 18F-deoxyglucose (FDG) uptake. Although lesions with increased FDG uptake are commonly assumed to be malignant, benign lesions may also exhibit increased uptake. The purpose of this pictorial essay is to demonstrate that benign thyroid and neck lesions can produce false-positive findings on PET/CT, and to identify various difficulties in interpretation. It is crucial to be aware that differentiating between benign and malignant lesions is difficult in a considerable proportion of cases, when relying only on PET/CT findings. Correlation of PET/CT findings with additional imaging modalities is essential to avoid misdiagnosis.

  4. Red lesion detection in retinal fundus images using Frangi-based filters.

    Science.gov (United States)

    Srivastava, Ruchir; Wong, Damon W K; Lixin Duan; Jiang Liu; Tien Yin Wong

    2015-08-01

    This paper presents a method to detect red lesions related to Diabetic Retinopathy (DR), namely Microaneurysms and Hemorrhages from retinal fundus images with robustness to the presence of blood vessels. Filters based on Frangi filters are used for the first time for this task. Green channel of the input image was decomposed into smaller sub images and proposed filters were applied to each sub image after initial preprocessing. Features were extracted from the filter response and used to train a Support Vector Machine classifier to predict whether a test image had lesions or not. Experiments were performed on a dataset of 143 retinal fundus and the proposed method achieved areas under the ROC curve equal to 0.97 and 0.87 for Microaneurysms and Hemorrhages respectively. Results show the effectiveness of the proposed method for detecting red lesions. This method can help significantly in automated detection of DR with fewer false positives.

  5. Background based Gaussian mixture model lesion segmentation in PET

    Energy Technology Data Exchange (ETDEWEB)

    Soffientini, Chiara Dolores, E-mail: chiaradolores.soffientini@polimi.it; Baselli, Giuseppe [DEIB, Department of Electronics, Information, and Bioengineering, Politecnico di Milano, Piazza Leonardo da Vinci 32, Milan 20133 (Italy); De Bernardi, Elisabetta [Department of Medicine and Surgery, Tecnomed Foundation, University of Milano—Bicocca, Monza 20900 (Italy); Zito, Felicia; Castellani, Massimo [Nuclear Medicine Department, Fondazione IRCCS Ca’ Granda Ospedale Maggiore Policlinico, via Francesco Sforza 35, Milan 20122 (Italy)

    2016-05-15

    Purpose: Quantitative {sup 18}F-fluorodeoxyglucose positron emission tomography is limited by the uncertainty in lesion delineation due to poor SNR, low resolution, and partial volume effects, subsequently impacting oncological assessment, treatment planning, and follow-up. The present work develops and validates a segmentation algorithm based on statistical clustering. The introduction of constraints based on background features and contiguity priors is expected to improve robustness vs clinical image characteristics such as lesion dimension, noise, and contrast level. Methods: An eight-class Gaussian mixture model (GMM) clustering algorithm was modified by constraining the mean and variance parameters of four background classes according to the previous analysis of a lesion-free background volume of interest (background modeling). Hence, expectation maximization operated only on the four classes dedicated to lesion detection. To favor the segmentation of connected objects, a further variant was introduced by inserting priors relevant to the classification of neighbors. The algorithm was applied to simulated datasets and acquired phantom data. Feasibility and robustness toward initialization were assessed on a clinical dataset manually contoured by two expert clinicians. Comparisons were performed with respect to a standard eight-class GMM algorithm and to four different state-of-the-art methods in terms of volume error (VE), Dice index, classification error (CE), and Hausdorff distance (HD). Results: The proposed GMM segmentation with background modeling outperformed standard GMM and all the other tested methods. Medians of accuracy indexes were VE <3%, Dice >0.88, CE <0.25, and HD <1.2 in simulations; VE <23%, Dice >0.74, CE <0.43, and HD <1.77 in phantom data. Robustness toward image statistic changes (±15%) was shown by the low index changes: <26% for VE, <17% for Dice, and <15% for CE. Finally, robustness toward the user-dependent volume initialization was

  6. Chronic low dose risperidone and clozapine alleviate positive but not negative symptoms in the rat neonatal ventral hippocampal lesion model of schizophrenia.

    Science.gov (United States)

    Rueter, Lynne E; Ballard, Michael E; Gallagher, Kelly B; Basso, Ana Maria; Curzon, Peter; Kohlhaas, Kathy L

    2004-11-01

    The rat neonatal ventral hippocampal (VH) ibotenic lesion model has been proposed as a developmental model of schizophrenia, based on evidence that it encompasses aspects of the disorder including psychomotor agitation (hyperactivity), deficits in prepulse inhibition (PPI), and deficits in social interaction (SI), measures presumed to reflect positive symptoms, sensory gating deficits and negative symptoms, respectively. However, validation of the model as a predictive pharmacological screening tool has been minimal. Determine the effects of a chronic 3-week low dose treatment of clozapine or risperidone on locomotor hyperactivity, PPI and SI in lesioned and control rats. Both clozapine, 2.5 mg/kg per day IP and risperidone, 0.1 mg/kg per day IP, reversed lesion-induced locomotor hyperactivity; however, the compounds also decreased locomotor activity in the non-lesioned controls. Clozapine 2.5 mg/kg per day and risperidone 0.1 mg/kg per day significantly attenuated lesion-induced PPI deficits. Neither compound induced a significant attenuation of lesion-induced SI deficits. In order to see if SI deficits required a higher dose of an antipsychotic, the dose of clozapine was increased to 4 mg/kg per day; however this dose induced such marked decreases in the activity and startle responses in the control rats, i.e. up to 74% decrease, that the effects on the lesioned rats could not be adequately interpreted. These data add further support to the neonatal VH lesion model as a predictive pharmacological screening assay for identifying compounds effective in the treatment of positive symptoms of schizophrenia. However, the usefulness of the model in detecting compounds effective in treating negative symptoms of schizophrenia is still in question.

  7. Difficulty of MRI based identification of lesion age by acute infra-tentorial ischemic stroke.

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    Florian Grosse-Dresselhaus

    Full Text Available Systemic thrombolysis in acute ischemic stroke is restricted to the 4.5 h time window. Many patients are excluded from this treatment because symptom onset is unknown. Magnetic resonance imaging (MRI studies have shown that stroke patients presenting with acute supra-tentorial diffusion-weighted imaging (DWI lesions that do not have matching lesions on fluid attenuated inversion recovery (FLAIR are likely to be within a 4.5 hour time window. This study examines the DWI-FLAIR mismatch in infra-tentorial stroke.This was a retrospectively conducted substudy of the "1000+" study; a prospective, single-center observational study (http://clinicaltrials.gov; NCT00715533. Fifty-six patients with infra-tentorial stroke confirmed by MRI and known symptom onset who underwent the scan within 24 h after symptom onset were analysed. Two neurologists blinded to clinical information separately rated the DWI lesion visibility on FLAIR. Lesion volume, relative signal intensities of DWI and relative apparent diffusion coefficient values were determined.Regarding baseline characteristics our study population had a median age of 66 years, a median time from symptom onset to MRI of 616.5 minutes, a median NIHSS of 3 and a median DWI lesion volume of 0.26 ml. A negative FLAIR allocated patients to a time window under 4.5 h correctly with a sensitivity of 55% and a specificity of 61%, a positive predictive value of 44% and a negative predictive value of 71%. FLAIR positivity decreased with age (p = 0.018, and showed no significant correlation to lesion volume (p = 0.145.In our study the DWI-FLAIR-Mismatch does not help to reliably identify patients within 4.5 h of symptom onset in acute ischemic infra-tentorial stroke. Thus therapeutical decisions based on the DWI-FLAIR mismatch estimation of time from onset cannot be recommended in patients with infra-tentorial stroke.

  8. Association between lesion location and language function in adult glioma using voxel-based lesion-symptom mapping.

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    Banerjee, Pia; Leu, Kevin; Harris, Robert J; Cloughesy, Timothy F; Lai, Albert; Nghiemphu, Phioanh L; Pope, Whitney B; Bookheimer, Susan Y; Ellingson, Benjamin M

    2015-01-01

    Management of language difficulties is an important aspect of clinical care for glioma patients, and accurately identifying the possible language deficits in patients based on lesion location would be beneficial to clinicians. To that end, we examined the relationship between lesion presence and language performance on tests of receptive language and expressive language using a highly specific voxel-based lesion-symptom mapping (VLSM) approach in glioma patients. 98 adults with primary glioma, who were pre-surgical candidates, were administered seven neurocognitive tests within the domains of receptive language and expressive language. The association between language performance and lesion presence was examined using VLSM. Statistical parametric maps were created for each test, and composite maps for both receptive language and expressive language were created to display the significant voxels common to all tests within these language domains. We identified clusters of voxels with a significant relationship between lesion presence and language performance. All tasks were associated with several white matter pathways. The receptive language tasks were additionally all associated with regions primarily within the lateral temporal lobe and medial temporal lobe. In contrast, the expressive language tasks shared little overlap, despite each task being independently associated with large anatomic areas. Our findings identify the key anatomic structures involved in language functioning in adult glioma patients using an innovative lesion analysis technique and suggest that expressive language abilities may be more task-dependent and distributed than receptive language abilities.

  9. Screening, prevalence, and risk factors for cervical lesions among HIV positive and HIV negative women in Swaziland

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    Pauline E. Jolly

    2017-02-01

    Full Text Available Abstract Background Cervical Cancer (CC is the number one cancer among women in sub-Saharan Africa. Although CC is preventable, most women in developing countries do not have access to screening. Methods This cross-sectional study was conducted to determine the prevalence and risk factors for cervical lesions using visual inspection with acetic acid (VIA among 112 HIV positive and 161 negative women aged 18–69 years. Results The presence of cervical lesions was greater among HIV positive (22.9% than HIV negative women (5.7%; p < 0.0001. In logistic models, the risk of cervical lesions among HIV positive women was 5.24 times higher when adjusted by age (OR 5.24, CI 2.31–11.88, and 4.06 times higher in a full model (OR 4.06, CI 1.61–10.25, than among HIV negative women. In the age-adjusted model women who had ≥2 lifetime sexual partners were 3 times more likely (OR 3.00, CI 1.02–8.85 to have cervical lesions compared to women with one lifetime partner and the odds of cervical lesions among women with a history of STIs were 2.16 greater (OR 2.16, CI 1.04–4.50 than among women with no previous STI. In the fully adjusted model women who had a previous cervical exam were 2.5 times more likely (OR 2.53, CI 1.06–6.05 to have cervical lesions than women who had not. Conclusions The high prevalence of HIV infection and the strong association between HIV and cervical lesions highlight the need for substantial scale-up of cervical screening to decrease the rate of CC in Swaziland.

  10. Cerebral lesions can impair fMRI-based language lateralization.

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    Wellmer, Jörg; Weber, Bernd; Urbach, Horst; Reul, Jürgen; Fernandez, Guillen; Elger, Christian E

    2009-10-01

    Several small patient studies and case reports raise concerns that the reliability of functional magnetic resonance imaging (fMRI) may be impaired in the vicinity of cerebral lesions. This could affect the clinical validity of fMRI for presurgical language lateralization. The current study sets out to identify if a systematic effect of lesion type and localization on fMRI exists. We classify lesions typically occurring in epilepsy patients according to (1) their potential to disturb blood oxygenation level dependent (BOLD)-effect generation or detection or to disturb spatial brain normalization, and (2) the proximity of lesions to protocol-specific volumes of interest (VOIs). The effect of lesions is evaluated through the examination of 238 epilepsy patients and a subgroup of 37 patients with suspected unilateral left-language dominance according to the Wada test. Patients with fMRI-critical lesions such as cavernomas, gliomas, and mass defects close to VOIs, or with severe atrophy, show lower lateralization indices (LIs) and more often discordant language lateralization with the Wada test than do patients without such lesions. This study points seriously toward fMRI-language lateralization being sensitive to cerebral lesions. Some lesion types and locations are more critical than others. Our results question the noncritical application of fMRI in patients with cerebral lesions.

  11. Clinical analysis of skin lesions in 796 Chinese HIV- positive patients.

    Science.gov (United States)

    Huang, Xiao-jie; Li, Hai-ying; Chen, De-xi; Wang, Xi-cheng; Li, Zai-chun; Wu, Ya-song; Zhang, Tong; Gao, Yan-qing; Wu, Hao

    2011-09-01

    Skin lesions are often associated with human immunodeficiency virus (HIV) infection, reflecting the immunocompromised status of the individual. We investigated the relationship between skin lesions and immune function in a retrospective study of 796 Chinese HIV patients with and without highly active antiretroviral therapy (HAART). Of the 651 patients who had not received HAART, we found that 531 (81.6%) had apparent skin lesions. The incidence of infectious skin diseases (fungi, viruses, bacteria, spirochetes and parasites) and non-infectious skin diseases (excluding skin cancer) was 68.8% and 34.9%, respectively. Mean CD4(+) T-cell counts and CD4(+)/CD8(+) ratios were lower in patients with skin lesions than in patients without lesions (178 ± 96/µl vs. 306 ± 189/µl (p Candidiasis (25.8%), eczema (19.2%), nodular prurigo (13.8%), dermatophyte infections (10.6%) and herpes zoster (9.4%) were most common in Chinese patients with HIV. Among the 145 patients who had started HAART, there was a significantly lower prevalence of skin diseases (29.0%), although drug eruptions (12.4%) were more commonly observed. These findings indicate that HAART often reduces the incidence of infectious and non-infectious skin lesions in patients with HIV, but can itself be the cause of drug eruptions.

  12. Evaluation of colonic lesions and pitfalls in CT colonography: A systematic approach based on morphology, attenuation and mobility

    International Nuclear Information System (INIS)

    Mang, Thomas; Gryspeerdt, Stefaan; Schima, Wolfgang; Lefere, Philippe

    2013-01-01

    Computed tomographic colonography is a reliable technique for the detection and classification of neoplastic and non-neoplastic lesions of the colon. It is based on a thin-section CT dataset of the cleansed and air-distended colon, acquired in prone and supine position. Two-dimensional and 3D projections are used in combination for image interpretation. The evaluation of CT colonography datasets is based on two steps, lesion perception to detect a polyp candidate and image interpretation to correctly characterize colonic filling defects. A thorough knowledge of the morphologic and attenuation characteristics of common colonic lesions and artifacts facilitates characterization of the findings. The purpose of this review article is to give an overview of the key CT colonographic imaging criteria to correctly characterize common colorectal lesions and to identify typical pitfalls and pseudolesions

  13. High prevalence of specific KIR types in patients with HHV-8 positive cutaneous vascular lesions: a possible predisposing factor?

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    Borghi, Alessandro; D'Accolti, Maria; Rizzo, Roberta; Virgili, Annarosa; Di Luca, Dario; Corazza, Monica; Caselli, Elisabetta

    2016-07-01

    Human herpesvirus 8 (HHV8) has been hypothesized to be a potential cofactor for the development of diverse cutaneous vascular proliferative lesions, including eruptive cherry angiomas. Recent reports evidenced the influence of killer cell immunoglobulin-like receptor (KIR) gene diversity in defining the susceptibility to symptomatic herpesvirus infections. In this study, skin samples from vascular lesions and healthy controls were characterized simultaneously for the presence of HHV8 and for the KIR genotype, focusing upon the presence of the KIR2DL2/DS2 and KIR2DL3 genes, which have been associated to herpesvirus susceptibility. The results showed that about 64 % of the vascular lesions resulted positive for the presence of HHV8, whereas no control healthy skin samples harbored HHV8 DNA. HHV8-positive patients had a significantly increased frequency of KIR2DL2/DS2 homozigosity and a concomitant decrease of the homozygous KIR2DL3 genotype, compared to healthy controls or HHV8-negative patients. Notably, the simultaneous presence of KIR2DL2/DS2 homozygosity and HHV8 infection resulted in a significantly increased risk to develop cutaneous lesions (OR 5.7) compared to the individual factors alone, suggesting that specific KIR genotypes might predispose to HHV8 symptomatic infection, allowing the virus to exert its angioproliferative activity at skin level.

  14. Triage for management of cervical high-grade squamous intraepithelial lesion patients with positive margin by conization: a retrospective analysis.

    Science.gov (United States)

    Dou, Yuya; Zhang, Xiaodan; Li, Yang; Wang, Fenfen; Xie, Xing; Wang, Xinyu

    2017-06-01

    The objective of this study is to guide a triage for the management of cervical high-grade squamous intraepithelial lesion (HSIL) patients with positive margin by conization. Clinico-pathological data of HSIL patients with positive margin by conization were retrospectively collected from January 2009 to December 2014. All patients underwent secondary conization or hysterectomy within 6 months. The rate of residual lesion was calculated, and the factors associated with residual lesion were analyzed by univariate and multivariate analyses. Among a total of 119 patients, 56 (47.06%) patients presented residual HSIL in their subsequent surgical specimens, including 4 cases of invasive cervical carcinoma (3 stage IA1 and 1 stage IA2 patients). Univariate analysis showed that patient age > 35 years (P = 0.005), menopausal period > 5 years (P = 0.0035), and multiple-quadrant involvement (P = 0.001) were significantly correlated with residual disease; however, multivariate analysis revealed that multiple-quadrant involvement (P = 0.001; OR, 3.701; 95%CI, 1.496-9.154) was an independent risk factor for residual disease. Nearly half of HSIL patients with positive margin by conization were disease-free in subsequent surgical specimens, and those with multiple positive margins may consider reconization or re-assessment.

  15. Lung lesion doubling times: values and variability based on method of volume determination

    International Nuclear Information System (INIS)

    Eisenbud Quint, Leslie; Cheng, Joan; Schipper, Matthew; Chang, Andrew C.; Kalemkerian, Gregory

    2008-01-01

    Purpose: To determine doubling times (DTs) of lung lesions based on volumetric measurements from thin-section CT imaging. Methods: Previously untreated patients with ≥ two thin-section CT scans showing a focal lung lesion were identified. Lesion volumes were derived using direct volume measurements and volume calculations based on lesion area and diameter. Growth rates (GRs) were compared by tissue diagnosis and measurement technique. Results: 54 lesions were evaluated including 8 benign lesions, 10 metastases, 3 lymphomas, 15 adenocarcinomas, 11 squamous carcinomas, and 7 miscellaneous lung cancers. Using direct volume measurements, median DTs were 453, 111, 15, 181, 139 and 137 days, respectively. Lung cancer DTs ranged from 23-2239 days. There were no significant differences in GRs among the different lesion types. There was considerable variability among GRs using different volume determination methods. Conclusions: Lung cancer doubling times showed a substantial range, and different volume determination methods gave considerably different DTs

  16. Diagnostic sensitivity of cutoff values of IgG4-positive plasma cell number and IgG4-positive/CD138-positive cell ratio in typical multiple lesions of patients with IgG4-related disease.

    Science.gov (United States)

    Mizushima, Ichiro; Yamada, Kazunori; Harada, Kenichi; Matsui, Shoko; Saeki, Takako; Kondo, Satoru; Takahira, Masayuki; Waseda, Yuko; Hamaguchi, Yasuhito; Fujii, Hiroshi; Yamagishi, Masakazu; Kawano, Mitsuhiro

    2018-03-01

    This study aimed to investigate the diagnostic sensitivity of the cutoff values of IgG4-positive plasma cell (PC) number and IgG4-positive/CD138-positive cell ratio proposed by the International consensus statement (ICS) on the pathology of IgG4-related disease (IgG4-RD) in typical multiple lesions of patients with IgG4-RD. We evaluated IgG4-positive PC number and IgG4-positive/CD138-positive cell ratio in 39 samples from 18 IgG4-RD patients having more than two typical lesions of IgG4-RD. We evaluated 12 submandibular, 12 ophthalmic, six skin, five kidney, two pancreatic, and one bronchus and prostate lesion each in 18 patients with typical clinical, serological, and radiographic features. Concerning IgG4 + PC number per high-power field, most ophthalmic (11/12), kidney (5/5), pancreatic (2/2), and bronchial lesions (1/1) fulfilled the cutoff value of ICS, whereas many of the submandibular (6/12) and skin lesions (0/6) did not. In contrast to the absolute number, all lesions fulfilled the cutoff value of IgG4+/CD138 + cell ratio. In eight cases, only one or two lesions in the same patient fulfilled the cutoff value of ICS, while the others did not. These results suggest that ICS criteria have different sensitivities among the affected organs for the diagnosis of IgG4-RD.

  17. Optical-Based Artificial Palpation Sensors for Lesion Characterization

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    Hee-Jun Park

    2013-08-01

    Full Text Available Palpation techniques are widely used in medical procedures to detect the presence of lumps or tumors in the soft breast tissues. Since these procedures are very subjective and depend on the skills of the physician, it is imperative to perform detailed a scientific study in order to develop more efficient medical sensors to measure and generate palpation parameters. In this research, we propose an optical-based, artificial palpation sensor for lesion characterization. This has been developed using a multilayer polydimethylsiloxane optical waveguide. Light was generated at the critical angle to reflect totally within the flexible and transparent waveguide. When a waveguide was compressed by an external force, its contact area would deform and cause the light to scatter. The scattered light was captured by a high-resolution camera and saved as an image format. To test the performance of the proposed system, we used a realistic tissue phantom with embedded hard inclusions. The experimental results show that the proposed sensor can detect inclusions and provide the relative value of size, depth, and Young’s modulus of an inclusion.

  18. A paradoxical decline: intracranial lesions in two HIV-positive patients recovering from cryptococcal meningitis.

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    Pettersen, Kenneth D; Pappas, Peter G; Chin-Hong, Peter; Baxi, Sanjiv M

    2015-10-16

    Cryptococcal immune reconstitution inflammatory syndrome (C-IRIS) is an increasingly important manifestation among patients with HIV/AIDS, especially as the use of antiretroviral therapy (ART) is expanding worldwide. Cryptococcus and associated C-IRIS are common causes of meningitis. While intracranial lesions are common in HIV/AIDS, they are rarely due to cryptococcosis or C-IRIS. We describe two cases of paradoxical C-IRIS associated with the development of intracranial cryptococcomas in HIV/AIDS. Both patients had an initial episode of cryptococcal meningitis treated with antifungal therapy. At the time, they had initiated or modified ART with subsequent evidence of immune reconstitution. Two months later, they developed aseptic meningitis with intracranial lesions. After exhaustive work ups, both patients were diagnosed with paradoxical C-IRIS and biopsy confirmed intracranial cryptococcomas. We review the important clinical, diagnostic and therapeutic features of cryptococcomas associated with C-IRIS in HIV/AIDS. 2015 BMJ Publishing Group Ltd.

  19. Effects of Ventral Striatum Lesions on Stimulus-Based versus Action-Based Reinforcement Learning.

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    Rothenhoefer, Kathryn M; Costa, Vincent D; Bartolo, Ramón; Vicario-Feliciano, Raquel; Murray, Elisabeth A; Averbeck, Bruno B

    2017-07-19

    Learning the values of actions versus stimuli may depend on separable neural circuits. In the current study, we evaluated the performance of rhesus macaques with ventral striatum (VS) lesions on a two-arm bandit task that had randomly interleaved blocks of stimulus-based and action-based reinforcement learning (RL). Compared with controls, monkeys with VS lesions had deficits in learning to select rewarding images but not rewarding actions. We used a RL model to quantify learning and choice consistency and found that, in stimulus-based RL, the VS lesion monkeys were more influenced by negative feedback and had lower choice consistency than controls. Using a Bayesian model to parse the groups' learning strategies, we also found that VS lesion monkeys defaulted to an action-based choice strategy. Therefore, the VS is involved specifically in learning the value of stimuli, not actions. SIGNIFICANCE STATEMENT Reinforcement learning models of the ventral striatum (VS) often assume that it maintains an estimate of state value. This suggests that it plays a general role in learning whether rewards are assigned based on a chosen action or stimulus. In the present experiment, we examined the effects of VS lesions on monkeys' ability to learn that choosing a particular action or stimulus was more likely to lead to reward. We found that VS lesions caused a specific deficit in the monkeys' ability to discriminate between images with different values, whereas their ability to discriminate between actions with different values remained intact. Our results therefore suggest that the VS plays a specific role in learning to select rewarded stimuli. Copyright © 2017 the authors 0270-6474/17/376902-13$15.00/0.

  20. Association between subcortical vascular lesion location and cognition: a voxel-based and tract-based lesion-symptom mapping study. The SMART-MR study.

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    J Matthijs Biesbroek

    Full Text Available INTRODUCTION: Lacunar lesions (LLs and white matter lesions (WMLs affect cognition. We assessed whether lesions located in specific white matter tracts were associated with cognitive performance taking into account total lesion burden. METHODS: Within the Second Manifestations of ARTerial disease Magnetic Resonance (SMART-MR study, cross-sectional analyses were performed on 516 patients with manifest arterial disease. We applied an assumption-free voxel-based lesion-symptom mapping approach to investigate the relation between LL and WML locations on 1.5 Tesla brain MRI and compound scores of executive functioning, memory and processing speed. Secondly, a multivariable linear regression model was used to relate the regional volume of LLs and WMLs within specific white matter tracts to cognitive functioning. RESULTS: Voxel-based lesion-symptom mapping identified several clusters of voxels with a significant correlation between WMLs and executive functioning, mostly located within the superior longitudinal fasciculus and anterior thalamic radiation. In the multivariable linear regression model, a statistically significant association was found between regional LL volume within the superior longitudinal fasciculus and anterior thalamic radiation and executive functioning after adjustment for total LL and WML burden. CONCLUSION: These findings identify the superior longitudinal fasciculus and anterior thalamic radiation as key anatomical structures in executive functioning and emphasize the role of strategically located vascular lesions in vascular cognitive impairment.

  1. Effect of lesion site on serial position during list learning: a study with the CVLT.

    Science.gov (United States)

    Albuquerque, Luisa; Loureiro, Clara; Martins, Isabel Pavao

    2008-07-01

    Successful learning of supraspan word lists such as the California Verbal Learning Test (CVLT) relies more on clustering strategies than rote learning, subserved by the frontal and temporal lobes. The authors studied the effect of word sequence in CVLT learning, in 15 patients with frontal (FLL) and 15 temporal (TLL) lesions, and 33 controls. Experimental measures were: number of clusters, number of first (FI), middle (MI) and last items (LI), in learning trials and in total immediate recall. FLL disclosed significantly lower FI along learning. Clusters were similar among groups. This difficulty is discussed according to the role of frontal lobes in learning and memory.

  2. Hippocampal lesions impair performance on a conditional delayed matching and non-matching to position task in the rat.

    Science.gov (United States)

    Sloan, Hazel L; Döbrössy, Màtè; Dunnett, Stephen B

    2006-08-10

    The hippocampus is thought to be involved in a range of cognitive processes, from the ability to acquire new memories, to the ability to learn about spatial relationships. Humans and monkeys with damage to the hippocampus are typically impaired on delayed matching to sample tasks, of which the operant delayed matching to position task (DMTP) is a rat analogue. The reported effects of hippocampal damage on DMTP vary, ranging from delay-dependent deficits to no deficit whatsoever. The present study investigates a novel memory task; the conditional delayed matching/non-matching to position task (CDM/NMTP) in the Skinner box. CDM/NMTP uses the presence of specific stimulus cues to signify whether a particular trial is matching or non-matching in nature. Thus, it incorporates both the task contingencies within one session, and supplements the requirement for remembering the side of the lever in the sample phase with attending to the stimulus and remembering the conditional discrimination for the rule. Rats were trained preoperatively and the effects of bilateral excitotoxic lesions of the hippocampus were examined on postoperative retention of the task. Rats with lesions of the hippocampus incurred a significant impairment on the task that was manifest at all delays intervals. Despite a bias towards matching during training, trials of either type were performed with equivalent accuracy and neither rule was affected differentially by the lesion. This task may prove useful in determining the cognitive roles of a range of brain areas.

  3. Evidence of end-effector based gait machines in gait rehabilitation after CNS lesion.

    Science.gov (United States)

    Hesse, S; Schattat, N; Mehrholz, J; Werner, C

    2013-01-01

    A task-specific repetitive approach in gait rehabilitation after CNS lesion is well accepted nowadays. To ease the therapists' and patients' physical effort, the past two decades have seen the introduction of gait machines to intensify the amount of gait practice. Two principles have emerged, an exoskeleton- and an endeffector-based approach. Both systems share the harness and the body weight support. With the end-effector-based devices, the patients' feet are positioned on two foot plates, whose movements simulate stance and swing phase. This article provides an overview on the end-effector based machine's effectiveness regarding the restoration of gait. For the electromechanical gait trainer GT I, a meta analysis identified nine controlled trials (RCT) in stroke subjects (n = 568) and were analyzed to detect differences between end-effector-based locomotion + physiotherapy and physiotherapy alone. Patients practising with the machine effected in a superior gait ability (210 out of 319 patients, 65.8% vs. 96 out of 249 patients, 38.6%, respectively, Z = 2.29, p = 0.020), due to a larger training intensity. Only single RCTs have been reported for other devices and etiologies. The introduction of end-effector based gait machines has opened a new succesful chapter in gait rehabilitation after CNS lesion.

  4. Cryptococcal neuroradiological lesions correlate with severity during cryptococcal meningoencephalitis in HIV-positive patients in the HAART era.

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    Caroline Charlier

    Full Text Available Cryptococcal meningoencephalitis has an overall global mortality rate of 20% in AIDS patients despite antifungals. There is a need for additional means of precise assessment of disease severity. We thus studied the radiological brain images available from 62 HIV-positive patients with cryptococcocal meningoencephalitis to analyse the brain lesions associated with cryptococcosis in relationship with disease severity, and the respective diagnostic contribution of magnetic resonance (MR versus computed tomography (CT. In this retrospective multicenter analysis, two neuroradiologists blindly reviewed the brain imaging. Prospectively acquired clinical and mycological data were available at baseline and during follow-up. Baseline images were abnormal on 92% of the MR scans contrasting with 53% of the CT scans. MR/CT cryptococcosis-related lesions included mass(es (21%/9%, dilated perivascular spaces (46%/5% and pseudocysts (8%/4%. The presence compared to absence of cryptococcosis-related lesions was significantly associated with high serum (78% vs. 42%, p = 0.008 and CSF (81% vs. 50%, p = 0.024 antigen titers, independently of neurological abnormalities. MR detected significantly more cryptococcosis-related lesions than CT for 17 patients who had had both investigations (76% vs. 24%, p = 0.005. In conclusion, MR appears more effective than CT for the evaluation of AIDS-associated cerebral cryptococcosis. Furthermore, brain imaging is an effective tool to assess the initial disease severity in this setting. Given this, we suggest that investigation for cryptococcosis-related lesions is merited, even in the absence of neurological abnormality, if a high fungal burden is suspected on the basis of high serum and/or CSF antigen titers.

  5. Effect of MTA-based sealer on the healing of periapical lesions

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    Joao Eduardo GOMES-FILHO

    2013-06-01

    Full Text Available Some manufacturers have recently added specific components to improve the ease of handling and insertion material properties of MTA in order to create MTA-based sealers. Objective The aim of this study was to evaluate the healing of periapical lesions in canine teeth after a single session of endodontic treatment with MTA Fillapex® compared with Sealapex® or Endo-CPM-Sealer®. Material and Methods Sixty-two root canals were performed on two 1-year-old male dogs. After coronal access and pulp extirpation, the canals were exposed to the oral cavity for 6 months in order to induce periapical lesions. The root canals were prepared, irrigated with a solution of 2.5% sodium hypochlorite and filled with gutta-percha and different sealers, according to the following groups: 1 Sealapex®; 2 Endo-CPM-Sealer®; and 3 MTA Fillapex®. Some teeth with periapical lesions were left untreated for use as positive controls. Healthy teeth were used as negative controls. After 6 months, the animals were sacrificed and serial sections from the roots were prepared for histomorphologic analysis and stained with hematoxylin and eosin and the Brown and Brenn technique. The lesions were scored according to pre-established histomorphologic parameters and the scores statistically analyzed using the Kruskal-Wallis test. Results All 3 materials produced similar patterns of healing (p>0.05; in particular, persistent inflammation and absence of complete periapical tissue healing were consistently noted. Conclusions Preparation of the infected root canals followed by filling with the materials studied was insufficient to provide complete healing of the periapical tissues.

  6. Effect of MTA-based sealer on the healing of periapical lesions.

    Science.gov (United States)

    Gomes-Filho, João Eduardo; Watanabe, Simone; Cintra, Luciano Tavares Angelo; Nery, Mauro Juvenal; Dezan-Júnior, Eloi; Queiroz, India Olinta Azevedo; Lodi, Carolina Simonetti; Basso, Maria Daniela

    2013-01-01

    Some manufacturers have recently added specific components to improve the ease of handling and insertion material properties of MTA in order to create MTA-based sealers. The aim of this study was to evaluate the healing of periapical lesions in canine teeth after a single session of endodontic treatment with MTA Fillapex® compared with Sealapex® or Endo-CPM-Sealer®. Sixty-two root canals were performed on two 1-year-old male dogs. After coronal access and pulp extirpation, the canals were exposed to the oral cavity for 6 months in order to induce periapical lesions. The root canals were prepared, irrigated with a solution of 2.5% sodium hypochlorite and filled with gutta-percha and different sealers, according to the following groups: 1) Sealapex®; 2) Endo-CPM-Sealer®; and 3) MTA Fillapex®. Some teeth with periapical lesions were left untreated for use as positive controls. Healthy teeth were used as negative controls. After 6 months, the animals were sacrificed and serial sections from the roots were prepared for histomorphologic analysis and stained with hematoxylin and eosin and the Brown and Brenn technique. The lesions were scored according to pre-established histomorphologic parameters and the scores statistically analyzed using the Kruskal-Wallis test. All 3 materials produced similar patterns of healing (p>0.05); in particular, persistent inflammation and absence of complete periapical tissue healing were consistently noted. Preparation of the infected root canals followed by filling with the materials studied was insufficient to provide complete healing of the periapical tissues.

  7. Identification of DNA lesions using a third base pair for amplification and nanopore sequencing

    Science.gov (United States)

    Riedl, Jan; Ding, Yun; Fleming, Aaron M.; Burrows, Cynthia J.

    2015-01-01

    Damage to the genome is implicated in the progression of cancer and stress-induced diseases. DNA lesions exist in low levels, and cannot be amplified by standard PCR because they are frequently strong blocks to polymerases. Here, we describe a method for PCR amplification of lesion-containing DNA in which the site and identity could be marked, copied and sequenced. Critical for this method is installation of either the dNaM or d5SICS nucleotides at the lesion site after processing via the base excision repair process. These marker nucleotides constitute an unnatural base pair, allowing large quantities of marked DNA to be made by PCR amplification. Sanger sequencing confirms the potential for this method to locate lesions by marking, amplifying and sequencing a lesion in the KRAS gene. Detection using the α-hemolysin nanopore is also developed to analyse the markers in individual DNA strands with the potential to identify multiple lesions per strand. PMID:26542210

  8. Imaging of cerebellopontine angle lesions: an update. Part 2: intra-axial lesions, skull base lesions that may invade the CPA region, and non-enhancing extra-axial lesions

    Energy Technology Data Exchange (ETDEWEB)

    Bonneville, Fabrice; Chiras, Jacques [Pitie-Salpetriere Hospital, Department of Neuroradiology, Paris (France); Savatovsky, Julien [Adolphe de Rothschild Foundation, Department of Radiology, Paris (France)

    2007-11-15

    Computed tomography (CT) and magnetic resonance (MR) imaging reliably demonstrate typical features of vestibular schwannomas or meningiomas in the vast majority of mass lesions responsible for cerebellopontine angle (CPA) syndrome. However, a large variety of unusual lesions can also be encountered in the CPA. Covering the entire spectrum of lesions potentially found in the CPA, these articles explain the pertinent neuroimaging features that radiologists need to know to make clinically relevant diagnoses in these cases, including data from diffusion- and perfusion-weighted imaging or MR spectroscopy, when available. A diagnostic algorithm based on the lesion's site of origin, shape and margins, density, signal intensity and contrast material uptake is also proposed. Non-enhancing extra-axial CPA masses are cystic (epidermoid cyst, arachnoid cyst, neurenteric cyst) or contain fat (dermoid cyst, lipoma). Tumours can also extend into the CPA by extension from the skull base (paraganglioma, chondromatous tumours, chordoma, cholesterol granuloma, endolymphatic sac tumour). Finally, brain stem or ventricular tumours can present with a significant exophytic component in the CPA that may be difficult to differentiate from an extra-axial lesion (lymphoma, hemangioblastoma, choroid plexus papilloma, ependymoma, glioma, medulloblastoma, dysembryoplastic neuroepithelial tumour). (orig.)

  9. Cerebral lesions can impair fMRI-based language lateralization.

    NARCIS (Netherlands)

    Wellmer, J.; Weber, B.; Urbach, H.; Reul, J.; Fernandez, G.S.E.; Elger, C.E.

    2009-01-01

    PURPOSE: Several small patient studies and case reports raise concerns that the reliability of functional magnetic resonance imaging (fMRI) may be impaired in the vicinity of cerebral lesions. This could affect the clinical validity of fMRI for presurgical language lateralization. The current study

  10. Anatomic Site Based Ploidy Analysis of Oral Premalignant Lesions

    Science.gov (United States)

    Islam, M. N.; Kornberg, L.; Veenker, E.; Cohen, D. M.

    2009-01-01

    The location of oral leukoplakia correlates strongly with the probability of finding dysplastic or malignant alterations at biopsy. It is well established that early detection can dramatically improve the 5-year survival rates for oral squamous cell carcinomas. Since aneuploidy is predictive of future conversion to malignancy, we hypothesized that dysplastic lesions from high-risk sites (floor of mouth, tongue and lips) would exhibit greater aneuploidy than low-risk sites (palate, gingiva and buccal mucosa). Epithelial sections from 60 archival samples diagnosed as mild dysplasia (36 females, 20 males) from various high/low risk locations were stained with Blue Feulgen Stain for DNA Ploidy Analysis (Clarient, Aliso Viejo, CA) and ploidy was analyzed using a ChromaVision ACIS II (Clarient, ALiso Viejo, CA) Image cytometry system. A DNA histogram was generated using an image analyzing software that evaluated the amount of Feulgen stain which is proportional to the amount of nuclear DNA. An ANOVA analysis followed by the Student’s‘t’ test revealed significant differences between means (P ≤ 0.05). Lesions originating from lateral/ventral tongue (85%), floor of mouth (50%) and soft palate (44%) exhibited a higher frequency of aneuploidy than lesions from gingiva (22%) and lower lip (25%). This pilot study demonstrates that dysplastic lesions from high-risk sites such as the floor of the mouth and lateral/ventral tongue have higher frequency of aneuploidy. PMID:20237983

  11. CT-based needle marking of superficial intracranial lesions for minimal invasive neurosurgery

    International Nuclear Information System (INIS)

    Marquardt, G.; Wolff, R.; Schick, U.; Lorenz, R.

    2000-01-01

    A CT-based method of marking superficial intracranial lesions with a needle is presented. This form of neuronavigation can be applied in every neurosurgical centre. Owing to its rapid application it is also suitable for cases of emergency. The neurosurgical approach can be centred precisely over this lesion providing for a minimally invasive operation. The method has proved its efficacy in numerous cases of haematomas and cystic lesions. (author)

  12. Frequency of fungal infection in biopsies of oral mucosal lesions: A prospective hospital-based study

    Directory of Open Access Journals (Sweden)

    Thimmarasa Venkappa Bhovi

    2015-01-01

    Full Text Available Aims and Objectives: To determine the frequency and common site of fungal infection in biopsies of oral mucosal lesions and also to detect the lesions most likely to be infected with fungal infection. Materials and Methods: A total of 100 patients with oral mucosal lesions were advised routine hematological examination followed by incisional biopsy under local anesthesia. The specimen were fixed in 10% neutral buffered formalin and processed. One section from the specimen was stained with hematoxylin and eosin staining for histopathological diagnosis of the lesion and a second section was stained with Periodic acid-Schiff (PAS stain for detection of fungal infection. Results: Out of the 100 patients, the most common mucosal lesion encountered was carcinoma (56% followed by lesions with dysplastic changes (28%, benign lesions (9%, squamous papilloma (2% and oral submucous fibrosis (5%. The most common anatomic location affected by the mucosal lesions were buccal mucosa, followed by the tongue, gingiva, maxillary tuberosity and floor of the mouth with values of 73%, 16%, 6%, 4% and 1%, respectively. Squamous papilloma had the highest positive association with fungal infection (100% followed by lesions with dysplastic changes (17.9% and carcinoma (8.9%. The maximum fungal positive association was encountered in the mucosal lesions over the tongue (18.7% followed by the buccal mucosa (12.3%. Conclusion: There is statistically significant association of fungal infection with dysplastic lesions and papilloma with the tongue and buccal mucosa as the most common sites. Hence a PAS stain should be performed whenever epithelial dysplasia on the tongue and buccal mucosa is diagnosed.

  13. Small shifts in craniotomy position in the lateral fluid percussion injury model are associated with differential lesion development.

    Science.gov (United States)

    Vink, R; Mullins, P G; Temple, M D; Bao, W; Faden, A I

    2001-08-01

    Previous studies have shown that location and direction of injury may affect outcome in experimental models of traumatic brain injury. Significant variability in outcome data has also been noted in studies using the lateral fluid percussion brain injury model (FPI) in rats. In recent studies from our laboratory, we observed considerable variability in localization and severity of tissue damage as a function of small changes in craniotomy position. To further address this issue, we examined the relationship between craniotomy position and brain lesion size/location in rats subjected to moderate FPI (2.28 +/- 0.18 atmospheres). With placement of a 5-mm craniotomy adjacent to the sagittal suture, there was both ipsilateral and contralateral damage as detected at 3 weeks posttrauma using T2-weighted magnetic resonance imaging (MRI). The MRI lesions were generally restricted to the hippocampus and subcortical layers. Shifting of the craniotomy site laterally was associated with increased ipsilateral tissue damage and a greater cortical component that correlated with distance from the sagittal suture. In contrast, the contralateral MRI lesion did not change significantly in size or location unless the center of the craniotomy was placed more than 3.5 mm from the sagittal suture, under which condition contralateral damage could no longer be detected. Ipsilateral tissue damage as determined from the MRI scans was linearly correlated to motor outcome but not with cognitive outcome as assessed by the Morris Water Maze. We conclude that craniotomy position is critical in determining extent and location of tissue injury produced during the lateral FPI model in rats. Addressing such potential variability is essential for studies that address either injury mechanisms or therapeutic treatments.

  14. Recurrence of cervical intraepithelial lesions after thermo-coagulation in HIV-positive and HIV-negative Nigerian women.

    Science.gov (United States)

    Oga, Emmanuel A; Brown, Jessica P; Brown, Clayton; Dareng, Eileen; Adekanmbi, Victor; Odutola, Michael; Olaniyan, Olayinka; Offiong, Richard; Obende, Kayode; Adewole, Ayodele Stephen; Peter, Achara; Dakum, Patrick; Adebamowo, Clement

    2016-05-11

    The burden of cervical cancer remains huge globally, more so in sub-Saharan Africa. Effectiveness of screening, rates of recurrence following treatment and factors driving these in Africans have not been sufficiently studied. The purpose of this study therefore was to investigate factors associated with recurrence of cervical intraepithelial lesions following thermo-coagulation in HIV-positive and HIV-negative Nigerian women using Visual Inspection with Acetic Acid (VIA) or Lugol's Iodine (VILI) for diagnosis. A retrospective cohort study was conducted, recruiting participants from the cervical cancer "see and treat" program of IHVN. Data from 6 sites collected over a 4-year period was used. Inclusion criteria were: age ≥18 years, baseline HIV status known, VIA or VILI positive and thermo-coagulation done. Logistic regression was performed to examine the proportion of women with recurrence and to examine factors associated with recurrence. Out of 177 women included in study, 67.8 % (120/177) were HIV-positive and 32.2 % (57/177) were HIV-negative. Recurrence occurred in 16.4 % (29/177) of participants; this was 18.3 % (22/120) in HIV-positive women compared to 12.3 % (7/57) in HIV-negative women but this difference was not statistically significant (p-value 0.31). Women aged ≥30 years were much less likely to develop recurrence, adjusted OR = 0.34 (95 % CI = 0.13, 0.92). Among HIV-positive women, CD4 count <200cells/mm(3) was associated with recurrence, adjusted OR = 5.47 (95 % CI = 1.24, 24.18). Recurrence of VIA or VILI positive lesions after thermo-coagulation occurs in a significant proportion of women. HIV-positive women with low CD4 counts are at increased risk of recurrent lesions and may be related to immunosuppression.

  15. Model Based Vision for Aircraft Position Determination

    Science.gov (United States)

    Sridhar, Banavar; Chatterji, Gano B.; Soni, Tarun; Showman, Robert D. (Technical Monitor)

    1994-01-01

    This paper investigates the use of imaging sensors to estimate the position of an aircraft with respect to the runway during landing. Passive vision techniques to estimate aircraft position during landing rely on the known runway model, images acquired by onboard imaging sensor, orientation information provided by the inertial navigation system and the position estimate provided by devices such as the global positioning system. Point features in the runway model are compared with the onboard sensor images of the features and the difference between the two is used to correct the aircraft position and orientation. In this paper the sensitivity of point features is examined as a means of determining the accuracy of such position estimation techniques. Expressions are derived for the sensitivity of image point to errors in the position and orientation of the sensor. Using these, the sensitivity of the image to aircraft position and orientation errors along a typical landing glide path is studied. A least squares technique based on this sensitivity analysis is described for the correction of position and orientation estimates. The final version of the paper will include results from the application of this analysis to real image sequences collected in flight.

  16. GTV-based prescription in SBRT for lung lesions using advanced dose calculation algorithms.

    Science.gov (United States)

    Lacornerie, Thomas; Lisbona, Albert; Mirabel, Xavier; Lartigau, Eric; Reynaert, Nick

    2014-10-16

    The aim of current study was to investigate the way dose is prescribed to lung lesions during SBRT using advanced dose calculation algorithms that take into account electron transport (type B algorithms). As type A algorithms do not take into account secondary electron transport, they overestimate the dose to lung lesions. Type B algorithms are more accurate but still no consensus is reached regarding dose prescription. The positive clinical results obtained using type A algorithms should be used as a starting point. In current work a dose-calculation experiment is performed, presenting different prescription methods. Three cases with three different sizes of peripheral lung lesions were planned using three different treatment platforms. For each individual case 60 Gy to the PTV was prescribed using a type A algorithm and the dose distribution was recalculated using a type B algorithm in order to evaluate the impact of the secondary electron transport. Secondly, for each case a type B algorithm was used to prescribe 48 Gy to the PTV, and the resulting doses to the GTV were analyzed. Finally, prescriptions based on specific GTV dose volumes were evaluated. When using a type A algorithm to prescribe the same dose to the PTV, the differences regarding median GTV doses among platforms and cases were always less than 10% of the prescription dose. The prescription to the PTV based on type B algorithms, leads to a more important variability of the median GTV dose among cases and among platforms, (respectively 24%, and 28%). However, when 54 Gy was prescribed as median GTV dose, using a type B algorithm, the variability observed was minimal. Normalizing the prescription dose to the median GTV dose for lung lesions avoids variability among different cases and treatment platforms of SBRT when type B algorithms are used to calculate the dose. The combination of using a type A algorithm to optimize a homogeneous dose in the PTV and using a type B algorithm to prescribe the

  17. SLAM - Based Approach to Dynamic Ship Positioning

    Directory of Open Access Journals (Sweden)

    Krzysztof Wrobel

    2014-03-01

    Full Text Available Dynamically positioned vessels, used by offshore industry, use not only satellite navigation but also different positioning systems, often referred to as reference' systems. Most of them use multiple technical devices located outside the vessel which creates some problems with their accessibility and performance. In this paper, a basic concept of reference system independent from any external device is presented, basing on hydroacoustics and Simultaneous Localization and Mapping (SLAM method. Theoretical analysis of its operability is also performed.

  18. Cauda equina enhancing lesion in a HIV-positive patient. Case report and literature revision.

    Directory of Open Access Journals (Sweden)

    Pasquale De Bonis

    2011-10-01

    Full Text Available We describe the case a spinal cord localization of neurological toxoplasmosis in a HIV-positive patient with Burkitt lymphoma, previously treated with chemotherapy and immunotherapy. This complication occurred while patient was in complete remission of lymphoma, with CD4+ T cell count of 270 /ml, undetectable HIV viremia, and despite the trimethoprim/ sulfamethoxazole prophylaxis. Indeed, we hypothesize that in our patient neurologic toxoplasmosis has been fostered more by previous immuno-chemotherapy than by HIV- related immunodeficiency. On the whole, this case suggests that parameters usually employed to predict the risk for opportunistic infections in HIV-positive people might not apply to patients with HIV-related lymphomas.

  19. Vehicle positioning based on UWB technology

    Science.gov (United States)

    Hu, Siquan; Kang, Min; She, Chundong

    2017-08-01

    In recent years, with the rapid increase of the number of urban cars, the vehicle internet is becoming a trend of smart transportion. In such vehicle network, accurate location is very crucial in many new applications such as autopilot, semi-autopilot and Car-to-x communications. UWB technology has been used for indoor closed range positioning and ranging widely, while UWB outdoor positioning and ranging research is relatively less. This paper proposed UWB as the vehicle positioning technology and developed a method based on two-way-ranging (TWR) to solve the ranging problem between vehicles. At the same time, the improved TOA method was used to locate vehicles, which has higher precision compared with traditional GPS or LBS. A hardware module is introduced and the simulation results show that the modules are capable of precise positioning for vehicles in vehicle network.

  20. HIV-positive women have higher risk of human papilloma virus infection, precancerous lesions, and cervical cancer.

    Science.gov (United States)

    Liu, Gui; Sharma, Monisha; Tan, Nicholas; Barnabas, Ruanne V

    2018-03-27

    HIV-positive women have higher human papillomavirus (HPV) prevalence and cervical cancer incidence than HIV-negative women, partly because of HIV's modifying effect on HPV pathogenesis. We synthesized the literature on the impact of HIV on HPV natural history. Systematic review and meta-analysis. We searched the literature for studies evaluating HPV acquisition and persistence or precancer progression by HIV status. Data on HPV natural history by HIV status, CD4 cell counts, viral load, and antiretroviral therapy (ART) were summarized using fixed effect models. Overall, 38 of 1845 abstracts identified met inclusion criteria. HIV-positive women had higher HPV acquisition [relative risk (RRpooled) 2.64, 95% confidence interval (CI) 2.04-3.42] and lower HPV clearance (hazard ratiopooled 0.72, 95% CI 0.62-0.84) than HIV-negative women. HPV acquisition was higher with declining CD4 cell count and was lower in those virally suppressed on ART. HIV was associated with higher incidence of low-grade squamous intraepithelial lesions (LSIL; RRpooled 3.73, 95% CI 2.62-5.32) and high-grade squamous intraepithelial lesions (HSIL; hazard ratiopooled 1.32, 95% CI 1.10-1.58), largely because of increased HPV persistence. ART lowered progression from normal cytology to LSIL (hazard ratiopooled 0.65, 95% CI 0.52-0.82), but not HSIL. Cervical cancer incidence was associated with HIV positivity (RR 4.1, 95% CI 2.3-6.6), but not with ART. HIV-positive women have higher risk of acquiring HPV, with risk inversely associated with CD4 cell count. ART lowered HPV acquisition, increased clearance, and reduced precancer progression, likely via immune reconstitution. Although some of our results are limited by small number of studies, our study can inform screening guidelines and mathematical modeling for cervical cancer prevention.

  1. Anatomic site based ploidy analysis of oral premalignant lesions.

    Science.gov (United States)

    Islam, M N; Kornberg, L; Veenker, E; Cohen, D M; Bhattacharyya, I

    2010-03-01

    The location of oral leukoplakia correlates strongly with the probability of finding dysplastic or malignant alterations at biopsy. It is well established that early detection can dramatically improve the 5-year survival rates for oral squamous cell carcinomas. Since aneuploidy is predictive of future conversion to malignancy, we hypothesized that dysplastic lesions from high-risk sites (floor of mouth, tongue and lips) would exhibit greater aneuploidy than low-risk sites (palate, gingiva and buccal mucosa). Epithelial sections from 60 archival samples diagnosed as mild dysplasia (36 females, 20 males) from various high/low risk locations were stained with Blue Feulgen Stain for DNA Ploidy Analysis (Clarient, Aliso Viejo, CA) and ploidy was analyzed using a ChromaVision ACIS II (Clarient, ALiso Viejo, CA) Image cytometry system. A DNA histogram was generated using an image analyzing software that evaluated the amount of Feulgen stain which is proportional to the amount of nuclear DNA. An ANOVA analysis followed by the Student's't' test revealed significant differences between means (P dysplastic lesions from high-risk sites such as the floor of the mouth and lateral/ventral tongue have higher frequency of aneuploidy.

  2. Cauda equina enhancing lesion in a HIV-positive patient. Case report and literature revision.

    Directory of Open Access Journals (Sweden)

    Luigi Maria Larocca

    2011-01-01

    Full Text Available

    We describe the case a spinal cord localization of neurological toxoplasmosis in a HIV-positive patient with Burkitt lymphoma, previously treated with chemotherapy and immunotherapy. This complication occurred while patient was in complete remission of lymphoma, with CD4+ T cell count of 270 /ml, undetectable HIV viremia, and despite the trimethoprim/ sulfamethoxazole prophylaxis. Indeed, we hypothesize that in our patient neurologic toxoplasmosis has been fostered more by previous immuno-chemotherapy than by HIV- related immunodeficiency. On the whole, this case suggests that parameters usually employed to predict the risk for opportunistic infections in HIV-positive people might not apply to patients with HIV-related lymphomas.

  3. Clinical and angiographic predictors of haemodynamically significant angiographic lesions: development and validation of a risk score to predict positive fractional flow reserve.

    Science.gov (United States)

    Sareen, Nishtha; Baber, Usman; Kezbor, Safwan; Sayseng, Sonny; Aquino, Melissa; Mehran, Roxana; Sweeny, Joseph; Barman, Nitin; Kini, Annapoorna; Sharma, Samin K

    2017-04-07

    Coronary revascularisation based upon physiological evaluation of lesions improves clinical outcomes. Angiographic or visual stenosis assessment alone is insufficient in predicting haemodynamic stenosis severity by fractional flow reserve (FFR) and therefore cannot be used to guide revascularisation, particularly in the lesion subset system formulated. Of 1,023 consecutive lesions (883 patients), 314 (31%) were haemodynamically significant. Characteristics associated with FFR ≤0.8 include male gender, higher SYNTAX score, lesions ≥20 mm, stenosis >50%, bifurcation, calcification, absence of tortuosity and smaller reference diameter. A user-friendly integer score was developed with the five variables demonstrating the strongest association. On prospective validation (in 279 distinct lesions), the increasing value of the score correlated well with increasing haemodynamic significance (C-statistic 0.85). We identified several clinical and angiographic characteristics and formulated a scoring system to guide the approach to intermediate lesions. This may translate into cost savings. Larger studies with prospective validation are required to confirm our results.

  4. Additional diagnostic value of MRI in patients with suspicious breast lesions based on ultrasound

    Science.gov (United States)

    Uluc, F

    2014-01-01

    Objective: Biopsy has long been the standard approach in Breast Imaging Reporting and Data System® (BI-RADS) 4 or BI-RADS 5 (American College of Radiology, Reston, VA) lesions despite a wide variation in reported incidence of malignancy in BI-RADS 4 lesions. This study examined the diagnostic value of breast MRI as well as its ability to decrease unnecessary biopsies in patients with solid breast lesions who had an indication for biopsy. Methods: In this retrospective study, 277 breast lesions with a documented histological diagnosis as established by ultrasound-guided biopsy were included. All patients were female, and biopsy was performed owing to a BI-RADS score of 4 or 5 on ultrasonography. In addition, all patients had undergone MRI before biopsy. Sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of MRI in predicting malignancy were calculated. Results: When all lesions were analysed, sensitivity, specificity, NPV and PPV of MRI in detecting malignancy were 94.2%, 56.1%, 90.7% and 68.1%, respectively. When only ultrasonographic BI-RADS 4 lesions are considered, the corresponding figures were as follows: 90.9%, 56.7%, 93.8% and 46.4%, respectively. False-negative rate of MRI for the latter group of lesions was 2.6%. 42% of unnecessary biopsies were avoided in sonographic BI-RADS 4 lesions. Conclusion: Despite promising results obtained in this study, dynamic MRI currently does not seem to be effective in ruling out the need for biopsy in the assessment of sonographic BI-RADS 4 lesions. However, advanced MRI techniques may assist in improving possible benefits of MRI in this patient group. PMID:24983629

  5. Evaluation of MR lymphography with positive lymphotropic contrast agent in diagnosing lymph node lesions

    International Nuclear Information System (INIS)

    Zhou Zhengyang; Yu Haiping; Chen Junkun; Zhu Bin

    2010-01-01

    Objective: To evaluate the interstital MR lymphography using positive lymphotropic contrast agent for differentiation of metastatic lymph nodes from inflammatory lymph nodes hyperplasm. Methods: Eighteen New Zealand white rabbits weighted at 2. 0-2. 5 kg were used. Inflammatory hyperplastic popliteal lymph node model was established in 9 rabbits by injection of complete freund adjuvant into the interdigitial skin of the dorsal aspect of one hind leg, and tumor-bearing popliteal lymph node model was established in another 9 rabbits by injection of VX2 tumor cell suspension. The popliteal lymph nodes of another hind leg of all 18 rabbits were assigned to the normal contral group. In each group, every rabbit underwent MR lymphography examination before and after the inoculation. Volumes of 0.2 ml of Gd [ DTPA-bis ( 2-aminoethoxy ) ethane ] polymeric contrast agent ( Gd-poly-DTPA-EOEA ) injection were injected subcutaneously into the dorsal feet of both hind legs of two groups of rabbits. T 1 -weighted 3D gradient-echo images were obtained, and source images were used to reconstruct images of MIP before and after the administration of agent. The maximum short-axis diameter (MSAD) of each popliteal lymph node was measured on the enhanced 3D MIP images, and the signal-to-noise ratio (SNR) measurement was performed in the largest popliteal node of each rabbit at each time point in delayed scan. Independent- samples t test was used to compare the sizes of popliteal nodes in MSADs between inflammatorily hyperplastic and tumor-bearing nodes after the inoculation, and the values of SNRs of popliteal nodes at each time point between inflammatorily hyperplastic, tumor-bearing and normal popliteal lymph nodes. Imaging results of the popliteal nodes were analyzed and correlated with pathological findings. Results: All of the rabbits were successfully inoculated except of the 2 rabbits in tumor-bearing nodal group. The size in MSAD of 13 inflammatorily hyperplastic and 11 tumor

  6. Transcutaneous contrast-enhanced sonography of pleural-based pulmonary lesions

    Energy Technology Data Exchange (ETDEWEB)

    Goerg, Christian [Department of Internal Medicine, Philipps-University, Baldingerstrasse, Marburg (Germany)], E-mail: goergc@med.uni-marburg.de

    2007-11-15

    Objective: Transcutaneous ultrasound enables visualization of pleural-based lesions but with a poor correlation to specific pathology. Ultrasound contrast agents in conjunction with contrast-specific imaging techniques are increasingly accepted in clinical use. Based on the dual arterial supply of the lung, this organ is suited for evaluation of arterial vascularity by contrast-enhanced sonography (CES). This review will present first data about practise and clinical use of CES in patient with peripheral lung lesions. Methods: This review is based on the experience of transcutaneous CES in 350 patients with chest pathology diagnosed by B-mode sonography at an internal medicine center. CES studies were performed with a contrast-devoted unit (Acuson, Sequoia, Siemens medical solution) that had contrast-specific, continuous-mode software. A low mechanical index was used. A sulfur hexafluoride-based microbubble contrast medium (Sonovue, Bracco SpA, Milan, Italy) was injected. Pulmonary lesions were characterized by CES regarding time to enhancement (TE) and extend of enhancement (EE). Results: CES in peripheral lung lesions is feasible and depending on underlying diseases lesions may show a variable TE and EE. CES enables to distinguish pulmonary arterial supply from bronchial arterial supply by TE. First experiences with CES have shown that various peripheral lung lesions do have a characteristic CES pattern regarding TE and EE. First clinical data show that there are clinical conditions, which may show a diagnostic advantage of CES in comparison to B-mode US. CES may be helpful (1) to confirm diagnosis of pleurisy, (2) to confirm diagnosis peripheral pulmonary embolism, (3) to characterize lung opafication to atelectasis, pneumonia, and tumor, and (4) to assist in interventional procedures. Conclusion: CES of the chest is limited to pleural-based lesions. CES enables to characterize lung lesions regarding TE and EE. The clinical benefit is yet unclear, but first

  7. Mass lesions in chronic pancreatitis: benign or malignant? An "evidence-based practice" approach.

    LENUS (Irish Health Repository)

    Gerstenmaier, Jan F

    2012-02-01

    The diagnosis of a pancreatic mass lesion in the presence of chronic pancreatitis can be extremely challenging. At the same time, a high level of certainty about the diagnosis is necessary for appropriate management planning. The aim of this study was to establish current best evidence about which imaging methods reliably differentiate a benign from a malignant lesion, and show how that evidence is best applied. A diagnostic algorithm based on Bayesian analysis is proposed.

  8. Clinical performance of fluorescence-based methods for detection of occlusal caries lesions in primary teeth

    Directory of Open Access Journals (Sweden)

    Laura Regina Antunes PONTES

    2017-11-01

    Full Text Available Abstract We aimed to investigate the performance of fluorescence-based methods (FBMs, compared to visual inspection after histological validation, in detecting and assessing the activity status of occlusal carious lesions in primary teeth. One examiner evaluated 50 primary molars close to exfoliation in 24 children. Teeth were assessed using quantitative light-induced fluorescence (QLF and pen-type laser fluorescence (LFpen. After exfoliation, histological validation was performed. Teeth were cut and sections were evaluated for lesion depth and activity status (after utilization of a pH indicator under a stereomicroscope. Parameters related to the performance of the methods in detecting caries lesions at two thresholds (initial and dentin lesions were calculated. Regarding the activity status, lesions were classified into sound+inactive or active, and the area under the ROC curve and the diagnostic odds ratio values of the methods were calculated and compared. Evaluation of red fluorescence using QLF presented higher sensitivity but lower specificity than visual inspection in detecting dentin caries lesions. However, QLF considering different parameters and LFpen had similar performance to that obtained with visual inspection. Regarding activity assessment, all FBMs and visual inspection also presented similar performance. In conclusion, FBMs did not prove advantageous for the detection and activity assessment of occlusal caries lesions in primary molars when compared to visual inspection.

  9. Clinical performance of fluorescence-based methods for detection of occlusal caries lesions in primary teeth.

    Science.gov (United States)

    Pontes, Laura Regina Antunes; Novaes, Tatiane Fernandes; Moro, Bruna Lorena Pereira; Braga, Mariana Minatel; Mendes, Fausto Medeiros

    2017-11-06

    We aimed to investigate the performance of fluorescence-based methods (FBMs), compared to visual inspection after histological validation, in detecting and assessing the activity status of occlusal carious lesions in primary teeth. One examiner evaluated 50 primary molars close to exfoliation in 24 children. Teeth were assessed using quantitative light-induced fluorescence (QLF) and pen-type laser fluorescence (LFpen). After exfoliation, histological validation was performed. Teeth were cut and sections were evaluated for lesion depth and activity status (after utilization of a pH indicator) under a stereomicroscope. Parameters related to the performance of the methods in detecting caries lesions at two thresholds (initial and dentin lesions) were calculated. Regarding the activity status, lesions were classified into sound+inactive or active, and the area under the ROC curve and the diagnostic odds ratio values of the methods were calculated and compared. Evaluation of red fluorescence using QLF presented higher sensitivity but lower specificity than visual inspection in detecting dentin caries lesions. However, QLF considering different parameters and LFpen had similar performance to that obtained with visual inspection. Regarding activity assessment, all FBMs and visual inspection also presented similar performance. In conclusion, FBMs did not prove advantageous for the detection and activity assessment of occlusal caries lesions in primary molars when compared to visual inspection.

  10. Health Physics Positions Data Base: Revision 1

    International Nuclear Information System (INIS)

    Kerr, G.D.; Borges, T.; Stafford, R.S.; Lu, P.Y.; Carter, D.

    1994-02-01

    The Health Physics Positions (HPPOS) Data Base of the Nuclear Regulatory Commission (NRC) is a collection of NRC staff positions on a wide range of topics involving radiation protection (health physics). It consists of 328 documents in the form of letters, memoranda, and excerpts from technical reports. The HPPOS Data Base was developed by the NRC Headquarters and Regional Offices to help ensure uniformity in inspections, enforcement, and licensing actions. Staff members of the Oak Ridge National Laboratory (ORNL) have assisted the NRC staff in summarizing the documents during the preparation of this NUREG report. These summaries are also being made available as a open-quotes stand aloneclose quotes software package for IBM and IBM-compatible personal computers. The software package for this report is called HPPOS Version 2.0. A variety of indexing schemes were used to increase the usefulness of the NUREG report and its associated software. The software package and the summaries in the report are written in the context of the open-quotes newclose quotes 10 CFR Part 20 (section section 20.1001--20.2401). The purpose of this NUREG report is to allow interested individuals to familiarize themselves with the contents of the HPPOS Data Base and with the basis of many NRC decisions and regulations. The HPPOS summaries and original documents are intended to serve as a source of information for radiation protection programs at nuclear research and power reactors, nuclear medicine, and other industries that either process or use nuclear materials

  11. Radio-isotope scanning using labelled bleomycin in positive and differential diagnosis of primary and secondary malignant pulmonary lesions

    International Nuclear Information System (INIS)

    Robert, J.; Bertrand, A.; Nouel, J.P.; Witz, H.

    1975-01-01

    A lung scan using bleomycin labelled with cobalt 57 was carried out in 308 patients representing 191 primary malignant tumours, 48 pulmonary metastases and 69 benign lesions. The primary and secondary malignant lesions always gave rise to a hyperactive focus except in 8 cases of primary lung tumour. The negative examination may be explained, either by the small size of the lesion or by radiotherapy in progress. Among the benign lesions, only advanced tuberculosis and very inflammatory lung diseases frequently took up labelled bleomycin (15 hyperactive foci out of 69 benign lesions). Quantitative measurements, i.e. ratio of the lesional activity/activity of healthy lung tissue, were carried out in all patients. The malignant lesions were usually more active than the benign lesions. There was no definite correlation between the uptake of labelled bleomycin and the histological nature of the lesion. However, undifferentiated and anaplastic carcinomas were often more active. One should emphasize that these results show that a hyperactive focus has a 94% chance of being a carcinoma. The absence of bleomycin uptake means that there is a 92% chance of a benign lesion [fr

  12. Multi-Sectional Views Textural Based SVM for MS Lesion Segmentation in Multi-Channels MRIs

    Science.gov (United States)

    Abdullah, Bassem A; Younis, Akmal A; John, Nigel M

    2012-01-01

    In this paper, a new technique is proposed for automatic segmentation of multiple sclerosis (MS) lesions from brain magnetic resonance imaging (MRI) data. The technique uses a trained support vector machine (SVM) to discriminate between the blocks in regions of MS lesions and the blocks in non-MS lesion regions mainly based on the textural features with aid of the other features. The classification is done on each of the axial, sagittal and coronal sectional brain view independently and the resultant segmentations are aggregated to provide more accurate output segmentation. The main contribution of the proposed technique described in this paper is the use of textural features to detect MS lesions in a fully automated approach that does not rely on manually delineating the MS lesions. In addition, the technique introduces the concept of the multi-sectional view segmentation to produce verified segmentation. The proposed textural-based SVM technique was evaluated using three simulated datasets and more than fifty real MRI datasets. The results were compared with state of the art methods. The obtained results indicate that the proposed method would be viable for use in clinical practice for the detection of MS lesions in MRI. PMID:22741026

  13. Standardized radiologic protocol for the study of common coccygodynia and characteristics of the lesions observed in the sitting position. Clinical elements differentiating luxation, hypermobility, and normal mobility.

    Science.gov (United States)

    Maigne, J Y; Tamalet, B

    1996-11-15

    Ninety-one patients with common coccygodynia and 47 control subjects prospectively underwent dynamic radiographic imagery. To standardize the radiologic protocol to better define normal and abnormal mobility of the coccyx, and to study clinical parameters useful in classifying and differentiating the lesions. In a previous study, comparison of films taken in the sitting and standing positions allowed to individualize two distinct coccygeal lesions: luxation and hypermobility. Measurement technique was precise and reproducible, but the control group was not pain-free. No specific clinical features were described. Standing films were made first. Control subjects were healthy volunteers. The following items were recorded: presence of an initial traumatic event, elapsed time before investigation, body mass index, presence of an acute pain when passing from sitting to standing, effect of intradiscal steroid injection, and angle of the coccyx with respect to the seat. Hypermobility was defined as a flexion of more than 25 degrees, luxation by displacement of more than 25% of the coccyx. The base angle is a good predictor of the direction in which the coccyx moves when sitting. In the "luxation" group, a history of initial trauma, a shorter clinical course, pain when standing up, increased body mass index, and satisfactory results with intradiscal injection were found more frequently than in the "normal" group. The "hypermobility" group had characteristics between these two groups. Common coccygodynia is associated in 48.4% of patients with a luxation or hypermobility of the coccyx. A distinct clinical presentation was found in individuals with luxation of the coccyx.

  14. Health Physics Positions Data Base: Revision 1

    Energy Technology Data Exchange (ETDEWEB)

    Kerr, G.D.; Borges, T.; Stafford, R.S.; Lu, P.Y. [Oak Ridge National Lab., TN (United States); Carter, D. [US Nuclear Regulatory Commission, Washington, DC (United States)

    1994-02-01

    The Health Physics Positions (HPPOS) Data Base of the Nuclear Regulatory Commission (NRC) is a collection of NRC staff positions on a wide range of topics involving radiation protection (health physics). It consists of 328 documents in the form of letters, memoranda, and excerpts from technical reports. The HPPOS Data Base was developed by the NRC Headquarters and Regional Offices to help ensure uniformity in inspections, enforcement, and licensing actions. Staff members of the Oak Ridge National Laboratory (ORNL) have assisted the NRC staff in summarizing the documents during the preparation of this NUREG report. These summaries are also being made available as a {open_quotes}stand alone{close_quotes} software package for IBM and IBM-compatible personal computers. The software package for this report is called HPPOS Version 2.0. A variety of indexing schemes were used to increase the usefulness of the NUREG report and its associated software. The software package and the summaries in the report are written in the context of the {open_quotes}new{close_quotes} 10 CFR Part 20 ({section}{section}20.1001--20.2401). The purpose of this NUREG report is to allow interested individuals to familiarize themselves with the contents of the HPPOS Data Base and with the basis of many NRC decisions and regulations. The HPPOS summaries and original documents are intended to serve as a source of information for radiation protection programs at nuclear research and power reactors, nuclear medicine, and other industries that either process or use nuclear materials.

  15. Molecular analysis of human Papillomavirus detected among women positive for cervical lesions by visual inspection with acetic acid/Lugol's iodine (VIA/VILI) in Libreville, Gabon.

    Science.gov (United States)

    Moussavou, Pamela Boundzanga; Koumakpayi, Ismaël Hervé; Nkili-Meyong, Andriniaina Andy; Labouba, Ingrid; Bisvigou, Ulrich; Chansi, Junie K; Engohan-Aloghe, Corinne; Dissanami, Frederic; Ambounda, Nathalie; Delannoy-Vieillard, Anne-Sophie; Diancourt, Laure; Nkoghe, Dieudonne; Leroy, Eric M; Belembaogo, Ernest; Berthet, Nicolas

    2016-01-01

    The human papillomavirus (HPV) is the causative agent of cervical cancer, which is the leading cancer-related cause of death for women in Sub-Saharan Africa. In 2013, the Gabonese Ministry of Health and the Sylvia Bongo Ondimba Foundation implemented cervical cancer screening programs based on the detection of cancerous lesions by visual inspection with acetic acid and/or Lugol's iodine (VIA/VILI). This pilot study was set up to determine the HPV profile and analyze the nucleotide sequence variation of HPV16 circulating in patients with cervical abnormalities detected by VIA/VILI testing. The cervical abnormalities observed upon VIA/VILI were confirmed by liquid-based cytology for all tested women. Nested PCR using the MY09/11 and GP5+/6+ primer sets was used to detect HPVs present in the extracted DNA. HPV genotypes were determined after sequencing of amplicons based on a high-throughput sequencing approach. For isolates of the HPV16 genotype, the E6 gene and the long control region (LCR) were directly sequenced using Sanger method. The study included 87 women who showed a positive VIA/VILI result. Cervical abnormalities were found in 40.23 % of women and 40 % were classified as high-grade lesions. The HPV detection rate was 82.9 % among women with abnormal cytology. Among all the identified high-risk HPV genotypes, HPV16, 18 and 33 were the most frequent. Multiple HPV infections were observed in 42.31 % of HPV-infected women. Analysis of the HPV16 sequence variation in the E6 gene and in the LCR showed that 85.3 and 14.7 % belonged to the African and European lineages, respectively. Among the African branch variants, Af2 was the most frequently identified in this study. This study offers the first report of the HPV detection rate and molecular epidemiology among Gabonese women with a positive result in a VIA/VILI screening test. Moreover, data on the HPV16 sequence variation confirm the predominance of African variants in high-grade lesions.

  16. Quantifying the margin sharpness of lesions on radiological images for content-based image retrieval

    International Nuclear Information System (INIS)

    Xu Jiajing; Napel, Sandy; Greenspan, Hayit; Beaulieu, Christopher F.; Agrawal, Neeraj; Rubin, Daniel

    2012-01-01

    . Equivalence across deformations was assessed using Schuirmann's paired two one-sided tests. Results: In simulated images, the concordance correlation between measured gradient and actual gradient was 0.994. The mean (s.d.) and standard deviation NDCG score for the retrieval of K images, K = 5, 10, and 15, were 84% (8%), 85% (7%), and 85% (7%) for CT images containing liver lesions, and 82% (7%), 84% (6%), and 85% (4%) for CT images containing lung nodules, respectively. The authors’ proposed method outperformed the two existing margin characterization methods in average NDCG scores over all K, by 1.5% and 3% in datasets containing liver lesion, and 4.5% and 5% in datasets containing lung nodules. Equivalence testing showed that the authors’ feature is more robust across all margin deformations (p < 0.05) than the two existing methods for margin sharpness characterization in both simulated and clinical datasets. Conclusions: The authors have described a new image feature to quantify the margin sharpness of lesions. It has strong correlation with known margin sharpness in simulated images and in clinical CT images containing liver lesions and lung nodules. This image feature has excellent performance for retrieving images with similar margin characteristics, suggesting potential utility, in conjunction with other lesion features, for content-based image retrieval applications.

  17. Diffusion-weighted imaging of suspicious (BI-RADS 4 breast lesions: stratification based on histopathology

    Directory of Open Access Journals (Sweden)

    João Ricardo Maltez de Almeida

    Full Text Available Abstract Objective: To test the use of diffusion-weighted imaging (DWI in stratifying suspicious breast lesions (BI-RADS 4, correlating them with histopathology. We also investigated the performance of DWI related to the main enhancement patterns (mass and non-mass and tested its reproducibility. Materials and Methods: Seventy-six patients presented 92 lesions during the sampling period. Two independent examiners reviewed magnetic resonance imaging studies, described the lesions, and determined the apparent diffusion coefficient (ADC values. Differences among benign, indeterminate- to high-risk, and malignant findings, in terms of the ADCs, were assessed by analysis of variance. Using receiver operating characteristic (ROC curves, we compared the performance of ADC values in masses and non-mass lesions, and tested the reproducibility of measurements by determining the coefficient of variation and smallest real difference. Results: Among the 92 lesions evaluated, the histopathology showed that 37 were benign, 11 were indeterminate- to high-risk, and 44 were malignant. The mean ADC differed significantly among those histopathological groups, the value obtained for the malignant lesions (1.10 × 10-3 mm2/s being significantly lower than that obtained for the other groups (p < 0.001. ROC curves demonstrated that DWI performed better when applied to masses than when applied to non-mass lesions (area under the curve, 0.88 vs. 0.67. Reproducibility was good (coefficient of variation, 7.03%; and smallest real difference, ± 0.242 × 10-3 mm2/s. Conclusion: DWI can differentiate between malignant and nonmalignant (benign or indeterminate- to high-risk lesions, showing better performance for masses. Nevertheless, stratification based on histopathological criteria that are more refined has yet to be achieved.

  18. Neural Network-Based Learning Kernel for Automatic Segmentation of Multiple Sclerosis Lesions on Magnetic Resonance Images

    OpenAIRE

    Khastavaneh, H.; Ebrahimpour-Komleh, H.

    2017-01-01

    Background: Multiple Sclerosis (MS) is a degenerative disease of central nervous system. MS patients have some dead tissues in their brains called MS lesions. MRI is an imaging technique sensitive to soft tissues such as brain that shows MS lesions as hyper-intense or hypo-intense signals. Since manual segmentation of these lesions is a laborious and time consuming task, automatic segmentation is a need. Materials and Methods: In order to segment MS lesions, a method based on learning kernels...

  19. Wire Position Monitoring with FPGA based Electronics

    International Nuclear Information System (INIS)

    Eddy, N.; Lysenko, O.

    2009-01-01

    This fall the first Tesla-style cryomodule cooldown test is being performed at Fermilab. Instrumentation department is preparing the electronics to handle the data from a set of wire position monitors (WPMs). For simulation purposes a prototype pipe with a WMP has been developed and built. The system is based on the measurement of signals induced in pickups by 320 MHz signal carried by a wire through the WPM. The wire is stretched along the pipe with a tensioning load of 9.07 kg. The WPM consists of four 50 (Omega) striplines spaced 90 o apart. FPGA based digitizer scans the WPM and transmits the data to a PC via VME interface. The data acquisition is based on the PC running LabView. In order to increase the accuracy and convenience of the measurements some modifications were required. The first is implementation of an average and decimation filter algorithm in the integrator operation in the FPGA. The second is the development of alternative tool for WPM measurements in the PC. The paper describes how these modifications were performed and test results of a new design. The last cryomodule generation has a single chain of seven WPMs (placed in critical positions: at each end, at the three posts and between the posts) to monitor a cold mass displacement during cooldown. The system was developed in Italy in collaboration with DESY. Similar developments have taken place at Fermilab in the frame of cryomodules construction for SCRF research. This fall preliminary cryomodule cooldown test is being performed. In order to prepare an appropriate electronic system for the test a prototype pipe with a WMP has been developed and built, figure 1. The system is based on the measurement of signals induced in pickups by 320 MHz signal carried by a wire through the WPM. The 0.5 mm diameter Cu wire is stretched along the pipe with a tensioning load of 9.07 kg and has a length of 1.1 m. The WPM consists of four 50 (Omega) striplines spaced 90 o apart. An FPGA based digitizer

  20. KIT D816V mutation-positive cell fractions in lesional skin biopsies from adults with systemic mastocytosis

    DEFF Research Database (Denmark)

    Kielsgaard Kristensen, Thomas; Broesby-Olsen, Sigurd; Vestergaard, Hanne

    2013-01-01

    Most adults with systemic mastocytosis (SM) carry the somatic KIT D816V mutation, but the occurrence of the mutation in lesional skin remains to be characterized.......Most adults with systemic mastocytosis (SM) carry the somatic KIT D816V mutation, but the occurrence of the mutation in lesional skin remains to be characterized....

  1. Bilateral effects of unilateral cerebellar lesions as detected by voxel based morphometry and diffusion imaging.

    Directory of Open Access Journals (Sweden)

    Giusy Olivito

    Full Text Available Over the last decades, the importance of cerebellar processing for cortical functions has been acknowledged and consensus was reached on the strict functional and structural cortico-cerebellar interrelations. From an anatomical point of view strictly contralateral interconnections link the cerebellum to the cerebral cortex mainly through the middle and superior cerebellar peduncle. Diffusion MRI (dMRI based tractography has already been applied to address cortico-cerebellar-cortical loops in healthy subjects and to detect diffusivity alteration patterns in patients with neurodegenerative pathologies of the cerebellum. In the present study we used dMRI-based tractography to determine the degree and pattern of pathological changes of cerebellar white matter microstructure in patients with focal cerebellar lesions. Diffusion imaging and high-resolution volumes were obtained in patients with left cerebellar lesions and in normal controls. Middle cerebellar peduncles and superior cerebellar peduncles were reconstructed by multi fiber diffusion tractography. From each tract, measures of microscopic damage were assessed, and despite the presence of unilateral lesions, bilateral diffusivity differences in white matter tracts were found comparing patients with normal controls. Consistently, bilateral alterations were also evidenced in specific brain regions linked to the cerebellum and involved in higher-level functions. This could be in line with the evidence that in the presence of unilateral cerebellar lesions, different cognitive functions can be affected and they are not strictly linked to the side of the cerebellar lesion.

  2. Automatic lesion tracking for a PET/CT based computer aided cancer therapy monitoring system

    Science.gov (United States)

    Opfer, Roland; Brenner, Winfried; Carlsen, Ingwer; Renisch, Steffen; Sabczynski, Jörg; Wiemker, Rafael

    2008-03-01

    Response assessment of cancer therapy is a crucial component towards a more effective and patient individualized cancer therapy. Integrated PET/CT systems provide the opportunity to combine morphologic with functional information. However, dealing simultaneously with several PET/CT scans poses a serious workflow problem. It can be a difficult and tedious task to extract response criteria based upon an integrated analysis of PET and CT images and to track these criteria over time. In order to improve the workflow for serial analysis of PET/CT scans we introduce in this paper a fast lesion tracking algorithm. We combine a global multi-resolution rigid registration algorithm with a local block matching and a local region growing algorithm. Whenever the user clicks on a lesion in the base-line PET scan the course of standardized uptake values (SUV) is automatically identified and shown to the user as a graph plot. We have validated our method by a data collection from 7 patients. Each patient underwent two or three PET/CT scans during the course of a cancer therapy. An experienced nuclear medicine physician manually measured the courses of the maximum SUVs for altogether 18 lesions. As a result we obtained that the automatic detection of the corresponding lesions resulted in SUV measurements which are nearly identical to the manually measured SUVs. Between 38 measured maximum SUVs derived from manual and automatic detected lesions we observed a correlation of 0.9994 and a average error of 0.4 SUV units.

  3. Neural Network-Based Learning Kernel for Automatic Segmentation of Multiple Sclerosis Lesions on Magnetic Resonance Images.

    Science.gov (United States)

    Khastavaneh, H; Ebrahimpour-Komleh, H

    2017-06-01

    Multiple Sclerosis (MS) is a degenerative disease of central nervous system. MS patients have some dead tissues in their brains called MS lesions. MRI is an imaging technique sensitive to soft tissues such as brain that shows MS lesions as hyper-intense or hypo-intense signals. Since manual segmentation of these lesions is a laborious and time consuming task, automatic segmentation is a need. In order to segment MS lesions, a method based on learning kernels has been proposed. The proposed method has three main steps namely; pre-processing, sub-region extraction and segmentation. The segmentation is performed by a kernel. This kernel is trained using a modified version of a special type of Artificial Neural Networks (ANN) called Massive Training ANN (MTANN). The kernel incorporates surrounding pixel information as features for classification of middle pixel of kernel. The materials of this study include a part of MICCAI 2008 MS lesion segmentation grand challenge data-set. Both qualitative and quantitative results show promising results. Similarity index of 70 percent in some cases is considered convincing. These results are obtained from information of only one MRI channel rather than multi-channel MRIs. This study shows the potential of surrounding pixel information to be incorporated in segmentation by learning kernels. The performance of proposed method will be improved using a special pre-processing pipeline and also a post-processing step for reducing false positives/negatives. An important advantage of proposed model is that it uses just FLAIR MRI that reduces computational time and brings comfort to patients.

  4. The role of smoking and alcohol intake in the development of high-grade squamous intraepithelial lesions among high-risk HPV-positive women

    DEFF Research Database (Denmark)

    Tolstrup, Janne; Munk, Christian; Thomsen, Birthe Lykke

    2006-01-01

    -risk human papillomavirus positive women with normal cytology, comparing 94 women who developed high-grade squamous intraepithelial lesions with 454 women who remained cytologically normal. Logistic regression was applied for statistical analysis. RESULTS: Compared with never smokers, the odds ratio for high...

  5. Cryotherapy for Intra- and Perianal High-Grade Squamous Intraepithelial Lesions in HIV-Positive Men who have Sex with Men

    NARCIS (Netherlands)

    Siegenbeek van Heukelom, Matthijs L.; Gosens, Karien C. M.; Prins, Jan M.; de Vries, Henry J. C.

    2018-01-01

    Background Available treatment options for anal high-grade squamous intraepithelial lesions (HSIL) in HIV-positive men who have sex with men (MSM) are limited by low response rates and frequent recurrences. Cryotherapy is an established therapeutic option for several pre-malignant skin disorders.

  6. Proportion of false-positive lesions at interim and end-of-treatment FDG-PET in lymphoma as determined by histology : Systematic review and meta-analysis

    NARCIS (Netherlands)

    Adams, Hugo J A; Kwee, Thomas C.

    2016-01-01

    Purpose To systematically review and meta-analyze the proportion of false-positive lesions at interim and end-of-treatment 18F-fluoro-2-deoxy-D-glucose positron emission tomography (FDG-PET) in lymphoma using biopsy as reference standard. Materials and methods Medline was searched for original

  7. Accurate Depth of Radiofrequency-Induced Lesions in Renal Sympathetic Denervation Based on a Fine Histological Sectioning Approach in a Porcine Model.

    Science.gov (United States)

    Sakaoka, Atsushi; Terao, Hisako; Nakamura, Shintaro; Hagiwara, Hitomi; Furukawa, Toshihito; Matsumura, Kiyoshi; Sakakura, Kenichi

    2018-02-01

    Ablation lesion depth caused by radiofrequency-based renal denervation (RDN) was limited to radiofrequency-RDN cannot ablate a substantial percentage of renal sympathetic nerves. We aimed to define the true lesion depth achieved with radiofrequency-RDN using a fine sectioning method and to investigate biophysical parameters that could predict lesion depth. Radiofrequency was delivered to 87 sites in 14 renal arteries from 9 farm pigs at various ablation settings: 2, 4, 6, and 9 W for 60 seconds and 6 W for 120 seconds. Electric impedance and electrode temperature were recorded during ablation. At 7 days, 2470 histological sections were obtained from the treated arteries. Maximum lesion depth increased at 2 to 6 W, peaking at 6.53 (95% confidence interval, 4.27-8.78) mm under the 6 W/60 s condition. It was not augmented by greater power (9 W) or longer duration (120 seconds). There were statistically significant tendencies at 6 and 9 W, with higher injury scores in the media, nerves, arterioles, and fat. Maximum lesion depth was positively correlated with impedance reduction and peak electrode temperature (Pearson correlation coefficients were 0.59 and 0.53, respectively). Lesion depth was 6.5 mm for radiofrequency-RDN at 6 W/60 s. The impedance reduction and peak electrode temperature during ablation were closely associated with lesion depth. Hence, these biophysical parameters could provide prompt feedback during radiofrequency-RDN procedures in the clinical setting. © 2018 The Authors.

  8. Is a single direct MR arthrography series in ABER position as accurate in detecting anteroinferior labroligamentous lesions as conventional MR arthography?

    Energy Technology Data Exchange (ETDEWEB)

    Schreinemachers, Saskia A.; Hulst, Victor P.M. van der; Woude, Henk-Jan van der [Onze Lieve Vrouwe Gasthuis, Department of Radiology, Amsterdam (Netherlands); Jaap Willems, W. [Onze Lieve Vrouwe Gasthuis, Orthopaedic Surgery, Amsterdam (Netherlands); Bipat, Shandra [University of Amsterdam, Department of Radiology, Academic Medical Centre, Amsterdam (Netherlands)

    2009-07-15

    The purpose of this study is to retrospectively compare accuracy of single magnetic resonance (MR) arthrography series in Abduction External Rotation (ABER) with conventional MR arthrography for detection and characterisation of anteroinferior labroligamentous lesions, with arthroscopy as reference standard. Inter-observer variability of both protocols was determined. Institutional review board approval was obtained; informed consent was waived. MR arthrograms, including oblique axial fat suppressed T1-weighted images in ABER position and conventional imaging directions of 250 patients (170 men, 80 women; mean age, 36 years), were retrospectively and independently evaluated by three reviewers. Reviewers were blinded to clinical information and arthroscopic results. Labroligamentous lesions were registered in both ABER and MRa. The lesions were sub-classified (Bankart, Perthes, anterior labrum periosteal sleeve avulsion (ALPSA) or lesions not otherwise specified). Inter-observer agreement was assessed by Kappa statistics for all 250 patients. Ninety-two of 250 patients underwent arthroscopy. Sensitivity, specificity and accuracy of ABER versus conventional MR arthrography were calculated and compared using paired McNemar test. Kappa values of the ABER and conventional MR arthrography ranged from 0.44 to 0.56 and 0.44 to 0.62, respectively. According to arthroscopy, 45 of 92 patients had an intact anteroinferior labrum, and in 44 patients, a labroligamentous lesion (eight Bankart, seven Perthes, 29 ALPSA and three lesions not otherwise specified) was diagnosed. There were no statistically significant differences between ABER and conventional MR arthrography regarding sensitivity (85-89%, 89-96%), specificity (82-91%, 84-89%) and overall accuracy (50-62%, 53-63%). The results of a single MR arthrography series in ABER position are comparable with those of conventional MR arthrography for detecting anteroinferior labroligamentous lesions. (orig.)

  9. Visualization of suspicious lesions in breast MRI based on intelligent neural systems

    Science.gov (United States)

    Twellmann, Thorsten; Lange, Oliver; Nattkemper, Tim Wilhelm; Meyer-Bäse, Anke

    2006-05-01

    Intelligent medical systems based on supervised and unsupervised artificial neural networks are applied to the automatic visualization and classification of suspicious lesions in breast MRI. These systems represent an important component of future sophisticated computer-aided diagnosis systems and enable the extraction of spatial and temporal features of dynamic MRI data stemming from patients with confirmed lesion diagnosis. By taking into account the heterogenity of the cancerous tissue, these techniques reveal the malignant, benign and normal kinetic signals and and provide a regional subclassification of pathological breast tissue. Intelligent medical systems are expected to have substantial implications in healthcare politics by contributing to the diagnosis of indeterminate breast lesions by non-invasive imaging.

  10. Computer-aided detection of breast lesions in DCE-MRI using region growing based on fuzzy C-means clustering and vesselness filter

    Science.gov (United States)

    B. Shokouhi, Shahriar; Fooladivanda, Aida; Ahmadinejad, Nasrin

    2017-12-01

    A computer-aided detection (CAD) system is introduced in this paper for detection of breast lesions in dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI). The proposed CAD system firstly compensates motion artifacts and segments the breast region. Then, the potential lesion voxels are detected and used as the initial seed points for the seeded region-growing algorithm. A new and robust region-growing algorithm incorporating with Fuzzy C-means (FCM) clustering and vesselness filter is proposed to segment any potential lesion regions. Subsequently, the false positive detections are reduced by applying a discrimination step. This is based on 3D morphological characteristics of the potential lesion regions and kinetic features which are fed to the support vector machine (SVM) classifier. The performance of the proposed CAD system is evaluated using the free-response operating characteristic (FROC) curve. We introduce our collected dataset that includes 76 DCE-MRI studies, 63 malignant and 107 benign lesions. The prepared dataset has been used to verify the accuracy of the proposed CAD system. At 5.29 false positives per case, the CAD system accurately detects 94% of the breast lesions.

  11. Characterizing stroke lesions using digital templates and lesion quantification tools in a web-based imaging informatics system for a large-scale stroke rehabilitation clinical trial

    Science.gov (United States)

    Wang, Ximing; Edwardson, Matthew; Dromerick, Alexander; Winstein, Carolee; Wang, Jing; Liu, Brent

    2015-03-01

    Previously, we presented an Interdisciplinary Comprehensive Arm Rehabilitation Evaluation (ICARE) imaging informatics system that supports a large-scale phase III stroke rehabilitation trial. The ePR system is capable of displaying anonymized patient imaging studies and reports, and the system is accessible to multiple clinical trial sites and users across the United States via the web. However, the prior multicenter stroke rehabilitation trials lack any significant neuroimaging analysis infrastructure. In stroke related clinical trials, identification of the stroke lesion characteristics can be meaningful as recent research shows that lesion characteristics are related to stroke scale and functional recovery after stroke. To facilitate the stroke clinical trials, we hope to gain insight into specific lesion characteristics, such as vascular territory, for patients enrolled into large stroke rehabilitation trials. To enhance the system's capability for data analysis and data reporting, we have integrated new features with the system: a digital brain template display, a lesion quantification tool and a digital case report form. The digital brain templates are compiled from published vascular territory templates at each of 5 angles of incidence. These templates were updated to include territories in the brainstem using a vascular territory atlas and the Medical Image Processing, Analysis and Visualization (MIPAV) tool. The digital templates are displayed for side-by-side comparisons and transparent template overlay onto patients' images in the image viewer. The lesion quantification tool quantifies planimetric lesion area from user-defined contour. The digital case report form stores user input into a database, then displays contents in the interface to allow for reviewing, editing, and new inputs. In sum, the newly integrated system features provide the user with readily-accessible web-based tools to identify the vascular territory involved, estimate lesion area

  12. Lesion registration for longitudinal disease tracking in an imaging informatics-based multiple sclerosis eFolder

    Science.gov (United States)

    Ma, Kevin; Liu, Joseph; Zhang, Xuejun; Lerner, Alex; Shiroishi, Mark; Amezcua, Lilyana; Liu, Brent

    2016-03-01

    We have designed and developed a multiple sclerosis eFolder system for patient data storage, image viewing, and automatic lesion quantification results stored in DICOM-SR format. The web-based system aims to be integrated in DICOM-compliant clinical and research environments to aid clinicians in patient treatments and data analysis. The system needs to quantify lesion volumes, identify and register lesion locations to track shifts in volume and quantity of lesions in a longitudinal study. In order to perform lesion registration, we have developed a brain warping and normalizing methodology using Statistical Parametric Mapping (SPM) MATLAB toolkit for brain MRI. Patients' brain MR images are processed via SPM's normalization processes, and the brain images are analyzed and warped according to the tissue probability map. Lesion identification and contouring are completed by neuroradiologists, and lesion volume quantification is completed by the eFolder's CAD program. Lesion comparison results in longitudinal studies show key growth and active regions. The results display successful lesion registration and tracking over a longitudinal study. Lesion change results are graphically represented in the web-based user interface, and users are able to correlate patient progress and changes in the MRI images. The completed lesion and disease tracking tool would enable the eFolder to provide complete patient profiles, improve the efficiency of patient care, and perform comprehensive data analysis through an integrated imaging informatics system.

  13. The brain and the subjective experience of time. A voxel based symptom-lesion mapping study.

    Science.gov (United States)

    Trojano, Luigi; Caccavale, Michelina; De Bellis, Francesco; Crisci, Claudio

    2017-06-30

    The aim of the study was to identify the anatomical bases involved in the subjective experience of time, by means of a voxel based symptom-lesion mapping (VLSM) study on patients with focal brain damage. Thirty-three patients (nineteen with right-hemisphere lesions -RBD, and fourteen with left lesion- LBD) and twenty-eight non-neurological controls (NNC) underwent the semi-structured QUEstionnaire for the Subjective experience of Time (QUEST) requiring retrospective and prospective judgements on self-relevant time intervals. All participants also completed tests to assess general cognitive functioning and two questionnaires to evaluate their emotional state. Both groups of brain-damaged patients achieved significantly different scores from NNC on the time performance, without differences between RBD and LBD. VLSM showed a cluster of voxels located in the right inferior parietal lobule significantly related to errors in the prospective items. The lesion subtraction analysis revealed two different patterns possibly associated with errors in the prospective items (the right inferior parietal cortex, rolandic operculum and posterior middle temporal gyrus) and in the retrospective items (superior middle temporal gyrus, white matter posterior to the insula). Copyright © 2017 Elsevier B.V. All rights reserved.

  14. Fusion of classifiers for REIS-based detection of suspicious breast lesions

    Science.gov (United States)

    Lederman, Dror; Wang, Xingwei; Zheng, Bin; Sumkin, Jules H.; Tublin, Mitchell; Gur, David

    2011-03-01

    After developing a multi-probe resonance-frequency electrical impedance spectroscopy (REIS) system aimed at detecting women with breast abnormalities that may indicate a developing breast cancer, we have been conducting a prospective clinical study to explore the feasibility of applying this REIS system to classify younger women (breast cancer. The system comprises one central probe placed in contact with the nipple, and six additional probes uniformly distributed along an outside circle to be placed in contact with six points on the outer breast skin surface. In this preliminary study, we selected an initial set of 174 examinations on participants that have completed REIS examinations and have clinical status verification. Among these, 66 examinations were recommended for biopsy due to findings of a highly suspicious breast lesion ("positives"), and 108 were determined as negative during imaging based procedures ("negatives"). A set of REIS-based features, extracted using a mirror-matched approach, was computed and fed into five machine learning classifiers. A genetic algorithm was used to select an optimal subset of features for each of the five classifiers. Three fusion rules, namely sum rule, weighted sum rule and weighted median rule, were used to combine the results of the classifiers. Performance evaluation was performed using a leave-one-case-out cross-validation method. The results indicated that REIS may provide a new technology to identify younger women with higher than average risk of having or developing breast cancer. Furthermore, it was shown that fusion rule, such as a weighted median fusion rule and a weighted sum fusion rule may improve performance as compared with the highest performing single classifier.

  15. Improved Automatic Segmentation of White Matter Hyperintensities in MRI Based on Multilevel Lesion Features.

    Science.gov (United States)

    Rincón, M; Díaz-López, E; Selnes, P; Vegge, K; Altmann, M; Fladby, T; Bjørnerud, A

    2017-07-01

    Brain white matter hyperintensities (WMHs) are linked to increased risk of cerebrovascular and neurodegenerative diseases among the elderly. Consequently, detection and characterization of WMHs are of significant clinical importance. We propose a novel approach for WMH segmentation from multi-contrast MRI where both voxel-based and lesion-based information are used to improve overall performance in both volume-oriented and object-oriented metrics. Our segmentation method (AMOS-2D) consists of four stages following a "generate-and-test" approach: pre-processing, Gaussian white matter (WM) modelling, hierarchical multi-threshold WMH segmentation and object-based WMH filtering using support vector machines. Data from 28 subjects was used in this study covering a wide range of lesion loads. Volumetric T1-weighted images and 2D fluid attenuated inversion recovery (FLAIR) images were used as basis for the WM model and lesion masks defined manually in each subject by experts were used for training and evaluating the proposed method. The method obtained an average agreement (in terms of the Dice similarity coefficient, DSC) with experts equivalent to inter-expert agreement both in terms of WMH number (DSC = 0.637 vs. 0.651) and volume (DSC = 0.743 vs. 0.781). It allowed higher accuracy in detecting WMH compared to alternative methods tested and was further found to be insensitive to WMH lesion burden. Good agreement with expert annotations combined with stable performance largely independent of lesion burden suggests that AMOS-2D will be a valuable tool for fully automated WMH segmentation in patients with cerebrovascular and neurodegenerative pathologies.

  16. Arrested pneumatization of the sphenoid sinus mimicking intraosseous lesions of the skull base

    Energy Technology Data Exchange (ETDEWEB)

    Jalali, Elnaz; Tadinada, Aditya [Dept. of Oral and Maxillofacial Radiology, University of Connecticut School of Dental Medicine, Farmington (United States)

    2015-03-15

    Arrested pneumatization of the sphenoid sinus is a developmental variant that is not always well recognized and is often confused with other pathologies associated with the skull base. This report describes the case of a patient referred for cone-beam computed tomography (CBCT) imaging for dental implant therapy. CBCT demonstrated a well-defined incidental lesion in the left sphenoid sinus with soft tissue-like density and sclerotic borders with internal curvilinear opacifications. The differential diagnoses included intraosseous lipoma, arrested pneumatization of the sphenoid sinus, chondrosarcoma, chondroid chordoma, and ossifying fibroma. The radiographic diagnosis of arrested pneumatization was based on the location of the lesion, its well-defined nature, the presence of internal opacifications, and lack of expansion. Gray-scale CBCT imaging of the area demonstrated values similar to fatty tissue. This case highlighted the fact that benign developmental variants associated with the skull base share similar radiographic features with more serious pathological entities.

  17. Natural history of chondroid skull base lesions - case report and review

    International Nuclear Information System (INIS)

    Schmidinger, A.; Rosahl, S.K.; Vorkapic, P.; Samii, M.

    2002-01-01

    Long-term follow-up reports on chondroid lesions of the skull base are rarely presented in the literature. There are virtually no data on natural growth rates of these tumors based on MRI obtained over a period of 10 years or longer. We followed a patient who has had such a lesion for more than 12 years. A non-progressive, slight abducens palsy has been the only associated symptom so far. Even though the patient was operated on for an additional intracranial arterio-venous malformation, clinical features and chromosomal testing excluded Maffucci's syndrome. The MRI follow-up in this case provides an extraordinary perspective on the natural history of chondroid skull base tumors. (orig.)

  18. Navigation studies based on the ubiquitous positioning technologies

    Science.gov (United States)

    Ye, Lei; Mi, Weijie; Wang, Defeng

    2007-11-01

    This paper summarized the nowadays positioning technologies, such as absolute positioning methods and relative positioning methods, indoor positioning and outdoor positioning, active positioning and passive positioning. Global Navigation Satellite System (GNSS) technologies were introduced as the omnipresent out-door positioning technologies, including GPS, GLONASS, Galileo and BD-1/2. After analysis of the shortcomings of GNSS, indoor positioning technologies were discussed and compared, including A-GPS, Cellular network, Infrared, Electromagnetism, Computer Vision Cognition, Embedded Pressure Sensor, Ultrasonic, RFID (Radio Frequency IDentification), Bluetooth, WLAN etc.. Then the concept and characteristics of Ubiquitous Positioning was proposed. After the ubiquitous positioning technologies contrast and selection followed by system engineering methodology, a navigation system model based on Incorporate Indoor-Outdoor Positioning Solution was proposed. And this model was simulated in the Galileo Demonstration for World Expo Shanghai project. In the conclusion, the prospects of ubiquitous positioning based navigation were shown, especially to satisfy the public location information acquiring requirement.

  19. Three dimensional quantitative coronary angiography can detect reliably ischemic coronary lesions based on fractional flow reserve.

    Science.gov (United States)

    Chung, Woo-Young; Choi, Byoung-Joo; Lim, Seong-Hoon; Matsuo, Yoshiki; Lennon, Ryan J; Gulati, Rajiv; Sandhu, Gurpreet S; Holmes, David R; Rihal, Charanjit S; Lerman, Amir

    2015-06-01

    Conventional coronary angiography (CAG) has limitations in evaluating lesions producing ischemia. Three dimensional quantitative coronary angiography (3D-QCA) shows reconstructed images of CAG using computer based algorithm, the Cardio-op B system (Paieon Medical, Rosh Ha'ayin, Israel). The aim of this study was to evaluate whether 3D-QCA can reliably predict ischemia assessed by myocardial fractional flow reserve (FFR) < 0.80. 3D-QCA images were reconstructed from CAG which also were evaluated with FFR to assess ischemia. Minimal luminal diameter (MLD), percent diameter stenosis (%DS), minimal luminal area (MLA), and percent area stenosis (%AS) were obtained. The results of 3D-QCA and FFR were compared. A total of 266 patients was enrolled for the present study. FFR for all lesions ranged from 0.57 to 1.00 (0.85 ± 0.09). Measurement of MLD, %DS, MLA, and %AS all were significantly correlated with FFR (r = 0.569, 0609, 0.569, 0.670, respectively, all P < 0.001). In lesions with MLA < 4.0 mm(2), %AS of more than 65.5% had a 80% sensitivity and a 83% specificity to predict FFR < 0.80 (area under curve, AUC was 0.878). 3D-QCA can reliably predict coronary lesions producing ischemia and may be used to guide therapeutic approach for coronary artery disease.

  20. The method for detecting small lesions in medical image based on sliding window

    Science.gov (United States)

    Han, Guilai; Jiao, Yuan

    2016-10-01

    At present, the research on computer-aided diagnosis includes the sample image segmentation, extracting visual features, generating the classification model by learning, and according to the model generated to classify and judge the inspected images. However, this method has a large scale of calculation and speed is slow. And because medical images are usually low contrast, when the traditional image segmentation method is applied to the medical image, there is a complete failure. As soon as possible to find the region of interest, improve detection speed, this topic attempts to introduce the current popular visual attention model into small lesions detection. However, Itti model is mainly for natural images. But the effect is not ideal when it is used to medical images which usually are gray images. Especially in the early stages of some cancers, the focus of a disease in the whole image is not the most significant region and sometimes is very difficult to be found. But these lesions are prominent in the local areas. This paper proposes a visual attention mechanism based on sliding window, and use sliding window to calculate the significance of a local area. Combined with the characteristics of the lesion, select the features of gray, entropy, corner and edge to generate a saliency map. Then the significant region is segmented and distinguished. This method reduces the difficulty of image segmentation, and improves the detection accuracy of small lesions, and it has great significance to early discovery, early diagnosis and treatment of cancers.

  1. Synthesis of modified oligonucleotides that contain purine and pyrimidine radio-induced base lesions

    International Nuclear Information System (INIS)

    Romieu, Anthony

    1999-01-01

    Different factors as oxidizing or carcinogenesis agents, UV and ionizing radiations,.... can generate a wide, spectrum of DNA base damages. In order to study the biochemical and structural features of these DNA damages, it is important to prepare short DNA fragments (20 to 50 bases long) bearing a single or several modifications at specific sites in their sequences. The chemical synthesis is a powerful tool to prepare such modified DNA fragments. This work focusses on the chemical incorporation of several modified nucleosides formed in DNA by ionizing radiations or by photo-sensitization. The first part of this study describes the preparation of a phosphoramidite synthon of 5-hydroxy-2'-deoxyuridine and its subsequent incorporation into synthetic oligonucleotides ranging from 14 to 33 bases long. In a second part (chapters Ill and IV), the synthesis and incorporation of original radiation-induced tandem lesions: the carbon-bridged cyclo-nucleosides are presented. Both (5'R)- and (5'S) diastereomers of 5',8-cyclo-2'-deoxyadenosine and 5',8-cyclo-2'-deoxyguanosine have been individually inserted into various different oligonucleotides (3 to 22 bases long) by using the standard phosphoramidite chemistry. The chemical incorporation of a pyrimidine analogue: (5'S, 6S)-5',6-cyclo-5,6-dihydro-thymidine has been also achieved. The loss of aromaticity of this modified nucleoside and its poor reactivity required the development of a synthetic strategy entirely different from that used for the preparation and subsequent incorporation of the phosphoramidite synthons of 5',8-cyclo-purine-2'-deoxyribo-nucleosides. The third part of this study deals with the synthesis of a phosphoramidite synthon of 4-hydroxy-8-oxo-4,8-dihydro-2'-deoxyguanosine. The two (4R)- and (4S)- diastereomers of this oxidized purine have been separated and individually inserted in several synthetic DNA fragments. No epimerization of C-4 position

  2. Degree of Enhancement on Contrast Enhanced Spectral Mammography (CESM) and Lesion Type on Mammography (MG): Comparison Based on Histological Results.

    Science.gov (United States)

    Łuczyńska, Elżbieta; Niemiec, Joanna; Hendrick, Edward; Heinze, Sylwia; Jaszczyński, Janusz; Jakubowicz, Jerzy; Sas-Korczyńska, Beata; Rys, Janusz

    2016-10-21

    BACKGROUND Contrast enhanced spectral mammography (CESM) is a new method of breast cancer diagnosis in which an iodinated contrast agent is injected and dual-energy mammography is obtained in multiple views of the breasts. The aim of this study was to compare the degree of enhancement on CESM with lesion characteristics on mammography (MG) and lesion histology in women with suspicious breast lesions. MATERIAL AND METHODS The degree of enhancement on CESM (absent, weak, medium, or strong) was compared to lesion characteristics on MG (mass, mass with microcalcifications, or microcalcifications alone) and histology (infiltrating carcinoma, intraductal carcinoma, or benign) to compare sensitivity of the two modalities and to establish correlations that might improve diagnostic accuracy. RESULTS Among 225 lesions identified with CESM and MG, histological evaluation revealed 143 carcinomas (127 infiltrating, 16 intraductal) and 82 benign lesions. This is the largest cohort investigated with CESM to date. The sensitivity of CESM was higher than that of MG (100% and 90%, respectively, p=0.010). Medium or strong enhancement on CESM and the presence of a mass on MG was the most likely indictor of malignancy (55.1% p=0.002). Among benign lesions, 60% presented as enhancement on CESM (were false-positive), and most frequently as medium or weak enhancement, together with a mass on MG (53%, p=0.047). Unfortunately, the study did not find combinations of MG findings and CESM enhancement patterns that would be helpful in defining false-positive lesions. We observed systematic overestimation of maximum lesion diameter on CESM compared to histology (mean difference: 2.29 mm). CONCLUSIONS Strong or medium enhancement on CESM and mass or mass with microcalcifications on MG were strong indicators of malignant transformation. However, we found no combination of MG and CESM characteristics helpful in defining false-positive lesions.

  3. [Treatment of degenerative meniscal lesions : From eminence to evidence-based medicine].

    Science.gov (United States)

    Becker, R; Bernard, M; Scheffler, S; Kopf, S

    2017-10-01

    The treatment of degenerative meniscal lesions has received increased attention since the publication of several Level 1 studies over the last few years. The following review of literature including the consensus statement given by ESSKA reports on the management of patients with degenerative meniscal lesions. The analysis includes the literature of Level 1 to 4 studies and the statement of the consensus group of ESSKA concerning the surgical or conservative management of these patients. Meniscal lesions cause progression in osteoarthritis. Patients presenting a combination of degenerative meniscal lesion and osteoarthritis show inferior clinical outcome. The average clinical outcome after surgical treatment was 70 points based on the Lysholm score. Level 1 studies show no difference in clinical outcome. However, over 30% of these patients require arthroscopy at the second stage after an interval of 3 to 6 months. Patients presenting a flap tear or complaining about mechanical symptoms show poor outcome after conservative treatment. Level 1 studies have focused on very selected patients. These patients do not represent the daily practice of orthopaedic surgeons. The findings of the level 1 studies should, therefore, not be generalized. According to the consensus statement of ESSKA, the treatment of degenerative meniscal lesions should start with conservative management. In the case of persistent symptoms, surgery should be considered after 3 months. In the case of mechanical symptoms, arthroscopy might be indicated earlier. Arthroscopy in advanced osteoarthritic knees is not indicated due to inferior clinical outcome.

  4. Establishment of a mathematical model for the influence of respiratory movement upon the position of an intrahepatic space-occupying lesion

    International Nuclear Information System (INIS)

    Yu Yonghua; Luo Limin; Li Baosheng; Yu Jinming; Liang Chaoqian; Zhao Yuehuan

    2002-01-01

    Objective: To investigate the extent of liver lesion shifting with respiration in an attempt to establish a relevant mathematical model. Methods: We measured breathing movements with B ultrasonography in 84 primary or metastatic liver tumors and defined the relation between the lesion shifting extent with age, sex, height, weight, lesion location and size analyzed with the SPSS statistic software. Results: The Z, X and Y breathing-axis motions were 1.029±0.321 cm (range: 0.6-1.9 cm), 0.301 ± 0.131 cm (range: 0.0-0.6 cm) and 0.387±0.130 cm (range: 0.2-0.7 cm), respectively. The movement-related factor analysis revealed that age, weight and (right lobe) lesion location presented a negative relationship but height, sex and lesion size presented a positive relationship for Z, Y and X breathing-axis motions. Their mathematical regression models were established as Z = -2.660 + 2.952 H-1.539 x 10 -2 W-3.928 x 10 -3 A; Y = -0. 926 + 0. 987 H-4.992 x 10 -3 W, and X = 0.507 + 7.629 x 10 -2 S-3.686 x 10 -3 W [H : height (m), W : weight (kg) A : age (year), S : sex(M:1, F: 0)]. The liver breathing movement was verified with the model in another 11 patients and the conformation rate was up to 91%. Conclusions: The impact of breathing movement on the location of intrahepatic lesion is mainly focused on the Z-axis motion. The practical accuracy in anticipating breathing movement with the mathematical model is so justified that the use of this model be recommended in stereotactic radiotherapy

  5. Base-pairing preferences, physicochemical properties and mutational behaviour of the DNA lesion 8-nitroguanine.

    Science.gov (United States)

    Bhamra, Inder; Compagnone-Post, Patricia; O'Neil, Ian A; Iwanejko, Lesley A; Bates, Andrew D; Cosstick, Richard

    2012-11-01

    8-Nitro-2'-deoxyguanosine (8-nitrodG) is a relatively unstable, mutagenic lesion of DNA that is increasingly believed to be associated with tissue inflammation. Due to the lability of the glycosidic bond, 8-nitrodG cannot be incorporated into oligodeoxynucleotides (ODNs) by chemical DNA synthesis and thus very little is known about its physicochemical properties and base-pairing preferences. Here we describe the synthesis of 8-nitro-2'-O-methylguanosine, a ribonucleoside analogue of this lesion, which is sufficiently stable to be incorporated into ODNs. Physicochemical studies demonstrated that 8-nitro-2'-O-methylguanosine adopts a syn conformation about the glycosidic bond; thermal melting studies and molecular modelling suggest a relatively stable syn-8-nitroG·anti-G base pair. Interestingly, when this lesion analogue was placed in a primer-template system, extension of the primer by either avian myeloblastosis virus reverse transcriptase (AMV-RT) or human DNA polymerase β (pol β), was significantly impaired, but where incorporation opposite 8-nitroguanine did occur, pol β showed a 2:1 preference to insert dA over dC, while AMV-RT incorporated predominantly dC. The fact that no 8-nitroG·G base pairing is seen in the primer extension products suggests that the polymerases may discriminate against this pairing system on the basis of its poor geometric match to a Watson-Crick pair.

  6. Base-pairing preferences, physicochemical properties and mutational behaviour of the DNA lesion 8-nitroguanine†

    Science.gov (United States)

    Bhamra, Inder; Compagnone-Post, Patricia; O’Neil, Ian A.; Iwanejko, Lesley A.; Bates, Andrew D.; Cosstick, Richard

    2012-01-01

    8-Nitro-2′-deoxyguanosine (8-nitrodG) is a relatively unstable, mutagenic lesion of DNA that is increasingly believed to be associated with tissue inflammation. Due to the lability of the glycosidic bond, 8-nitrodG cannot be incorporated into oligodeoxynucleotides (ODNs) by chemical DNA synthesis and thus very little is known about its physicochemical properties and base-pairing preferences. Here we describe the synthesis of 8-nitro-2′-O-methylguanosine, a ribonucleoside analogue of this lesion, which is sufficiently stable to be incorporated into ODNs. Physicochemical studies demonstrated that 8-nitro-2′-O-methylguanosine adopts a syn conformation about the glycosidic bond; thermal melting studies and molecular modelling suggest a relatively stable syn-8-nitroG·anti-G base pair. Interestingly, when this lesion analogue was placed in a primer-template system, extension of the primer by either avian myeloblastosis virus reverse transcriptase (AMV-RT) or human DNA polymerase β (pol β), was significantly impaired, but where incorporation opposite 8-nitroguanine did occur, pol β showed a 2:1 preference to insert dA over dC, while AMV-RT incorporated predominantly dC. The fact that no 8-nitroG·G base pairing is seen in the primer extension products suggests that the polymerases may discriminate against this pairing system on the basis of its poor geometric match to a Watson–Crick pair. PMID:22965127

  7. Pigmented skin lesion detection using random forest and wavelet-based texture

    Science.gov (United States)

    Hu, Ping; Yang, Tie-jun

    2016-10-01

    The incidence of cutaneous malignant melanoma, a disease of worldwide distribution and is the deadliest form of skin cancer, has been rapidly increasing over the last few decades. Because advanced cutaneous melanoma is still incurable, early detection is an important step toward a reduction in mortality. Dermoscopy photographs are commonly used in melanoma diagnosis and can capture detailed features of a lesion. A great variability exists in the visual appearance of pigmented skin lesions. Therefore, in order to minimize the diagnostic errors that result from the difficulty and subjectivity of visual interpretation, an automatic detection approach is required. The objectives of this paper were to propose a hybrid method using random forest and Gabor wavelet transformation to accurately differentiate which part belong to lesion area and the other is not in a dermoscopy photographs and analyze segmentation accuracy. A random forest classifier consisting of a set of decision trees was used for classification. Gabor wavelets transformation are the mathematical model of visual cortical cells of mammalian brain and an image can be decomposed into multiple scales and multiple orientations by using it. The Gabor function has been recognized as a very useful tool in texture analysis, due to its optimal localization properties in both spatial and frequency domain. Texture features based on Gabor wavelets transformation are found by the Gabor filtered image. Experiment results indicate the following: (1) the proposed algorithm based on random forest outperformed the-state-of-the-art in pigmented skin lesions detection (2) and the inclusion of Gabor wavelet transformation based texture features improved segmentation accuracy significantly.

  8. Evaluation of Dixon Sequence on Hybrid PET/MR Compared with Contrast-Enhanced PET/CT for PET-Positive Lesions

    International Nuclear Information System (INIS)

    Jeong, Ju Hye; Cho, Ihn Ho; Kong, Eun Jung; Chun, Kyung Ah

    2014-01-01

    Hybrid positron emission tomography and magnetic resonance (PET/MR) imaging performs a two-point Dixon MR sequence for attenuation correction. However, MR data in hybrid PET/MR should provide anatomic and morphologic information as well as an attenuation map. We evaluated the Dixon sequence of hybrid PET/MR for anatomic correlation of PET-positive lesions compared with contrast-enhanced PET/computed tomography (CT) in patients with oncologic diseases. Twelve patients underwent a single injection, dual imaging protocol. PET/CT was performed with an intravenous contrast agent (85±13 min after 18 F-FDG injection of 403± 45 MBq) and then (125±19 min after injection) PET/MR was performed. Attenuation correction and anatomic allocation of PET were performed using contrast-enhanced CT for PET/CT and Dixon MR sequence for hybrid PET/MR. The Dixon MR sequence and contrast-enhanced CT were compared for anatomic correlation of PET-positive lesions (scoring scale ranging from 0 to 3 for visual ratings). Additionally, standardized uptake values (SUVs) for the detected lesions were assessed for quantitative comparison. Both hybrid PET/MR and contrast-enhanced PET/CT identified 55 lesions with increased FDG uptake in ten patients. In total, 28 lymph nodes, 11 bone lesions, 3 dermal nodules, 3 pleural thickening lesions, 2 thyroid nodules, 1 pancreas, 1 liver, 1 ovary, 1 uterus, 1 breast, 1 soft tissue and 2 lung lesions were present. The best performance was observed for anatomic correlation of PET findings by the contrast-enhanced CT scans (contrast-enhanced CT, 2.64± 0.70; in-phase, 1.29±1.01; opposed-phase, 1.29±1.15; water-weighted, 1.71±1.07; fat weighted, 0.56±1.03). A significant difference was observed between the scores obtained from the contrast-enhanced CT and all four coregistered Dixon MR images. Quantitative evaluation revealed a high correlation between the SUVs measured with hybrid PET/MR (SUVmean, 2.63±1.62; SUVmax, 4.30±2.88) and contrast-enhanced PET

  9. Evaluation of Dixon Sequence on Hybrid PET/MR Compared with Contrast-Enhanced PET/CT for PET-Positive Lesions

    Energy Technology Data Exchange (ETDEWEB)

    Jeong, Ju Hye; Cho, Ihn Ho; Kong, Eun Jung; Chun, Kyung Ah [Yeungnam Univ. Hospital, Daegu (Korea, Republic of)

    2014-03-15

    Hybrid positron emission tomography and magnetic resonance (PET/MR) imaging performs a two-point Dixon MR sequence for attenuation correction. However, MR data in hybrid PET/MR should provide anatomic and morphologic information as well as an attenuation map. We evaluated the Dixon sequence of hybrid PET/MR for anatomic correlation of PET-positive lesions compared with contrast-enhanced PET/computed tomography (CT) in patients with oncologic diseases. Twelve patients underwent a single injection, dual imaging protocol. PET/CT was performed with an intravenous contrast agent (85±13 min after {sup 18}F-FDG injection of 403± 45 MBq) and then (125±19 min after injection) PET/MR was performed. Attenuation correction and anatomic allocation of PET were performed using contrast-enhanced CT for PET/CT and Dixon MR sequence for hybrid PET/MR. The Dixon MR sequence and contrast-enhanced CT were compared for anatomic correlation of PET-positive lesions (scoring scale ranging from 0 to 3 for visual ratings). Additionally, standardized uptake values (SUVs) for the detected lesions were assessed for quantitative comparison. Both hybrid PET/MR and contrast-enhanced PET/CT identified 55 lesions with increased FDG uptake in ten patients. In total, 28 lymph nodes, 11 bone lesions, 3 dermal nodules, 3 pleural thickening lesions, 2 thyroid nodules, 1 pancreas, 1 liver, 1 ovary, 1 uterus, 1 breast, 1 soft tissue and 2 lung lesions were present. The best performance was observed for anatomic correlation of PET findings by the contrast-enhanced CT scans (contrast-enhanced CT, 2.64± 0.70; in-phase, 1.29±1.01; opposed-phase, 1.29±1.15; water-weighted, 1.71±1.07; fat weighted, 0.56±1.03). A significant difference was observed between the scores obtained from the contrast-enhanced CT and all four coregistered Dixon MR images. Quantitative evaluation revealed a high correlation between the SUVs measured with hybrid PET/MR (SUVmean, 2.63±1.62; SUVmax, 4.30±2.88) and contrast

  10. LGBTQ relationally based positive psychology: An inclusive and systemic framework.

    Science.gov (United States)

    Domínguez, Daniela G; Bobele, Monte; Coppock, Jacqueline; Peña, Ezequiel

    2015-05-01

    Positive psychologists have contributed to our understandings of how positive emotions and flexible cognition enhance resiliency. However, positive psychologists' research has been slow to address the relational resources and interactions that help nonheterosexual families overcome adversity. Addressing overlooked lesbian, gay, bisexual, transgender, or queer (LGBTQ) and systemic factors in positive psychology, this article draws on family resilience literature and LGBTQ literature to theorize a systemic positive psychology framework for working with nonheterosexual families. We developed the LGBTQ relationally based positive psychology framework that integrates positive psychology's strengths-based perspective with the systemic orientation of Walsh's (1996) family resilience framework along with the cultural considerations proposed by LGBTQ family literature. We theorize that the LGBTQ relationally based positive psychology framework takes into consideration the sociopolitical adversities impacting nonheterosexual families and sensitizes positive psychologists, including those working in organized care settings, to the systemic interactions of same-sex loving relationships. (c) 2015 APA, all rights reserved).

  11. [Arthroscopic treatment of chondral lesions of the ankle joint. Evidence-based therapy].

    Science.gov (United States)

    Thomas, M; Jordan, M; Hamborg-Petersen, E

    2016-02-01

    Ankle sprains are the most relevant injuries of the lower extremities and can lead to damage to ligaments and osteochondral lesions. Up to 50 % of patients with a sprained ankle later develop a lesion of the cartilage in the ankle joint or an osteochondral lesion of the talus. This can lead to osteoarthritis of the injured ankle joint. Spontaneous healing is possible in all age groups in cases of a bone bruise in the subchondral bone but in isolated chondral injuries is only useful in pediatric patients. In many cases chondral and osteochondral injuries lead to increasing demarcation of the affected area and can result in progressive degeneration of the joint if not recognized in time. There also exist a certain number of osteochondral changes of the articular surface of the talus without any history of relevant trauma, which are collectively grouped under the term osteochondrosis dissecans. Perfusion disorders are discussed as one of many possible causes of these alterations. Nowadays, chondral and osteochondral defects can be treated earlier due to detection using very sensitive magnetic resonance imaging (MRI) and computed tomography (CT) techniques. The use of conservative treatment only has a chance of healing in pediatric patients. Conservative measures for adults should only be considered as adjuvant treatment to surgery.Based on a comprehensive analysis of the current literature, this article gives an overview and critical analysis of the current concepts for treatment of chondral and osteochondral injuries and lesions of the talus. With arthroscopic therapy curettage and microfracture of talar lesions are the predominant approaches or retrograde drilling of the defect is another option when the chondral coating is retained. Implantation of autologous chondral cells or homologous juvenile cartilage tissue is also possible with arthroscopic techniques. Osteochondral fractures (flake fracture) are usually performed as a mini-open procedure supported by

  12. A study on the magnetic resonance imaging (MRI)-based radiation treatment planning of intracranial lesions

    Science.gov (United States)

    Stanescu, T.; Jans, H.-S.; Pervez, N.; Stavrev, P.; Fallone, B. G.

    2008-07-01

    The aim of this study is to develop a magnetic resonance imaging (MRI)-based treatment planning procedure for intracranial lesions. The method relies on (a) distortion correction of raw magnetic resonance (MR) images by using an adaptive thresholding and iterative technique, (b) autosegmentation of head structures relevant to dosimetric calculations (scalp, bone and brain) using an atlas-based software and (c) conversion of MR images into computed tomography (CT)-like images by assigning bulk CT values to organ contours and dose calculations performed in Eclipse (Philips Medical Systems). Standard CT + MRI-based and MRI-only plans were compared by means of isodose distributions, dose volume histograms and several dosimetric parameters. The plans were also ranked by using a tumor control probability (TCP)-based technique for heterogeneous irradiation, which is independent of radiobiological parameters. For our 3 T Intera MRI scanner (Philips Medical Systems), we determined that the total maximum image distortion corresponding to a typical brain study was about 4 mm. The CT + MRI and MRI-only plans were found to be in good agreement for all patients investigated. Following our clinical criteria, the TCP-based ranking tool shows no significant difference between the two types of plans. This indicates that the proposed MRI-based treatment planning procedure is suitable for the radiotherapy of intracranial lesions.

  13. Age trends in the prevalence of cervical squamous intraepithelial lesions among HIV-positive women in Cameroon: a cross-sectional study

    LENUS (Irish Health Repository)

    Atashili, Julius

    2012-10-29

    AbstractBackgroundCervical squamous intra-epithelial lesions (SIL) are more frequent in HIV-positive women overall. However the appropriate age at which to begin and end cervical cancer screening for early detection of lesions in HIV-positive women is not clear. We assessed the age-specific prevalence of any SIL and SIL requiring colposcopy in HIV-positive women in Cameroon.MethodsWe enrolled, interviewed and conducted conventional cervical cytology in 282 women, aged 19--68 years, initiating antiretroviral therapy in three clinics in Cameroon. In bivariable analyses, the crude relationship between age and the presence of lesions was assessed using locally weighted regression (LOWESS) methods. In multivariate analyses, generalized linear models with prevalence as the outcome, an identity link and a binomial distribution, were used to estimate prevalence differences. Bias analyses were conducted to assess the potential effect of inaccuracies in cytology.ResultsSIL were detected in 43.5% of the 276 women with satisfactory samples, 17.8% of whom had ASC-H\\/HSIL. On average, women aged 26 to 59 tended to have a slightly higher prevalence of any SIL than other women (Prevalence difference PD: 6.5%; 95%CI: -11.4, 24.4%). This PD was a function of CD4 count (heterogeneity test p-value =0.09): amongst patients with CD4 counts less than 200cells\\/uL, the prevalence was higher in patients aged 26--59, while there was essentially no difference amongst women with CD4 counts greater than 200 cells\\/uL. ASC-H\\/HSIL were present in women as young as 19 and as old as 62. Overall the prevalence of ASC-H\\/HSIL increased by 0.7% (95%CI: -3.8%, 5.1%) per decade increase in age.ConclusionBoth severe and less severe lesions were prevalent at all ages suggesting little utility of age-targeted screening among HIV-positive women. Nevertheless, the long-term evolution of these lesions needs to be assessed in prospective studies.

  14. The Structural Location of DNA Lesions in Nucleosome Core Particles Determines Accessibility by Base Excision Repair Enzymes*

    Science.gov (United States)

    Rodriguez, Yesenia; Smerdon, Michael J.

    2013-01-01

    Packaging of DNA into chromatin affects accessibility of DNA regulatory factors involved in transcription, replication, and repair. Evidence suggests that even in the nucleosome core particle (NCP), accessibility to damaged DNA is hindered by the presence of the histone octamer. Base excision repair is the major pathway in mammalian cells responsible for correcting a large number of chemically modified bases. We have measured the repair of site-specific uracil and single nucleotide gaps along the surface of the NCP. Our results indicate that removal of DNA lesions is greatly dependent on their rotational and translational positioning in NCPs. Significantly, the rate of uracil removal with outwardly oriented DNA backbones is 2–10-fold higher than those with inwardly oriented backbones. In general, uracils with inwardly oriented backbones farther away from the dyad center of the NCP are more accessible than those near the dyad. The translational positioning of outwardly oriented gaps is the key factor driving gap filling activity. An outwardly oriented gap near the DNA ends exhibits a 3-fold increase in gap filling activity as compared with one near the dyad with the same rotational orientation. Near the dyad, uracil DNA glycosylase/APE1 removes an outwardly oriented uracil efficiently; however, polymerase β activity is significantly inhibited at this site. These data suggest that the hindrance presented by the location of a DNA lesion is dependent on the structural requirements for enzyme catalysis. Therefore, remodeling at DNA damage sites in NCPs is critical for preventing accumulation of aborted intermediates and ensuring completion of base excision repair. PMID:23543741

  15. A new background distribution-based active contour model for three-dimensional lesion segmentation in breast DCE-MRI

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Hui; Liu, Yiping; Qiu, Tianshuang [Department of Biomedical Engineering, Dalian University of Technology, Dalian 116024 (China); Zhao, Zuowei, E-mail: liuhui@dlut.edu.cn [Second Affiliated Hospital, Dalian Medical University, Dalian 116027 (China); Zhang, Lina [Department of Radiology, First Affiliated Hospital, Dalian Medical University, Dalian 116027 (China)

    2014-08-15

    Purpose: To develop and evaluate a computerized semiautomatic segmentation method for accurate extraction of three-dimensional lesions from dynamic contrast-enhanced magnetic resonance images (DCE-MRIs) of the breast. Methods: The authors propose a new background distribution-based active contour model using level set (BDACMLS) to segment lesions in breast DCE-MRIs. The method starts with manual selection of a region of interest (ROI) that contains the entire lesion in a single slice where the lesion is enhanced. Then the lesion volume from the volume data of interest, which is captured automatically, is separated. The core idea of BDACMLS is a new signed pressure function which is based solely on the intensity distribution combined with pathophysiological basis. To compare the algorithm results, two experienced radiologists delineated all lesions jointly to obtain the ground truth. In addition, results generated by other different methods based on level set (LS) are also compared with the authors’ method. Finally, the performance of the proposed method is evaluated by several region-based metrics such as the overlap ratio. Results: Forty-two studies with 46 lesions that contain 29 benign and 17 malignant lesions are evaluated. The dataset includes various typical pathologies of the breast such as invasive ductal carcinoma, ductal carcinomain situ, scar carcinoma, phyllodes tumor, breast cysts, fibroadenoma, etc. The overlap ratio for BDACMLS with respect to manual segmentation is 79.55% ± 12.60% (mean ± s.d.). Conclusions: A new active contour model method has been developed and shown to successfully segment breast DCE-MRI three-dimensional lesions. The results from this model correspond more closely to manual segmentation, solve the weak-edge-passed problem, and improve the robustness in segmenting different lesions.

  16. Expression of P-glycoprotein is positively correlated with p53 in human papilloma virus induced squamous intraepithelial lesions of uterine cervix: poor prognosis association.

    Science.gov (United States)

    Singh, Madhulika; Singh, Uma; Mathur, Neeraj; Shukla, Yogeshwer

    2012-01-01

    This study was conducted to assess the predictive value of p-glycoprotein (p-gp) and p53 immunoexpression in human papillomavirus (HPV) infected cases of cervical dysplasia. Expression of both p-gp and p53 proteins was detected in cervical smears from 177 squamous intraepithelial lesions (SIL) cases along with 183 "atypical squamous cells of unknown significance" (ASCUS) and 150 normal cases. HPV 16 and 18 infection was detected by polymerase chain reaction using type-specific primers for HPV sub-types. There were no significant detectable p53 and p-gp expression in the normal cervix smears (p>0.05). In the ASCUS group 10 cases were positive for both p53 and p-gp immunoreactivity. In cervical dysplasia cases, p53 was positive in 86 (48.58%) while p-gp was positive in 93 (52.54%) and the two markers showed a highly significant correlation (r=0.92, pbiomarker for detection of HPV-associated cervical lesions. Additionally, a significant positive correlation between ascending grades of SIL and labeling indices of markers suggests that p53 and p-gp can be used as an adjunct to cytomorphological interpretation of conventional cervical Pap smears.

  17. The anterior interhemispheric approach: a safe and effective approach to anterior skull base lesions.

    Science.gov (United States)

    Mielke, Dorothee; Mayfrank, Lothar; Psychogios, Marios Nikos; Rohde, Veit

    2014-04-01

    Many approaches to the anterior skull base have been reported. Frequently used are the pterional, the unilateral or bilateral frontobasal, the supraorbital and the frontolateral approach. Recently, endoscopic transnasal approaches have become more popular. The benefits of each approach has to be weighted against its complications and limitations. The aim of this study was to investigate if the anterior interhemispheric approach (AIA) could be a safe and effective alternative approach to tumorous and non-tumorous lesions of the anterior skull base. We screened the operative records of all patients with an anterior skull base lesion undergoing transcranial surgery. We have used the AIA in 61 patients. These were exclusively patients with either olfactory groove meningioma (OGM) (n = 43), ethmoidal dural arteriovenous fistula (dAVF) ( n = 6) or frontobasal fractures of the anterior midline with cerebrospinal fluid (CSF) leakage ( n = 12). Patient records were evaluated concerning accessibility of the lesion, realization of surgical aims (complete tumor removal, dAVF obliteration, closure of the dural tear), and approach related complications. The use of the AIA exclusively in OGMs, ethmoidal dAVFs and midline frontobasal fractures indicated that we considered lateralized frontobasal lesions not suitable to be treated successfully. If restricted to these three pathologies, the AIA is highly effective and safe. The surgical aim (complete tumor removal, complete dAVF occlusion, no rhinorrhea) was achieved in all patients. The complication rate was 11.5 % (wound infection (n = 2; 3.2 %), contusion of the genu of the corpus callosum, subdural hygroma, epileptic seizure, anosmia and asymptomatic bleed into the tumor cavity (n = 1 each). Only the contusion of the corpus callosum was directly related to the approach (1.6 %). Olfaction, if present before surgery, was preserved in all patients, except one (1.6 %). The AIA is an effective and a safe approach

  18. Spectral embedding based active contour (SEAC): application to breast lesion segmentation on DCE-MRI

    Science.gov (United States)

    Agner, Shannon C.; Xu, Jun; Rosen, Mark; Karthigeyan, Sudha; Englander, Sarah; Madabhushi, Anant

    2011-03-01

    Spectral embedding (SE), a graph-based manifold learning method, has previously been shown to be useful in high dimensional data classification. In this work, we present a novel SE based active contour (SEAC) segmentation scheme and demonstrate its applications in lesion segmentation on breast dynamic contrast enhance magnetic resonance imaging (DCE-MRI). In this work, we employ SE on DCE-MRI on a per voxel basis to embed the high dimensional time series intensity vector into a reduced dimensional space, where the reduced embedding space is characterized by the principal eigenvectors. The orthogonal eigenvector-based data representation allows for computation of strong tensor gradients in the spectrally embedded space and also yields improved region statistics that serve as optimal stopping criteria for SEAC. We demonstrate both analytically and empirically that the tensor gradients in the spectrally embedded space are stronger than the corresponding gradients in the original grayscale intensity space. On a total of 50 breast DCE-MRI studies, SEAC yielded a mean absolute difference (MAD) of 3.2+/-2.1 pixels and mean Dice similarity coefficient (DSC) of 0.74+/-0.13 compared to manual ground truth segmentation. An active contour in conjunction with fuzzy c-means (FCM+AC), a commonly used segmentation method for breast DCE-MRI, produced a corresponding MAD of 7.2+/-7.4 pixels and mean DSC of 0.58+/-0.32. In conjunction with a set of 6 quantitative morphological features automatically extracted from the SEAC derived lesion boundary, a support vector machine (SVM) classifier yielded an area under the curve (AUC) of 0.73, for discriminating between 10 benign and 30 malignant lesions; the corresponding SVM classifier with the FCM+AC derived morphological features yielded an AUC of 0.65.

  19. Base-pairing preferences, physicochemical properties and mutational behaviour of the DNA lesion 8-nitroguanine †

    OpenAIRE

    Bhamra, Inder; Compagnone-Post, Patricia; O’Neil, Ian A.; Iwanejko, Lesley A.; Bates, Andrew D.; Cosstick, Richard

    2012-01-01

    8-Nitro-2′-deoxyguanosine (8-nitrodG) is a relatively unstable, mutagenic lesion of DNA that is increasingly believed to be associated with tissue inflammation. Due to the lability of the glycosidic bond, 8-nitrodG cannot be incorporated into oligodeoxynucleotides (ODNs) by chemical DNA synthesis and thus very little is known about its physicochemical properties and base-pairing preferences. Here we describe the synthesis of 8-nitro-2′-O-methylguanosine, a ribonucleoside analogue of this lesi...

  20. Modelling a Compliant-Based Precise Positioning Stage

    Directory of Open Access Journals (Sweden)

    Giedrius Augustinavičius

    2012-12-01

    Full Text Available The paper presents modelling precise dual axis flexure-based precision positioning systems for micro-positioning applications. The positioning system is featured with monolithic architecture, flexure-based joints and piezo stacks. Its workspace has been evaluated via analytical approaches. Amplification mechanism is optimally designed. The mathematical model of the positioning system has been derived and verified by resorting to finite element analysis (FEA. The established analytical and (FEA models are helpful for optimizing reliable architecture and improving the performance of the positioning system.

  1. Modelling a Compliant-Based Precise Positioning Stage

    Directory of Open Access Journals (Sweden)

    Giedrius Augustinavičius

    2013-02-01

    Full Text Available The paper presents modelling precise dual axis flexure-based precision positioning systems for micro-positioning applications. The positioning system is featured with monolithic architecture, flexure-based joints and piezo stacks. Its workspace has been evaluated via analytical approaches. Amplification mechanism is optimally designed. The mathematical model of the positioning system has been derived and verified by resorting to finite element analysis (FEA. The established analytical and (FEA models are helpful for optimizing reliable architecture and improving the performance of the positioning system.

  2. False-positive Papanicolaou (PAP) test rates in the College of American Pathologists PAP education and PAP proficiency test programs: evaluation of false-positive responses of high-grade squamous intraepithelial lesion or cancer to a negative reference diagnosis.

    Science.gov (United States)

    Crothers, Barbara A; Booth, Christine Noga; Darragh, Teresa Marie; Zhao, Chengquan; Souers, Rhona J; Thomas, Nicole; Moriarty, Ann T

    2014-05-01

    In cytology proficiency testing (PT), participants fail for incorrectly interpreting a high-grade squamous intraepithelial lesion or cancer (HSIL+) Papanicolaou test result as negative. This penalty may lead to a false-positive interpretation of negative slides as HSIL+ to avoid failure. To investigate factors related to false-positive responses in a PT versus an educational environment. We analyzed 420,079 responses from 9414 validated negative reference slides in the College of American Pathologists Interlaboratory Comparison Program in Gynecologic Cytopathology (PAP Education) and compared them with responses from the Gynecologic Cytology Proficiency Testing Program for the percentage of false-positive (HSIL+) interpretations in each of 7 negative subcategories. We evaluated the influence of preparation type (ThinPrep, SurePath, and conventional Papanicolaou test), participant type (pathologist or cytotechnologist), and program time interval (preproficiency test or PT) on a false-positive response. Reference diagnosis and participant type, but not preparation type, were statistically correlated to false-positive responses. The interaction between program time interval and participant type was also significant. Pathologists had higher rates of false-positive results on preproficiency test (1.2% [800 of 68,690]) than they did on PT (0.8% [993 of 129,857]). Cytotechnologists had no differences between program time intervals (preproficiency, 0.9% [515 of 63,281] versus PT, 1.0 [1231 of 121,621]; P = .91). Negative subcategories frequently mistaken for HSIL+ were reparative changes (4.7% [427 of 9069]), atrophic vaginitis (1.8% [18 of 987]), and negative for intraepithelial lesion or malignancy (1.2% [2143 of 178,651]), but during PT, false-positive rates were significantly increased only for the negative for intraepithelial lesion or malignancy and herpes simplex virus (P Testing Program than they did in PAP Education, but participants were more likely to report a

  3. Self-Inflicted Lesions in Dermatology: A Management and TherapeuticApproach - A Position Paper From the European Society for Derma-tology and Psychiatry.

    Science.gov (United States)

    Tomas-Aragones, Lucía; Consoli, Silla M; Consoli, Sylvie G; Poot, Francoise; Taube, Klaus-Michael; Linder, M Dennis; Jemec, Gregor B E; Szepietowski, Jacek C; de Korte, John; Lvov, Andrey N; Gieler, Uwe

    2017-02-08

    The classification of self-inflicted skin lesions proposed by the European Society for Dermatology and Psychiatry (ESDaP) group generated questions with regard to specific treatments that could be recommended for such cases. The therapeutic guidelines in the current paper integrate new psychotherapies and psychotropic drugs without forgetting the most important relational characteristics required for dealing with people with these disorders. The management of self-inflicted skin lesions necessitates empathy and a doctor-patient relationship based on trust and confidence. Cognitive behavioural therapy and/or psychodynamic and psychoanalytic psychotherapy (alone, or combined with the careful use of psychotropic drugs) seem to achieve the best results in the most difficult cases. Relatively new therapeutic techniques, such as habit reversal and mentalization-based psychotherapy, may be beneficial in the treatment of skin picking syndromes.

  4. Application of a data-mining method based on Bayesian networks to lesion-deficit analysis

    Science.gov (United States)

    Herskovits, Edward H.; Gerring, Joan P.

    2003-01-01

    Although lesion-deficit analysis (LDA) has provided extensive information about structure-function associations in the human brain, LDA has suffered from the difficulties inherent to the analysis of spatial data, i.e., there are many more variables than subjects, and data may be difficult to model using standard distributions, such as the normal distribution. We herein describe a Bayesian method for LDA; this method is based on data-mining techniques that employ Bayesian networks to represent structure-function associations. These methods are computationally tractable, and can represent complex, nonlinear structure-function associations. When applied to the evaluation of data obtained from a study of the psychiatric sequelae of traumatic brain injury in children, this method generates a Bayesian network that demonstrates complex, nonlinear associations among lesions in the left caudate, right globus pallidus, right side of the corpus callosum, right caudate, and left thalamus, and subsequent development of attention-deficit hyperactivity disorder, confirming and extending our previous statistical analysis of these data. Furthermore, analysis of simulated data indicates that methods based on Bayesian networks may be more sensitive and specific for detecting associations among categorical variables than methods based on chi-square and Fisher exact statistics.

  5. Incidence of chronic knee lesions in long-distance runners based on training level: Findings at MRI

    International Nuclear Information System (INIS)

    Schueller-Weidekamm, Claudia; Schueller, Gerd; Uffmann, Martin; Bader, Till

    2006-01-01

    Purpose: The purpose of this study was to evaluate the incidence of chronic knee changes in long-distance runners based on the training status, including distance, running frequency, training pace, and running experience. Methods: MRI of the knee was performed in 26 non-professional runners 5 days after their last training unit. Lesions of the menisci and cartilage (5-point scale), bone marrow and ligaments (3-point scale), and joint effusion were evaluated. A total score comprising all knee lesions in each runner was evaluated. The incidence of the knee changes was correlated with the training level, gender, and age of the runners. Results: Grade 1 lesions of the menisci were found in six runners with a high training level, and in only four runners with a low training level. Grade 1 cartilage lesions were found in three high-trained runners and in one low-trained runner, and grade 2 lesions were found in one high-trained runner and in two low-trained runners, respectively. Grade 1 anterior cruciate ligament lesions were seen in three runners with a high- and in two runners with a low-training level. Runners with a higher training level showed a statistically significant higher score for all chronic knee lesions than those with a lower training level (p < 0.05). Conclusions: MRI findings indicate that a higher training level in long-distance runners is a risk factor for chronic knee lesions

  6. A hybrid approach based on logistic classification and iterative contrast enhancement algorithm for hyperintense multiple sclerosis lesion segmentation.

    Science.gov (United States)

    da Silva Senra Filho, Antonio Carlos

    2017-11-18

    Multiple sclerosis (MS) is a neurodegenerative disease with increasing importance in recent years, in which the T2 weighted with fluid attenuation inversion recovery (FLAIR) MRI imaging technique has been addressed for the hyperintense MS lesion assessment. Many automatic lesion segmentation approaches have been proposed in the literature in order to assist health professionals. In this study, a new hybrid lesion segmentation approach based on logistic classification (LC) and the iterative contrast enhancement (ICE) method is proposed (LC+ICE). T1 and FLAIR MRI images from 32 secondary progressive MS (SPMS) patients were used in the LC+ICE method, in which manual segmentation was used as the ground truth lesion segmentation. The DICE, Sensitivity, Specificity, Area under the ROC curve (AUC), and Volume Similarity measures showed that the LC+ICE method is able to provide a precise and robust lesion segmentation estimate, which was compared with two recent FLAIR lesion segmentation approaches. In addition, the proposed method also showed a stable segmentation among lesion loads, showing a wide applicability to different disease stages. The LC+ICE procedure is a suitable alternative to assist the manual FLAIR hyperintense MS lesion segmentation task.

  7. Schema-based learning of adaptable and flexible prey- catching in anurans II. Learning after lesioning.

    Science.gov (United States)

    Corbacho, Fernando; Nishikawa, Kiisa C; Weerasuriya, Ananda; Liaw, Jim-Shih; Arbib, Michael A

    2005-12-01

    The previous companion paper describes the initial (seed) schema architecture that gives rise to the observed prey-catching behavior. In this second paper in the series we describe the fundamental adaptive processes required during learning after lesioning. Following bilateral transections of the hypoglossal nerve, anurans lunge toward mealworms with no accompanying tongue or jaw movement. Nevertheless anurans with permanent hypoglossal transections eventually learn to catch their prey by first learning to open their mouth again and then lunging their body further and increasing their head angle. In this paper we present a new learning framework, called schema-based learning (SBL). SBL emphasizes the importance of the current existent structure (schemas), that defines a functioning system, for the incremental and autonomous construction of ever more complex structure to achieve ever more complex levels of functioning. We may rephrase this statement into the language of Schema Theory (Arbib 1992, for a comprehensive review) as the learning of new schemas based on the stock of current schemas. SBL emphasizes a fundamental principle of organization called coherence maximization, that deals with the maximization of congruence between the results of an interaction (external or internal) and the expectations generated for that interaction. A central hypothesis consists of the existence of a hierarchy of predictive internal models (predictive schemas) all over the control center-brain-of the agent. Hence, we will include predictive models in the perceptual, sensorimotor, and motor components of the autonomous agent architecture. We will then show that predictive models are fundamental for structural learning. In particular we will show how a system can learn a new structural component (augment the overall network topology) after being lesioned in order to recover (or even improve) its original functionality. Learning after lesioning is a special case of structural

  8. Evaluation of lesion detection capabilities of anatomically based MAP image reconstruction methods using the computer observer model

    International Nuclear Information System (INIS)

    Kobayashi, Tetsuya; Kudo, Hiroyuki

    2010-01-01

    This study was conducted to evaluate the lesion detection capabilities of anatomically based maximum a posteriori (MAP) image reconstruction methods in emission computed tomography using the computer observer model. In lesion detection tasks, conventional anatomically based MAP reconstruction methods cannot preserve lesions not present in the anatomical image with high contrast and at the same time suppress noise in the background regions. We previously proposed a new anatomically based MAP reconstruction method called the SOS-MAP method, which is based on the spots-on-smooth image model in which the image is modeled by the sum of the smooth background image and the sparse spot image, and showed that the SOS-MAP method can overcome the above-mentioned drawback of conventional anatomically based MAP methods. However, the lesion detection capabilities of the SOS-MAP method remained to be clarified. In the present study, the computer observer model was used to evaluate the lesion detection capabilities of the SOS-MAP method, and it was found that the SOS-MAP method is superior to conventional anatomically based MAP methods for the detection of lesions. (author)

  9. Positive predictive values of Breast Imaging Reporting and Data System (BI-RADS® categories 3, 4 and 5 in breast lesions submitted to percutaneous biopsy

    Directory of Open Access Journals (Sweden)

    Gustavo Machado Badan

    2013-07-01

    Full Text Available Objective To evaluate the BI-RADS as a predictive factor of suspicion for malignancy in breast lesions by correlating radiological with histological results and calculating the positive predictive value for categories 3, 4 and 5 in a breast cancer reference center in the city of São Paulo. Materials and Methods Retrospective, analytical and cross-sectional study including 725 patients with mammographic and/or sonographic findings classified as BI-RADS categories 3, 4 and 5 who were referred to the authors' institution to undergo percutaneous biopsy. The tests results were reviewed and the positive predictive value was calculated by means of a specific mathematical equation. Results Positive predictive values found for categories 3, 4 and 5 were respectively the following: 0.74%, 33.08% and 92.95%, for cases submitted to ultrasound-guided biopsy, and 0.00%, 14.90% and 100% for cases submitted to stereotactic biopsy. Conclusion The present study demonstrated high suspicion for malignancy in lesions classified as category 5 and low risk for category 3. As regards category 4, the need for systematic biopsies was observed.

  10. Proportion of false-positive lesions at interim and end-of-treatment FDG-PET in lymphoma as determined by histology: Systematic review and meta-analysis

    Energy Technology Data Exchange (ETDEWEB)

    Adams, Hugo J.A., E-mail: h.j.a.adams@gmail.com; Kwee, Thomas C.

    2016-11-15

    Purpose: To systematically review and meta-analyze the proportion of false-positive lesions at interim and end-of-treatment {sup 18}F-fluoro-2-deoxy-D-glucose positron emission tomography (FDG-PET) in lymphoma using biopsy as reference standard. Materials and methods: Medline was searched for original studies. Methodological quality of included studies was evaluated, and results were meta-analytically summarized using random effects (in case of interstudy heterogeneity [I{sup 2} ≤ 50%]) or fixed effects (in case of no interstudy heterogeneity [I{sup 2} > 50%]). Results: Eleven studies, comprising 139 patients who underwent biopsy of an FDG-avid lesion during or after completion of antilymphoma treatment, were included. Overall methodological quality was moderate. The proportion of false-positive results among all biopsied FDG-avid lesions at PET performed during of after completion of treatment ranged between 7.7% and 90.5% (the vast majority was due to inflammatory changes), with a weighted summary proportion (random effects, I{sup 2} = 75.7%) of 55.7% (95% confidence interval [CI]: 32.6–76.6%). There were no available studies on interim FDG-PET in Hodgkin lymphoma. The pooled summary false-positive proportions were 83.0% (95% CI: 72.0%–90.2%) for interim FDG-PET in non-Hodgkin lymphoma (fixed effects, I{sup 2} = 27.7%), 23.1% (95% CI: 4.7%–64.5%) for end-of-treatment FDG-PET in Hodgkin lymphoma (random effects; I{sup 2} = 67.1%), and 31.5% (95% CI: 3.9%–83.9%) for end-of-treatment FDG-PET in non-Hodgkin lymphoma (random effects, I{sup 2} = 68.3%). Conclusion: Both interim and end-of-treatment FDG-PET scans in patients with lymphoma suffer from a very high number of false-positive FDG-avid lesions. This finding, in combination with the previously reported high number of false-negative FGD-PET scans for residual disease detection, suggests that the role of interim and end-of-treatment FDG-PET should be reconsidered.

  11. Proportion of false-positive lesions at interim and end-of-treatment FDG-PET in lymphoma as determined by histology: Systematic review and meta-analysis

    International Nuclear Information System (INIS)

    Adams, Hugo J.A.; Kwee, Thomas C.

    2016-01-01

    Purpose: To systematically review and meta-analyze the proportion of false-positive lesions at interim and end-of-treatment 18 F-fluoro-2-deoxy-D-glucose positron emission tomography (FDG-PET) in lymphoma using biopsy as reference standard. Materials and methods: Medline was searched for original studies. Methodological quality of included studies was evaluated, and results were meta-analytically summarized using random effects (in case of interstudy heterogeneity [I 2 ≤ 50%]) or fixed effects (in case of no interstudy heterogeneity [I 2 > 50%]). Results: Eleven studies, comprising 139 patients who underwent biopsy of an FDG-avid lesion during or after completion of antilymphoma treatment, were included. Overall methodological quality was moderate. The proportion of false-positive results among all biopsied FDG-avid lesions at PET performed during of after completion of treatment ranged between 7.7% and 90.5% (the vast majority was due to inflammatory changes), with a weighted summary proportion (random effects, I 2 = 75.7%) of 55.7% (95% confidence interval [CI]: 32.6–76.6%). There were no available studies on interim FDG-PET in Hodgkin lymphoma. The pooled summary false-positive proportions were 83.0% (95% CI: 72.0%–90.2%) for interim FDG-PET in non-Hodgkin lymphoma (fixed effects, I 2 = 27.7%), 23.1% (95% CI: 4.7%–64.5%) for end-of-treatment FDG-PET in Hodgkin lymphoma (random effects; I 2 = 67.1%), and 31.5% (95% CI: 3.9%–83.9%) for end-of-treatment FDG-PET in non-Hodgkin lymphoma (random effects, I 2 = 68.3%). Conclusion: Both interim and end-of-treatment FDG-PET scans in patients with lymphoma suffer from a very high number of false-positive FDG-avid lesions. This finding, in combination with the previously reported high number of false-negative FGD-PET scans for residual disease detection, suggests that the role of interim and end-of-treatment FDG-PET should be reconsidered.

  12. Descriptions of spinal MRI lesions and definition of a positive MRI of the spine in axial spondyloarthritis

    DEFF Research Database (Denmark)

    Hermann, Kay-Geert A; Baraliakos, Xenofon; van der Heijde, Désirée M F M

    2012-01-01

    The aim of this study was to define characteristic MRI findings in the spine of patients with axial spondyloarthritis (SpA) and provide a definition of a positive spinal MRI for inflammation and structural changes.......The aim of this study was to define characteristic MRI findings in the spine of patients with axial spondyloarthritis (SpA) and provide a definition of a positive spinal MRI for inflammation and structural changes....

  13. Focal retrograde amnesia: voxel-based morphometry findings in a case without MRI lesions.

    Directory of Open Access Journals (Sweden)

    Bernhard Sehm

    Full Text Available Focal retrograde amnesia (FRA is a rare neurocognitive disorder presenting with an isolated loss of retrograde memory. In the absence of detectable brain lesions, a differentiation of FRA from psychogenic causes is difficult. Here we report a case study of persisting FRA after an epileptic seizure. A thorough neuropsychological assessment confirmed severe retrograde memory deficits while anterograde memory abilities were completely normal. Neurological and psychiatric examination were unremarkable and high-resolution MRI showed no neuroradiologically apparent lesion. However, voxel-based morphometry (VBM-comparing the MRI to an education-, age-and sex-matched control group (n = 20 disclosed distinct gray matter decreases in left temporopolar cortex and a region between right posterior parahippocampal and lingual cortex. Although the results of VBM-based comparisons between a single case and a healthy control group are generally susceptible to differences unrelated to the specific symptoms of the case, we believe that our data suggest a causal role of the cortical areas detected since the retrograde memory deficit is the preeminent neuropsychological difference between patient and controls. This was paralleled by grey matter differences in central nodes of the retrograde memory network. We therefore suggest that these subtle alterations represent structural correlates of the focal retrograde amnesia in our patient. Beyond the implications for the diagnosis and etiology of FRA, our results advocate the use of VBM in conditions that do not show abnormalities in clinical radiological assessment, but show distinct neuropsychological deficits.

  14. Impact of Lesion Placement on Efficacy and Safety of Catheter-Based Radiofrequency Renal Denervation.

    Science.gov (United States)

    Mahfoud, Felix; Tunev, Stefan; Ewen, Sebastian; Cremers, Bodo; Ruwart, Jennifer; Schulz-Jander, Daniel; Linz, Dominik; Davies, Justin; Kandzari, David E; Whitbourn, Robert; Böhm, Michael; Melder, Robert J

    2015-10-20

    Insufficient procedural efficacy has been proposed to explain nonresponse to renal denervation (RDN). The aim of this study was to examine the impact of different patterns of lesion placements on the efficacy and consistency of catheter-based radiofrequency RDN in pigs. The impact of increasing number of lesions versus location of RDN was investigated in a porcine model (Group 1; n = 51). The effect of treating the main artery, the branches, and the 2 combined was compared in Group 2 (n = 48). The durability of response and safety of combined treatment of the main artery plus branches was examined in Group 3 (n = 16). Renal norepinephrine (NE) tissue content and renal cortical axon density were assessed. Increasing the number of RF lesions (4, 8, and 12) in the main renal artery was not sufficient to yield a clear dose-response relationship on NE content and axon density. In contrast, targeted treatment of the renal artery branches or distal segment of the main renal artery resulted in markedly less variability of response and significantly greater reduction of both NE and axon density than conventional treatment of only the main renal artery. Combination treatment (main artery plus branches) produced the greatest change in renal NE and axon density with the least heterogeneity. The changes were durable through 28 days post-treatment. These data provide the rationale for investigation of an optimized approach for RDN in future clinical studies. This may have profound implications for the clinical application of RDN, as this approach may not only achieve greater reductions in sympathetic activity but also reduce treatment effect variability. Copyright © 2015 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

  15. Simulation on Temperature Field of Radiofrequency Lesions System Based on Finite Element Method

    International Nuclear Information System (INIS)

    Xiao, D; Qian, Z; Li, W; Qian, L

    2011-01-01

    This paper mainly describes the way to get the volume model of damaged region according to the simulation on temperature field of radiofrequency ablation lesion system in curing Parkinson's disease based on finite element method. This volume model reflects, to some degree, the shape and size of the damaged tissue during the treatment with all tendencies in different time or core temperature. By using Pennes equation as heat conduction equation of radiofrequency ablation of biological tissue, the author obtains the temperature distribution field of biological tissue in the method of finite element for solving equations. In order to establish damage models at temperature points of 60 deg. C, 65 deg. C, 70 deg. C, 75 deg. C, 80 deg. C, 85 deg. C and 90 deg. C while the time points are 30s, 60s, 90s and 120s, Parkinson's disease model of nuclei is reduced to uniform, infinite model with RF pin at the origin. Theoretical simulations of these models are displayed, focusing on a variety of conditions about the effective lesion size on horizontal and vertical. The results show the binary complete quadratic non-linear joint temperature-time models of the maximum damage diameter and maximum height. The models can comprehensively reflect the degeneration of target tissue caused by radio frequency temperature and duration. This lay the foundation for accurately monitor of clinical RF treatment of Parkinson's disease in the future.

  16. OD Matrix Acquisition Based on Mobile Phone Positioning Data

    Directory of Open Access Journals (Sweden)

    Xiaoqing ZUO

    2014-06-01

    Full Text Available Dynamic OD matrix is basic data of traffic travel guidance, traffic control, traffic management and traffic planning, and reflects the basic needs of travelers on the traffic network. With the rising popularity of positioning technology and the communication technology and the generation of huge mobile phone users, the mining and use of mobile phone positioning data, can get more traffic intersections and import and export data. These data will be integrated into obtaining the regional OD matrix, which is bound to bring convenience. In this article, mobile phone positioning data used in the data acquisition of intelligent transportation system, research a kind of regional dynamic OD matrix acquisition method based on the mobile phone positioning data. The method based on purpose of transportation, using time series similarity classification algorithm based on piecewise linear representation of the corner point (CP-PLR, mapping each base station cell to traffic zone of different traffic characteristics, and through a series of mapping optimization of base station cell to traffic zone to realize city traffic zone division based on mobile phone traffic data, on the basis, adjacency matrix chosen as the physical data structure of OD matrix storage, the principle of obtaining regional dynamic OD matrix based on the mobile phone positioning data are expounded, and the algorithm of obtaining regional dynamic OD matrix based on mobile phone positioning data are designed and verified.

  17. Schiff Base Metal Derivatives Enhance the Expression of HSP70 and Suppress BAX Proteins in Prevention of Acute Gastric Lesion

    Directory of Open Access Journals (Sweden)

    Shahram Golbabapour

    2013-01-01

    Full Text Available Schiff base complexes have appeared to be promising in the treatment of different diseases and disorders and have drawn a lot of attention to their biological activities. This study was conducted to evaluate the regulatory effect of Schiff base metal derivatives on the expression of heat shock proteins (HSP 70 and BAX in protection against acute haemorrhagic gastric ulcer in rats. Rats were assigned to 6 groups of 6 rats: the normal control (Tween 20 5% v/v, 5 mL/kg, the positive control (Tween 20 5% v/v, 5 mL/kg, and four Schiff base derivative groups named Schiff_1, Schiff_2, Schiff_3, and Schiff_4 (25 mg/kg. After 1 h, all of the groups received ethanol 95% (5 mL/kg but the normal control received Tween 20 (Tween 20 5% v/v, 5 mL/kg. The animals were euthanized after 60 min and the stomachs were dissected for histology (H&E, immunohistochemistry, and western blot analysis against HSP70 and BAX proteins. The results showed that the Schiff base metal derivatives enhanced the expression of HSP70 and suppressed the expression of BAX proteins during their gastroprotection against ethanol-induced gastric lesion in rats.

  18. Improved spring model-based collaborative indoor visible light positioning

    Science.gov (United States)

    Luo, Zhijie; Zhang, WeiNan; Zhou, GuoFu

    2016-06-01

    Gaining accuracy with indoor positioning of individuals is important as many location-based services rely on the user's current position to provide them with useful services. Many researchers have studied indoor positioning techniques based on WiFi and Bluetooth. However, they have disadvantages such as low accuracy or high cost. In this paper, we propose an indoor positioning system in which visible light radiated from light-emitting diodes is used to locate the position of receivers. Compared with existing methods using light-emitting diode light, we present a high-precision and simple implementation collaborative indoor visible light positioning system based on an improved spring model. We first estimate coordinate position information using the visible light positioning system, and then use the spring model to correct positioning errors. The system can be employed easily because it does not require additional sensors and the occlusion problem of visible light would be alleviated. We also describe simulation experiments, which confirm the feasibility of our proposed method.

  19. Vision-Based Position Estimation Utilizing an Extended Kalman Filter

    Science.gov (United States)

    2016-12-01

    POSITION ESTIMATION UTILIZING AN EXTENDED KALMAN FILTER by Joseph B. Testa III December 2016 Thesis Advisor: Vladimir Dobrokhodov Co...TYPE AND DATES COVERED Master’s thesis 4. TITLE AND SUBTITLE VISION-BASED POSITION ESTIMATION UTILIZING AN EXTENDED KALMAN FILTER 5. FUNDING...spots” and network relay between the boarding team and ship. 14. SUBJECT TERMS UAV, ROS, extended Kalman filter , Matlab

  20. Saliency-Based Lesion Segmentation Via Background Detection in Dermoscopic Images.

    Science.gov (United States)

    Ahn, Euijoon; Kim, Jinman; Bi, Lei; Kumar, Ashnil; Li, Changyang; Fulham, Michael; Feng, David Dagan

    2017-11-01

    The segmentation of skin lesions in dermoscopic images is a fundamental step in automated computer-aided diagnosis of melanoma. Conventional segmentation methods, however, have difficulties when the lesion borders are indistinct and when contrast between the lesion and the surrounding skin is low. They also perform poorly when there is a heterogeneous background or a lesion that touches the image boundaries; this then results in under- and oversegmentation of the skin lesion. We suggest that saliency detection using the reconstruction errors derived from a sparse representation model coupled with a novel background detection can more accurately discriminate the lesion from surrounding regions. We further propose a Bayesian framework that better delineates the shape and boundaries of the lesion. We also evaluated our approach on two public datasets comprising 1100 dermoscopic images and compared it to other conventional and state-of-the-art unsupervised (i.e., no training required) lesion segmentation methods, as well as the state-of-the-art unsupervised saliency detection methods. Our results show that our approach is more accurate and robust in segmenting lesions compared to other methods. We also discuss the general extension of our framework as a saliency optimization algorithm for lesion segmentation.

  1. Fundamental study of the radiation monitoring system based on evaluation of DNA lesions

    International Nuclear Information System (INIS)

    Shimizu, K.; Matuo, Y.; Izumi, Y.; Ikeda, T.

    2011-01-01

    The biological dosemeter that measures biological responses to ionising radiation is useful for radiation protection. This paper presents the development and characterisation of a gamma ray irradiation dosimetry system based on real-time PCR (polymerase chain reaction) methodology. Real-time PCR is used to amplify and simultaneously quantify a targeted DNA molecule. If there are no limitations due to limiting substrates or reagents, at each extension step, the amount of DNA target is doubled, leading to exponential (geometric) amplification of the specific DNA fragment. The essential point of this assay is that DNA lesions caused by ionising radiation block DNA synthesis by DNA polymerase, resulting in a decrease in the amplification of a damaged DNA template compared with that of non-damaged DNA templates. (authors)

  2. Ultrasound-guided versus computed tomography-scan guided biopsy of pleural-based lung lesions.

    Science.gov (United States)

    Khosla, Rahul; McLean, Anna W; Smith, Jessica A

    2016-01-01

    Computed tomography (CT) guided biopsies have long been the standard technique to obtain tissue from the thoracic cavity and is traditionally performed by interventional radiologists. Ultrasound (US) guided biopsy of pleural-based lesions, performed by pulmonologists is gaining popularity and has the advantage of multi-planar imaging, real-time technique, and the absence of radiation exposure to patients. In this study, we aim to determine the diagnostic accuracy, the time to diagnosis after the initial consult placement, and the complications rates between the two different modalities. A retrospective study of electronic medical records was done of patients who underwent CT-guided biopsies and US-guided biopsies for pleural-based lesions between 2005 and 2014 and the data collected were analyzed for comparing the two groups. A total of 158 patients underwent 162 procedures during the study period. 86 patients underwent 89 procedures in the US group, and 72 patients underwent 73 procedures in the CT group. The overall yield in the US group was 82/89 (92.1%) versus 67/73 (91.8%) in the CT group (P = 1.0). Average days to the procedure was 7.2 versus 17.5 (P = 0.00001) in the US and CT group, respectively. Complication rate was higher in CT group 17/73 (23.3%) versus 1/89 (1.1%) in the US group (P guided biopsy is similar to that of CT-guided biopsy, with a lower complication rate and a significantly reduced time to the procedure.

  3. Analysis of density based and fuzzy c-means clustering methods on lesion border extraction in dermoscopy images.

    Science.gov (United States)

    Kockara, Sinan; Mete, Mutlu; Chen, Bernard; Aydin, Kemal

    2010-10-07

    Computer-aided segmentation and border detection in dermoscopic images is one of the core components of diagnostic procedures and therapeutic interventions for skin cancer. Automated assessment tools for dermoscopy images have become an important research field mainly because of inter- and intra-observer variations in human interpretation. In this study, we compare two approaches for automatic border detection in dermoscopy images: density based clustering (DBSCAN) and Fuzzy C-Means (FCM) clustering algorithms. In the first approach, if there exists enough density--greater than certain number of points--around a point, then either a new cluster is formed around the point or an existing cluster grows by including the point and its neighbors. In the second approach FCM clustering is used. This approach has the ability to assign one data point into more than one cluster. Each approach is examined on a set of 100 dermoscopy images whose manually drawn borders by a dermatologist are used as the ground truth. Error rates; false positives and false negatives along with true positives and true negatives are quantified by comparing results with manually determined borders from a dermatologist. The assessments obtained from both methods are quantitatively analyzed over three accuracy measures: border error, precision, and recall. As well as low border error, high precision and recall, visual outcome showed that the DBSCAN effectively delineated targeted lesion, and has bright future; however, the FCM had poor performance especially in border error metric.

  4. Surface errors without semantic impairment in acquired dyslexia: a voxel-based lesion-symptom mapping study.

    Science.gov (United States)

    Binder, Jeffrey R; Pillay, Sara B; Humphries, Colin J; Gross, William L; Graves, William W; Book, Diane S

    2016-05-01

    Patients with surface dyslexia have disproportionate difficulty pronouncing irregularly spelled words (e.g. pint), suggesting impaired use of lexical-semantic information to mediate phonological retrieval. Patients with this deficit also make characteristic 'regularization' errors, in which an irregularly spelled word is mispronounced by incorrect application of regular spelling-sound correspondences (e.g. reading plaid as 'played'), indicating over-reliance on sublexical grapheme-phoneme correspondences. We examined the neuroanatomical correlates of this specific error type in 45 patients with left hemisphere chronic stroke. Voxel-based lesion-symptom mapping showed a strong positive relationship between the rate of regularization errors and damage to the posterior half of the left middle temporal gyrus. Semantic deficits on tests of single-word comprehension were generally mild, and these deficits were not correlated with the rate of regularization errors. Furthermore, the deep occipital-temporal white matter locus associated with these mild semantic deficits was distinct from the lesion site associated with regularization errors. Thus, in contrast to patients with surface dyslexia and semantic impairment from anterior temporal lobe degeneration, surface errors in our patients were not related to a semantic deficit. We propose that these patients have an inability to link intact semantic representations with phonological representations. The data provide novel evidence for a post-semantic mechanism mediating the production of surface errors, and suggest that the posterior middle temporal gyrus may compute an intermediate representation linking semantics with phonology. © The Author (2016). Published by Oxford University Press on behalf of the Guarantors of Brain. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  5. High prevalence and incidence of HPV-related anal cancer precursor lesions in HIV-positive women in the late HAART era.

    Science.gov (United States)

    Hidalgo-Tenorio, Carmen; de Jesus, Samantha E; Esquivias, Javier; Pasquau, Juan

    2017-12-02

    Anal cancer is one of the most common non-AIDS defining malignancies, especially in men who have sex with men and women living with HIV (WLHIV). To evaluate the prevalence and incidence of precursor lesions (high-grade squamous intraepithelial lesions [HSIL]) and anal cancer in our cohort of women and to compare them to cervical lesions; to calculate the percentage of patients that acquire and clear oncogenic genotypes (HR-HPV) in the anal canal; and to determine predictive factors for anal HPV infection. Prospective-longitudinal study (May 2012-December 2016). At baseline (V1) and follow up visits, anal mucosa samples were taken in liquid medium for cytology and HPV PCR. In cases of abnormal anal cytology and/or positive HR-HPV PCR results, a high resolution anoscopy was performed. Patients were also referred to the gynaecologist. Ninety five women with an average age of 43.7years were included. At baseline, 11.6% had cervical abnormalities (4.1% CIN1, 2.2% CIN2/3, 1.1% cervical cancer), 64.3% anal abnormalities (50% LSIL/AIN1, 9.5% HSIL/AIN2/3 and 2.4% anal cancer) and 49.4% had HR-HPV genotypes. During 36months of follow up, the incidence of anal HSIL was 16×1,000 person-years; 14.8% acquired HR-HPV genotypes and 51.2% cleared them, P=.007. No patients presented CIN1/2/3/ or cervical cancer. In the multivariate analysis we found the following predictive factors for HR-HPV infection: smoking (RR: 1.55, 95%CI: 0.99-2.42), number of sexual partners >3 (RR: 1.69; 95%CI: 1.09-2.62), cervical and anal dysplasia (RR: 1.83; 95%CI: 1.26-2.67) and (RR: 1.55; 95%CI: 1.021-2.35), respectively. Despite clearance rates of anal oncogenic genotypes being higher than acquisition rates, prevalence and incidence of HSIL were still high and greater than cervical HSIL. Therefore, screening for these lesions should perhaps be offered to all WLHIV. Copyright © 2017 Elsevier España, S.L.U. and Sociedad Española de Enfermedades Infecciosas y Microbiología Clínica. All rights

  6. Evaluation of the diagnostic value of a Modified Liquid-Based Cytology using OralCDx Brush in early detection of oral potentially malignant lesions and oral cancer.

    Science.gov (United States)

    Delavarian, Zahra; Mohtasham, Nooshin; Mosannen-Mozafari, Pegah; Pakfetrat, Atessa; Shakeri, Mohammad-Taghi; Ghafoorian-Maddah, Rasoul

    2010-09-01

    To determine diagnostic value of modified Liquid Based Brush Biopsy technique. 26 oral premalignant and malignant lesions in 25 patients (12 females; 54.23+/-19.77 years and 13 males; 53.77+/-15.43 years) underwent Modified (Liquid Based) Brush Biopsy and scalpel biopsy simultaneously from the same area. There were 16 positive and 10 negative brush biopsy results, with no inadequate readings. Histological findings were compatible with oral leukoplakia (n=5) with dysplasia, Oral lichen planus and lichenoid reaction (n=7) (with or without dysplasia) oral squamous cell carcinoma (n=11),verrucous carcinoma (n=1) and granular cell tumors (n=2). Sensitivity, specificity, positive predictive value, negative predictive value, positive diagnostic likelihood ratio (LR+) and negative diagnostic likelihood ratio (LR-) were 88.8%, 100%, 100%, 80%, infinity and 0.11 respectively (no false positive results). It is the first attempt to do LBC with a specialized oral brush. Our results show that modified technique is a useful tool for screening of oral premalignant and malignant lesions.

  7. Imaging spectrum and pitfalls of {sup 11}C-methionine position emission tomography in a series of patients with intracranial lesions

    Energy Technology Data Exchange (ETDEWEB)

    Ito, Kimiteru [Dept. of Radiology, Tokyo Metropolitan Geriatric Hospital and Institute of Gerontology, Tokyo (Japan); Matsuda, Hiroshi [Integrative Brain Imaging Center, National Center of Neurology and Psychiatry, Tokyo (Japan); Kubota, Kazoo [Div. of Nuclear Medicine, National Center for Global Health and Medicine, Tokyo (Japan)

    2016-06-15

    {sup 11}C-methionine (Met) positron emission tomography (PET) is one of the most commonly used PET tracers for evaluating brain tumors. However, few reports have described tips and pitfalls of {sup 11}C-Met PET for general practitioners. Physiological {sup 11}C-Met uptake, anatomical variations, vascular disorders, non-tumorous lesions such as inflammation or dysplasia, benign brain tumors and patient condition during {sup 11}C-Met PET examination can potentially affect the image interpretation and cause false positives and negatives. These pitfalls in the interpretation of {sup 11}C-Met PET images are important for not only nuclear medicine physicians but also general radiologists. Familiarity with the spectrum and pitfalls of {sup 11}C-Met images could help prevent unfavorable clinical results caused by misdiagnoses.

  8. Determinants of cerebral white matter lesions: A longitudinal population based MRI study

    NARCIS (Netherlands)

    H.F. de Leeuw (Frank)

    1999-01-01

    textabstractW hite matter lesions are frequently found on cerebral magnetic resonance imaging scans of elderly non-demented and demented people. l-4 The pathogenesis of white matter lesions is largely unknown. However age and high diastolic and systolic blood pressure levels and indicators of

  9. Network-based High Accuracy Positioning with the GPSTk

    OpenAIRE

    Salazar Hernández, Dagoberto José; Hernández Pajares, Manuel; Juan Zornoza, José Miguel; Sanz Subirana, Jaume

    2010-01-01

    This paper presents an implementation of a postprocess kinematic positioning technique similar to PPP (Precise Point Positioning) but based on a network of stations. This technique is independent of precise clock information because it estimates satellite clock offsets ’on-the-fly’, and thence it only needs reasonable accurate orbits information (for instance, IGS precise, rapid or even predicted products) to work. Moreover, with this approach the solution rate is only li...

  10. Hybrid ANN optimized artificial fish swarm algorithm based classifier for classification of suspicious lesions in breast DCE-MRI

    Science.gov (United States)

    Janaki Sathya, D.; Geetha, K.

    2017-12-01

    Automatic mass or lesion classification systems are developed to aid in distinguishing between malignant and benign lesions present in the breast DCE-MR images, the systems need to improve both the sensitivity and specificity of DCE-MR image interpretation in order to be successful for clinical use. A new classifier (a set of features together with a classification method) based on artificial neural networks trained using artificial fish swarm optimization (AFSO) algorithm is proposed in this paper. The basic idea behind the proposed classifier is to use AFSO algorithm for searching the best combination of synaptic weights for the neural network. An optimal set of features based on the statistical textural features is presented. The investigational outcomes of the proposed suspicious lesion classifier algorithm therefore confirm that the resulting classifier performs better than other such classifiers reported in the literature. Therefore this classifier demonstrates that the improvement in both the sensitivity and specificity are possible through automated image analysis.

  11. Celestial positioning method based on centroid correction of STAR trajectory

    Science.gov (United States)

    Liu, Dianjian; Zhang, Zhili; Zhou, Zhaofa; Zhao, Junyang; Liu, Xianyi

    2017-05-01

    In order to reduce the position deviations between the centroid extracted from the star points and the actual centroid and reduce the influence of coarse errors contained in the astronomical information of star calculation on astronomical positioning accuracy of the digital zenith equipment, an astronomical locating method to correct star centroid location is proposed. Based on the star trajectory equation obtained from the imaging model of the starimage pointson the image plane of the zenith equipment, the center-of-mass centroid trajectory parameters are obtained by least-square method with the information of star point centroid position extracted from the multi-frame star images shot at the same observation station, which is used to identify the theoretical centroid position and correct the original centroid position, so as to participate in the astronomical positioning solution. For the simulation star map of gaussian white noise with distribution n (0, 52), after the centroid correction, the accuracy of the longitude of the astronomical rectangle is improved by 0.058″, the latitude improvement by 0.176″ to the mostand the position of the satellite by about 5m. Experimental results show that this method has good applicability, which can improve the celestial position accuracy of digital zenith equipment effectively.

  12. Malignant sweat gland tumor presenting as an unusual dural-based lesion: case report.

    Science.gov (United States)

    Lee, Jung-Shun; Chang, Kung-Chao; Chen, Hsing-Hong; Sze, Chun-I

    2010-09-01

    Malignant sweat gland tumors are rare neoplasms with high recurrence and metastasis rates of over 50%. Clinically, they are often either not diagnosed or diagnosed improperly and are encountered as a histological surprise. Herein, we report a 50-year-old woman who suffered from chronic headaches and a left-side limping gait. Magnetic resonance imaging revealed a T1 and T2 heterogeneous intense dural-based lesion at right-frontal convexity. The pathological diagnosis of papillary meningioma was rendered at the time. Because there was no evidence of residual tumor, tumor recurrence, or distant metastases during the three-year follow-up, the clinician believed questioning the initial diagnosis was warranted. After pathological review, the final diagnosis was low-grade hidradenocarcinoma. A review of the literature suggests this is the first reported case of dural-based hidradenocarcinoma with local brain invasion. Given the lack of scalp or skull bone involvement, we speculated that the tumor may have arisen from ectopic sweat gland cells entrapped in the dural mater.

  13. Characterization of oral precancerous lesions based on higher-harmonic generation microscopy

    Science.gov (United States)

    Lin, Chen-Yu; Lin, Chih-Feng; Sun, Chi-Kuang

    2013-03-01

    It is generally accepted that oral cancer arises in the presence of oral precancerous lesions. However, the clinical courses of these lesions are quite unpredictable, and a fundamental enigma remains that when and how these lesions turn to malignant growth. Characterization of these potentially malignant lesions is thus important and could serve as early indicators of this neoplastic transformation process, potentially facilitates the treatment outcome and improves the survival rate. Higher harmonic generation microscope (HGM), providing images with a leaving photodamages in the tissues, was used for this purpose. Oral cavity biopsies were obtained from 18 patients with clinical suspected oral precancerous lesions scheduled for surgical biopsy. HGM images were compared with histological images to determine the results. By visualization of subtle cellular and morphological changes, the preliminary result of this HGM image discloses excellent consistency with traditional histolopathology studies, without the need for fixation, sectioning and staining. More specifically speaking, the keratin thickness was found to be increased comparing with normal adjacent controls. In some cases, variations in cell size, nuclear size and increased nuclear/cytoplasmic ratio, and increased size of nucleoli were identified, indicating different stages of malignant transformation. These results together indicated that HGM provides the capability to characterize features of oral precancerous lesions as well as oral cancer progression, and holds the greatest potential as an ideal tool for clinical screening and surveillance of suspicious oral lesions.

  14. Detection of lesions in retina photographs based on the wavelet transform.

    Science.gov (United States)

    Quellec, Gwénolé; Lamard, Mathieu; Josselin, Pierre Marie; Cazuguel, Guy; Cochener, Béatrice; Roux, Christian

    2006-01-01

    In this article, we propose an automatic diabetic retinopathy screening method. In particular, we focus on detecting microaneurysms in retina photographs, as they are the most common and first appearing lesions in the disease development. This is done by matching a lesion template in the wavelet domain, using the sum of the squared errors as a criterion on some decomposition subbands. The method outperforms classification methods in the wavelet domain, which seem unfitted to describe small structures shapes. More, it could be generalized to other small lesions. Results are evaluated on a manually segmented retinal images database for different usual mother wavelets.

  15. Prevailence of Patch Test Positivity with Some Bases

    Directory of Open Access Journals (Sweden)

    J S Pasricha

    1987-01-01

    Full Text Available To evaluate the suitability of some chemicals to act as bases for antigens for patch tests, patch tests were performed with these agents in patients having contact dermatitis. Propylene glycol′used as such produced positive reactions in 25 (50% patients of which 12 were 2 + or more, polyethylene glycol 200 produced positive reactions in 9 (18% cases of which 4 cases were 2 + or more, a mixture of liquid paraffin and hard paraffin gave rise to positive reactions in 10 (10% cases 3 of these being 2 +, a mixture of liquid paraffin and bees wax was positive in 14 (14,Yo cases 3 of these being 2 +, yellow petrolatum was positive in 4 (8% cases, one of which was 2 +, white petrolatum was positive in S (6% cases all of these being + reactions only, and glycerol gave rise to a I + reaction in only one (2% caw. In tropical countries, water should be as base for as many antigens as possible for others, a control test with the b must be included.

  16. Communication-based positioning systems: past, present and prospects

    International Nuclear Information System (INIS)

    Ma Guanyi; Wan Qingtao; Gan Tong

    2012-01-01

    This paper reviews positioning systems in the context of communication systems. First, the basic positioning technique is described for location based service (LBS) in mobile communication systems. Then the high integrity global positioning system (iGPS) is introduced in terms of aspects of what it is and how the low Earth orbit (LEO) Iridium telecommunication satellites enhance the global positioning system (GPS). Emphasis is on the Chinese Area Positioning System (CAPS) which is mainly based on commercial geostationary (GEO) communication satellites, including decommissioned GEO and inclined geosynchronous communication satellites. Characterized by its low cost, high flexibility, wide-area coverage and ample frequency resources, a distinctive feature of CAPS is that its navigation messages are generated on the ground, then uploaded to and forwarded by the communication satellites. Fundamental principles and key technologies applied in the construction of CAPS are presented in detail from the CAPS validation phase to its experimental system setup. A prospective view of CAPS has concluded it to be a seamless, high accuracy, large capacity navigation and communication system which can be achieved by expanding it world wide and enhancing it with LEO satellites and mobile base stations. Hence, this system is a potential candidate for the next generation of radio navigation after GPS. (invited reviews)

  17. Forward and correctional OFDM-based visible light positioning

    Science.gov (United States)

    Li, Wei; Huang, Zhitong; Zhao, Runmei; He, Peixuan; Ji, Yuefeng

    2017-09-01

    Visible light positioning (VLP) has attracted much attention in both academic and industrial areas due to the extensive deployment of light-emitting diodes (LEDs) as next-generation green lighting. Generally, the coverage of a single LED lamp is limited, so LED arrays are always utilized to achieve uniform illumination within the large-scale indoor environment. However, in such dense LED deployment scenario, the superposition of the light signals becomes an important challenge for accurate VLP. To solve this problem, we propose a forward and correctional orthogonal frequency division multiplexing (OFDM)-based VLP (FCO-VLP) scheme with low complexity in generating and processing of signals. In the first forward procedure of FCO-VLP, an initial position is obtained by the trilateration method based on OFDM-subcarriers. The positioning accuracy will be further improved in the second correctional procedure based on the database of reference points. As demonstrated in our experiments, our approach yields an improved average positioning error of 4.65 cm and an enhanced positioning accuracy by 24.2% compared with trilateration method.

  18. Study of genital lesions

    Directory of Open Access Journals (Sweden)

    Anand Kumar B

    2003-03-01

    Full Text Available A total of one hundred patients (75 males and 25 females age ranged from 17-65 years with genital lesions attending the STD clinic of Bowring and LC Hospitals Bangalore constituted the study group. Based on clinical features, the study groups were classified as syphilis (39, chancroid (30, herpes genitolis (13, condylomato lato (9, LGV (7t condylomata acuminata (5, genital scabies (3, granuloma inguinole (2 and genital candidiasis (1. In 68% microbiological findings confirmed the clinical diagnosis. Of the 100 cases 13% and 2% were positive for HIV antibodies and HbsAg respectively.

  19. Radiofrequency ablation lesion detection using MR-based electrical conductivity imaging: a feasibility study of ex vivo liver experiments.

    Science.gov (United States)

    Chauhan, Munish; Jeong, Woo Chul; Kim, Hyung Joong; Kwon, Oh In; Woo, Eung Je

    2013-11-01

    The aim of this study was to show the potential of magnetic resonance electrical impedance tomography (MREIT) conductivity imaging in terms of its capability to detect ablated lesions and differentiate tissue conditions in liver radiofrequency (RF) ablation. RF ablation procedures were performed in bovine livers using a LeVeen RF needle electrode. Ablation lesions were created using a power-controlled mode at 30, 50, and 70 W for 1, 3, and 5 min of exposure time, respectively. After the ablation, the liver was cut into several blocks including the ablated lesion, and positioned inside a phantom filled with agarose gel. Electrodes were attached on the side of the phantom and it was placed inside the MRI bore. For MREIT imaging, multi-spin-echo pulse sequence was used to obtain the magnetic flux density data according to the injection currents. The conductivity of ablation lesions was significantly changed with the increase of exposure time (pKW W, significant differences between the coagulation necrosis and hyperaemic rim were observed for more than 5 min and 3 min, respectively (pMW W, all cases showed significant differences except 3 min (pMW < 0.01). The positive correlation between the exposure time and tissue conductivity was observed in both two ablation areas (pSC < 0.01, Spearman correlation). This ex vivo feasibility study demonstrates that current MREIT conductivity imaging can detect liver RF ablation lesions without using any contrast media or additional MR scan.

  20. An image based system to automatically and objectivelly score the degreeof redness and scaling in psoriasi lesions

    DEFF Research Database (Denmark)

    Gomez, David Delgado; Ersbøll, Bjarne Kjær; Carstensen, Jens Michael

    2004-01-01

    In this work, a combined statistical and image analysis method to automatically evaluate the severity of scaling in psoriasis lesions is proposed. The method separates the different regions of the disease in the image and scores the degree of scaling based on the properties of these areas. The pr...

  1. Incidence of symptomatic osteochondritis dissecans lesions of the knee : A population-based study in Olmsted County

    NARCIS (Netherlands)

    Pareek, A.; Sanders, T. L.; Wu, I. T.; Larson, D. R.; Saris, D. B.F.; Krych, A.J.

    2017-01-01

    Objective: To (1) define population-based incidence of knee Osteochondritis dissecans (OCD) lesions using the population of Olmsted County, (2) examine trends over time, and (3) evaluate rate of surgical management over time. Method: Study population included 302 individuals who were diagnosed with

  2. Voxel-based lesion analysis of brain regions underlying reading and writing.

    Science.gov (United States)

    Baldo, Juliana V; Kacinik, Natalie; Ludy, Carl; Paulraj, Selvi; Moncrief, Amber; Piai, Vitória; Curran, Brian; Turken, And; Herron, Tim; Dronkers, Nina F

    2018-03-20

    The neural basis of reading and writing has been a source of inquiry as well as controversy in the neuroscience literature. Reading has been associated with both left posterior ventral temporal zones (termed the "visual word form area") as well as more dorsal zones, primarily in left parietal cortex. Writing has also been associated with left parietal cortex, as well as left sensorimotor cortex and prefrontal regions. Typically, the neural basis of reading and writing are examined in separate studies and/or rely on single case studies exhibiting specific deficits. Functional neuroimaging studies of reading and writing typically identify a large number of activated regions but do not necessarily identify the core, critical hubs. Last, due to constraints on the functional imaging environment, many previous studies have been limited to measuring the brain activity associated with single-word reading and writing, rather than sentence-level processing. In the current study, the brain correlates of reading and writing at both the single- and sentence-level were studied in a large sample of 111 individuals with a history of chronic stroke using voxel-based lesion symptom mapping (VLSM). VLSM provides a whole-brain, voxel-by-voxel statistical analysis of the role of distinct regions in a particular behavior by comparing performance of individuals with and without a lesion at every voxel. Rather than comparing individual cases or small groups with particular behavioral dissociations in reading and writing, VLSM allowed us to analyze data from a large, well-characterized sample of stroke patients exhibiting a wide range of reading and writing impairments. The VLSM analyses revealed that reading was associated with a critical left inferior temporo-occipital focus, while writing was primarily associated with the left supramarginal gyrus. Separate VLSM analyses of single-word versus sentence-level reading showed that sentence-level reading was uniquely associated with anterior

  3. A voxel-based lesion study on facial emotion recognition after penetrating brain injury

    Science.gov (United States)

    Dal Monte, Olga; Solomon, Jeffrey M.; Schintu, Selene; Knutson, Kristine M.; Strenziok, Maren; Pardini, Matteo; Leopold, Anne; Raymont, Vanessa; Grafman, Jordan

    2013-01-01

    The ability to read emotions in the face of another person is an important social skill that can be impaired in subjects with traumatic brain injury (TBI). To determine the brain regions that modulate facial emotion recognition, we conducted a whole-brain analysis using a well-validated facial emotion recognition task and voxel-based lesion symptom mapping (VLSM) in a large sample of patients with focal penetrating TBIs (pTBIs). Our results revealed that individuals with pTBI performed significantly worse than normal controls in recognizing unpleasant emotions. VLSM mapping results showed that impairment in facial emotion recognition was due to damage in a bilateral fronto-temporo-limbic network, including medial prefrontal cortex (PFC), anterior cingulate cortex, left insula and temporal areas. Beside those common areas, damage to the bilateral and anterior regions of PFC led to impairment in recognizing unpleasant emotions, whereas bilateral posterior PFC and left temporal areas led to impairment in recognizing pleasant emotions. Our findings add empirical evidence that the ability to read pleasant and unpleasant emotions in other people's faces is a complex process involving not only a common network that includes bilateral fronto-temporo-limbic lobes, but also other regions depending on emotional valence. PMID:22496440

  4. Position-based quantum cryptography and catalytic computation

    NARCIS (Netherlands)

    Speelman, F.

    2016-01-01

    In this thesis, we present several results along two different lines of research. The first part concerns the study of position-based quantum cryptography, a topic in quantum cryptography. By combining quantum mechanics with special relativity theory, new cryptographic tasks can be developed that

  5. Particle based 3D modeling of positive streamer inception

    NARCIS (Netherlands)

    H.J. Teunissen (Jannis)

    2012-01-01

    htmlabstractIn this report we present a particle based 3D model for the study of streamer inception near positive electrodes in air. The particle code is of the PIC-MCC type and an electrode is included using the charge simulation method. An algorithm for the adaptive creation of super-particles is

  6. Analysis of Financial Position Based on the Balance Sheet

    OpenAIRE

    Spineanu-Georgescu Luciana

    2011-01-01

    Analysis of financial position based on the balance sheet is mainly aimed at assessing the extent to which financial structure chosen by the firm, namely, financial resources, covering the needs reflected in the balance sheet financed. This is done through an analysis known as horizontal analysis balance sheet financial imbalances.

  7. LESIONS OF THE MANDIBLE - A PATTERN BASED APPROACH TO DIAGNOSIS BY OPG

    Directory of Open Access Journals (Sweden)

    Anil Govind

    2015-12-01

    Full Text Available The present study of 95 orthopentograms focused on importance of OPG as a first line of investigation in the diagnosis of mandibular lesions and establish its role beyond doubt in some the conditions due to its pathognomonic appearance. It also narrows down the list of differential diagnosis. INTRODUCTION Mandibular lesions cause a variety of problems ranging from swelling, tooth mobility, displacement of adjacent teeth, mild sensitivity, root deformation of developing permanent teeth and potential to expand the bone causing fractures. Some of these mandibular lesions are silent in their progression and pose a challenge in early diagnosis for clinicians. Radiographic characteristics such as location, margin, density, relation to tooth, along with clinical notes is the first step in interpreting mandibular pathologies. Orthopentogram is a simple, accurate and cost effective technique commonly employed for diagnosing dental and maxillofacial lesions. We retrospectively evaluated spectrum of mandibular lesions from a database of groundwork diagnostic OPGs. METHODS We reviewed a total of 2690 orthopentograms of patients with tooth ache and/or swelling, referred to the radiologist for the preliminary diagnosis. All osteolytic lesions more than 10 mm. and having characteristics of root abscess were included for evaluation. OPG taken for orthodontic work up, showing dental abscess less than 10 mm and OPG of patients with Gingival and T.M. joint pathologies were excluded. RESULTS In our study, we found 0.35% (95/2690 of patients were having a spectrum of mandibular lesions. The frequency of appearance of mandibular lesions on OPG was buccal-neoplasm>dentigerous-cysts>dental-cyst>neoplastic=traumatic-bone-cyst= osteomyelitis >kerato-cyst. The most frequent sites of these lesions were 80/103(77.6% molars, 14/103(13.6% incisors, and 9/103(8.7% angle of mandibles. No lesions were found on condyles. CONCLUSION The present study proves that OPG is a first

  8. Position-based quantum cryptography over untrusted networks

    International Nuclear Information System (INIS)

    Nadeem, Muhammad

    2014-01-01

    In this article, we propose quantum position verification (QPV) schemes where all the channels are untrusted except the position of the prover and distant reference stations of verifiers. We review and analyze the existing QPV schemes containing some pre-shared data between the prover and verifiers. Most of these schemes are based on non-cryptographic assumptions, i.e. quantum/classical channels between the verifiers are secure. It seems impractical in an environment fully controlled by adversaries and would lead to security compromise in practical implementations. However, our proposed formula for QPV is more robust, secure and according to the standard assumptions of cryptography. Furthermore, once the position of the prover is verified, our schemes establish secret keys in parallel and can be used for authentication and secret communication between the prover and verifiers. (paper)

  9. Dynamic positioning system based on active disturbance rejection technology

    Science.gov (United States)

    Lei, Zhengling; Guo, Chen; Fan, Yunsheng

    2015-08-01

    A dynamically positioned vessel, by the International Maritime Organization (IMO) and the certifying class societies (DNV, ABS, LR, etc.), is defined as a vessel that maintains its position and heading (fixed location or pre-determined track) exclusively by means of active thrusters. The development of control technology promotes the upgrading of dynamic positioning (DP) systems. Today there are two different DP systems solutions available on the market: DP system based on PID regulator and that based on model-based control. Both systems have limited disturbance rejection capability due to their design principle. In this paper, a new DP system solution is proposed based on Active Disturbance Rejection Control (ADRC) technology. This technology is composed of Tracking-Differentiator (TD), Extended State Observer (ESO) and Nonlinear Feedback Combination. On one hand, both TD and ESO can act as filters and can be used in place of conventional filters; on the other hand, the total disturbance of the system can be estimated and compensated by ESO, which therefore enhances the system's disturbance rejection capability. This technology's advantages over other methods lie in two aspects: 1) This method itself can not only achieve control objectives but also filter noisy measurements without other specialized filters; 2) This method offers a new useful approach to suppress the ocean disturbance. The simulation results demonstrate the effectiveness of the proposed method.

  10. A modular positive feedback-based gene amplifier

    Directory of Open Access Journals (Sweden)

    Bhalerao Kaustubh D

    2010-02-01

    Full Text Available Abstract Background Positive feedback is a common mechanism used in the regulation of many gene circuits as it can amplify the response to inducers and also generate binary outputs and hysteresis. In the context of electrical circuit design, positive feedback is often considered in the design of amplifiers. Similar approaches, therefore, may be used for the design of amplifiers in synthetic gene circuits with applications, for example, in cell-based sensors. Results We developed a modular positive feedback circuit that can function as a genetic signal amplifier, heightening the sensitivity to inducer signals as well as increasing maximum expression levels without the need for an external cofactor. The design utilizes a constitutively active, autoinducer-independent variant of the quorum-sensing regulator LuxR. We experimentally tested the ability of the positive feedback module to separately amplify the output of a one-component tetracycline sensor and a two-component aspartate sensor. In each case, the positive feedback module amplified the response to the respective inducers, both with regards to the dynamic range and sensitivity. Conclusions The advantage of our design is that the actual feedback mechanism depends only on a single gene and does not require any other modulation. Furthermore, this circuit can amplify any transcriptional signal, not just one encoded within the circuit or tuned by an external inducer. As our design is modular, it can potentially be used as a component in the design of more complex synthetic gene circuits.

  11. Unconditionally secure commitment in position-based quantum cryptography.

    Science.gov (United States)

    Nadeem, Muhammad

    2014-10-27

    A new commitment scheme based on position-verification and non-local quantum correlations is presented here for the first time in literature. The only credential for unconditional security is the position of committer and non-local correlations generated; neither receiver has any pre-shared data with the committer nor does receiver require trusted and authenticated quantum/classical channels between him and the committer. In the proposed scheme, receiver trusts the commitment only if the scheme itself verifies position of the committer and validates her commitment through non-local quantum correlations in a single round. The position-based commitment scheme bounds committer to reveal valid commitment within allocated time and guarantees that the receiver will not be able to get information about commitment unless committer reveals. The scheme works for the commitment of both bits and qubits and is equally secure against committer/receiver as well as against any third party who may have interests in destroying the commitment. Our proposed scheme is unconditionally secure in general and evades Mayers and Lo-Chau attacks in particular.

  12. Model-Free Visualization of Suspicious Lesions in Breast MRI Based on Supervised and Unsupervised Learning.

    Science.gov (United States)

    Twellmann, Thorsten; Meyer-Baese, Anke; Lange, Oliver; Foo, Simon; Nattkemper, Tim W

    2008-03-01

    Dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) has become an important tool in breast cancer diagnosis, but evaluation of multitemporal 3D image data holds new challenges for human observers. To aid the image analysis process, we apply supervised and unsupervised pattern recognition techniques for computing enhanced visualizations of suspicious lesions in breast MRI data. These techniques represent an important component of future sophisticated computer-aided diagnosis (CAD) systems and support the visual exploration of spatial and temporal features of DCE-MRI data stemming from patients with confirmed lesion diagnosis. By taking into account the heterogeneity of cancerous tissue, these techniques reveal signals with malignant, benign and normal kinetics. They also provide a regional subclassification of pathological breast tissue, which is the basis for pseudo-color presentations of the image data. Intelligent medical systems are expected to have substantial implications in healthcare politics by contributing to the diagnosis of indeterminate breast lesions by non-invasive imaging.

  13. Restoration outcomes after restoring vital teeth with advanced caries lesions: a practice-based retrospective study.

    Science.gov (United States)

    Schwendicke, Falk; Krüger, Hannes; Schlattmann, Peter; Paris, Sebastian

    2016-09-01

    Maintaining pulpal vitality and achieving long-term restoration success are challenging when treating advanced caries lesions. We aimed at assessing success, survival, and influencing factors of treating advanced lesions in general dental practice. Patient record databases from six practices in Germany were assessed. Permanent posterior teeth with lesions radiographically extending into inner dentin with sensible (vital) pulps were retrospectively evaluated. Outcome parameters were success (absence of re-treatment) and survival (absence of extraction). Mean success/survival times were estimated, and effect of treatment modifiers assessed using Lee, Wei, and Amato (LWA) regression. Two hundred thirty-two patients (308 teeth) were assessed. Lesions (93 %) included proximal surfaces. Eight teeth showed preoperative intermitting or provocation pain. Thirty four % of teeth experienced pulpal exposure during excavation. Mean follow-up time was 74 months. Mean success time was 130 months. Teeth (142/308) required re-interventions, mostly due to secondary caries and restorative or endodontic complications. Only 13 teeth required extraction (mean survival time 307 months). Hazard of failure was significantly reduced in younger patients (<40 years) (hazard ratio (HR) [95 % confidence interval (CI)] 0.57 [0.35/0.91]) and teeth without preoperative pain (0.39 [0.17/0.90]). Compared with teeth receiving amalgams, those restored using cements (2.44 [1.05/3.98]) or composites (1.64 [1.15/2.38]) had higher risk of failure. Hazard of extraction was higher in teeth with pulpal exposure (4.90 [1.36/17.7] or cement restorations (23.6 [5.56/100]). Teeth with advanced lesions had high risk of failure, while risk of extraction was low. Teeth treated for advanced lesions required re-treatment frequently but were retained long term. Age, pulpal exposure, and restoration type were associated with risk of failure or extraction.

  14. Adaptive algorithm for mobile user positioning based on environment estimation

    Directory of Open Access Journals (Sweden)

    Grujović Darko

    2014-01-01

    Full Text Available This paper analyzes the challenges to realize an infrastructure independent and a low-cost positioning method in cellular networks based on RSS (Received Signal Strength parameter, auxiliary timing parameter and environment estimation. The proposed algorithm has been evaluated using field measurements collected from GSM (Global System for Mobile Communications network, but it is technology independent and can be applied in UMTS (Universal Mobile Telecommunication Systems and LTE (Long-Term Evolution networks, also.

  15. Current concepts on posterior meniscal root lesion: A treatment algorithm based on the currently available evidence

    Directory of Open Access Journals (Sweden)

    Guan-Yang Song

    2014-07-01

    Full Text Available Meniscal root lesion is defined as an avulsion of the tibial insertion of the meniscus or a radial tear close to the meniscal insertion, which is commonly observed at the posterior region in the clinical practice. Although a number of biomechanical and clinical studies have shown the importance of the integrity of the posterior meniscal roots, the appropriate treatment is still controversial. The purposes of this review are to develop a current understanding of how the posterior meniscal root functions and to review the available treatment options for posterior meniscal root lesion.

  16. Development of a web-based DICOM-SR viewer for CAD data of multiple sclerosis lesions in an imaging informatics-based efolder

    Science.gov (United States)

    Ma, Kevin; Wong, Jonathan; Zhong, Mark; Zhang, Jeff; Liu, Brent

    2014-03-01

    In the past, we have presented an imaging-informatics based eFolder system for managing and analyzing imaging and lesion data of multiple sclerosis (MS) patients, which allows for data storage, data analysis, and data mining in clinical and research settings. The system integrates the patient's clinical data with imaging studies and a computer-aided detection (CAD) algorithm for quantifying MS lesion volume, lesion contour, locations, and sizes in brain MRI studies. For compliance with IHE integration protocols, long-term storage in PACS, and data query and display in a DICOM compliant clinical setting, CAD results need to be converted into DICOM-Structured Report (SR) format. Open-source dcmtk and customized XML templates are used to convert quantitative MS CAD results from MATLAB to DICOM-SR format. A web-based GUI based on our existing web-accessible DICOM object (WADO) image viewer has been designed to display the CAD results from generated SR files. The GUI is able to parse DICOM-SR files and extract SR document data, then display lesion volume, location, and brain matter volume along with the referenced DICOM imaging study. In addition, the GUI supports lesion contour overlay, which matches a detected MS lesion with its corresponding DICOM-SR data when a user selects either the lesion or the data. The methodology of converting CAD data in native MATLAB format to DICOM-SR and displaying the tabulated DICOM-SR along with the patient's clinical information, and relevant study images in the GUI will be demonstrated. The developed SR conversion model and GUI support aim to further demonstrate how to incorporate CAD post-processing components in a PACS and imaging informatics-based environment.

  17. Blue lesions.

    Science.gov (United States)

    Longo, Caterina; Scope, Alon; Lallas, Aimilios; Zalaudek, Iris; Moscarella, Elvira; Gardini, Stefano; Argenziano, Giuseppe; Pellacani, Giovanni

    2013-10-01

    Blue color is found in a wide range of malignant and benign melanocytic and nonmelanocytic lesions and in lesions that result from penetration of exogenous materials, such as radiation or amalgam tattoo or traumatic penetration of particles. Discriminating between different diagnostic entities that display blue color relies on careful patient examination and lesion assessment. Dermoscopically, the extent, distribution, and patterns created by blue color can help diagnose lesions with specificity and differentiate between benign and malignant entities. This article provides an overview of the main diagnoses whereby blue color can be found, providing simple management rules for these lesions. Copyright © 2013 Elsevier Inc. All rights reserved.

  18. Angled screw holes for anterior posts and a frame-positioning device for gamma knife radiosurgery: allowing for better targeting of intracranial lesions.

    Science.gov (United States)

    Quiñones-Hinojosa, Alfredo; McDermott, Michael W

    2007-04-01

    Gamma knife radiosurgery requires frame positioning so that the treatment target is as close to the center of the frame and as low as possible to cover all of the posterior fossa contents. In this study, we report the use of two devices developed by the senior author (MWM) that facilitate these two crucial objectives in the treatment of intracranial targets using the gamma knife. Custom front posts with threaded screw holes drilled at 5-, 10-, and 15-degree angles were created by the manufacturer at our request. A U-shaped metal device for frame positioning was designed in-house and fits into the holes at the 100-mm mark on the lateral sides of the Leksell stereotactic frame base. This allowed the positioning device to snap securely into the frame for use in positioning. The positioning device was constructed so that the lowest possible frame position would be achieved with each frame application, while avoiding collisions with the magnetic resonance imaging localizer box. Angled front posts allowed for pin contacts with the cranium anterior and/or superior to the superior temporal line despite a lateral or posterior position of the frame. This avoided penetration of the temporalis muscle and reduced discomfort for patients. The U-shaped metal device was used in place of the Velcro straps or ear bars routinely used for frame positioning in which the distance from the frame base to the top of the head must always be measured to avoid collisions with the localizer box. During the past 2 years, these devices have been used on a daily basis, achieving the desired results. In many cases, their use has avoided the need for frame repositioning and rescanning for targets that cannot be reached because of inexact frame positioning. A new design with angled screw holes in the front posts used for gamma knife radiosurgery allows surgeons to avoid penetration of the temporalis muscle and to maintain a perpendicular orientation of the fixation screw to the outer table of the

  19. Design about position and display of GPS based on singlechip

    Directory of Open Access Journals (Sweden)

    WU Dongdong

    2016-02-01

    Full Text Available GPS is used in ships,vehicles,aircraft and other moving objects.GPS also has the important application in vehicle monitoring system.However,with the expansion of the specialized functions of GPS,its high cost makes so many ordinary consumers unbearable.This paper proposes a simple design of GPS based on singlechip.The design Improves the basic utility functions of system and adds the speed and mileage measurement.GPS module uses the differential technology to improve the positioning accuracy.Therefore,the navigation device is compact,easy to carry and of high precision positioning.Through getting the data of 3D coordinates from the observation point and the factor of position accuracy,the average of which is less than five,indicating that the position accuracy can be improved by differential technology to achieve the desired range.At last,the feasibility of this design is verified through the current data tested in the outdoors.

  20. Uav Positioning and Collision Avoidance Based on RSS Measurements

    Science.gov (United States)

    Masiero, A.; Fissore, F.; Guarnieri, A.; Pirotti, F.; Vettore, A.

    2015-08-01

    In recent years, Unmanned Aerial Vehicles (UAVs) are attracting more and more attention in both the research and industrial communities: indeed, the possibility to use them in a wide range of remote sensing applications makes them a very flexible and attractive solution in both civil and commercial cases (e.g. precision agriculture, security and control, monitoring of sites, exploration of areas difficult to reach). Most of the existing UAV positioning systems rely on the use of the GPS signal. Despite this can be a satisfactory solution in open environments where the GPS signal is available, there are several operating conditions of interest where it is unavailable or unreliable (e.g. close to high buildings, or mountains, in indoor environments). Consequently, a different approach has to be adopted in these cases. This paper considers the use ofWiFi measurements in order to obtain position estimations of the device of interest. More specifically, to limit the costs for the devices involved in the positioning operations, an approach based on radio signal strengths (RSS) measurements is considered. Thanks to the use of a Kalman filter, the proposed approach takes advantage of the temporal dynamic of the device of interest in order to improve the positioning results initially provided by means of maximum likelihood estimations. The considered UAVs are assumed to be provided with communication devices, which can allow them to communicate with each other in order to improve their cooperation abilities. In particular, the collision avoidance problem is examined in this work.

  1. Accurate position estimation methods based on electrical impedance tomography measurements

    Science.gov (United States)

    Vergara, Samuel; Sbarbaro, Daniel; Johansen, T. A.

    2017-08-01

    Electrical impedance tomography (EIT) is a technology that estimates the electrical properties of a body or a cross section. Its main advantages are its non-invasiveness, low cost and operation free of radiation. The estimation of the conductivity field leads to low resolution images compared with other technologies, and high computational cost. However, in many applications the target information lies in a low intrinsic dimensionality of the conductivity field. The estimation of this low-dimensional information is addressed in this work. It proposes optimization-based and data-driven approaches for estimating this low-dimensional information. The accuracy of the results obtained with these approaches depends on modelling and experimental conditions. Optimization approaches are sensitive to model discretization, type of cost function and searching algorithms. Data-driven methods are sensitive to the assumed model structure and the data set used for parameter estimation. The system configuration and experimental conditions, such as number of electrodes and signal-to-noise ratio (SNR), also have an impact on the results. In order to illustrate the effects of all these factors, the position estimation of a circular anomaly is addressed. Optimization methods based on weighted error cost functions and derivate-free optimization algorithms provided the best results. Data-driven approaches based on linear models provided, in this case, good estimates, but the use of nonlinear models enhanced the estimation accuracy. The results obtained by optimization-based algorithms were less sensitive to experimental conditions, such as number of electrodes and SNR, than data-driven approaches. Position estimation mean squared errors for simulation and experimental conditions were more than twice for the optimization-based approaches compared with the data-driven ones. The experimental position estimation mean squared error of the data-driven models using a 16-electrode setup was less

  2. Accurate position estimation methods based on electrical impedance tomography measurements

    International Nuclear Information System (INIS)

    Vergara, Samuel; Sbarbaro, Daniel; Johansen, T A

    2017-01-01

    Electrical impedance tomography (EIT) is a technology that estimates the electrical properties of a body or a cross section. Its main advantages are its non-invasiveness, low cost and operation free of radiation. The estimation of the conductivity field leads to low resolution images compared with other technologies, and high computational cost. However, in many applications the target information lies in a low intrinsic dimensionality of the conductivity field. The estimation of this low-dimensional information is addressed in this work. It proposes optimization-based and data-driven approaches for estimating this low-dimensional information. The accuracy of the results obtained with these approaches depends on modelling and experimental conditions. Optimization approaches are sensitive to model discretization, type of cost function and searching algorithms. Data-driven methods are sensitive to the assumed model structure and the data set used for parameter estimation. The system configuration and experimental conditions, such as number of electrodes and signal-to-noise ratio (SNR), also have an impact on the results. In order to illustrate the effects of all these factors, the position estimation of a circular anomaly is addressed. Optimization methods based on weighted error cost functions and derivate-free optimization algorithms provided the best results. Data-driven approaches based on linear models provided, in this case, good estimates, but the use of nonlinear models enhanced the estimation accuracy. The results obtained by optimization-based algorithms were less sensitive to experimental conditions, such as number of electrodes and SNR, than data-driven approaches. Position estimation mean squared errors for simulation and experimental conditions were more than twice for the optimization-based approaches compared with the data-driven ones. The experimental position estimation mean squared error of the data-driven models using a 16-electrode setup was less

  3. Resection of highly language-eloquent brain lesions based purely on rTMS language mapping without awake surgery.

    Science.gov (United States)

    Ille, Sebastian; Sollmann, Nico; Butenschoen, Vicki M; Meyer, Bernhard; Ringel, Florian; Krieg, Sandro M

    2016-12-01

    The resection of left-sided perisylvian brain lesions harbours the risk of postoperative language impairment. Therefore the individual patient's language distribution is investigated by intraoperative direct cortical stimulation (DCS) during awake surgery. Yet, not all patients qualify for awake surgery. Non-invasive language mapping by repetitive navigated transcranial magnetic stimulation (rTMS) has frequently shown a high correlation in comparison with the results of DCS language mapping in terms of language-negative brain regions. The present study analyses the extent of resection (EOR) and functional outcome of patients who underwent left-sided perisylvian resection of brain lesions based purely on rTMS language mapping. Four patients with left-sided perisylvian brain lesions (two gliomas WHO III, one glioblastoma, one cavernous angioma) underwent rTMS language mapping prior to surgery. Data from rTMS language mapping and rTMS-based diffusion tensor imaging fibre tracking (DTI-FT) were transferred to the intraoperative neuronavigation system. Preoperatively, 5 days after surgery (POD5), and 3 months after surgery (POM3) clinical follow-up examinations were performed. No patient suffered from a new surgery-related aphasia at POM3. Three patients underwent complete resection immediately, while one patient required a second rTMS-based resection some days later to achieve the final, complete resection. The present study shows for the first time the feasibility of successfully resecting language-eloquent brain lesions based purely on the results of negative language maps provided by rTMS language mapping and rTMS-based DTI-FT. In very select cases, this technique can provide a rescue strategy with an optimal functional outcome and EOR when awake surgery is not feasible.

  4. Imaging liver lesions using grating-based phase-contrast computed tomography with bi-lateral filter post-processing.

    Directory of Open Access Journals (Sweden)

    Julia Herzen

    Full Text Available X-ray phase-contrast imaging shows improved soft-tissue contrast compared to standard absorption-based X-ray imaging. Especially the grating-based method seems to be one promising candidate for clinical implementation due to its extendibility to standard laboratory X-ray sources. Therefore the purpose of our study was to evaluate the potential of grating-based phase-contrast computed tomography in combination with a novel bi-lateral denoising method for imaging of focal liver lesions in an ex vivo feasibility study. Our study shows that grating-based phase-contrast CT (PCCT significantly increases the soft-tissue contrast in the ex vivo liver specimens. Combining the information of both signals--absorption and phase-contrast--the bi-lateral filtering leads to an improvement of lesion detectability and higher contrast-to-noise ratios. The normal and the pathological tissue can be clearly delineated and even internal structures of the pathological tissue can be visualized, being invisible in the absorption-based CT alone. Histopathology confirmed the presence of the corresponding findings in the analyzed tissue. The results give strong evidence for a sufficiently high contrast for different liver lesions using non-contrast-enhanced PCCT. Thus, ex vivo imaging of liver lesions is possible with a polychromatic X-ray source and at a spatial resolution of ∼100 µm. The post-processing with the novel bi-lateral denoising method improves the image quality by combining the information from the absorption and the phase-contrast images.

  5. Differential diagnosis of mesiotemporal lesions: case report of neurosyphilis

    International Nuclear Information System (INIS)

    Vieira Santos, A.; Matias, S.; Saraiva, P.; Goulao, A.

    2005-01-01

    We report a clinical and imaging case of suspected herpes simplex encephalitis subsequently diagnosed as neurosyphilis based on positive antibodies in the CSF. MRI of the brain showed cortical and subcortical lesions in the mesial temporal region, septal area, insula and cingulated gyrus of the right cerebral hemisphere. Neurosyphilis should be included in the differential diagnosis of mesial temporal region lesions on MRI. (orig.)

  6. Cellular automaton-based position sensitive detector equalization

    International Nuclear Information System (INIS)

    Ferrando, Nestor; Herrero, V.; Cerda, J.; Lerche, C.W.; Colom, R.J.; Gadea, R.; Martinez, J.D.; Monzo, J.M.; Mateo, F.; Sebastia, A.; Benlloch, J.M.

    2009-01-01

    Indirect position detectors based on scintillator crystals lack of spacial uniformity in their response. This happens due to crystal inhomogeneities and gain differences among the photomultiplier anodes. In order to solve this, PESIC, an integrated front-end for multianode photomultiplier based nuclear imaging devices was created. One of its main features is the digitally programmable gain adjustment for every photomultiplier output. On another front, cellular automata have been proved to be a useful method for dynamic system modeling. In this paper, a cellular automaton which emulates the behavior of the scintillator crystal, the photomultiplier and the front-end is introduced. Thanks to this model, an automatic energy-based calibration of the detector can be done by configuring the cellular automaton with experimental data and making it evolve up to an stable state. This can be useful as a precalibration method of the detector.

  7. Beam based measurement of beam position monitor electrode gains

    Directory of Open Access Journals (Sweden)

    D. L. Rubin

    2010-09-01

    Full Text Available Low emittance tuning at the Cornell Electron Storage Ring (CESR test accelerator depends on precision measurement of vertical dispersion and transverse coupling. The CESR beam position monitors (BPMs consist of four button electrodes, instrumented with electronics that allow acquisition of turn-by-turn data. The response to the beam will vary among the four electrodes due to differences in electronic gain and/or misalignment. This variation in the response of the BPM electrodes will couple real horizontal offset to apparent vertical position, and introduce spurious measurements of coupling and vertical dispersion. To alleviate this systematic effect, a beam based technique to measure the relative response of the four electrodes has been developed. With typical CESR parameters, simulations show that turn-by-turn BPM data can be used to determine electrode gains to within ∼0.1%.

  8. Eukaryotic promoter prediction based on relative entropy and positional information.

    Science.gov (United States)

    Wu, Shuanhu; Xie, Xudong; Liew, Alan Wee-Chung; Yan, Hong

    2007-04-01

    The eukaryotic promoter prediction is one of the most important problems in DNA sequence analysis, but also a very difficult one. Although a number of algorithms have been proposed, their performances are still limited by low sensitivities and high false positives. We present a method for improving the performance of promoter regions prediction. We focus on the selection of most effective features for different functional regions in DNA sequences. Our feature selection algorithm is based on relative entropy or Kullback-Leibler divergence, and a system combined with position-specific information for promoter regions prediction is developed. The results of testing on large genomic sequences and comparisons with the PromoterInspector and Dragon Promoter Finder show that our algorithm is efficient with higher sensitivity and specificity in predicting promoter regions.

  9. Absolute scale-based imaging position encoder with submicron accuracy

    Science.gov (United States)

    Anisimov, Andrey G.; Pantyushin, Anton V.; Lashmanov, Oleg U.; Vasilev, A. S.; Timofeev, Alexander N.; Korotaev, Valery V.; Gordeev, Sergey V.

    2013-04-01

    Study is devoted to experimental research and development of absolute imaging position encoder based on standard calibrated scale of invar alloy with 1 mm spacing. The encoder uses designed imaging system as a vernier and absolute magnetic encoder as a rough indication. The features of optical design, choice and use of imaging system as long as indexes images processing algorithm are described. A shadow method was implemented: indexes images on a CCD array are formed by the lens focused at the scale surface; the laser module lights up the scale through a beam-splitting prism by a parallel beam. Further dark indexes images on a light scale background are detected and analyzed to estimate the encoder position. Full range of experimental tests was set to calibrate the encoder and to estimate the accuracy. As a result, accuracy close to 1 μm at 1 m was achieved.

  10. Management of precancerous anal intraepithelial lesions in human immunodeficiency virus-positive men who have sex with men: Clinical effectiveness and cost-effectiveness.

    Science.gov (United States)

    Deshmukh, Ashish A; Chiao, Elizabeth Y; Cantor, Scott B; Stier, Elizabeth A; Goldstone, Stephen E; Nyitray, Alan G; Wilkin, Timothy; Wang, Xiaojie; Chhatwal, Jagpreet

    2017-12-01

    Human immunodeficiency virus (HIV)-positive men who have sex with men (MSM) are at disproportionately high risk for anal cancer. There is no definitive approach to the management of high-grade squamous intraepithelial lesions (HSIL), which are precursors of anal cancer, and evidence suggests that posttreatment adjuvant quadrivalent human papillomavirus (qHPV) vaccination improves HSIL treatment effectiveness. The objectives of this study were to evaluate the optimal HSIL management strategy with respect to clinical effectiveness and cost-effectiveness and to identify the optimal age for initiating HSIL management. A decision analytic model of the natural history of anal carcinoma and HSIL management strategies was constructed for HIV-positive MSM who were 27 years old or older. The model was informed by the Surveillance, Epidemiology, and End Results-Medicare database and published studies. Outcomes included the lifetime cost, life expectancy, quality-adjusted life expectancy, cumulative risk of cancer and cancer-related deaths, and cost-effectiveness from a societal perspective. Active monitoring was the most effective approach in patients 29 years or younger; thereafter, HSIL treatment plus adjuvant qHPV vaccination became most effective. When cost-effectiveness was considered (ie, an incremental cost-effectiveness ratio [ICER] < $100,000/quality-adjusted life-year), do nothing was cost-effective until the age of 38 years, and HSIL treatment plus adjuvant qHPV vaccination was cost-effective beyond the age of 38 years (95% confidence interval, 34-43 years). The ICER decreased as the age at HSIL management increased. Outcomes were sensitive to the rate of HSIL regression or progression and the cost of high-resolution anoscopy and biopsy. The management of HSIL in HIV-positive MSM who are 38 years old or older with treatment plus adjuvant qHPV vaccination is likely to be cost-effective. The conservative approach of no treatment is likely to be cost-effective in

  11. Guidewire bias in rotational atherectomy in the angled lesion: evaluation based on the thickness of the ablated intima and media.

    Science.gov (United States)

    Oishi, Yoshihiko; Okamoto, Mitsunori; Sueda, Takashi; Hashimoto, Masaki; Karakawa, Shinji; Kambe, Masayuki

    2002-07-01

    The effect of guidewire bias on angled-lesion ablation by rotational atherectomy (RA) was assessed by measuring the changes in vertical lumen diameter, horizontal lumen diameter and the intima-media thickness of the coronary artery, using intravascular ultrasound in 10 lesions with an angle greater than 10 degrees. The vertical and horizontal diameters significantly increased after RA. The intima-media thickness at the 4 orthogonal sites significantly decreased. There was a significant positive correlation between vertical diameter change and angle (r=0.642, p=0.045), but none between horizontal diameter change and angle. There was no correlation between intima-media thickness change at 0 degrees and angle; however, at 180 degrees there was a tendency to correlation with angle (r=0.602, p=0.066). These data suggest that in cases of angled lesions, the increase in vertical lumen diameter is caused more by ablation of the 180 degrees wall than by that of the 0 degrees wall, which is brought about by guidewire bias toward the vascular wall at 180 degrees.

  12. Intra-lesional spatial correlation of static and dynamic FET-PET parameters with MRI-based cerebral blood volume in patients with untreated glioma

    Energy Technology Data Exchange (ETDEWEB)

    Goettler, Jens; Preibisch, Christine [TU Muenchen, Department of Neuroradiology, Klinikum rechts der Isar, Munich (Germany); TU Muenchen, TUM Neuroimaging Center (TUM-NIC), Klinikum rechts der Isar, Munich (Germany); Lukas, Mathias; Mustafa, Mona; Schwaiger, Markus; Pyka, Thomas [TU Muenchen, Department of Nuclear Medicine, Klinikum rechts der Isar, Munich (Germany); Kluge, Anne; Kaczmarz, Stephan; Zimmer, Claus [TU Muenchen, Department of Neuroradiology, Klinikum rechts der Isar, Munich (Germany); Gempt, Jens; Ringel, Florian; Meyer, Bernhard [TU Muenchen, Department of Neurosurgery, Klinikum rechts der Isar, Munich (Germany); Foerster, Stefan [TU Muenchen, TUM Neuroimaging Center (TUM-NIC), Klinikum rechts der Isar, Munich (Germany); TU Muenchen, Department of Nuclear Medicine, Klinikum rechts der Isar, Munich (Germany); Klinikum Bayreuth, Department of Nuclear Medicine, Bayreuth (Germany)

    2017-03-15

    {sup 18}F-fluorethyltyrosine-(FET)-PET and MRI-based relative cerebral blood volume (rCBV) have both been used to characterize gliomas. Recently, inter-individual correlations between peak static FET-uptake and rCBV have been reported. Herein, we assess the local intra-lesional relation between FET-PET parameters and rCBV. Thirty untreated glioma patients (27 high-grade) underwent simultaneous PET/MRI on a 3 T hybrid scanner obtaining structural and dynamic susceptibility contrast sequences. Static FET-uptake and dynamic FET-slope were correlated with rCBV within tumour hotspots across patients and intra-lesionally using a mixed-effects model to account for inter-individual variation. Furthermore, maximal congruency of tumour volumes defined by FET-uptake and rCBV was determined. While the inter-individual relationship between peak static FET-uptake and rCBV could be confirmed, our intra-lesional, voxel-wise analysis revealed significant positive correlations (median r = 0.374, p < 0.0001). Similarly, significant inter- and intra-individual correlations were observed between FET-slope and rCBV. However, rCBV explained only 12% of the static and 5% of the dynamic FET-PET variance and maximal overlap of respective tumour volumes was 37% on average. Our results show that the relation between peak values of MR-based rCBV and static FET-uptake can also be observed intra-individually on a voxel basis and also applies to a dynamic FET parameter, possibly determining hotspots of higher biological malignancy. However, just a small part of the FET-PET signal variance is explained by rCBV and tumour volumes determined by the two modalities showed only moderate overlap. These findings indicate that FET-PET and MR-based rCBV provide both congruent and complimentary information on glioma biology. (orig.)

  13. Current concepts on posterior meniscal root lesion: A treatment algorithm based on the currently available evidence

    OpenAIRE

    Guan-Yang Song; Jin Zhang; Xu Li; Yue Li; Hua Feng

    2014-01-01

    Meniscal root lesion is defined as an avulsion of the tibial insertion of the meniscus or a radial tear close to the meniscal insertion, which is commonly observed at the posterior region in the clinical practice. Although a number of biomechanical and clinical studies have shown the importance of the integrity of the posterior meniscal roots, the appropriate treatment is still controversial. The purposes of this review are to develop a current understanding of how the posterior meniscal root...

  14. Efficient quantum key distribution based on pulse-position modulation

    Science.gov (United States)

    Zhang, Yequn; Djordjevic, Ivan B.; Neifeld, Mark A.

    2014-10-01

    Pulse-position modulation (PPM) is a promising technique that can be used to improve the efficiency of quantum key distribution (QKD) based on a Poisson photon source. In this paper, we first investigate a simple entanglement-and- PPM-based QKD protocol and demonstrate the improvement in secret key rate. However, such a PPM-based QKD protocol that utilizes only frames with a single click is still inefficient because it ignores frames with two and more clicks. For this reason we propose to use such multi-click frames to further improve the efficiency of PPM-based QKD by employing a better sifting strategy. Specifically, we focus on using the frames with two clicks in addition to those with a single click. Finally, we analyze the secret key rate under various noise levels in the scenario of high channel loss, which has been faced by most QKD applications. With the analytical results, we show the advantage of the proposed PPM-based QKD.

  15. Nucleotide Excision Repair Lesion-Recognition Protein Rad4 Captures a Pre-Flipped Partner Base in a Benzo[a]pyrene-Derived DNA Lesion: How Structure Impacts the Binding Pathway

    Science.gov (United States)

    2017-01-01

    The xeroderma pigmentosum C protein complex (XPC) recognizes a variety of environmentally induced DNA lesions and is the key in initiating their repair by the nucleotide excision repair (NER) pathway. When bound to a lesion, XPC flips two nucleotide pairs that include the lesion out of the DNA duplex, yielding a productively bound complex that can lead to successful lesion excision. Interestingly, the efficiencies of NER vary greatly among different lesions, influencing their toxicity and mutagenicity in cells. Though differences in XPC binding may influence NER efficiency, it is not understood whether XPC utilizes different mechanisms to achieve productive binding with different lesions. Here, we investigated the well-repaired 10R-(+)-cis-anti-benzo[a]pyrene-N2-dG (cis-B[a]P-dG) DNA adduct in a duplex containing normal partner C opposite the lesion. This adduct is derived from the environmental pro-carcinogen benzo[a]pyrene and is likely to be encountered by NER in the cell. We have extensively investigated its binding to the yeast XPC orthologue, Rad4, using umbrella sampling with restrained molecular dynamics simulations and free energy calculations. The NMR solution structure of this lesion in duplex DNA has shown that the dC complementary to the adducted dG is flipped out of the DNA duplex in the absence of XPC. However, it is not known whether the “pre-flipped” base would play a role in its recognition by XPC. Our results show that Rad4 first captures the displaced dC, which is followed by a tightly coupled lesion-extruding pathway for productive binding. This binding path differs significantly from the one deduced for the small cis-syn cyclobutane pyrimidine dimer lesion opposite mismatched thymines [MuH., (2015) Biochemistry, 54(34), 5263−726270861]. The possibility of multiple paths that lead to productive binding to XPC is consistent with the versatile lesion recognition by XPC that is required for successful NER. PMID:28460163

  16. Image annotation based on positive-negative instances learning

    Science.gov (United States)

    Zhang, Kai; Hu, Jiwei; Liu, Quan; Lou, Ping

    2017-07-01

    Automatic image annotation is now a tough task in computer vision, the main sense of this tech is to deal with managing the massive image on the Internet and assisting intelligent retrieval. This paper designs a new image annotation model based on visual bag of words, using the low level features like color and texture information as well as mid-level feature as SIFT, and mixture the pic2pic, label2pic and label2label correlation to measure the correlation degree of labels and images. We aim to prune the specific features for each single label and formalize the annotation task as a learning process base on Positive-Negative Instances Learning. Experiments are performed using the Corel5K Dataset, and provide a quite promising result when comparing with other existing methods.

  17. Lesion activity assessment

    DEFF Research Database (Denmark)

    Ekstrand, K R; Zero, D T; Martignon, S

    2009-01-01

    in response to cariogenic plaque as well as lesion arrest. Based on this understanding, different clinical scoring systems have been developed to assess the severity/depth and activity of lesions. A recent system has been devised by the International Caries Detection and Assessment System Committee......This chapter focusses on the probability of a caries lesion detected during a clinical examination being active (progressing) or arrested. Visual and tactile methods to assess primary coronal lesions and primary root lesions are considered. The evidence level is rated as low (R....... The literature suggests that there is a fair agreement between visual/tactile external scripts of caries and the severity/depth of the lesion. The reproducibility of the different systems is, in general, substantial. No single clinical predictor is able to reliably assess activity. However, a combination...

  18. Positive Instruction in Music Studios: Introducing a New Model for Teaching Studio Music in Schools Based upon Positive Psychology.

    Science.gov (United States)

    Patston, Tim; Waters, Lea

    This practice paper explores the intersection of school studio-music pedagogy and positive psychology in order to enhance students' learning and engagement. The paper has a practitioner focus and puts forward a new model of studio teaching, the Positive Instruction in Music Studios (PIMS) model that guides teachers through four key positive psychology processes that can be used in a music lesson: positive priming, strengths spotting, positive pause, and process praise. The model provides a new, positively oriented approach to studio-music pedagogy that can be integrated into specific methods-based programs to enhance student learning and engagement.

  19. Monitoring imaging of lesions induced by high intensity focused ultrasound based on differential ultrasonic attenuation and integrated backscatter estimation.

    Science.gov (United States)

    Zhong, Hui; Wan, Ming-Xi; Jiang, Yi-Feng; Wang, Su-Pin

    2007-01-01

    We investigated the feasibility of two monitoring imaging methods to visualize and evaluate the high intensity focused ultrasound (HIFU) induced lesions in vitro during and after their formation, which were based on differential ultrasonic parameter estimation. Firstly, ultrasonic attenuation slope of tissue sample was estimated based on the spectral analysis of ultrasound RF backscattered signals. The differential attenuation slope maps were acquired, which were interpreted as the differences between the pretreatment image and those obtained in different stages during HIFU therapy. Secondly, ultrasonic integrated backscatter (IBS), defined as the frequency average of the backscatter transfer function over the useful bandwidth, was proposed quantitatively to evaluate the extent of lesions with the same RF signals as the first method. Differential IBS maps were also acquired to visualize temporal evolution of lesion formation. It was found in pig liver in vitro that more precise definition of the treated area was obtained from the differential IBS images than from differential attenuation slope images. Dramatic increase in both attenuation and IBS value was observed during the therapy, which may be related to dramatic enhancement of cavitation due to boiling and accompanying tissue damage. Two methods to obtain one differential image were compared and the cumulative differential image was found to be able to eliminate noises and artifacts to some extent, which was the cumulation of a series of differential images acquired from the differences between the temporally adjacent RF data frames. Moreover, we presented a bidirectional color code for identification of the artifacts due to tissue movements caused by HIFU radiation force. We conclude that cumulative differential IBS images have the potential to monitor the formation of HIFU-induced lesions.

  20. A Solar Position Sensor Based on Image Vision.

    Science.gov (United States)

    Ruelas, Adolfo; Velázquez, Nicolás; Villa-Angulo, Carlos; Acuña, Alexis; Rosales, Pedro; Suastegui, José

    2017-07-29

    Solar collector technologies operate with better performance when the Sun beam direction is normal to the capturing surface, and for that to happen despite the relative movement of the Sun, solar tracking systems are used, therefore, there are rules and standards that need minimum accuracy for these tracking systems to be used in solar collectors' evaluation. Obtaining accuracy is not an easy job, hence in this document the design, construction and characterization of a sensor based on a visual system that finds the relative azimuth error and height of the solar surface of interest, is presented. With these characteristics, the sensor can be used as a reference in control systems and their evaluation. The proposed sensor is based on a microcontroller with a real-time clock, inertial measurement sensors, geolocation and a vision sensor, that obtains the angle of incidence from the sunrays' direction as well as the tilt and sensor position. The sensor's characterization proved how a measurement of a focus error or a Sun position can be made, with an accuracy of 0.0426° and an uncertainty of 0.986%, which can be modified to reach an accuracy under 0.01°. The validation of this sensor was determined showing the focus error on one of the best commercial solar tracking systems, a Kipp & Zonen SOLYS 2. To conclude, the solar tracking sensor based on a vision system meets the Sun detection requirements and components that meet the accuracy conditions to be used in solar tracking systems and their evaluation or, as a tracking and orientation tool, on photovoltaic installations and solar collectors.

  1. A Solar Position Sensor Based on Image Vision

    Directory of Open Access Journals (Sweden)

    Adolfo Ruelas

    2017-07-01

    Full Text Available Solar collector technologies operate with better performance when the Sun beam direction is normal to the capturing surface, and for that to happen despite the relative movement of the Sun, solar tracking systems are used, therefore, there are rules and standards that need minimum accuracy for these tracking systems to be used in solar collectors’ evaluation. Obtaining accuracy is not an easy job, hence in this document the design, construction and characterization of a sensor based on a visual system that finds the relative azimuth error and height of the solar surface of interest, is presented. With these characteristics, the sensor can be used as a reference in control systems and their evaluation. The proposed sensor is based on a microcontroller with a real-time clock, inertial measurement sensors, geolocation and a vision sensor, that obtains the angle of incidence from the sunrays’ direction as well as the tilt and sensor position. The sensor’s characterization proved how a measurement of a focus error or a Sun position can be made, with an accuracy of 0.0426° and an uncertainty of 0.986%, which can be modified to reach an accuracy under 0.01°. The validation of this sensor was determined showing the focus error on one of the best commercial solar tracking systems, a Kipp & Zonen SOLYS 2. To conclude, the solar tracking sensor based on a vision system meets the Sun detection requirements and components that meet the accuracy conditions to be used in solar tracking systems and their evaluation or, as a tracking and orientation tool, on photovoltaic installations and solar collectors.

  2. Laryngeal giant cell tumour presenting as a tongue base lesion causing severe dysphagia

    Directory of Open Access Journals (Sweden)

    Mohd Razi M. Saud, MBBS

    2018-04-01

    Full Text Available الملخص: أورام الخلايا العملاقة هي آفات حميدة وغير مألوفة تظهر في الحنجرة. قد يصاب المريض بصعوبة في البلع، وبحة في الصوت وتورم في الجهة الأمامية من الرقبة. أورام الخلايا العملاقة هي نادرة للغاية، وهناك حالات قليلة في الأدبيات المنشورة. نعرض لحالة إمرأة مسنة قدمت بصعوبة شديدة في البلع، وورم في قاعدة اللسان. أظهرت نتيجة الورم بأنه ورم الخلايا العملاقة في الحنجرة وتم علاجه بنجاح باستخدام المعالجة الكيميائية. Abstract: Giant cell tumours are benign lesions that are uncommonly found in the larynx. Patients with these tumours may present with dysphagia, hoarseness and anterior neck swelling. Giant cell tumours are extremely rare and only a few cases have been reported. We present a case of an elderly woman who presented with severe dysphagia and a mass at the base of her tongue. The mass was found to be a laryngeal giant cell tumour and was successfully treated with chemotherapy. الكلمات المفتاحية: أورام الخلايا العملاقة, الحنجرة, صعوبة البلع, دينوسوماب, المعالجة الكيميائية, Keywords: Chemotherapy, Denosumab, Dysphagia, Giant cell tumour, Larynx

  3. ALA-based fluorescent diagnosis of malignant oral lesions in the presence of bacterial porphyrin formation

    Science.gov (United States)

    Schleier, P.; Berndt, A.; Zinner, K.; Zenk, W.; Dietel, W.; Pfister, W.

    2006-02-01

    The aminolevulinic acid (5-ALA) -based fluorescence diagnosis has been found to be promising for an early detection and demarcation of superficial oral squamous cell carcinomas (OSCC). This method has previously demonstrated high sensitivity, however this clinical trial showed a specificity of approximately 62 %. This specificity was mainly restricted by tumor detection in the oral cavity in the presence of bacteria. After topical ALA application in the mouth of patients with previously diagnosed OSSC, red fluorescent areas were observed which did not correlate to confirm histological findings. Swabs and plaque samples were taken from 44 patients and cultivated microbiologically. Fluorescence was investigated (OMA-system) from 32 different bacteria strains found naturally in the oral cavity. After ALA incubation, 30 of 32 strains were found to synthesize fluorescent porphyrins, mainly Protoporphyrin IX. Also multiple fluorescent spectra were obtained having peak wavelengths of 636 nm and around 618 nm - 620 nm indicating synthesis of different porphyrins, such as the lipophylic Protoporphyrin IX (PpIX) and hydrophylic porphyrins (water soluble porphyrins, wsp). Of the 32 fluorescent bacterial strains, 18 produced wsp, often in combination with PpIX, and 5 produced solely wsp. These results clarify that ALA-based fluorescence diagnosis without consideration or suppression of bacteria fluorescence may lead to false-positive findings. It is necessary to suppress bacteria fluorescence with suitable antiseptics before starting the procedure. In this study, when specific antiseptic pre-treatment was performed bacterial associated fluorescence was significantly reduced.

  4. Position Mooring Control Based on a Structural Reliability Criterion

    DEFF Research Database (Denmark)

    Fang, Shaoji; Leira, Bernt J.; Blanke, Mogens

    2013-01-01

    To prevent failure of mooring lines in modern position mooring (PM) systems, position moored vessels are kept within a small distance from a desired reference position. A safe position within such region is where stress in all mooring lines are kept well below tensile strength. To prevent several...

  5. World wide web-based cytological analysis of atypical squamous cells cannot exclude high-grade intraepithelial lesions.

    Science.gov (United States)

    Washiya, Kiyotada; Takamizu, Ryuichi; Kumagai, Yukie; Himeji, Yukari; Kobayashi, Takako; Iwai, Muneo; Watanabe, Jun

    2012-01-01

    It has been reported that the low level of consistency of diagnosis of atypical squamous cells cannot exclude high-grade squamous intraepithelial lesions (ASC-H) in uterine cervical cancer screening using the Bethesda System, indicating the necessity of a large-scale survey. We presented cases cytologically judged as ASC-H on our website and invited our members to give their opinions regarding the diagnosis by voting online. The Web voting results were analyzed and ASC-H was cytologically investigated. Virtual slides of atypical cells in cytology preparations of 53 cases were prepared and presented on a website. ASC-H cases were divided into 42 cases sampled by brush scraping and 11 cases sampled by cotton swab scraping. Fifty-three cases cytologically judged as ASC-H were classified into benign and CIN2/3, and their patterns of arrangement of atypical cells and 8 cytological parameters were morphologically investigated. The frequency of ASC-H diagnosis in the Web votes was low: 29.2% for brush-scraped and 26.2% for cotton swab-scraped cases. Three-dimensionality, coarse chromatin and irregular nuclei were significantly different between high-grade squamous intraepithelial lesions and benign cases. Web-based surveys showed the difference of cytological findings between high-grade squamous intraepithelial lesions and benign cases. To increase interobserver consistency, it may be useful to share information online, which avoids geographical and temporal limitations. Copyright © 2012 S. Karger AG, Basel.

  6. Digital tomosynthesis as a problem-solving imaging technique to confirm or exclude potential thoracic lesions based on chest X-ray radiography.

    Science.gov (United States)

    Quaia, Emilio; Baratella, Elisa; Poillucci, Gabriele; Kus, Sara; Cioffi, Vincenzo; Cova, Maria Assunta

    2013-05-01

    To assess the capability of digital tomosynthesis (DTS) as a problem-solving imaging technique to confirm or exclude potential thoracic lesions based on chest x-ray radiography (CXR). Four hundred and-sixty five patients (263 male, 202 female; age, 72.47 ± 11.33 years) with suspected thoracic lesion(s) after the initial onsite analysis of CXR underwent DTS. Two independent readers prospectively analyzed in consensus CXR and DTS images on a picture archiving and communications system-integrated workstation and proposed a diagnosis according to a confidence score for each lesion: 1 or 2 = definite or probable pulmonary or pleural benign lesion or pseudolesion deserving no further diagnostic work-up; 3 = indeterminate; 4 or 5 = probable or definite pulmonary lesion deserving further diagnostic work-up by computed tomography (CT). In patients who did not undergo chest CT, the DTS findings had to be confirmed by 6 to 12 months' imaging follow-up. Finally, 229 pulmonary lesions (193 thoracic and 36 pleural lesions) and 236 pseudolesions were identified. Based on DTS images, readers correctly classified all pseudolesions except for 10/236 (reader 1) or 11/236 (reader 2) pseudolesions and 7 (reader 1) or 6 (reader 2) pulmonary subpleural lesions located in the anterior or posterior lung region close to the thoracic wall. Chest CT was performed in 127/465 (27%) patients, whereas in 338/465 patients (73%) CXR doubtful findings were resolved by DTS. DTS allowed to exclude most pseudolesions initially considered as potential thoracic lesions on the preliminary onsite assessment of CXR and allowed to exclude pulmonary lesions deserving CT assessment in about three fourths of the patients. Copyright © 2013 AUR. Published by Elsevier Inc. All rights reserved.

  7. HISTOPATHOLOGICAL PROFILE OF LIVER LESIONS IN AUTOPSY EXAMINATION- A HOSPITAL-BASED STUDY

    Directory of Open Access Journals (Sweden)

    Ratan Konjengbam

    2017-06-01

    Full Text Available BACKGROUND Liver is the main site of various primary and secondary diseases including variety of external agents. Most of the chronic liver diseases remained asymptomatic even in the late stage. In apparently healthy persons, many liver lesions are detected incidentally following a postmortem examination. MATERIALS AND METHODS The present study was done for a period of 5 years in a tertiary hospital to evaluate the histopathological profile of liver specimen in autopsy examination. Haematoxylin and Eosin sections of liver specimen were studied. A total of 352 samples were evaluated with male predominates the female sex in the ratio of 5.2:1. RESULTS The most common lesion was fatty liver (19% followed by cirrhosis (11.8%, venous congestion (11.5%, portal triaditis (10.9%, chronic hepatitis (6.2%, granulomatous hepatitis (2.1%, autolysis (16% and others (0.96%. Liver finding was normal in 14% of the cases. CONCLUSION Silent liver diseases are a quite regular finding in autopsy cases and thereby may implicate a common occurrence in general population. Autopsy examination of liver is a must for detection of silent liver diseases like fatty change, cirrhosis and chronic hepatitis.

  8. IS IT NECESSARY TO EXCISE ALL BREAST LESIONS? EXPERIENCE FROM A UNIVERSITY-BASED BREAST UNIT

    Directory of Open Access Journals (Sweden)

    YIP CH

    2009-01-01

    Full Text Available Background: Breast cancer is becoming more important in Asia since it affect the younger age group. Question arises whether it is safe for breast lesions to be left in-situ if all the elements in triple assessment are benign. The aim of this study is to audit all the excision biopsies of breast lumps done in the University Malaya Medical Centre (UMMC, to review the association of age with the type of pathological finding and to evaluate the rate of carcinoma in these biopsies. Methods: We conducted a retrospective study of all women who had excision biopsy of a breast lump in the University Malaya Medical Centre from January 2005 to December 2006. All patients with malignant preoperative biopsies were excluded. Results: Of 717 lesions in 664 patients, 459 (64% were fibroadenoma, 114 (15.9% were fibrocystic disease, 20 (2.8% were phylloides tumour, 27 (3.8% were papilloma, 59 (8.2% were malignant and 38 (5.3% were of other pathology. Of the 717 open biopsies, 449 (62.6% had fine-needle aspiration cytology (FNAC, 31 (4.3% had core needle biopsy (CNB, while 14 (2.0% had both FNAC and CNB done prior to excision biopsy. 251 (35% had neither FNAC nor CNB. The incidence of fibroadenoma decreased with increasing age and the incidence of fibrocystic changes and papilloma increased with increasing age. There was no association of age with phylloides tumour. The incidence of unexpected malignancy increased with increasing age. The incidence rates were 0.3%, 4.5%, 19.4%, 29.7% and 29.6% for the age group below 30, 30-39, 40-49, 50-59 and above 60 years of age respectively. Of the 59 malignant lesions, FNAC was performed on 47 (79.7% and CNB on 16 (27.1%. 9 had both FNAC and CNB and 3 had neither FNAC nor CNB. Out of the 56 lesions where FNAC/CNB were done, 23 (41.1% were reported as benign, 20 (35.7% as suspicious, 4 (7.1% as atypical, 5 (8.9% as inadequate, 2 (3.6% as equivocal and 2 (3.6% as lymphoid lesions. Out of the 23 prior biopsies reported as

  9. Gender-based comorbidity in benign paroxysmal positional vertigo.

    Directory of Open Access Journals (Sweden)

    Oluwaseye Ayoola Ogun

    Full Text Available It has been noted that benign paroxysmal positional vertigo (BPPV may be associated with certain disorders and medical procedures. However, most studies to date were done in Europe, and epidemiological data on the United States (US population are scarce. Gender-based information is even rarer. Furthermore, it is difficult to assess the relative prevalence of each type of association based solely on literature data, because different comorbidities were reported by various groups from different countries using different patient populations and possibly different inclusion/exclusion criteria. In this study, we surveyed and analyzed a large adult BPPV population (n = 1,360 surveyed, 227 completed, most of which were recurrent BPPV cases from Omaha, NE, US, and its vicinity, all diagnosed at Boys Town National Research Hospital (BTNRH over the past decade using established and consistent diagnostic criteria. In addition, we performed a retrospective analysis of patients' diagnostic records (n = 1,377, with 1,360 adults and 17 children. The following comorbidities were found to be significantly more prevalent in the BPPV population when compared to the age- and gender-matched general population: ear/hearing problems, head injury, thyroid problems, allergies, high cholesterol, headaches, and numbness/paralysis. There were gender differences in the comorbidities. In addition, familial predisposition was fairly common among the participants. Thus, the data confirm some previously reported comorbidities, identify new ones (hearing loss, thyroid problems, high cholesterol, and numbness/paralysis, and suggest possible predisposing and triggering factors and events for BPPV.

  10. Self-inflicted lesions in dermatology: terminology and classification--a position paper from the European Society for Dermatology and Psychiatry (ESDaP)

    NARCIS (Netherlands)

    Gieler, Uwe; Consoli, Sylvie G.; Tomás-Aragones, Lucía; Linder, Dennis M.; Jemec, Gregor B. E.; Poot, Francoise; Szepietowski, Jacek C.; de Korte, John; Taube, Klaus-Michael; Lvov, Andrey; Consoli, Silla M.

    2013-01-01

    The terminology, classification, diagnosis and treatment of self-inflicted dermatological lesions are subjects of open debate. The present study is the result of various meetings of a task force of dermatologists, psychiatrists and psychologists, all active in the field of psychodermatology, aimed

  11. Self-Inflicted Lesions in Dermatology: A Management and Therapeutic Approach - A Position Paper From the European Society for Dermatology and Psychiatry

    NARCIS (Netherlands)

    Tomas-Aragones, Lucia; Consoli, Silla M.; Consoli, Sylvie G.; Poot, Francoise; Taube, Klaus-Michael; Linder, M. Dennis; Jemec, Gregor B. E.; Szepietowski, Jacek C.; de Korte, John; Lvov, Andrey; Gieler, Uwe

    2017-01-01

    The classification of self-inflicted skin lesions proposed by the European Society for Dermatology and Psychiatry (ESDaP) group generated questions with regard to specific treatments that could be recommended for such cases. The therapeutic guidelines in the current paper integrate new

  12. Advanced Multipath Mitigation Techniques for Satellite-Based Positioning Applications

    Directory of Open Access Journals (Sweden)

    Mohammad Zahidul H. Bhuiyan

    2010-01-01

    Full Text Available Multipath remains a dominant source of ranging errors in Global Navigation Satellite Systems (GNSS, such as the Global Positioning System (GPS or the future European satellite navigation system Galileo. Multipath is generally considered undesirable in the context of GNSS, since the reception of multipath can make significant distortion to the shape of the correlation function used for time delay estimation. However, some wireless communications techniques exploit multipath in order to provide signal diversity though in GNSS, the major challenge is to effectively mitigate the multipath, since we are interested only in the satellite-receiver transit time offset of the Line-Of-Sight (LOS signal for the receiver's position estimate. Therefore, the multipath problem has been approached from several directions in order to mitigate the impact of multipath on navigation receivers, including the development of novel signal processing techniques. In this paper, we propose a maximum likelihood-based technique, namely, the Reduced Search Space Maximum Likelihood (RSSML delay estimator, which is capable of mitigating the multipath effects reasonably well at the expense of increased complexity. The proposed RSSML attempts to compensate the multipath error contribution by performing a nonlinear curve fit on the input correlation function, which finds a perfect match from a set of ideal reference correlation functions with certain amplitude(s, phase(s, and delay(s of the multipath signal. It also incorporates a threshold-based peak detection method, which eventually reduces the code-delay search space significantly. However, the downfall of RSSML is the memory requirement which it uses to store the reference correlation functions. The multipath performance of other delay-tracking methods previously studied for Binary Phase Shift Keying-(BPSK- and Sine Binary Offset Carrier- (SinBOC- modulated signals is also analyzed in closed loop model with the new Composite

  13. Classification of breast mass lesions using model-based analysis of the characteristic kinetic curve derived from fuzzy c-means clustering.

    Science.gov (United States)

    Chang, Yeun-Chung; Huang, Yan-Hao; Huang, Chiun-Sheng; Chang, Pei-Kang; Chen, Jeon-Hor; Chang, Ruey-Feng

    2012-04-01

    The purpose of this study is to evaluate the diagnostic efficacy of the representative characteristic kinetic curve of dynamic contrast-enhanced (DCE) magnetic resonance imaging (MRI) extracted by fuzzy c-means (FCM) clustering for the discrimination of benign and malignant breast tumors using a novel computer-aided diagnosis (CAD) system. About the research data set, DCE-MRIs of 132 solid breast masses with definite histopathologic diagnosis (63 benign and 69 malignant) were used in this study. At first, the tumor region was automatically segmented using the region growing method based on the integrated color map formed by the combination of kinetic and area under curve color map. Then, the FCM clustering was used to identify the time-signal curve with the larger initial enhancement inside the segmented region as the representative kinetic curve, and then the parameters of the Tofts pharmacokinetic model for the representative kinetic curve were compared with conventional curve analysis (maximal enhancement, time to peak, uptake rate and washout rate) for each mass. The results were analyzed with a receiver operating characteristic curve and Student's t test to evaluate the classification performance. Accuracy, sensitivity, specificity, positive predictive value and negative predictive value of the combined model-based parameters of the extracted kinetic curve from FCM clustering were 86.36% (114/132), 85.51% (59/69), 87.30% (55/63), 88.06% (59/67) and 84.62% (55/65), better than those from a conventional curve analysis. The A(Z) value was 0.9154 for Tofts model-based parametric features, better than that for conventional curve analysis (0.8673), for discriminating malignant and benign lesions. In conclusion, model-based analysis of the characteristic kinetic curve of breast mass derived from FCM clustering provides effective lesion classification. This approach has potential in the development of a CAD system for DCE breast MRI. Copyright © 2012 Elsevier Inc

  14. Gender-Based Comorbidity in Benign Paroxysmal Positional Vertigo

    Science.gov (United States)

    Ogun, Oluwaseye Ayoola; Janky, Kristen L.; Cohn, Edward S.; Büki, Bela; Lundberg, Yunxia Wang

    2014-01-01

    It has been noted that benign paroxysmal positional vertigo (BPPV) may be associated with certain disorders and medical procedures. However, most studies to date were done in Europe, and epidemiological data on the United States (US) population are scarce. Gender-based information is even rarer. Furthermore, it is difficult to assess the relative prevalence of each type of association based solely on literature data, because different comorbidities were reported by various groups from different countries using different patient populations and possibly different inclusion/exclusion criteria. In this study, we surveyed and analyzed a large adult BPPV population (n = 1,360 surveyed, 227 completed, most of which were recurrent BPPV cases) from Omaha, NE, US, and its vicinity, all diagnosed at Boys Town National Research Hospital (BTNRH) over the past decade using established and consistent diagnostic criteria. In addition, we performed a retrospective analysis of patients’ diagnostic records (n = 1,377, with 1,360 adults and 17 children). The following comorbidities were found to be significantly more prevalent in the BPPV population when compared to the age- and gender-matched general population: ear/hearing problems, head injury, thyroid problems, allergies, high cholesterol, headaches, and numbness/paralysis. There were gender differences in the comorbidities. In addition, familial predisposition was fairly common among the participants. Thus, the data confirm some previously reported comorbidities, identify new ones (hearing loss, thyroid problems, high cholesterol, and numbness/paralysis), and suggest possible predisposing and triggering factors and events for BPPV. PMID:25187992

  15. The Prohibitive Link between Position-based Routing and Planarity

    Directory of Open Access Journals (Sweden)

    David Cairns

    2013-12-01

    Full Text Available Position-based routing is touted as an ideal routing strategy for resource-constrained wireless networks. One persistent barrier to adoption is due to its recovery phase, where messages are forwarded according to leftor right-hand rule (LHR. This is often referred to as face-routing. In this paper we investigate the limits of LHR with respect to planarity.We show that the gap between non-planarity and successful delivery is a single link within a single configuration. Our work begins with an analysis to enumerate all node configurations that cause intersections in the unit-disc graph. We find that left-hand rule is able to recover from all but a single case, the ‘umbrella’ configuration so named for its appearance. We use this information to propose the Prohibitive Link Detection Protocol (PLDP that can guarantee delivery over non-planar graphs using standard face-routing techniques. As the name implies, the protocol detects and circumvents the ‘bad’ links that hamper LHR. The goal of this work is to maintain routing guarantees while disturbing the network graph as little as possible. In doing so, a new starting point emerges from which to build rich distributed protocols in the spirit of CLDP and GDSTR.

  16. Optimised filtering for improved energy and position resolution in position-sensitive TES based X-ray detectors

    International Nuclear Information System (INIS)

    Smith, Stephen J.; Whitford, Chris H.; Fraser, George W.

    2006-01-01

    We report on a new optimal filtering algorithm for improved energy and position resolution in position sensitive Transition Edge Sensor (TES) based X-ray detectors. This algorithm takes account of the noise correlation between the detector outputs to minimise the variance on the estimated photon energy and position. Using numerical methods we show that improved energy and position resolution can be obtained than from previously published methods. Our simulations also reveal the trade-offs resulting from changes in the thermal conductances and heat capacities of the detector elements

  17. Local CD34-positive capillaries decrease in mouse models of kidney disease associating with the severity of glomerular and tubulointerstitial lesions.

    Science.gov (United States)

    Masum, Md Abdul; Ichii, Osamu; Elewa, Yaser Hosny Ali; Nakamura, Teppei; Kon, Yasuhiro

    2017-09-04

    The renal vasculature plays important roles in both homeostasis and pathology. In this study, we examined pathological changes in the renal microvascular in mouse models of kidney diseases. Glomerular lesions (GLs) in autoimmune disease-prone male BXSB/MpJ-Yaa (Yaa) mice and tubulointerstitial lesions (TILs) in male C57BL/6 mice subjected to unilateral ureteral obstruction (UUO) for 7 days were studied. Collected kidneys were examined using histopathological techniques. A nonparametric Mann-Whitney U test (P < 0.05) was performed to compare healthy controls and the experimental mice. The Kruskal-Wallis test was used to compare three or more groups, and multiple comparisons were performed using Scheffe's method when significant differences were observed (P < 0.05). Yaa mice developed severe autoimmune glomerulonephritis, and the number of CD34 + glomerular capillaries decreased significantly in GLs compared to that in control mice. However, UUO-treated mice showed severe TILs only, and CD34 + tubulointerstitial capillaries were decreased significantly in TILs with the progression of tubulointerstitial fibrosis compared to those in untreated control kidneys. Infiltrations of B-cells, T-cells, and macrophages increased significantly in the respective lesions of both disease models (P < 0.05). In observations of vascular corrosion casts by scanning electron microscopy and of microfil rubber-perfused thick kidney sections by fluorescence microscopy, segmental absences of capillaries were observed in the GLs and TILs of Yaa and UUO-treated mice, respectively. Further, transmission electron microscopy revealed capillary endothelial injury in the respective lesions of both models. The numbers of CD34 + glomerular and tubulointerstitial capillaries were negatively correlated with all examined parameters in GLs (P < 0.05) and TILs (P < 0.01), respectively. From the analysis of mouse models, we identified inverse pathological correlations between the number of

  18. Practitioner, patient and carious lesion characteristics associated with type of restorative material: findings from The Dental Practice-Based Research Network.

    Science.gov (United States)

    Makhija, Sonia K; Gordan, Valeria V; Gilbert, Gregg H; Litaker, Mark S; Rindal, D Brad; Pihlstrom, Daniel J; Qvist, Vibeke

    2011-06-01

    The authors conducted a study to identify factors associated with the materials that dentists in The Dental Practice-Based Research Network (DPBRN) use when placing the first restoration on permanent posterior tooth surfaces. A total of 182 DPBRN practitioner-investigators provided data regarding 5,599 posterior teeth with caries. Practitioner-investigators completed an enrollment questionnaire that included the dentist's age, sex, practice workload, practice type and number of years since graduation. When patients who had provided informed consent to participate in the investigation sought treatment for a previously unrestored carious surface, the practitioner-investigator recorded patient and tooth characteristics. Practitioner-investigators used amalgam more often than they used direct resin-based composite (RBC) for posterior carious lesions. Practitioner and practice characteristics (years since graduation and type of practice); patient characteristics (sex, race, age and dental insurance status); and lesion characteristics (tooth location and surface, preoperative and postoperative lesion depth) were associated with the type of restorative material used. Several practitioner and practice, patient and lesion characteristics were associated significantly with use of amalgam and RBC: geographical region, years since dentist's graduation, patient's dental insurance status, tooth location and surface, and preoperative and postoperative lesion depth. Despite advances in esthetic dentistry, U.S. dentists still are placing amalgam on posterior teeth with carious lesions. Amalgam was used more often than RBC in older patients, who may have had deeper carious lesions.

  19. MWA Versus RFA for Perivascular and Peribiliary CRLM: A Retrospective Patient- and Lesion-Based Analysis of Two Historical Cohorts

    Energy Technology Data Exchange (ETDEWEB)

    Tilborg, Aukje A. J. M. van, E-mail: a.vantilborg@vumc.nl; Scheffer, Hester J.; Jong, Marcus C. de; Vroomen, Laurien G. P. H. [VU University Medical Centre, Department of Radiology and Nuclear Medicine (Netherlands); Nielsen, Karin [VU University Medical Centre, Department of Surgical Oncology (Netherlands); Kuijk, Cornelis van [VU University Medical Centre, Department of Radiology and Nuclear Medicine (Netherlands); Tol, Petrousjka M. P. van den [VU University Medical Centre, Department of Surgical Oncology (Netherlands); Meijerink, Martijn R. [VU University Medical Centre, Department of Radiology and Nuclear Medicine (Netherlands)

    2016-10-15

    PurposeTo retrospectively analyse the safety and efficacy of radiofrequency ablation (RFA) versus microwave ablation (MWA) in the treatment of unresectable colorectal liver metastases (CRLM) in proximity to large vessels and/or major bile ducts.Method and MaterialsA database search was performed to include patients with unresectable histologically proven and/or {sup 18}F–FDG–PET avid CRLM who were treated with RFA or MWA between January 2001 and September 2014 in a single centre. All lesions that were considered to have a peribiliary and/or perivascular location were included. Univariate logistic regression analysis was performed to assess the distribution of patient, tumour and procedure characteristics. Multivariate logistic regression was used to correct for potential confounders.ResultsTwo hundred and forty-three patients with 774 unresectable CRLM were ablated. One hundred and twenty-two patients (78 males; 44 females) had at least one perivascular or peribiliary lesion (n = 199). Primary efficacy rate of RFA was superior to MWA after 3 and 12 months of follow-up (P = 0.010 and P = 0.022); however, after multivariate analysis this difference was non-significant at 12 months (P = 0.078) and vanished after repeat ablations (P = 0.39). More CTCAE grade III complications occurred after MWA versus RFA (18.8 vs. 7.9 %; P = 0.094); biliary complications were especially common after peribiliary MWA (P = 0.002).ConclusionFor perivascular CRLM, RFA and MWA are both safe treatment options that appear equally effective. For peribiliary CRLM, MWA has a higher complication rate than RFA, with similar efficacy. Based on these results, it is advised to use RFA for lesions in the proximity of major bile ducts.

  20. Computer aided detection of oral lesions on CT images

    International Nuclear Information System (INIS)

    Galib, S.; Islam, F.; Lee, H.K.; Abir, M.

    2015-01-01

    Oral lesions are important findings on computed tomography (CT) images. In this study, a fully automatic method to detect oral lesions in mandibular region from dental CT images is proposed. Two methods were developed to recognize two types of lesions namely (1) Close border (CB) lesions and (2) Open border (OB) lesions, which cover most of the lesion types that can be found on CT images. For the detection of CB lesions, fifteen features were extracted from each initial lesion candidates and multi layer perceptron (MLP) neural network was used to classify suspicious regions. Moreover, OB lesions were detected using a rule based image processing method, where no feature extraction or classification algorithm were used. The results were validated using a CT dataset of 52 patients, where 22 patients had abnormalities and 30 patients were normal. Using non-training dataset, CB detection algorithm yielded 71% sensitivity with 0.31 false positives per patient. Furthermore, OB detection algorithm achieved 100% sensitivity with 0.13 false positives per patient. Results suggest that, the proposed framework, which consists of two methods, has the potential to be used in clinical context, and assist radiologists for better diagnosis

  1. Strength-based leadership coaching in organizations an evidence-based guide to positive leadership development

    CERN Document Server

    MacKie, Doug

    2016-01-01

    Positive organizational psychology, with its focus on the identification and development of strengths, is a natural ally to executive development and leadership coaching. However, this approach is only just beginning to come to the attention of organizations and consequently, the research base for strength-based coaching is in its early stages of development. Strength-based Leadership Coaching in Organizations reviews strength-based approaches to positive leadership development and evaluates the evidence for their effectiveness, critically assesses their apparent distinctiveness and considers how strengths can be reliably assessed and developed in their organizational context. This book reviews key areas of leader and team development are reviewed and outlines and describes a model of strengths development in organizations. The application of strength-based leadership coaching will be discussed from the managerial and external perspective within the context of career stage, seniority, role challenges and orga...

  2. Pink lesions.

    Science.gov (United States)

    Giacomel, Jason; Zalaudek, Iris

    2013-10-01

    Dermoscopy (dermatoscopy or surface microscopy) is an ancillary dermatologic tool that in experienced hands can improve the accuracy of diagnosis of a variety of benign and malignant pigmented skin tumors. The early and more accurate diagnosis of nonpigmented, or pink, tumors can also be assisted by dermoscopy. This review focuses on the dermoscopic diagnosis of pink lesions, with emphasis on blood vessel morphology and pattern. A 3-step algorithm is presented, which facilitates the timely and more accurate diagnosis of pink tumors and subsequently guides the management for such lesions. Copyright © 2013 Elsevier Inc. All rights reserved.

  3. Peripheral zone lesions of intermediary risk in multiparametric prostate MRI: Frequency and validation of the PI-RADSv2 risk stratification algorithm based on focal contrast enhancement.

    Science.gov (United States)

    Benndorf, Matthias; Waibel, Lorenz; Krönig, Malte; Jilg, Cordula Annette; Langer, Mathias; Krauss, Tobias

    2018-02-01

    To validate the risk stratification algorithm of the Prostate Imaging Reporting and Data System (PI-RADSv2) for intermediary risk lesions (PI-RADSv2 category 3) in the peripheral zone based on focal contrast enhancement and to compare cancer rates in category 3, upgraded category 4 and category 4 based on markedly low ADC value. We retrospectively analyze 172 consecutive patients undergoing prostate MRI with 315 histopathologically verified lesions. We select all lesions either assigned category 3 or category 4 in the peripheral zone for further analysis. We compare cancer rates with the two-sided chi-squared test. To determine inter-observer agreement about contrast enhancement two blinded radiologists evaluate the subset of category 3 lesions based on the diffusion weighted sequence. The frequency of peripheral PI-RADS 3, upgraded PI-RADS 4 and PI-RADS 4 lesions based on markedly low ADC value is 10.8%, 10.8% and 20.3%, respectively. Cancer rates (significant cancer only) in these subgroups are 8.8% (3/34), 23.5% (8/34) and 40.6% (26/64), P PI-RADSv2 category 3 to upgraded category 4 to category 4 based on markedly low ADC value. Peripheral lesions of intermediary risk in the diffusion weighted sequence account for 21.6% of all prostate lesions encountered. Since it is likely that patient management recommendations will be linked to assessment categories in future versions of PI-RADS, cancer rates in upgraded category 4 and category 4 based on markedly low ADC values should be in a similar range. We conclude that in future studies of PI-RADSv2 upgraded category 4 and category 4 based on markedly low ADC value should be reported separately to generate a database for meta-analysis of cancer rates. Copyright © 2017 Elsevier B.V. All rights reserved.

  4. Intraosseous osteolytic lesions

    Energy Technology Data Exchange (ETDEWEB)

    Adler, C.P.; Wenz, W.

    1981-10-01

    Any pathological damage occurring in a bone will produce either an osteolytic or osteosclerotic lesion which can be seen in the macroscopic specimen as well as in the roentgenogram. Various bone lesions may lead to local destructions of the bone. An osteoma or osteoplastic osteosarcoma produces an osteosclerotic lesion showing a dense mass in the roentgenogram; a chondroblastoma or an osteoclastoma, on the other hand, induces an osteolytic focal lesion. This paper presents examples of different osteolytic lesions of the humerus. An osteolytic lesion seen in the roentgenogram may be either produced by an underlying non-ossifying fibroma of the bone, by fibrous dysplasia, osteomyelitis or Ewing's sarcoma. Differential diagnostic considerations based on the radiological picture include eosinophilic bone granuloma, juvenile or aneurysmal bone cyst, multiple myeloma or bone metastases. Serious differential diagnostic problems may be involved in case of osteolytic lesions occurring in the humerus. Cases of this type involving complications have been reported and include the presence of an teleangiectatic osteosarcoma as well as that of a hemangiosarcoma of the bone.

  5. Troponina T positiva em paciente chagásico com taquicardia ventricular sustentada e cinecoronariografia sem lesões obstrutivas Positive troponin T in a chagasic patient with sustained ventricular tachycardia and no obstructive lesions on cine coronary angiography

    Directory of Open Access Journals (Sweden)

    Maurício de Nassau Machado

    2005-02-01

    Full Text Available A avaliação e estratificação de pacientes com dor torácica na sala de emergência pode nos direcionar a terapêutica adequada a cada paciente baseada na probabilidade da presença de doença coronariana aguda e no risco de eventos cardíacos maiores desta coronariopatia. Esta avaliação é baseada no tripé: quadro clínico, achados eletrocardiográficos e nos marcadores de lesão miocárdica. Relatamos o caso de um paciente chagásico de 58 anos de idade admitido na unidade de emergência por dor torácica e palpitações, com eletrocardiograma mostrando uma taquicardia ventricular sustentada e com dosagem de troponina positiva (0,99 ng/ml, submetido a cinecoronariografia, que não evidenciou doença coronariana obstrutiva.The assessment and stratification of patients with chest pain in the emergency unit may indicate the appropriate therapy for each patient based on the probability of the presence of acute coronary artery disease and on the risk of its major cardiac events. That assessment is based on the triplet: clinical setting, electrocardiographic findings, and markers of myocardial lesion. We report the case of a 58-year-old male chagasic patient admitted to the emergency unit due to chest pain and palpitations, with an electrocardiogram showing sustained ventricular tachycardia and positive troponin measurement (0.99 ng/mL. The patient underwent cine coronary angiography, which evidenced no obstructive coronary artery disease.

  6. Can the Diagnostics of Triangular Fibrocartilage Complex Lesions Be Improved by MRI-Based Soft-Tissue Reconstruction? An Imaging-Based Workup and Case Presentation

    Directory of Open Access Journals (Sweden)

    Niels Hammer

    2017-01-01

    Full Text Available Introduction. The triangular fibrocartilage complex (TFCC provides both mobility and stability of the radiocarpal joint. TFCC lesions are difficult to diagnose due to the complex anatomy. The standard treatment for TFCC lesions is arthroscopy, posing surgery-related risks onto the patients. This feasibility study aimed at developing a workup for soft-tissue reconstruction using clinical imaging, to verify these results in retrospective patient data. Methods. Microcomputed tomography (μ-CT, 3 T magnetic resonance imaging (MRI, and plastination were used to visualize the TFCC in cadaveric specimens applying segmentation-based 3D reconstruction. This approach further trialed the MRI dataset of a patient with minor radiological TFCC alterations but persistent pain. Results. TFCC reconstruction was impossible using μ-CT only but feasible using MRI, resulting in an appreciation of its substructures, as seen in the plastinates. Applying this approach allowed for visualizing a Palmer 2C lesion in a patient, confirming ex postum the arthroscopy findings, being markedly different from MRI (Palmer 1B. Discussion. This preliminary study showed that image-based TFCC reconstruction may help to identify pathologies invisible in standard MRI. The combined approach of μ-CT, MRI, and plastination allowed for a three-dimensional appreciation of the TFCC. Image quality and time expenditure limit the approach’s usefulness as a diagnostic tool.

  7. A fully automatic end-to-end method for content-based image retrieval of CT scans with similar liver lesion annotations.

    Science.gov (United States)

    Spanier, A B; Caplan, N; Sosna, J; Acar, B; Joskowicz, L

    2018-01-01

    The goal of medical content-based image retrieval (M-CBIR) is to assist radiologists in the decision-making process by retrieving medical cases similar to a given image. One of the key interests of radiologists is lesions and their annotations, since the patient treatment depends on the lesion diagnosis. Therefore, a key feature of M-CBIR systems is the retrieval of scans with the most similar lesion annotations. To be of value, M-CBIR systems should be fully automatic to handle large case databases. We present a fully automatic end-to-end method for the retrieval of CT scans with similar liver lesion annotations. The input is a database of abdominal CT scans labeled with liver lesions, a query CT scan, and optionally one radiologist-specified lesion annotation of interest. The output is an ordered list of the database CT scans with the most similar liver lesion annotations. The method starts by automatically segmenting the liver in the scan. It then extracts a histogram-based features vector from the segmented region, learns the features' relative importance, and ranks the database scans according to the relative importance measure. The main advantages of our method are that it fully automates the end-to-end querying process, that it uses simple and efficient techniques that are scalable to large datasets, and that it produces quality retrieval results using an unannotated CT scan. Our experimental results on 9 CT queries on a dataset of 41 volumetric CT scans from the 2014 Image CLEF Liver Annotation Task yield an average retrieval accuracy (Normalized Discounted Cumulative Gain index) of 0.77 and 0.84 without/with annotation, respectively. Fully automatic end-to-end retrieval of similar cases based on image information alone, rather that on disease diagnosis, may help radiologists to better diagnose liver lesions.

  8. Margin Reflex Distance: Differences Based on Camera and Flash Positions.

    Science.gov (United States)

    Choi, Catherine J; Chou, Jonathan C; Lefebvre, Daniel R; Yoon, Michael K

    2016-01-01

    To evaluate the effect of camera flash position on the measurement of photographic margin reflex distances (MRD). Subjects without any ophthalmic disease were prospectively enrolled after institutional review board approval. Clinical measurements of MRD1 and interpalpebral fissure were obtained. Photographs were then taken with a digital single lens reflex with built-in pop-up flash (dSLR-pop), a dSLR with lens-mounted ring flash (dSLR-ring), a point-and-shoot camera, and a smartphone, each in 4 positions: with the camera upright, rotated 90°, 180°, and 270°. The images were analyzed using ImageJ software to measure MRD1, interpalpebral fissure, horizontal white-to-white, and distance from nasal limbus to the corneal light reflex. Thirty-two eyes of 16 subjects were included (ages 27-65). When using the dSLR-ring, point-and-shoot, and smartphone, the difference between clinical and photographic MRD1 did not reach statistical significance. There was, however, a statistically significant difference in the upright position with dSLR-pop (mean difference 0.703 mm, σ = 0.984 mm, p = 0.0008). For dSLR-pop, photographic MRD1 in upright versus inverted position differed significantly (mean difference -0.562 mm, σ =0.348 mm, p MRD1 between dSLR-pop and dSLR-ring showed significant difference in upright position (mean difference -0.572 mm, σ = 0.701 mm, p = 0.0002). There were no statistically significant differences between clinical and photographic interpalpebral fissure, and among white-to-white and nasal limbus to light reflex measurements in any position in all 4 cameras. When using photographs for measurement of MRD1, cameras with a near-coaxial light source and aperture have values that are most similar to clinical measurements.

  9. Position Detection Based on Intensities of Reflected Infrared Light

    DEFF Research Database (Denmark)

    Christensen, Henrik Vie

    measurements of reflected light intensities, and includes easy calibration. The method for reconstructing 3D positions has been implemented in a prototype of a “non-Touch Screen” for a computer, so that the user can control a cursor in three dimensions by moving his/hers hand in front of the computer screen....... The 2D position reconstruction method is mplemented in a prototype of a human-machine interface (HMI) for an electrically powered wheelchair, such that the wheelchair user can control the movement of the wheelchair by head movements. Both “non-Touch Screen” prototype and wheelchair HMI has been tested...

  10. Precision positioning system based on intelligent Fuzzy-PID control

    Science.gov (United States)

    Liu, Zhen; Zhang, Liqiong; Li, Yan

    2010-08-01

    To break through the limitations of static and dynamic characteristics of conventional step motor driven open-loop positioning devices, a two-dimensional precision positioning system with a travel range of 100mm×100mm has been developed. This paper presents its structure, control principle and performance experiments. This system, equipped with cross roller guides working as linear guiding elements, is driven by step motors through ball screw transmission. A threeaxis dual-frequency laser interferometric measurement system is established for real-time measurement and feedback of system's movements in three degrees of freedom (DOF) and an intelligent Fuzzy-PID controller is implemented for this system's motion control. In the controller, the PID module calculates the output from motor drivers and its initial parameters are tuned through expansion of critical proportioning method; the Fuzzy module optimizes PID parameters to fulfill specific requirements of different movement stages. A dead zone control mechanism is developed in this controller to minimize the oscillations around target position. Experimental results indicate that system with Fuzzy-PID controller shows faster response than that with ordinary PID controller. Moreover, with this controller implemented, the developed precision positioning system achieves better repeatability (+/-2μm) and accuracy (+/-2.5μm) within the full range than open-loop system using step motor.

  11. A Hybrid Positioning Method Based on Hypothesis Testing

    DEFF Research Database (Denmark)

    Amiot, Nicolas; Pedersen, Troels; Laaraiedh, Mohamed

    2012-01-01

    We consider positioning in the scenario where only two reliable range estimates, and few less reliable power observations are available. Such situations are difficult to handle with numerical maximum likelihood methods which require a very accurate initialization to avoid being stuck into local...

  12. Evidence-based treatments for the asymptomatic HIV- positive ...

    African Journals Online (AJOL)

    banzi

    The absolute risk reduction (ARR) was. 11% which translates to a number needed to treat (NNT) of 9 (95%. CI 7 - 14). In other words, using this regimen one needs to treat on average only 9 HIV-positive preg- nant mothers to prevent 1 infant from getting AIDS. Even when shorter regimens were used several. RCTs22-24.

  13. Shape based automated detection of pulmonary nodules with surface feature based false positive reduction

    International Nuclear Information System (INIS)

    Nomura, Y.; Itoh, H.; Masutani, Y.; Ohtomo, K.; Maeda, E.; Yoshikawa, T.; Hayashi, N.

    2007-01-01

    We proposed a shape based automated detection of pulmonary nodules with surface feature based false positive (FP) reduction. In the proposed system, the FP existing in internal of vessel bifurcation is removed using extracted surface of vessels and nodules. From the validation with 16 chest CT scans, we find that the proposed CAD system achieves 18.7 FPs/scan at 90% sensitivity, and 7.8 FPs/scan at 80% sensitivity. (orig.)

  14. Lesion-based detection of early chemosensitivity using serial static FDG PET/CT in metastatic colorectal cancer

    Energy Technology Data Exchange (ETDEWEB)

    Buvat, Irene; Necib, Hatem [IMNC UMR 8165 CNRS - Paris 7 and Paris 11 Universities, Orsay cedex (France); Garcia, Camilo; Wagner, Antoine; Vanderlinden, Bruno; Flamen, Patrick [Universite Libre de Bruxelles, Nuclear Medicine Department, Institut Jules Bordet, Brussels (Belgium); Emonts, Patrick [Universite Libre de Bruxelles, Radiology Department, Institut Jules Bordet, Brussels (Belgium); Hendlisz, Alain [Universite Libre de Bruxelles, Digestive Oncology, Institut Jules Bordet, Brussels (Belgium)

    2012-10-15

    Medical oncology needs early identification of patients that are not responding to systemic therapy. {sup 18}F-Fluorodeoxyglucose (FDG) positron emission tomography (PET) performed before and early during treatment has been proposed for this purpose. However, the best way to assess the change in FDG uptake between two scans has not been identified. We studied cutoff thresholds to identify responding tumours as a function of the method used to measure tumour uptake. The study included 28 metastatic colorectal cancer (mCRC) patients who underwent 2 FDG PET/CT scans (baseline and at day 14 of the first course of polychemotherapy). For 78 tumour lesions, 4 standardized uptake value (SUV) indices were measured: maximum SUV (SUV{sub max}) and mean SUV in a region obtained using an isocontour (SUV{sub 40} {sub %}), with each of these SUV normalized either by the patient body weight (BW) or body surface area (BSA). The per cent change and absolute change in tumour uptake between the baseline and the early PET scans were measured based on these four indices. These changes were correlated to the RECIST 1.0-based response using contrast-enhanced CT at baseline and at 6-8 weeks on treatment. The 78 tumours were classified as non-responding (NRL, n = 58) and responding lesions (RL, n = 20). Receiver-operating characteristic (ROC) curves characterizing the performance in NRL/RL classification using early FDG PET uptake had areas under the curve between 0.75 and 0.84, without significant difference between the indices. The cutoff threshold in FDG uptake per cent change to get a 95 % sensitivity of RL detection depended on the way uptake was measured: -14 % (specificity of 53 %) and -22 % (specificity of 64 %) for SUV{sub max} and SUV{sub 40} {sub %}, respectively. Thresholds expressed as absolute SUV decrease instead of per cent change were less sensitive to the SUV definition: an SUV decline by 1.2 yielded a sensitivity of RL detection of 95 % for SUV{sub max} and SUV{sub 40

  15. Petrous apex mass lesions

    International Nuclear Information System (INIS)

    Settanni, Flavio A.P.; Testa, Jose Ricardo Gurgel; Campos, Roberto Augusto de Carvalho; Goes Filho, Jose Francisco de; Guerrero, Andre Luiz; Nascimento, Luiz Augusto; Frazatto, Ricardo

    2000-01-01

    The authors discuss the difficulties in diagnosing lesions of the petrous apex. Petrous apex involvement remains silent until the disease reaches and advanced stage of development. Symptoms and signs related to these lesions are due to involvement of adjacent neurovascular structures and may be nonspecific early in the course of the disease. The diagnosis is based on a combined CT and MRI evaluation of the temporal bone region. CT and MRI findings are often sufficient for a confident preoperative differentiation and diagnosis. Characteristic imaging findings associated with their pattern of erosion and spreading can distinguish the types of expansive lesions arising from the petrous apex such as trigeminal schwannomas, cholesterol granulomas, cholesteatomas and aneurysms of the petrous portion of the internal carotid artery. However, an arteriographic evaluation should be performed if a vascular lesion is strongly suspected. (author)

  16. Managing Carious Lesions

    DEFF Research Database (Denmark)

    Schwendicke, F; Frencken, J E; Bjørndal, L

    2016-01-01

    The International Caries Consensus Collaboration undertook a consensus process and here presents clinical recommendations for carious tissue removal and managing cavitated carious lesions, including restoration, based on texture of demineralized dentine. Dentists should manage the disease dental...... caries and control activity of existing cavitated lesions to preserve hard tissues and retain teeth long-term. Entering the restorative cycle should be avoided as far as possible. Controlling the disease in cavitated carious lesions should be attempted using methods which are aimed at biofilm removal...... or control first. Only when cavitated carious lesions either are noncleansable or can no longer be sealed are restorative interventions indicated. When a restoration is indicated, the priorities are as follows: preserving healthy and remineralizable tissue, achieving a restorative seal, maintaining pulpal...

  17. Beam based measurement of beam position monitor electrode gains

    OpenAIRE

    D. L. Rubin; M. Billing; R. Meller; M. Palmer; M. Rendina; N. Rider; D. Sagan; J. Shanks; C. Strohman

    2010-01-01

    Low emittance tuning at the Cornell Electron Storage Ring (CESR) test accelerator depends on precision measurement of vertical dispersion and transverse coupling. The CESR beam position monitors (BPMs) consist of four button electrodes, instrumented with electronics that allow acquisition of turn-by-turn data. The response to the beam will vary among the four electrodes due to differences in electronic gain and/or misalignment. This variation in the response of the BPM electrodes will couple ...

  18. The lesion in stereotactic suscaudate tractotomy.

    Science.gov (United States)

    Newcombe, R

    1975-05-01

    The anatomical distribution of 25 stereotactic tractotomy lesions is described. The posterior half of these lesions lie in a subcaudate position and the anterior half, for the most part, lies beneath the central segment of frontal white matter.

  19. Analysis of pulmonary coin lesions

    International Nuclear Information System (INIS)

    Kim, O; Kim, K. H.; Oh, K. K.; Park, C. Y.

    1979-01-01

    For A long time the solitary pulmonary nodule has remained a difficult problem to solve and has attracted a great deal of attension in recent years. Circumscribed coin lesions of the lung were generally peripheral in location with respect to the pulmonary hilus. Because of this, important clinical problem in management and diagnosis arise. Such a lesion is discovered through roentgenologic examination. So the roentgenologists is the first be in a position to offer advise. This presentation is an attempt to correlate a useful diagnosis with roentgenologic findings of pulmonary coin lesion which enables us to get differential diagnosis of benign and malignant lesion. Histologically proven 120 cases of the pulmonary coin lesion during the period of 8 years were reviewed through plain film, tomogram, bronchoscopy, variable laboratory findings, and clinical history. The results are as follows: 1. Male to female sex ratio was 3 : 1. In age distribution, most of the malignant pulmonary coin lesion appeared in 6th decade (39%) and 5th decade (27%). In benign lesion, the most cases were in 3 rd decade. 2. Pathological cell type are as follows: Primary bronchogenic cancer 43.3%, tuberculoma 25.8%, inflammatory lesion 17.5%, benign tumor 10%, and bronchial adenoma, harmartoma, A.V. malformation, mesothelioma, are 1 case respectively. As a result benign and malignant lesion showed equal distribution (49.1% : 50.3%). 3. In symptom analysis ; cough is the most common (43.5%) symptom in malignant lesion, next follows hemoptysis (20.9%) and chest pain (14.5%). In benign lesion, most of the patient (32.7%) did not complain any symptom. 4. In malignant lesion, the most common nodular size was 4 cm (32.3%), and in benign lesion 2 cm sized coin was most common (39.3%). 5. In general, margin of nodule was very sharp and well demarcated in benign lesion (83.3%), and in malignant lesion that was less demarcated and poorly defined. 6. Most case of calcification (82.7%) was seen in benign

  20. Deep learning based classification of morphological patterns in RCM to guide noninvasive diagnosis of melanocytic lesions (Conference Presentation)

    Science.gov (United States)

    Kose, Kivanc; Bozkurt, Alican; Ariafar, Setareh; Alessi-Fox, Christi A.; Gill, Melissa; Dy, Jennifer G.; Brooks, Dana H.; Rajadhyaksha, Milind

    2017-02-01

    In this study we present a deep learning based classification algorithm for discriminating morphological patterns that appear in RCM mosaics of melanocytic lesions collected at the dermal epidermal junction (DEJ). These patterns are classified into 6 distinct types in the literature: background, meshwork, ring, clod, mixed, and aspecific. Clinicians typically identify these morphological patterns by examination of their textural appearance at 10X magnification. To mimic this process we divided mosaics into smaller regions, which we call tiles, and classify each tile in a deep learning framework. We used previously acquired DEJ mosaics of lesions deemed clinically suspicious, from 20 different patients, which were then labelled according to those 6 types by 2 expert users. We tried three different approaches for classification, all starting with a publicly available convolutional neural network (CNN) trained on natural image, consisting of a series of convolutional layers followed by a series of fully connected layers: (1) We fine-tuned this network using training data from the dataset. (2) Instead, we added an additional fully connected layer before the output layer network and then re-trained only last two layers, (3) We used only the CNN convolutional layers as a feature extractor, encoded the features using a bag of words model, and trained a support vector machine (SVM) classifier. Sensitivity and specificity were generally comparable across the three methods, and in the same ranges as our previous work using SURF features with SVM . Approach (3) was less computationally intensive to train but more sensitive to unbalanced representation of the 6 classes in the training data. However we expect CNN performance to improve as we add more training data because both the features and the classifier are learned jointly from the data. *First two authors share first authorship.

  1. Equipment location in hospitals using RFID-based positioning system.

    Science.gov (United States)

    Shirehjini, Ali Asghar Nazari; Yassine, Abdulsalam; Shirmohammadi, Shervin

    2012-11-01

    Throughout various complex processes within hospitals, context-aware services and applications can help to improve the quality of care and reduce costs. For example, sensors and radio frequency identification (RFID) technologies for e-health have been deployed to improve the flow of material, equipment, personal, and patient. Bed tracking, patient monitoring, real-time logistic analysis, and critical equipment tracking are famous applications of real-time location systems (RTLS) in hospitals. In fact, existing case studies show that RTLS can improve service quality and safety, and optimize emergency management and time critical processes. In this paper, we propose a robust system for position and orientation determination of equipment. Our system utilizes passive (RFID) technology mounted on flooring plates and several peripherals for sensor data interpretation. The system is implemented and tested through extensive experiments. The results show that our system's average positioning and orientation measurement outperforms existing systems in terms of accuracy. The details of the system as well as the experimental results are presented in this paper.

  2. [The spa-and-health resort-based rehabilitation of the patients presenting with frequently recurring erosive and ulcerative lesions in the oesophagus, stomach, and duodenum in the phase of subsiding exacerbation].

    Science.gov (United States)

    Efimenko, N V; Kaĭsinova, A S

    2014-01-01

    To develop a new medical technology for the spa-and-health resort-based treatment of the patients presenting with frequently recurring erosive and ulcerative lesions in the oesophagus, stomach, and duodenum in the phase of subsiding exacerbation. A total of 100 patients presenting with frequently recurring erosive and ulcerative lesions in the oesophagus, stomach, and duodenum in the phase of subsiding exacerbation were available for the examination that included detailed investigations of the clinical picture, characteristics of the immune status, and psychological testing before and after a course of the spa-and-health resort-based treatment. The effectiveness of two therapeutic modalities was evaluated. One of them (control) prescribed to 50 patients consisted of standard antiulcer pharmacotherapy in combination with Essentuki Novaya drinking mineral water and carbon dioxide mineral baths, the other given to 50 patients included radon baths instead of carbon dioxide mineral baths. The combined application of drinking mineral waters, radon baths, and standard antiulcer pharmacotherapy produced the most conspicuous clinical effect in the framework of spa-and-health resort-based rehabilitation of the patients presenting with frequently recurring erosive and ulcerative lesions in the oesophagus, stomach, and duodenum in the phase of subsiding exacerbation as confirmed by positive dynamics of their psychoemotional status in 97.7% of the cases, regression of pain syndrome (91.5%), and improvement of humoral and cellular immunity (94%). An important result of the spa-and-health resort-based rehabilitation is the intensification of the reparative processes in gastroduodenal mucosa responsible for the healing of ulcers and erosions in 94.7% of the patients. The spa-and-health resort-based rehabilitation is a pathogenetically sound and efficacious approach to the management of the patients presenting with frequently recurring erosive and ulcerative lesions in the

  3. A review on prevention and treatment of post-orthodontic white spot lesions - evidence-based methods and emerging technologies

    DEFF Research Database (Denmark)

    Bergstrand, Fredrik; Twetman, Svante

    2011-01-01

    The aim of this paper was to update the evidence for primary and secondary prevention (treatment) of white spot lesions (WSL) adjacent to fixed orthodontic appliances.......The aim of this paper was to update the evidence for primary and secondary prevention (treatment) of white spot lesions (WSL) adjacent to fixed orthodontic appliances....

  4. A model to environmental monitoring based on glutathione-S-transferase activity and branchial lesions in catfish

    Science.gov (United States)

    Neta, Raimunda Nonata Fortes Carvalho; Torres, Audalio Rebelo

    2017-11-01

    In this work, we validate the glutathione-S-transferase and branchial lesions as biomarkers in catfish Sciades herzbergii to obtain a predictive model of the environmental impact effects in a harbor of Brazil. The catfish were sampled from a port known to be contaminated with heavy metals and organic compounds and from a natural reserve in São Marcos Bay, Maranhão. Two biomarkers, hepatic glutathione S-transferase (GST) activity and branchial lesions were analyzed. The values for GST activity were modeled with the occurrence of branchial lesions by fitting a third order polynomial. Results from the mathematical model indicate that GST activity has a strong polynomial relationship with the occurrence of branchial lesions in both the wet and the dry seasons, but only at the polluted port site. Our mathematic model indicates that when the GST ceases to act, serious branchial lesions are observed in the catfish of the contaminated port area.

  5. Changing pattern of oral cavity lesions and personal habits over a decade: Hospital based record analysis from Allahabad

    Directory of Open Access Journals (Sweden)

    Misra Vatsala

    2009-01-01

    Full Text Available Aim: To do a prospective clinicohistological study of premalignant and malignant lesions of the oral cavity, and compare it with a 10-year retrospective data, especially in terms of incidence, age distribution, personal habits, and site and type of lesion. Material and Methods: Sections from 776 lesions of the oral cavity, which included 647 lesions of a 10-year (1993 - 2003 retrospective study and 129 lesions of a one-year (2003 - 2004 prospective study, were observed clinically, and a histological correlation was carried out. Results: Premalignant lesions included 78 cases of leukoplakia, 68 cases of oral submucous fibrosis, and 76 cases of squamous papilloma. Their incidence has increased in the last decade from 0.15 to 0.53. These lesions commonly presented in the fourth decade of life, as white patches in leukoplakia and oral submucous fibrosis, and as a growth in squamous cell papilloma. Squamous cell carcinoma was the commonest lesion (57%. Its incidence has increased significantly in the last decade. The mean age of presentation was the sixth decade. A personal history of tobacco chewing was given by most of the patients in the retrospective group, while the use of pan masala was found to be maximum in the prospective group. The overall agreement between the clinical and histological diagnosis was 95.36% (740 / 776 and the kappa coefficient of agreement was 0.9256. Conclusion: Histology along with a detailed clinical workup was found to be a useful, reliable, and accurate diagnostic technique for lesions of the oral cavity. An increase in premalignant lesions in the prospective study, associated with increased pan masala intake is alarming and needs to be taken care of.

  6. Using the local positioning system based on Pulse Width Modulation ...

    African Journals Online (AJOL)

    Michael Horsfall

    submitted to the department of aeronautics of. Stanford university in partial fulfilment of the requirements for the degree of doctor of philosophy,. August, 2004. 6-“ Robotics-based location sensing for wireless. Ethernet” A. M. Ladd, K. E. Bekris, G. Marceau,. A. Rudys, D. S. Wallach, and L. E. Kavraki, In ACM. MobiCom, 2002.

  7. Time-based position estimation in monolithic scintillator detectors

    NARCIS (Netherlands)

    Tabacchini, V.; Borghi, G.; Schaart, D.R.

    2015-01-01

    Gamma-ray detectors based on bright monolithic scintillation crystals coupled to pixelated photodetectors are currently being considered for several applications in the medical imaging field. In a typical monolithic detector, both the light intensity and the time of arrival of the earliest

  8. Positive versus Negative Communication Strategies in Task-Based Learning

    Science.gov (United States)

    Rohani, Siti

    2013-01-01

    This study aimed at describing how the implementation of Task-Based Learning (TBL) would shape or change students' use of oral communication strategies. Students' problems and strategies to solve the problems during the implementation of TBL were also explored. The study was a mixed method, employing both quantitative and qualitative analysis…

  9. Position Paper: Moving Task-Based Language Teaching Forward

    Science.gov (United States)

    Ellis, Rod

    2017-01-01

    The advocacy of task-based language teaching (TBLT) has met with resistance. The critiques of TBLT and the misconceptions that underlie them have already been addressed in Ellis (2009) and Long (2016). The purpose of this article is to move forward by examining a number of real problems that TBLT faces--such as how a "task" should be…

  10. Study protocol for an approach based on diagnosis and therapy of cutaneous radiation induced lesions

    International Nuclear Information System (INIS)

    Di Giorgio, Marina; Vallerga, Maria B.; Radl, Analia; Portas, Mercedes

    2008-01-01

    -rector cancer patients (24.9 ± 10.4 minutes). In this paper, 10 representative cases, in which the research protocol was applied, have been evaluated retrospectively. Therapeutic response and its correlation with radiosensitivity test results have also been studied. Overall, 4 cases showed positive (favorable) local recovery and almost complete to complete remission of signs and symptoms after 5 to 12 months of the beginning of the treatment. In these patients, both MN frequencies and comet assay showed values compatible with normal (average) radiosensitivity. However, three cases showing average radio sensitivity presented complications attributed to radiation exposure (treatment or diagnosis) or to co-morbidity factors. Finally, 3 cases presented a partial response with pain and acute repetitive crisis. In vitro radiosensitivity test results indicated that these patients (over-reactors) presented a greater risk than average patients of developing radiation toxicity. These results would ensure in vitro radiosensitivity test to constitute one of the prognostic score parameters, jointly with applied radiation dose, radiation quality, localization (including thickness and vascularisation of the dermis) in case of CRS for the design of therapeutic strategies. The appearance in delay of this syndrome often results in non specialized medical treatment, so the conformation of an ad hoc interdisciplinary group for CRS approach offer to these patients a content frame that provides them with the availability of diagnostic methods and therapeutic strategies, tailoring patient's treatment both in normal and in radiological emergency conditions. (author)

  11. Value of probe-based confocal laser endomicroscopy (pCLE) and dual focus narrow-band imaging (dNBI) in diagnosing early squamous cell neoplasms in esophageal Lugol's voiding lesions.

    Science.gov (United States)

    Prueksapanich, Piyapan; Pittayanon, Rapat; Rerknimitr, Rungsun; Wisedopas, Naruemon; Kullavanijaya, Pinit

    2015-08-01

    Lugol's chromoendoscopy provides excellent sensitivity for the detection of early esophageal squamous cell neoplasms (ESCN), but its specificity is suboptimal. An endoscopy technique for real-time histology is required to decrease the number of unnecessary biopsies. This study aimed to compare the ESCN diagnostic capability of probed-based confocal laser endomicroscopy (pCLE) and dual focus narrow-band imaging (dNBI) in Lugol's voiding lesions. Patients with a history of head and neck cancer without dysphagia were recruited. Lugol's voiding lesions larger than 5 mm were sequentially characterized by dNBI and pCLE by two independent operators. Finally, all lesions larger than 5 mm were biopsied followed by histological analysis, which is considered to be the gold standard in cancer diagnosis. The primary outcomes were the sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and the accuracy of the two techniques. In total, 44 patients were enrolled with a mean age of 60 years; 80 % were male. Twenty-one Lugol's voiding lesions larger than 5 mm were detected in 12 patients. Seven lesions (33 %) from four patients were histologically diagnosed as ESCNs (four with high grade dysplasia and three with low grade dysplasia). The other 14 lesions were histologically confirmed as non-neoplastic: active esophagitis, glycogenation with inflammation, acute ulcer, inlet patch, and unremarkable changes. The sensitivity, specificity, PPV, NPV, and accuracy of pCLE vs. dNBI were 83 % vs. 85 %, 92 % vs. 62 %, 83 % vs. 54 %, 92 % vs. 89 %, and 89 % vs. 70 %, respectively (NS). Asymptomatic patients with a history of head and neck cancer underwent Lugol's chromoendoscopy based ESCN surveillance. Further characterization of the Lugol's voiding lesions by advanced imaging showed that both pCLE and dNBI provided good sensitivity in diagnosing ESCN, and pCLE tended to provide higher specificity, PPV, and accuracy than d

  12. Value of probe-based confocal laser endomicroscopy (pCLE) and dual focus narrow-band imaging (dNBI) in diagnosing early squamous cell neoplasms in esophageal Lugol’s voiding lesions

    Science.gov (United States)

    Prueksapanich, Piyapan; Pittayanon, Rapat; Rerknimitr, Rungsun; Wisedopas, Naruemon; Kullavanijaya, Pinit

    2015-01-01

    Background and study aims: Lugol’s chromoendoscopy provides excellent sensitivity for the detection of early esophageal squamous cell neoplasms (ESCN), but its specificity is suboptimal. An endoscopy technique for real-time histology is required to decrease the number of unnecessary biopsies. This study aimed to compare the ESCN diagnostic capability of probed-based confocal laser endomicroscopy (pCLE) and dual focus narrow-band imaging (dNBI) in Lugol’s voiding lesions. Patients and methods: Patients with a history of head and neck cancer without dysphagia were recruited. Lugol’s voiding lesions larger than 5 mm were sequentially characterized by dNBI and pCLE by two independent operators. Finally, all lesions larger than 5 mm were biopsied followed by histological analysis, which is considered to be the gold standard in cancer diagnosis. The primary outcomes were the sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and the accuracy of the two techniques. Results: In total, 44 patients were enrolled with a mean age of 60 years; 80 % were male. Twenty-one Lugol’s voiding lesions larger than 5 mm were detected in 12 patients. Seven lesions (33 %) from four patients were histologically diagnosed as ESCNs (four with high grade dysplasia and three with low grade dysplasia). The other 14 lesions were histologically confirmed as non-neoplastic: active esophagitis, glycogenation with inflammation, acute ulcer, inlet patch, and unremarkable changes. The sensitivity, specificity, PPV, NPV, and accuracy of pCLE vs. dNBI were 83 % vs. 85 %, 92 % vs. 62 %, 83 % vs. 54 %, 92 % vs. 89 %, and 89 % vs. 70 %, respectively (NS). Conclusions: Asymptomatic patients with a history of head and neck cancer underwent Lugol’s chromoendoscopy based ESCN surveillance. Further characterization of the Lugol’s voiding lesions by advanced imaging showed that both pCLE and dNBI provided good sensitivity in

  13. Direct assay of radiation-induced DNA base lesions in mammalian cells

    International Nuclear Information System (INIS)

    1992-01-01

    Adenine (Ade), 2'-deoxyadenosine (dAdo), 5'-deoxyadenosine monophosphate (dAUT), single stranded poly adenylic acid [poly (dA)], double stranded deoxyadenylic-thymidylic acid [ds poly (dA-T)] and salmon testis DNA were irradiated with 500 Gy under oxic and anoxic conditions. The major damage products were analyzed by BPLC with optical detection and quantitated in terms of the percentage of the adenosine in each model compound found as a specific damage product. Outside of the Ade free base, 8-OH-dAdo was the major oxic damage product from each model compound. The type and quantity of the major damage products depended on the sequence and conformation of the model compounds under anoxic conditions. When dAdo and dAMP were irradiated under anoxic conditions, the major damage product was either the R or S isomer of 8,5'cdAdo and little Ade or α-dAdo was observed. However, when poly(dA), poly(dA-dT), and salmon testis DNA were γ-irradiated under nitrogen, the major deoxyadenosine damage product was identified as the α-anomer of deoxyadenosine. No α-deoxyadenosine was detected after irradiation under oxic conditions. The presence of nucleotides with the α-configuration at the anomeric carbon atom in the DNA chain may have a significant effect on its tertiary structure and possibly modify its biological activity

  14. Indoor Positioning Using Nonparametric Belief Propagation Based on Spanning Trees

    Directory of Open Access Journals (Sweden)

    Savic Vladimir

    2010-01-01

    Full Text Available Nonparametric belief propagation (NBP is one of the best-known methods for cooperative localization in sensor networks. It is capable of providing information about location estimation with appropriate uncertainty and to accommodate non-Gaussian distance measurement errors. However, the accuracy of NBP is questionable in loopy networks. Therefore, in this paper, we propose a novel approach, NBP based on spanning trees (NBP-ST created by breadth first search (BFS method. In addition, we propose a reliable indoor model based on obtained measurements in our lab. According to our simulation results, NBP-ST performs better than NBP in terms of accuracy and communication cost in the networks with high connectivity (i.e., highly loopy networks. Furthermore, the computational and communication costs are nearly constant with respect to the transmission radius. However, the drawbacks of proposed method are a little bit higher computational cost and poor performance in low-connected networks.

  15. Abuse of dominant position in Albania based in jurisprudence

    Directory of Open Access Journals (Sweden)

    Endri Papajorgji

    2016-11-01

    Full Text Available Competition law and cartel is the basis of a modern economy. While in the US, competition law exists and is terminologically known and is part of legislation since 1890 (Sherman Law, in Europe, it has become part of the founding treaties of the EU since 1957 by the Treaty of Rome. However, at that time, “culture of competition” would be born in the member states of the EU, which traditionally favour cartel agreements, state aid and the promotion of national products. Some EU member states have included competition law in their national legislation in the early 90-s. Rules were set for the first time on competition in the coal and steel market under Articles 65 and 66 of the Treaty of Rome, constituted a new terminology for member states. Albania has worked during these 24 years of democracy, to apply the basic principles of market economy and along with it the Lisbon Treaty, Regulations and EU Directives in the frame of competition. Main purpose of this manuscript is to give an overview of the abuse of dominant position in the frame of the most important court decision of this legal institution in Albania.

  16. Epidemiology of benign paroxysmal positional vertigo: a population based study.

    Science.gov (United States)

    von Brevern, M; Radtke, A; Lezius, F; Feldmann, M; Ziese, T; Lempert, T; Neuhauser, H

    2007-07-01

    To examine the prevalence and incidence, clinical presentation, societal impact and comorbid conditions of benign paroxysmal positional vertigo (BPPV) in the general population. Cross-sectional, nationally representative neurotological survey of the general adult population in Germany with a two stage sampling design: screening of 4869 participants from the German National Telephone Health Interview Survey 2003 (response rate 52%) for moderate or severe dizziness or vertigo, followed by validated neurotological interviews (n = 1003; response rate 87%). Diagnostic criteria for BPPV were at least five attacks of vestibular vertigo lasting vertigo. The lifetime prevalence of BPPV was 2.4%, the 1 year prevalence was 1.6% and the 1 year incidence was 0.6%. The median duration of an episode was 2 weeks. In 86% of affected individuals, BPPV led to medical consultation, interruption of daily activities or sick leave. In total, only 8% of affected participants received effective treatment. On multivariate analysis, age, migraine, hypertension, hyperlipidaemia and stroke were independently associated with BPPV. BPPV is a common vestibular disorder leading to significant morbidity, psychosocial impact and medical costs.

  17. Performance of visual inspection with acetic acid and human papillomavirus testing for detection of high-grade cervical lesions in HIV positive and HIV negative Tanzanian women

    DEFF Research Database (Denmark)

    Dartell, Myassa Arkam; Rasch, Vibeke; Iftner, Thomas

    2014-01-01

    The aim of this cross sectional study was to assess type distribution of human papillomavirus (HPV) among HIV positive and HIV negative women who underwent cervical cancer screening, and to examine the ability of visual inspection with acetic acid (VIA), the standard detection method in Tanzania,...... of establishing a screening program which also reaches HIV positive women. Our results highlight the importance of continuous training of staff performing VIA, and also point to the need for other screening methods such as HPV-testing at low cost.......-testing for detection of HSIL+. The sensitivity of VIA varied with staff VIA experience, HIV status and age. Vaccines including HPV16, HPV52 and HPV18 will likely reduce the number of HSIL+ cases independently of HIV status. The frequency of HSIL+ was high among HIV positive women, emphasizing the importance...

  18. Headache, migraine, and structural brain lesions and function: population based Epidemiology of Vascular Ageing-MRI study

    International Nuclear Information System (INIS)

    Kurth, T.; Mohamed, S.; Zhu, Y.C.; Dufouil, C.; Tzourio, Ch.; Kurth, T.; Zhu, Y.C.; Dufouil, C.; Tzourio, Ch.; Kurth, T.; Maillard, P.; Mazoyer, B.; Zhu, Y.C.; Chabriat, H.; Bousser, M.G.; Tzourio, Ch.; Zhu, Y.C.; Chabriat, H.; Bousser, M.G.; Mazoyer, B.

    2011-01-01

    Objective: To evaluate the association of overall and specific headaches with volume of white matter hyper-intensities, brain infarcts, and cognition. Design: Population based, cross sectional study. Setting: Epidemiology of Vascular Ageing study, Nantes, France. Participants: 780 participants (mean age 69, 58.5% women) with detailed headache assessment. Main outcome measures: Brain scans were evaluated for volume of white matter hyper-intensities (by fully automated imaging processing) and for classification of infarcts (by visual reading with a standardised assessment grid). Cognitive function was assessed by a battery of tests including the mini-mental state examination. Results: 163 (20.9%) participants reported a history of severe headache and 116 had migraine, of whom 17 (14.7%) reported aura symptoms. An association was found between any history of severe headache and increasing volume of white matter hyper-intensities. The adjusted odds ratio of being in the highest third for total volume of white matter hyper-intensities was 2.0 (95% confidence interval 1.3 to 3.1, P for trend 0.002) for participants with any history of severe headache when compared with participants without severe headache being in the lowest third. The association pattern was similar for all headache types. Migraine with aura was the only headache type strongly associated with volume of deep white matter hyper-intensities (highest third odds ratio 12.4, 1.6 to 99.4, P for trend 0.005) and with brain infarcts (3.4, 1.2 to 9.3). The location of infarcts was predominantly outside the cerebellum and brain stem. Evidence was lacking for cognitive impairment for any headache type with or without brain lesions. Conclusions: In this population based study, any history of severe headache was associated with an increased volume of white matter hyper-intensities. Migraine with aura was the only headache type associated with brain infarcts. Evidence that headache of any type by itself or in

  19. Community Based Integrated Intervention, Lesions Learn from Rural Remote Areas of Bangladesh

    International Nuclear Information System (INIS)

    Talukder, Shamim; Farhana, Dina; Shajedul Haque, Haque; Maruf, Kazi

    2014-01-01

    health and nutrition, special emphasis was given at the WVB project activities. However, projects had great impact on behavior change components and mothers’ knowledge on basic concepts of nutrition has increased vastly, doesn’t effect on reducing severe and moderate malnutrition. The proportions of mildly under nourished children were underweight (30.2%), stunted (29.3%) and wasted (22.8%). The proportions of children being moderately under nourished were underweight (29.6%), stunted (19.9%) and wasted (24.1%). Indeed progress of achieving severe malnutrition, wasting has decreased drastically to 8% which was 17% in the baseline, however, severe underweight and stunting increased compared to baseline and also slightly higher compare to national data. Access in taking services have increased and among the children suffering from Diarrhea, 92.9% treated by the nearest facilities. Among the children eligible for vaccination, around 63.3% has reported to be fully immunized. Conclusions: While such community based intervention has impact on changing knowledge and uptake of services, limited in reducing acute malnutrition indeed. So, nutrition intervention redesign is necessary and food supplementation as well as treatment of acute malnourished children should be prioritized. (author)

  20. Younger age of onset and multiple primary lesions associated with esophageal squamous cell carcinoma cases with a positive family history of the cancer suggests genetic predisposition.

    Science.gov (United States)

    Jia, Nan; Wen, Xiaoduo; Zhang, Nan; Yang, Yi; Zhang, Liwei; Wang, Xiaoling; Wang, Na; Wen, Denggui

    2014-01-01

    Previous epidemiological studies have consistently found a positive family history of esophageal cancer is associated with a significantly increased risk of the cancer. However, whether the elevated risk could be attributed to common household exposure or inherited susceptibility is uncertain. This study aimed to highlight the effect of genetic predisposition by noting the significant differences in onset age and multiple primary cancers between esophageal squamous cell carcinoma (ESCC) cases with or without a positive family history of the cancer. Age at onset and the percentage of multiple primary cancers were compared between ESCCs with (n = 766) or without (n = 1 776) a positive family history of the cancer in a consecutive surgery cohort at the Department of Thoracic Surgery of Hebei Tumor Hospital and the Fourth Hospital of Hebei Medical University. Overall, ESCCs with a positive family history of the cancer featured both a significantly younger age of onset and significantly more multiple primary cancers than those with a negative family history (onset age 51.83 vs. 53.49 years old, P genetic predisposition. The results of subgroup analyses indicate a younger age of ESCC development results from the interaction of environmental and genetic risk factors, but multiple primary cancers may be related only to genetic predisposition.

  1. Lesões anorretais em pacientes HIV positivos usuários de terapia anti-retroviral de alta efetividade Anorrectal lesions in HIV-positive patients using highly active antiretroviral therapy

    Directory of Open Access Journals (Sweden)

    Manuel Retamozo-Palacios

    2007-06-01

    Full Text Available As lesões anorretais são comuns nos pacientes positivos para o vírus da imunodeficiência humana. A terapia antirretroviral de alta efetividade tem pouca influência na progressão das neoplasias anais. Estudou-se a prevalência das lesões anorretais em 88 pacientes HIV positivos atendidos no serviço de doenças infecto-parasitárias do Hospital Universitário de Brasília, em uso de terapia antirretroviral de alta efetividade. Dados sócio-demográficos foram coletados usando um questionário pré-elaborado e os pacientes foram submetidos a exame proctológico. Cerca de 71% relataram coito anal e 30,7% estavam em uso de inibidor de protease. A prevalência das lesões anorretais foi 36,4%, sendo as mais freqüentes: condiloma acuminado e fissura anal. O condiloma acuminado foi a lesão anorretal mais prevalente e teve associação com o uso de lopinavir/ritonavir. Sugere-se o rastreamento das lesões anorretais causadas pelo papilomavírus humano nos pacientes HIV positivos/AIDS em uso de inibidor de protease.Anorectal lesions are common in patients with human immunodeficiency virus (HIV. Highly active anti-retroviral therapy (HAART has little influence on the progression of anal neoplasms. The prevalence of anorectal lesions in 88 HIV-positive patients attended at the infectious diseases service of the University Hospital of Brasília who were using HAART was studied. Sociodemographic data were collected using a pre-prepared questionnaire and then the patients underwent proctological examination. Around 71% of the patients said they practiced anal intercourse. 30.7% were using a protease inhibitor. The prevalence of anorectal lesions was 36.4%, and condyloma acuminata and anal fissure were the most frequent of these. Condyloma acuminata was the most prevalent anorectal lesion and was strongly associated with the use of lopinavir/ritonavir. Screening for anorectal lesions caused by human papillomavirus in HIV/AIDS patients who use protease

  2. Microcontroller-based mobile robot positioning and obstacle avoidance

    Directory of Open Access Journals (Sweden)

    Aziza M. Zaki

    2014-05-01

    Full Text Available The use of mobile robots is growing in manufacturing facilities, hazardous materials handling, etc. Usually, several sensor systems are used in combination. The task of combining the information into a usable form, suitable for making navigation decisions, is known as sensor fusion. In this paper, the navigation system built on a mobile robot operating in a warehouse is presented focusing on the sensory system used. Hybrid navigation system that combines the perception and dead reckoning is used and gives satisfactory operation. A microcontroller system is designed to control the navigation of a mobile robot while avoiding obstacles. A system of 24 ultrasonic sensors was designed and the operation algorithms were described. The encoder and the ultrasonic sensors used are presented in detail together with the navigation system designed based on their operation.

  3. Multi-probe-based resonance-frequency electrical impedance spectroscopy for detection of suspicious breast lesions: improving performance using partial ROC optimization

    Science.gov (United States)

    Lederman, Dror; Zheng, Bin; Wang, Xingwei; Wang, Xiao Hui; Gur, David

    2011-03-01

    We have developed a multi-probe resonance-frequency electrical impedance spectroscope (REIS) system to detect breast abnormalities. Based on assessing asymmetry in REIS signals acquired between left and right breasts, we developed several machine learning classifiers to classify younger women (i.e., under 50YO) into two groups of having high and low risk for developing breast cancer. In this study, we investigated a new method to optimize performance based on the area under a selected partial receiver operating characteristic (ROC) curve when optimizing an artificial neural network (ANN), and tested whether it could improve classification performance. From an ongoing prospective study, we selected a dataset of 174 cases for whom we have both REIS signals and diagnostic status verification. The dataset includes 66 "positive" cases recommended for biopsy due to detection of highly suspicious breast lesions and 108 "negative" cases determined by imaging based examinations. A set of REIS-based feature differences, extracted from the two breasts using a mirror-matched approach, was computed and constituted an initial feature pool. Using a leave-one-case-out cross-validation method, we applied a genetic algorithm (GA) to train the ANN with an optimal subset of features. Two optimization criteria were separately used in GA optimization, namely the area under the entire ROC curve (AUC) and the partial area under the ROC curve, up to a predetermined threshold (i.e., 90% specificity). The results showed that although the ANN optimized using the entire AUC yielded higher overall performance (AUC = 0.83 versus 0.76), the ANN optimized using the partial ROC area criterion achieved substantially higher operational performance (i.e., increasing sensitivity level from 28% to 48% at 95% specificity and/ or from 48% to 58% at 90% specificity).

  4. MRI can accurately detect meniscal ramp lesions of the knee.

    Science.gov (United States)

    Arner, Justin W; Herbst, Elmar; Burnham, Jeremy M; Soni, Ashish; Naendrup, Jan-Hendrik; Popchak, Adam; Fu, Freddie H; Musahl, Volker

    2017-12-01

    Posterior horn meniscal tears are commonly found in conjunction with anterior cruciate ligament (ACL) injury. Some believe tears in the posterior meniscocapsular zone, coined ramp lesions, are important to knee stability. The purpose of this study was to determine whether pre-operative MRI evaluation was able to accurately and reproducibly identify ramp lesions. Three blinded reviewers assessed MRIs twice for the presence of ramp lesions in patients undergoing ACL reconstruction. Sensitivity, specificity, negative predictive value, and positive predictive value for MRI were calculated based on arthroscopic diagnosis of a ramp lesion. Intra-class correlation coefficient was calculated to assess intra- and interobserver reliability of the MRI assessment between the three examiners. Significance was set at p lesions, while the other 77 had other meniscal pathology. Sensitivity of detecting a ramp lesion on MRI ranged from 53.9 to 84.6%, while specificity was 92.3-98.7%. Negative predictive value was 91.1-97.4%, while positive predictive value was 50.0-90.0%. Inter-rater reliability between three reviewers was moderate at 0.56. The observers had excellent intra-rater reliability ranging from 0.75 to 0.81. This study demonstrates high sensitivity and excellent specificity in detecting meniscal ramp lesions on MRI. Ramp lesions are likely more common and may have greater clinical implications than previously appreciated; the outcomes of untreated lesions must be investigated. Pre-operative identification of ramp lesions may aid clinicians in surgical planning and patient education to improve outcomes by addressing pathology which may have otherwise been missed. III.

  5. Immunohistochemical study of porcine lung lesions associated with Pasteurella multocida.

    Science.gov (United States)

    Pors, Susanne E; Hansen, Mette S; Bisgaard, Magne; Jensen, Henrik E; Iburg, Tine M

    2013-08-01

    Infectious bronchopneumonia is a widespread disease in modern commercial pig production and Pasteurella multocida is frequently associated with the lesions. To evaluate porcine lung lesions associated with P. multocida, populations of inflammatory cells were examined by immunohistochemistry in necrotic lung lesions from nine pigs and exudative lung lesions from eleven pigs. Lungs from five pigs served as controls. All cases were selected from naturally infected pigs using co-infection based criteria to make them as comparable as possible. The inflammatory cells demonstrated by immunohistochemistry were T-lymphocytes (CD3(+), CD4(+) and CD8(+) subsets), B-lymphocytes, neutrophils, macrophages, and IgA(+), IgM(+) and IgG(+) cells. The results showed that (1) a significant increase in all inflammatory cells was found in lesions associated with P. multocida, (2) necrotic lesions had a larger number of CD3(+) T-lymphocytes and IgA(+) cells, and (3) cases with exudative lesions had a more CD8(+) T-lymphocytes, B-lymphocytes, macrophages and neutrophils. No differences in the numbers of CD4(+) T-lymphocytes, IgG(+) and IgM(+) positive cells were found between necrotic and exudative cases. The results show that P. multocida significantly alters the inflammatory response in the lung and that lesions associated with P. multocida display diverse inflammatory responses according to their distinct morphological pattern. Copyright © 2013 Elsevier Ltd. All rights reserved.

  6. Shearwave Elastography Increases Diagnostic Accuracy in Characterization of Breast Lesions

    Science.gov (United States)

    Ng, Wei Lin; Rahmat, Kartini; Fadzli, Farhana; Rozalli, Faizatul Izza; Mohd-Shah, Mohammad Nazri; Chandran, Patricia Ann; Westerhout, Caroline Judy; Vijayananthan, Anushya; Abdul Aziz, Yang Faridah

    2016-01-01

    Abstract The purpose of this study was to investigate the diagnostic efficacy of shearwave elastography (SWE) in differentiating between benign and malignant breast lesions. One hundred and fifty-nine lesions were assessed using B-mode ultrasound (US) and SWE parameters were recorded (Emax, Emean, Emin, Eratio, SD). SWE measurements were then correlated with histopathological diagnosis. The final sample contained 85 benign and 74 malignant lesions. The maximum stiffness (Emax) with a cutoff point of ≥ 56.0 kPa (based on ROC curves) provided sensitivity of 100.0%, specificity of 97.6%, positive predictive value (PPV) of 97.4%, and negative predictive value (NPV) of 100% in detecting malignant lesions. A cutoff of ≥80 kPa managed to downgrade 95.5% of the Breast Imaging-Reporting and Data System (BI-RADS) 4a lesions to BI-RADS 3, negating the need for biopsy. Using a combination of BI-RADS and SWE, the authors managed to improve the PPV from 2.3% to 50% in BI-RADS 4a lesions. SWE of the breast provides highly specific and sensitive quantitative values that are beneficial in the characterization of breast lesions. Our results showed that Emax is the most accurate value for differentiating benign from malignant lesions. PMID:27015196

  7. The Impact of Diffusion Tensor Imaging Fiber Tracking of the Corticospinal Tract Based on Navigated Transcranial Magnetic Stimulation on Surgery of Motor-Eloquent Brain Lesions.

    Science.gov (United States)

    Raffa, Giovanni; Conti, Alfredo; Scibilia, Antonino; Cardali, Salvatore Massimiliano; Esposito, Felice; Angileri, Filippo Flavio; La Torre, Domenico; Sindorio, Carmela; Abbritti, Rosaria Viola; Germanò, Antonino; Tomasello, Francesco

    2017-11-29

    Navigated transcranial magnetic stimulation (nTMS) enables preoperative mapping of the motor cortex (M1). The combination of nTMS with diffusion tensor imaging fiber tracking (DTI-FT) of the corticospinal tract (CST) has been described; however, its impact on surgery of motor-eloquent lesions has not been addressed. To analyze the impact of nTMS-based mapping on surgery of motor-eloquent lesions. In this retrospective case-control study, we reviewed the data of patients operated for suspected motor-eloquent lesions between 2012 and 2015. The patients underwent nTMS mapping of M1 and, from 2014, nTMS-based DTI-FT of the CST. The impact on the preoperative risk/benefit analysis, surgical strategy, craniotomy size, extent of resection (EOR), and outcome were compared with a control group. We included 35 patients who underwent nTMS mapping of M1 (group A), 35 patients who also underwent nTMS-based DTI-FT of the CST (group B), and a control group composed of 35 patients treated without nTMS (group C). The patients in groups A and B received smaller craniotomies (P = .01; P = .001), had less postoperative seizures (P = .02), and a better postoperative motor performance (P = .04) and Karnofsky Performance Status (P = .009) than the controls. Group B exhibited an improved risk/benefit analysis (P = .006), an increased EOR of nTMS-negative lesions in absence of preoperative motor deficits (P = .01), and less motor and Karnofsky Performance Status worsening in case of preoperative motor deficits (P = .02, P = .03) than group A. nTMS-based mapping enables a tailored surgical approach for motor-eloquent lesions. It may improve the risk/benefit analysis, EOR and outcome, particularly when nTMS-based DTI-FT is performed. Copyright © 2017 by the Congress of Neurological Surgeons

  8. Human brain lesion-deficit inference remapped.

    Science.gov (United States)

    Mah, Yee-Haur; Husain, Masud; Rees, Geraint; Nachev, Parashkev

    2014-09-01

    . Positively, we show that novel machine learning techniques employing high-dimensional inference can nonetheless accurately converge on the true locus. We conclude that current inferences about human brain function and deficits based on lesion mapping must be re-evaluated with methodology that adequately captures the high-dimensional structure of lesion data. © The Author (2014). Published by Oxford University Press on behalf of the Guarantors of Brain.

  9. Visualization of small lesions in rat cartilage by means of laboratory-based x-ray phase contrast imaging

    Science.gov (United States)

    Marenzana, Massimo; Hagen, Charlotte K.; Das Neves Borges, Patricia; Endrizzi, Marco; Szafraniec, Magdalena B.; Ignatyev, Konstantin; Olivo, Alessandro

    2012-12-01

    Being able to quantitatively assess articular cartilage in three-dimensions (3D) in small rodent animal models, with a simple laboratory set-up, would prove extremely important for the development of pre-clinical research focusing on cartilage pathologies such as osteoarthritis (OA). These models are becoming essential tools for the development of new drugs for OA, a disease affecting up to 1/3 of the population older than 50 years for which there is no cure except prosthetic surgery. However, due to limitations in imaging technology, high-throughput 3D structural imaging has not been achievable in small rodent models, thereby limiting their translational potential and their efficiency as research tools. We show that a simple laboratory system based on coded-aperture x-ray phase contrast imaging (CAXPCi) can correctly visualize the cartilage layer in slices of an excised rat tibia imaged both in air and in saline solution. Moreover, we show that small, surgically induced lesions are also correctly detected by the CAXPCi system, and we support this finding with histopathology examination. Following these successful proof-of-concept results in rat cartilage, we expect that an upgrade of the system to higher resolutions (currently underway) will enable extending the method to the imaging of mouse cartilage as well. From a technological standpoint, by showing the capability of the system to detect cartilage also in water, we demonstrate phase sensitivity comparable to other lab-based phase methods (e.g. grating interferometry). In conclusion, CAXPCi holds a strong potential for being adopted as a routine laboratory tool for non-destructive, high throughput assessment of 3D structural changes in murine articular cartilage, with a possible impact in the field similar to the revolution that conventional microCT brought into bone research.

  10. Imaging inflammatory acne: lesion detection and tracking

    Science.gov (United States)

    Cula, Gabriela O.; Bargo, Paulo R.; Kollias, Nikiforos

    2010-02-01

    It is known that effectiveness of acne treatment increases when the lesions are detected earlier, before they could progress into mature wound-like lesions, which lead to scarring and discoloration. However, little is known about the evolution of acne from early signs until after the lesion heals. In this work we computationally characterize the evolution of inflammatory acne lesions, based on analyzing cross-polarized images that document acne-prone facial skin over time. Taking skin images over time, and being able to follow skin features in these images present serious challenges, due to change in the appearance of skin, difficulty in repositioning the subject, involuntary movement such as breathing. A computational technique for automatic detection of lesions by separating the background normal skin from the acne lesions, based on fitting Gaussian distributions to the intensity histograms, is presented. In order to track and quantify the evolution of lesions, in terms of the degree of progress or regress, we designed a study to capture facial skin images from an acne-prone young individual, followed over the course of 3 different time points. Based on the behavior of the lesions between two consecutive time points, the automatically detected lesions are classified in four categories: new lesions, resolved lesions (i.e. lesions that disappear completely), lesions that are progressing, and lesions that are regressing (i.e. lesions in the process of healing). The classification our methods achieve correlates well with visual inspection of a trained human grader.

  11. The impact of sensor errors and building structures on particle filter-based inertial positioning

    DEFF Research Database (Denmark)

    Toftkjær, Thomas; Kjærgaard, Mikkel Baun

    2012-01-01

    Positioning systems that do not depend on in-building infrastructures are critical for enabling a range of applications within pervasive computing. Particle filter-based inertial positioning promises infrastructure-less positioning, but previous research has not provided an understanding of how t...

  12. Ground-Based Global Positioning System (GPS) Meteorology Integrated Precipitable Water Vapor (IPW)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Ground-Based Global Positioning System (GPS) Meteorology Integrated Precipitable Water Vapor (IPW) data set measures atmospheric water vapor using ground-based...

  13. Optimal Sensor placement for acoustic range-based underwater robotic positioning

    Digital Repository Service at National Institute of Oceanography (India)

    Glotzbach, T.; Moreno-Salinas, D.; Aranda, J.; Pascoal, A.M.

    of transponders. In what follow, we give a very brief overview of range-based positioning systems. To estimate the position of an underwater agent by means of acoustic range measurements, one needs several objects (reference objects or ROs henceforward... between target position and optimal acoustic sensor positions. For real sea operations, where the accuracy of range measuring devices is plagued by intermittent failures, outliers, and multipath propagation effects, it is important to have...

  14. Performance comparison of deep learning and segmentation-based radiomic methods in the task of distinguishing benign and malignant breast lesions on DCE-MRI

    Science.gov (United States)

    Antropova, Natasha; Huynh, Benjamin; Giger, Maryellen

    2017-03-01

    Intuitive segmentation-based CADx/radiomic features, calculated from the lesion segmentations of dynamic contrast-enhanced magnetic resonance images (DCE-MRIs) have been utilized in the task of distinguishing between malignant and benign lesions. Additionally, transfer learning with pre-trained deep convolutional neural networks (CNNs) allows for an alternative method of radiomics extraction, where the features are derived directly from the image data. However, the comparison of computer-extracted segmentation-based and CNN features in MRI breast lesion characterization has not yet been conducted. In our study, we used a DCE-MRI database of 640 breast cases - 191 benign and 449 malignant. Thirty-eight segmentation-based features were extracted automatically using our quantitative radiomics workstation. Also, 2D ROIs were selected around each lesion on the DCE-MRIs and directly input into a pre-trained CNN AlexNet, yielding CNN features. Each method was investigated separately and in combination in terms of performance in the task of distinguishing between benign and malignant lesions. Area under the ROC curve (AUC) served as the figure of merit. Both methods yielded promising classification performance with round-robin cross-validated AUC values of 0.88 (se =0.01) and 0.76 (se=0.02) for segmentationbased and deep learning methods, respectively. Combination of the two methods enhanced the performance in malignancy assessment resulting in an AUC value of 0.91 (se=0.01), a statistically significant improvement over the performance of the CNN method alone.

  15. Fusion Based on Visible Light Positioning and Inertial Navigation Using Extended Kalman Filters.

    Science.gov (United States)

    Li, Zhitian; Feng, Lihui; Yang, Aiying

    2017-05-11

    With the rapid development of smart technology, the need for location-based services (LBS) increases every day. Since classical positioning technology such as GPS cannot satisfy the needs of indoor positioning, new indoor positioning technologies, such as Bluetooth, Wi-Fi, and Visible light communication (VLC), have already cut a figure. VLC positioning has been proposed because it has higher accuracy, costs less, and is easier to accomplish in comparison to the other indoor positioning technologies. However, the practicality of VLC positioning is limited since it is easily affected by multipath effects and the layout of LEDs. Thus, we propose a fusion positioning system based on extended Kalman filters, which can fuse the VLC position and the inertial navigation data. The accuracy of the fusion positioning system is in centimeters, which is better compared to the VLC-based positioning or inertial navigation alone. Furthermore, the fusion positioning system has high accuracy, saves energy, costs little, and is easy to install, making it a promising candidate for future indoor positioning applications.

  16. 26 CFR 301.6114-1 - Treaty-based return positions.

    Science.gov (United States)

    2010-04-01

    ... business is not subject to U.S. taxation because it is income treated as derived from sources outside the... 26 Internal Revenue 18 2010-04-01 2010-04-01 false Treaty-based return positions. 301.6114-1....6114-1 Treaty-based return positions. (a) Reporting requirement—(1) General rule. (i) Except as...

  17. A Comparison of 3 Ways of Conventional Pap Smear, Liquid-Based Cytology and Colposcopy vs Cervical Biopsy for Early Diagnosis of Premalignant Lesions or Cervical Cancer in Women with Abnormal Conventional Pap Test.

    Science.gov (United States)

    Karimi-Zarchi, Mojgan; Peighmbari, Fateme; Karimi, Neda; Rohi, Mitra; Chiti, Zohre

    2013-12-01

    The most cost effective method of prevention and detection of cervical cancer is the Pap smear. In abnormal Pap smear, colposcopy, endocervical curettage and biopsy will be done. Gold standard method in detecting cervical lesion is biopsy. Now in two ways conventional Pap smear and liquid base are routine diagnostic technique in Iran and given easily and cost-effectiveness of this method in the detection of cervical lesions to determine the sensitivity the objective of this study was compare three methods of Pap smear and colposcopy in detection of any lesion to gold standard biopsy in the positive ASC cases who referred to gynecologic Oncology Clinic of shahid Sadoughi University of Medical Science. This study is a descriptive analytic in 2009-2010 years on 150 cases of patients with Atypical Squamose Cell (ASC) results in previous pap smear ,conventional pap smear, liquid based pap smear, colposcopy and cervical biopsy had been done for all patient and finally data were analyzed with chi-square statistical test on spss ver 16 saftware. Average age of patients in this study was, 42 ± 9.9 year and reason for referring patients in 35.4% of cases was due to follow-up of abnormal results of previous Pap smear, in 30% bleeding, 12% Pain and 2.6% percent of cases was checking-up. In final results of sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and accuracy any of the methods conventional and liquid based Pap smear and colposcopy were compared with cervical biopsy as a gold standard. The conventional Pap smear method had a sensitivity 51%, specificity 66.6%, PPV 96%, NPV was 8% and accuracy was 92%, about the liquid base Pap smear method, sensitivity was 55.3%, specificity was 77.7%, PPV was 97.5%, NPV was 10% and accuracy was 56/6%. About the colposcopy, sensitivity was70/9 % specificity 44/4%, PPV was 95.2%, NPV was 8/8% and accuracy was 69.3%. The relationship between sensitivity results of conventional Pap smear and

  18. Molecular Triage of Premalignant Lesions in Liquid-Based Cervical Cytology and Circulating Cell-Free DNA from Urine, Using a Panel of Methylated Human Papilloma Virus and Host Genes.

    Science.gov (United States)

    Guerrero-Preston, Rafael; Valle, Blanca L; Jedlicka, Anne; Turaga, Nitesh; Folawiyo, Oluwasina; Pirini, Francesca; Lawson, Fahcina; Vergura, Angelo; Noordhuis, Maartje; Dziedzic, Amanda; Pérez, Gabriela; Renehan, Marisa; Guerrero-Diaz, Carolina; De Jesus Rodríguez, Edgar; Diaz-Montes, Teresa; Rodríguez Orengo, José; Méndez, Keimari; Romaguera, Josefina; Trock, Bruce J; Florea, Liliana; Sidransky, David

    2016-12-01

    Clinically useful molecular tools to triage women for a biopsy upon referral to colposcopy are not available. We aimed to develop a molecular panel to detect cervical intraepithelial neoplasia (CIN) grade 2 or higher lesions (CIN2 + ) in women with abnormal cervical cytology and high-risk HPV (HPV + ). We tested a biomarker panel in cervical epithelium DNA obtained from 211 women evaluated in a cervical cancer clinic in Chile from 2006 to 2008. Results were verified in a prospective cohort of 107 women evaluated in a high-risk clinic in Puerto Rico from 2013 to 2015. Promoter methylation of ZNF516, FKBP6, and INTS1 discriminated cervical brush samples with CIN2 + lesions from samples with no intraepithelial lesions or malignancy (NILM) with 90% sensitivity, 88.9% specificity, 0.94 area under the curve (AUC), 93.1% positive predictive value (PPV), and 84.2% negative predictive value (NPV). The panel results were verified in liquid-based cervical cytology samples from an independent cohort with 90.9% sensitivity, 60.9% specificity, 0.90 AUC, 52.6% PPV, and 93.3% NPV, after adding HPV16-L1 methylation to the panel. Next-generation sequencing results in HPV + cultured cells, and urine circulating cell-free DNA (ccfDNA) were used to design assays that show clinical feasibility in a subset (n = 40) of paired plasma (AUC = 0.81) and urine (AUC = 0.86) ccfDNA samples obtained from the prospective cohort. Viral and host DNA methylation panels can be tested in liquid cytology and urine ccfDNA from women referred to colposcopy, to triage CIN2 + lesions for biopsy and inform personalized screening algorithms. Cancer Prev Res; 9(12); 915-24. ©2016 AACR. ©2016 American Association for Cancer Research.

  19. Seasonal pattern of lesion development in diseased Fraxinus excelsior infected by Hymenoscyphus pseudoalbidus.

    Directory of Open Access Journals (Sweden)

    Stina Barbro Katrin Bengtsson

    Full Text Available Ash dieback is a recent widespread disease on ash (Fraxinus sp. that is causing important economic and ecological losses throughout Europe. The disease is initiated by the ascomycetous fungus Hymenoscyphus pseudoalbidus (anamorph Chalara fraxinea. The main aim of this study was to investigate seasonal pattern of lesion development associated with ash dieback. We present data on the spread of 324 natural lesions in ash shoots, branches and stems surveyed over a 32 month period. Most lesions were active and showed the greatest rate of growth during the summer; however, lesions were active throughout the year. Tree mortality was high, with more than a third of the surveyed trees dying during the study. Although many lesions permanently ceased to develop, the rate at which new lesions emerged was greater than the rate at which lesions entered a resting phase. The most common cause for a lesion going into a permanent state of rest was that it had encountered a branch-base. Genotype analysis showed that multiple infections can occur in a single tree given that different genotypes were identified in different lesions as well as in single lesions. A weak positive correlation was noted between tree health and tree size and a weak negative correlation was noted between tree overall health and lesion activity. The lower limit for H. pseudoalbidus growth in culture was between 4.0°C and 0.5°C.

  20. Toward a non-invasive screening tool for differentiation of pancreatic lesions based on intra-voxel incoherent motion derived parameters

    International Nuclear Information System (INIS)

    Graf, Markus; Simon, Dirk; Mang, Sarah; Lemke, Andreas; Gruenberg, Katharina

    2013-01-01

    Early recognition of and differential diagnosis between pancreatic cancer and chronic pancreatitis is an important step in successful therapy. Parameters of the IVIM (intra-voxel incoherent motion) theory can be used to differentiate between those lesions. The objective of this work is to evaluate the effects of rigid image registration on IVIM derived parameters for differentiation of pancreatic lesions such as pancreatic cancer and solid mass forming pancreatitis. The effects of linear image registration methods on reproducibility and accuracy of IVIM derived parameters were quantified on MR images of ten volunteers. For this purpose, they were evaluated statistically by comparison of registered and unregistered parameter data. Further, the perfusion fraction f was used to differentiate pancreatic lesions on eleven previously diagnosed patient data sets. Its diagnostic power with and without rigid registration was evaluated using receiver operating curves (ROC) analysis. The pancreas was segmented manually on MR data sets of healthy volunteers as well as the patients showing solid pancreatic lesions. Diffusion weighted imaging was performed in 10 blocks of breath-hold phases. Linear registration of the weighted image stack leads to a 3.7% decrease in variability of the IVIM derived parameter f due to an improved anatomical overlap of 5%. Consequently, after registration the area under the curve in the ROC-analysis for the differentiation approach increased by 2.7%. In conclusion, rigid registration improves the differentiation process based on f-values. (orig.)

  1. Periapical and endodontic status scale based on periapical bone lesions and endodontic treatment quality evaluation using cone-beam computed tomography.

    Science.gov (United States)

    Venskutonis, Tadas; Plotino, Gianluca; Tocci, Luigi; Gambarini, Gianluca; Maminskas, Julius; Juodzbalys, Gintaras

    2015-02-01

    The purpose of this study was to present a new periapical and endodontic status scale (PESS) that is based on the complex periapical index (COPI), which was designed for the identification and classification of periapical bone lesions in cases of apical periodontitis, and the endodontically treated tooth index, which was designed for endodontic treatment quality evaluation by means of cone-beam computed tomographic (CBCT) analysis. Periapical and endodontic status parameters were selected from the already known indexes and scientific literature for radiologic evaluation. Radiographic images (CBCT imaging, digital orthopantomography [DOR], and digital periapical radiography) from 55 patients were analyzed. All parameters were evaluated on CBCT, DOR, and digital periapical radiographic images by 2 external observers. The statistical analysis was performed with software SPSS version 19.0 (SPSS Inc, Chicago, IL). Chi-square tests were used to compare frequencies of qualitative variables. The level of significance was set at P ≤ .05. Overall intraobserver and interobserver agreements were very good and good, respectively. CBCT analysis found more lesions and lesions of bigger dimension (P analysis, more root canals and more canals associated with lesions were found. The most informative and reproducible periapical and endodontic status parameters were selected, and a new PESS was proposed. The classification proposed in the present study seems to be reproducible and objective and adds helpful information with respect to the existing indexes. Future studies need to be conducted to validate PESS. Copyright © 2015 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  2. Toward a non-invasive screening tool for differentiation of pancreatic lesions based on intra-voxel incoherent motion derived parameters

    Energy Technology Data Exchange (ETDEWEB)

    Graf, Markus; Simon, Dirk; Mang, Sarah [Deutsches Krebsforschungszentrum (DKFZ), Heidelberg (Germany). Software Development for Integrated Therapy and Diagnostics; Lemke, Andreas [Heidelberg Univ., Mannheim (Germany). Dept. of Computer Assisted Clinical Medicine; Gruenberg, Katharina [Deutsches Krebsforschungszentrum (DKFZ), Heidelberg (Germany). Dept. of Radiology

    2013-03-01

    Early recognition of and differential diagnosis between pancreatic cancer and chronic pancreatitis is an important step in successful therapy. Parameters of the IVIM (intra-voxel incoherent motion) theory can be used to differentiate between those lesions. The objective of this work is to evaluate the effects of rigid image registration on IVIM derived parameters for differentiation of pancreatic lesions such as pancreatic cancer and solid mass forming pancreatitis. The effects of linear image registration methods on reproducibility and accuracy of IVIM derived parameters were quantified on MR images of ten volunteers. For this purpose, they were evaluated statistically by comparison of registered and unregistered parameter data. Further, the perfusion fraction f was used to differentiate pancreatic lesions on eleven previously diagnosed patient data sets. Its diagnostic power with and without rigid registration was evaluated using receiver operating curves (ROC) analysis. The pancreas was segmented manually on MR data sets of healthy volunteers as well as the patients showing solid pancreatic lesions. Diffusion weighted imaging was performed in 10 blocks of breath-hold phases. Linear registration of the weighted image stack leads to a 3.7% decrease in variability of the IVIM derived parameter f due to an improved anatomical overlap of 5%. Consequently, after registration the area under the curve in the ROC-analysis for the differentiation approach increased by 2.7%. In conclusion, rigid registration improves the differentiation process based on f-values. (orig.)

  3. Multicenter assessment of the reproducibility of volumetric radiofrequency-based intravascular ultrasound measurements in coronary lesions that were consecutively stented

    DEFF Research Database (Denmark)

    Huisman, Jennifer; Egede, Rasmus; Rdzanek, Adam

    2012-01-01

    To assess in a multicenter design the between-center reproducibility of volumetric virtual histology intravascular ultrasound (VH-IVUS) measurements with a semi-automated, computer-assisted contour detection system in coronary lesions that were consecutively stented. To evaluate the reproducibility...

  4. Maxillary Bone Regeneration Based on Nanoreservoirs Functionalized ε-Polycaprolactone Biomembranes in a Mouse Model of Jaw Bone Lesion

    Directory of Open Access Journals (Sweden)

    Marion Strub

    2018-01-01

    Full Text Available Current approaches of regenerative therapies constitute strategies for bone tissue reparation and engineering, especially in the context of genetical diseases with skeletal defects. Bone regeneration using electrospun nanofibers’ implant has the following objectives: bone neoformation induction with rapid healing, reduced postoperative complications, and improvement of bone tissue quality. In vivo implantation of polycaprolactone (PCL biomembrane functionalized with BMP-2/Ibuprofen in mouse maxillary defects was followed by bone neoformation kinetics evaluation using microcomputed tomography. Wild-Type (WT and Tabby (Ta mice were used to compare effects on a normal phenotype and on a mutant model of ectodermal dysplasia (ED. After 21 days, no effect on bone neoformation was observed in Ta treated lesion (4% neoformation compared to 13% in the control lesion. Between the 21st and the 30th days, the use of biomembrane functionalized with BMP-2/Ibuprofen in maxillary bone lesions allowed a significant increase in bone neoformation peaks (resp., +8% in mutant Ta and +13% in WT. Histological analyses revealed a neoformed bone with regular trabecular structure, areas of mineralized bone inside the membrane, and an improved neovascularization in the treated lesion with bifunctionalized membrane. In conclusion, PCL functionalized biomembrane promoted bone neoformation, this effect being modulated by the Ta bone phenotype responsible for an alteration of bone response.

  5. Positioning of aquatic animals based on time-of-arrival and random walk models using YAPS (Yet Another Positioning Solver)

    DEFF Research Database (Denmark)

    Baktoft, Henrik; Gjelland, Karl Øystein; Økland, Finn

    2017-01-01

    Aquatic positional telemetry offers vast opportunities to study in vivo behaviour of wild animals, but there is room for improvement in the data quality provided by current procedures for estimating positions. Here we present a novel positioning method called YAPS (Yet Another Positioning Solver...

  6. Lesões destrutivas da linha média induzidas por cocaína com ANCA positivo mimetizando a granulomatose de Wegener Cocaine-induced midline destruction lesions with positive ANCA test mimicking Wegener's granulomatosis

    Directory of Open Access Journals (Sweden)

    Letícia Stahelin

    2012-06-01

    diagnosed with WG for five months, being on prednisone and cyclophosphamide. On her physical examination, perforation of her nasal septum and palate was observed. Laboratory tests showed elevated acute phase proteins and a positive p-ANCA test. ELISA assays anti-proteinase 3 and myeloperoxidase were negative. The paranasal sinus computed tomography (CT showed destruction of the nasal septum and palate, in addition to bilateral maxillary sinusitis. Chest CT was normal. Nasal mucosal biopsy revealed an inflammatory infiltrate, with neither granuloma nor vasculitis. When questioned, she admitted being a cocaine user for five years. Medical therapy and cocaine use were withdrawn. She has been followed up for six months and no other lesion or other organ symptoms occurred. Differential diagnosis in patients with midline destructive lesions can be very challenging. Evaluation should include enquiry about intranasal use of cocaine. Although ANCA testing does not clearly differentiate the ANCA found in some patients with CIMDL from those found in WG patients, the localized involvement and the biopsy findings non-characteristic of small vessel granulomatous vasculitis should be recognized as features for cocaine-induced lesions.

  7. Detection and measurement of artificial periapical lesions by cone-beam computed tomography.

    Science.gov (United States)

    Liang, Y-H; Jiang, L; Gao, X-J; Shemesh, H; Wesselink, P R; Wu, M-K

    2014-04-01

    To test the ability of periapical radiography (PA) and cone-beam computed tomography (CBCT) to determine the presence/absence of periapical lesions and examine the reliability of volumetric measurements of periapical lesions on CBCT scans. After tooth extractions in human mandibles, bone defects were cut at the base of extraction sockets to mimic periapical bone lesions. The teeth were then returned into the extraction sockets. Sixty-three roots of anterior teeth, premolars and molars with artificial periapical lesions and 37 roots without lesions were examined with PA and CBCT. Presence/absence of periapical lesion was noted. The CBCT-based volume of each lesion (Vct) was measured using Amira software 5.4 (Visage Imaging GmbH, Berlin, Germany). A replica of each lesion was created using silicone impression material, and the volume of the replica was measured using a water displacement method, representing the physical volume of the lesion (Vp). Regression analysis was used to test the correlation between the Vp and Vct values. The positive and negative predictive values and accuracy for CBCT in diagnosing periapical lesions were all 1, compared with 1, 0.64 and 0.79 for PA diagnosis. Twenty-one (33%) lesions were undetected by PA. The Vp (21.5 ± 11.0 mm(3) ) and Vct (21.4 ± 11.5 mm(3) ) values of 63 lesions were highly correlated (R(2) = 96.9%, P periapical lesions associated with mandibular teeth. The volumes of artificial mandibular periapical lesions were accurately measured with CBCT data. © 2013 International Endodontic Journal. Published by John Wiley & Sons Ltd.

  8. RFID-based vehicle positioning and its applications in connected vehicles.

    Science.gov (United States)

    Wang, Jianqiang; Ni, Daiheng; Li, Keqiang

    2014-03-04

    This paper proposed an RFID-based vehicle positioning approach to facilitate connected vehicles applications. When a vehicle passes over an RFID tag, the vehicle position is given by the accurate position stored in the tag. At locations without RFID coverage, the vehicle position is estimated from the most recent tag location using a kinematics integration algorithm till updates from the next tag. The accuracy of RFID positioning is verified empirically in two independent ways with one using radar and the other a photoelectric switch. The former is designed to verify whether the dynamic position obtained from RFID tags matches the position measured by radar that is regarded as accurate. The latter aims to verify whether the position estimated from the kinematics integration matches the position obtained from RFID tags. Both means supports the accuracy of RFID-based positioning. As a supplement to GPS which suffers from issues such as inaccuracy and loss of signal, RFID positioning is promising in facilitating connected vehicles applications. Two conceptual applications are provided here with one in vehicle operational control and the other in Level IV intersection control.

  9. An update of 77 cases diagnosed as oral hemangiomas based on GLUT-1 positivity.

    Science.gov (United States)

    da Silva Filho, Tiago João; de Oliveira, Denise Hélen Imaculada Pereira; Brasil, Veruska Lima Moura; Nonaka, Cassiano Francisco Weege; da Silveira, Éricka Janine Dantas; Queiroz, Lélia Maria Guedes

    2017-08-01

    To evaluate cases diagnosed as "oral hemangiomas" based on the immunohistochemical expression of human glucose transporter protein (GLUT-1) and on histopathological features, and to investigate whether the classification proposed by the ISSVA was used correctly to classify these lesions. All cases stored in the archives of an Oral Pathology Service and diagnosed as "oral hemangiomas" were reviewed. Seventy-seven cases were analyzed regarding the expression of GLUT-1. GLUT-1(+) specimens were classified as true infantile hemangioma (IH) and GLUT-1(-) specimens were reclassified based on their histopathological features. The nomenclature of these lesions was evaluated and some cases were reclassified. Only 26 (33.8%) of the specimens were indeed IHs. Among the GLUT-1(-) specimens, 20 (26.0%) were reclassified as pyogenic granulomas (PGs) and 31 (40.2%) as vascular malformations. Considering the previously applied nomenclature, only 47.5% of the cases initially diagnosed as "hemangiomas" were IHs. In the group of "capillary hemangiomas", most cases (56.2%) were PGs. Among the three "cellular hemangiomas", two were PGs and one was IH. Most (88.8%) "cavernous hemangiomas" were vascular malformations. Careful and parameterized review of cases of vascular anomalies is necessary using auxiliary tools such as GLUT-1, since the exclusive use of histopathological findings might be insufficient to differentiate some anomalies. Accurate clinical examination and the use of biomarkers such as GLUT-1 are essential for the diagnosis. Copyright © 2017. Published by Elsevier Inc.

  10. Integrated Positioning for Coal Mining Machinery in Enclosed Underground Mine Based on SINS/WSN

    Science.gov (United States)

    Hui, Jing; Wu, Lei; Yan, Wenxu; Zhou, Lijuan

    2014-01-01

    To realize dynamic positioning of the shearer, a new method based on SINS/WSN is studied in this paper. Firstly, the shearer movement model is built and running regularity of the shearer in coal mining face has been mastered. Secondly, as external calibration of SINS using GPS is infeasible in enclosed underground mine, WSN positioning strategy is proposed to eliminate accumulative error produced by SINS; then the corresponding coupling model is established. Finally, positioning performance is analyzed by simulation and experiment. Results show that attitude angle and position of the shearer can be real-timely tracked by integrated positioning strategy based on SINS/WSN, and positioning precision meet the demand of actual working condition. PMID:24574891

  11. Research on the Collinear Equation Model of Visual Positioning Based on Visible Light Communication

    Directory of Open Access Journals (Sweden)

    Wang Yuqi

    2015-01-01

    Full Text Available A positioning method based on visible light communication is proposed, which receiving visible light information by low-resolution photodiode array and receiving visual information by the front camera of mobile phone. The terminal position is determined by matching spot information provided by photodiode array with visual information and position information provided by visible light communication. A collinear equation model is derived which based on mobile phone front camera. A hardware-in-loop simulation has been conducted to verify the collinear equation. The three-dimensional positioning error is on the level of decimeter. Moreover, the main factors which affect the positioning accuracy are analyzed in order to further improve the positioning accuracy.

  12. Integrated positioning for coal mining machinery in enclosed underground mine based on SINS/WSN.

    Science.gov (United States)

    Fan, Qigao; Li, Wei; Hui, Jing; Wu, Lei; Yu, Zhenzhong; Yan, Wenxu; Zhou, Lijuan

    2014-01-01

    To realize dynamic positioning of the shearer, a new method based on SINS/WSN is studied in this paper. Firstly, the shearer movement model is built and running regularity of the shearer in coal mining face has been mastered. Secondly, as external calibration of SINS using GPS is infeasible in enclosed underground mine, WSN positioning strategy is proposed to eliminate accumulative error produced by SINS; then the corresponding coupling model is established. Finally, positioning performance is analyzed by simulation and experiment. Results show that attitude angle and position of the shearer can be real-timely tracked by integrated positioning strategy based on SINS/WSN, and positioning precision meet the demand of actual working condition.

  13. Infection with CagA-positive Helicobacter pylori strain containing three EPIYA C phosphorylation sites is associated with more severe gastric lesions in experimentally infected Mongolian gerbils (Meriones unguiculatus

    Directory of Open Access Journals (Sweden)

    M. Ferreira Júnior

    2015-04-01

    Full Text Available Infection with Helicobacter pylori strains containing high number of EPIYA-C phosphorylation sites in the CagA is associated with significant gastritis and increased risk of developing pre-malignant gastric lesions and gastric carcinoma. However, these findings have not been reproduced in animal models yet. Therefore, we investigated the effect on the gastric mucosa of Mongolian gerbil (Meriones unguiculatus infected with CagA-positive H. pylori strains exhibiting one or three EPIYA-C phosphorilation sites. Mongolian gerbils were inoculated with H. pylori clonal isolates containing one or three EPIYA-C phosphorylation sites. Control group was composed by uninfected animals challenged with Brucella broth alone. Gastric fragments were evaluated by the modified Sydney System and digital morphometry. Clonal relatedness between the isolates was considered by the identical RAPD-PCR profiles and sequencing of five housekeeping genes, vacA i/d region and of oipA. The other virulence markers were present in both isolates (vacA s1i1d1m1, iceA2, and intact dupA. CagA of both isolates was translocated and phosphorylated in AGS cells. After 45 days of infection, there was a significant increase in the number of inflammatory cells and in the area of the lamina propria in the infected animals, notably in those infected by the CagA-positive strain with three EPIYA-C phosphorylation sites. After six months of infection, a high number of EPIYA-C phosphorylation sites was associated with progressive increase in the intensity of gastritis and in the area of the lamina propria. Atrophy, intestinal metaplasia, and dysplasia were also observed more frequently in animals infected with the CagA-positive isolate with three EPIYA-C sites.  We conclude that infection with H. pylori strain carrying a high number of CagA EPIYA-C phosphorylation sites is associated with more severe gastric lesions in an animal model of H. pylori infection.

  14. Automated detection of Lupus white matter lesions in MRI

    Directory of Open Access Journals (Sweden)

    Eloy Roura Perez

    2016-08-01

    Full Text Available Brain magnetic resonance imaging provides detailed information which can be used to detect and segment white matter lesions (WML. In this work we propose an approach to automatically segment WML in Lupus patients by using T1w and fluid-attenuated inversion recovery (FLAIR images. Lupus WML appear as small focal abnormal tissue observed as hyperintensities in the FLAIR images. The quantification of these WML is a key factor for the stratification of lupus patients and therefore both lesion detection and segmentation play an important role. In our approach, the T1w image is first used to classify the three main tissues of the brain, white matter (WM, gray matter (GM and cerebrospinal fluid (CSF, while the FLAIR image is then used to detect focal WML as outliers of its GM intensity distribution. A set of post-processing steps based on lesion size, tissue neighborhood, and location are used to refine the lesion candidates. The proposal is evaluated on 20 patients, presenting qualitative and quantitative results in terms of precision and sensitivity of lesion detection (True Positive Rate (62% and Positive Prediction Value (80% respectively as well as segmentation accuracy (Dice Similarity Coefficient (72%. Obtained results illustrate the validity of the approach to automatically detect and segment lupus lesions. Besides, our approach is publicly available as a SPM8/12 toolbox extension with a simple parameter configuration.

  15. Adaptive Indoor Positioning Model Based on WLAN-Fingerprinting for Dynamic and Multi-Floor Environments

    Directory of Open Access Journals (Sweden)

    Iyad Husni Alshami

    2017-08-01

    Full Text Available The Global Positioning System demonstrates the significance of Location Based Services but it cannot be used indoors due to the lack of line of sight between satellites and receivers. Indoor Positioning Systems are needed to provide indoor Location Based Services. Wireless LAN fingerprints are one of the best choices for Indoor Positioning Systems because of their low cost, and high accuracy, however they have many drawbacks: creating radio maps is time consuming, the radio maps will become outdated with any environmental change, different mobile devices read the received signal strength (RSS differently, and peoples’ presence in LOS between access points and mobile device affects the RSS. This research proposes a new Adaptive Indoor Positioning System model (called DIPS based on: a dynamic radio map generator, RSS certainty technique and peoples’ presence effect integration for dynamic and multi-floor environments. Dynamic in our context refers to the effects of people and device heterogeneity. DIPS can achieve 98% and 92% positioning accuracy for floor and room positioning, and it achieves 1.2 m for point positioning error. RSS certainty enhanced the positioning accuracy for floor and room for different mobile devices by 11% and 9%. Then by considering the peoples’ presence effect, the error is reduced by 0.2 m. In comparison with other works, DIPS achieves better positioning without extra devices.

  16. Voxel-based lesion symptom mapping analysis of depressive mood in patients with isolated cerebellar stroke: A pilot study

    Directory of Open Access Journals (Sweden)

    Na Young Kim, MD

    2017-01-01

    Voxel-wise subtraction and χ (Ayerbe et al., 2014 analyses indicated that damage to the left posterior cerebellar hemisphere was associated with depression. Significant correlations were also found between the severity of depressive symptoms and lesions in lobules VI, VIIb, VIII, Crus I, and Crus II of the left cerebellar hemisphere (Pcorrected = 0.045. Our results suggest that damage to the left posterior cerebellum is associated with increased depressive mood severity in patients with isolated cerebellar stroke.

  17. SU-F-T-469: A Clinically Observed Discrepancy Between Image-Based and Log- Based MLC Position

    Energy Technology Data Exchange (ETDEWEB)

    Neal, B; Ahmed, M; Siebers, J [University of Virginia Health System, Charlottesville, VA (United States)

    2016-06-15

    Purpose: To present a clinical case which challenges the base assumption of log-file based QA, by showing that the actual position of a MLC leaf can suddenly deviate from its programmed and logged position by >1 mm as observed with real-time imaging. Methods: An EPID-based exit-fluence dosimetry system designed to prevent gross delivery errors was used in cine mode to capture portal images during treatment. Visual monitoring identified an anomalous MLC leaf pair gap not otherwise detected by the automatic position verification. The position of the erred leaf was measured on EPID images and log files were analyzed for the treatment in question, the prior day’s treatment, and for daily MLC test patterns acquired on those treatment days. Additional standard test patterns were used to quantify the leaf position. Results: Whereas the log file reported no difference between planned and recorded positions, image-based measurements showed the leaf to be 1.3±0.1 mm medial from the planned position. This offset was confirmed with the test pattern irradiations. Conclusion: It has been clinically observed that log-file derived leaf positions can differ from their actual positions by >1 mm, and therefore cannot be considered to be the actual leaf positions. This cautions the use of log-based methods for MLC or patient quality assurance without independent confirmation of log integrity. Frequent verification of MLC positions through independent means is a necessary precondition to trusting log file records. Intra-treatment EPID imaging provides a method to capture departures from MLC planned positions. Work was supported in part by Varian Medical Systems.

  18. A Spatial Division Clustering Method and Low Dimensional Feature Extraction Technique Based Indoor Positioning System

    Directory of Open Access Journals (Sweden)

    Yun Mo

    2014-01-01

    Full Text Available Indoor positioning systems based on the fingerprint method are widely used due to the large number of existing devices with a wide range of coverage. However, extensive positioning regions with a massive fingerprint database may cause high computational complexity and error margins, therefore clustering methods are widely applied as a solution. However, traditional clustering methods in positioning systems can only measure the similarity of the Received Signal Strength without being concerned with the continuity of physical coordinates. Besides, outage of access points could result in asymmetric matching problems which severely affect the fine positioning procedure. To solve these issues, in this paper we propose a positioning system based on the Spatial Division Clustering (SDC method for clustering the fingerprint dataset subject to physical distance constraints. With the Genetic Algorithm and Support Vector Machine techniques, SDC can achieve higher coarse positioning accuracy than traditional clustering algorithms. In terms of fine localization, based on the Kernel Principal Component Analysis method, the proposed positioning system outperforms its counterparts based on other feature extraction methods in low dimensionality. Apart from balancing online matching computational burden, the new positioning system exhibits advantageous performance on radio map clustering, and also shows better robustness and adaptability in the asymmetric matching problem aspect.

  19. 78 FR 65006 - National Space-Based Positioning, Navigation, and Timing (PNT) Advisory Board; Meeting

    Science.gov (United States)

    2013-10-30

    ..., Public Law 92-463, as amended, and the President's 2004 U.S. Space-Based Positioning, Navigation, and.... ADDRESSES: The Omni Shoreham Hotel, 2500 Calvert Street NW., Washington, DC 20008. FOR FURTHER INFORMATION...

  20. 78 FR 23598 - National Space-Based Positioning, Navigation, and Timing (PNT) Advisory Board; Meeting

    Science.gov (United States)

    2013-04-19

    ..., Public Law 92-463, as amended, and the President's 2004 U.S. Space-Based Positioning, Navigation, and...: The Melrose Hotel, 2430 Pennsylvania Ave NW., Washington, DC 20037. FOR FURTHER INFORMATION CONTACT...

  1. A program to compute geographical positions of underwater artifact based on linear measurements

    Digital Repository Service at National Institute of Oceanography (India)

    Ganesan, P.

    While carrying out underwater positioning in shallow waters, the Diver Archaeologists measure lengths and bearings from a base line of the well-established control network to each and every corner of the artifact. A program in Basic language...

  2. The effect of textile-based inductive coil sensor positions for heart rate monitoring.

    Science.gov (United States)

    Koo, Hye Ran; Lee, Young-Jae; Gi, Sunok; Khang, Seonah; Lee, Joo Hyeon; Lee, Jae-Ho; Lim, Min-Gyu; Park, Hee-Jung; Lee, Jeong-Whan

    2014-02-01

    In the research related to heart rate measurement, few studies have been done using magnetic-induced conductivity sensing methods to measure the heart rate. The aim of this study was to analyze the effect of the position of a textile-based inductive coil sensor on the measurement of the heart rate. In order to assess the capability of the textile-based inductive coil sensor and the repeatability of measured cardiac muscle contractions, we proposed a new quality index based on the morphology of measured signals using a textile-based inductive coil sensor. We initially explored eight potential positions of the inductive sensor in a pilot experiment, followed by three sensor positions in the main experiment. A simultaneously measured electrocardiography (ECG) signal (Lead II) which was used as a reference signal for a comparison of the R-peak location with signals obtained from selected positions of the textile-based inductive coil sensor. The result of the main experiment indicated that the total quality index obtained from the sensor position 'P3', which was located 3 cm away from the left side from the center front line on the chest circumference line, was the highest (QI value = 1.30) among the three positions across all the subjects. This finding led us to conclude that (1) the position of the textile-based inductive coil sensor significantly affected the quality of the measurement results, and that (2) P3 would be the most appropriate position for the textile-based inductive coil sensor for heart rate measurements based on the magnetic-induced conductivity sensing principle.

  3. Position Estimation for Switched Reluctance Motor Based on the Single Threshold Angle

    Science.gov (United States)

    Zhang, Lei; Li, Pang; Yu, Yue

    2017-05-01

    This paper presents a position estimate model of switched reluctance motor based on the single threshold angle. In view of the relationship of between the inductance and rotor position, the position is estimated by comparing the real-time dynamic flux linkage with the threshold angle position flux linkage (7.5° threshold angle, 12/8SRM). The sensorless model is built by Maltab/Simulink, the simulation are implemented under the steady state and transient state different condition, and verified its validity and feasibility of the method..

  4. Incidental benign parotid lesions on FDG-PET: prevalence and clinico-pathologic findings

    International Nuclear Information System (INIS)

    Lim, Il Han; Lee, Won Woo; Chung, Jin Haeng; Park, So Yeon; Kim, Yu Kyeong; Kim, Sang Eun

    2007-01-01

    Incidental parotid lesions on F-18 FDG-PET can mimic distant metastasis of underlying malignancy. The prevalence and the clinico-pathologic findings of PET positive parotid lesions have not been known. We investigated how often incidental parotid lesions are found on clinical FDG-PET studies and what the clinico-pathologic characteristics of those parotid lesions are in the present study. We retrospectively reviewed 3, 344 cases of FDG-PET which had been obtained in our hospital from May 2003 to Dec 2006. The indications of FDG-PET were: evaluation of known/suspected cancer (n=3, 212) or screening of cancer in healthy subjects (n=132). Incidental parotid lesion on FDG-PET was defined as an un-expected FDG uptake in one of parotid glands which was not primary target lesion of current FDG-PET. FDG uptake was represented by maximum standardized uptake value (maxSUV). Final diagnosis was made by pathologic analysis or clinical follow-up assessment. Fifteen (0.45% = 15/3, 344) incidental parotid lesions were found and they were all benign lesions. The maxSUV ranged from 1.7 to 8.6 (means.d.=3.71.9). Final diagnoses of the incidental parotid lesions were; Warthin's tumor (n=2), pleomorphic adenoma (n=1), other un-specified benign lesion (n=1), and benign lesions under bases of imaging studies (n=3) and of clinical follow-up (n=8). All of incidentally found parotid lesions in clinical FDG-PET studies were confirmed as benign lesions with prevalence of 0.45%. Close follow up using PET or CT might be a reasonable approach for determining the nature of incidentally found parotid lesions

  5. Speech repetition as a window on the neurobiology of auditory-motor integration for speech: A voxel-based lesion symptom mapping study.

    Science.gov (United States)

    Rogalsky, Corianne; Poppa, Tasha; Chen, Kuan-Hua; Anderson, Steven W; Damasio, Hanna; Love, Tracy; Hickok, Gregory

    2015-05-01

    For more than a century, speech repetition has been used as an assay for gauging the integrity of the auditory-motor pathway in aphasia, thought classically to involve a linkage between Wernicke's area and Broca's area via the arcuate fasciculus. During the last decade, evidence primarily from functional imaging in healthy individuals has refined this picture both computationally and anatomically, suggesting the existence of a cortical hub located at the parietal-temporal boundary (area Spt) that functions to integrate auditory and motor speech networks for both repetition and spontaneous speech production. While functional imaging research can pinpoint the regions activated in repetition/auditory-motor integration, lesion-based studies are needed to infer causal involvement. Previous lesion studies of repetition have yielded mixed results with respect to Spt's critical involvement in speech repetition. The present study used voxel-based lesion symptom mapping (VLSM) to investigate the neuroanatomy of repetition of both real words and non-words in a sample of 47 patients with focal left hemisphere brain damage. VLSMs identified a large voxel cluster spanning gray and white matter in the left temporal-parietal junction, including area Spt, where damage was significantly related to poor non-word repetition. Repetition of real words implicated a very similar dorsal network including area Spt. Cortical regions including Spt were implicated in repetition performance even when white matter damage was factored out. In addition, removing variance associated with speech perception abilities did not alter the overall lesion pattern for either task. Together with past functional imaging work, our results suggest that area Spt is integral in both word and non-word repetition, that its contribution is above and beyond that made by white matter pathways, and is not driven by perceptual processes alone. These findings are highly consistent with the claim that Spt is an area of

  6. An RFID Indoor Positioning Algorithm Based on Bayesian Probability and K-Nearest Neighbor.

    Science.gov (United States)

    Xu, He; Ding, Ye; Li, Peng; Wang, Ruchuan; Li, Yizhu

    2017-08-05

    The Global Positioning System (GPS) is widely used in outdoor environmental positioning. However, GPS cannot support indoor positioning because there is no signal for positioning in an indoor environment. Nowadays, there are many situations which require indoor positioning, such as searching for a book in a library, looking for luggage in an airport, emergence navigation for fire alarms, robot location, etc. Many technologies, such as ultrasonic, sensors, Bluetooth, WiFi, magnetic field, Radio Frequency Identification (RFID), etc., are used to perform indoor positioning. Compared with other technologies, RFID used in indoor positioning is more cost and energy efficient. The Traditional RFID indoor positioning algorithm LANDMARC utilizes a Received Signal Strength (RSS) indicator to track objects. However, the RSS value is easily affected by environmental noise and other interference. In this paper, our purpose is to reduce the location fluctuation and error caused by multipath and environmental interference in LANDMARC. We propose a novel indoor positioning algorithm based on Bayesian probability and K -Nearest Neighbor (BKNN). The experimental results show that the Gaussian filter can filter some abnormal RSS values. The proposed BKNN algorithm has the smallest location error compared with the Gaussian-based algorithm, LANDMARC and an improved KNN algorithm. The average error in location estimation is about 15 cm using our method.

  7. An RFID Indoor Positioning Algorithm Based on Bayesian Probability and K-Nearest Neighbor

    Directory of Open Access Journals (Sweden)

    He Xu

    2017-08-01

    Full Text Available The Global Positioning System (GPS is widely used in outdoor environmental positioning. However, GPS cannot support indoor positioning because there is no signal for positioning in an indoor environment. Nowadays, there are many situations which require indoor positioning, such as searching for a book in a library, looking for luggage in an airport, emergence navigation for fire alarms, robot location, etc. Many technologies, such as ultrasonic, sensors, Bluetooth, WiFi, magnetic field, Radio Frequency Identification (RFID, etc., are used to perform indoor positioning. Compared with other technologies, RFID used in indoor positioning is more cost and energy efficient. The Traditional RFID indoor positioning algorithm LANDMARC utilizes a Received Signal Strength (RSS indicator to track objects. However, the RSS value is easily affected by environmental noise and other interference. In this paper, our purpose is to reduce the location fluctuation and error caused by multipath and environmental interference in LANDMARC. We propose a novel indoor positioning algorithm based on Bayesian probability and K-Nearest Neighbor (BKNN. The experimental results show that the Gaussian filter can filter some abnormal RSS values. The proposed BKNN algorithm has the smallest location error compared with the Gaussian-based algorithm, LANDMARC and an improved KNN algorithm. The average error in location estimation is about 15 cm using our method.

  8. The use of GPS for Handling Lack of Indoor Constraints in Particle Filter-based Inertial Positioning

    DEFF Research Database (Denmark)

    Toftkjær, Thomas; Kjærgaard, Mikkel Baun

    of the layout of building structures on the positioning accuracy using a particle filter-based inertial positioning system named Pro-Position. We also consider methods for using GPS positioning with particle filter-based inertial positioningto improve accuracy in areas, where positioning is poor because of lack...

  9. Actual Excitation-Based Rotor Position Sensing in Switched Reluctance Drives

    Directory of Open Access Journals (Sweden)

    Ibrahim AL-BAHADLY

    2008-04-01

    Full Text Available The sensing of the rotor position for Switched Reluctance (SR motor is necessary for excitation control so as to obtain the best performance. The rotor position for SR motor control has usually been measured using a physical rotor position transducer attached to the rotor shaft. The fitting of a rotor position transducer on an SR motor requires additional electrical connections and additional cost, it is also a potential source of unreliability. Considerable attention has recently been applied to various methods for sensorless rotor position measurement, generally based on measurement of phase current and flux and a preknowledge of the magnetic characteristics. This paper presents two methods which deduce sensorless rotor position information by monitoring the actual excitation signals of the motor phases. This is done without the injection of diagnostic current pulses and has the advantages that the measured current is large and mutual effects from other phases are negligible.

  10. AUV Positioning Method Based on Tightly Coupled SINS/LBL for Underwater Acoustic Multipath Propagation

    Directory of Open Access Journals (Sweden)

    Tao Zhang

    2016-03-01

    Full Text Available This paper researches an AUV (Autonomous Underwater Vehicle positioning method based on SINS (Strapdown Inertial Navigation System/LBL (Long Base Line tightly coupled algorithm. This algorithm mainly includes SINS-assisted searching method of optimum slant-range of underwater acoustic propagation multipath, SINS/LBL tightly coupled model and multi-sensor information fusion algorithm. Fuzzy correlation peak problem of underwater LBL acoustic propagation multipath could be solved based on SINS positional information, thus improving LBL positional accuracy. Moreover, introduction of SINS-centered LBL locating information could compensate accumulative AUV position error effectively and regularly. Compared to loosely coupled algorithm, this tightly coupled algorithm can still provide accurate location information when there are fewer than four available hydrophones (or within the signal receiving range. Therefore, effective positional calibration area of tightly coupled system based on LBL array is wider and has higher reliability and fault tolerance than loosely coupled. It is more applicable to AUV positioning based on SINS/LBL.

  11. Base excision repair pathway is involved in the repair of lesions generated by flavonoid-enriched fractions of pepper tree (Schinus terebinthifolius, Raddi) stem bark.

    Science.gov (United States)

    Varela-Barca, Francisco Napoleão Túlio; Agnez-Lima, Lucymara Fassarella; de Medeiros, Sílvia Regina Batistuzzo

    2007-10-01

    Cell-free and bacterial assays indicate that flavonoid-enriched fractions and the flavonoids of pepper tree stem bark from Schinus terebinthifolius Raddi have genotoxic rather than antigenotoxic properties. In the present report, we have examined the ability of flavonoid-enriched fractions to damage plasmid DNA and the repair pathways involved in the recognition of these DNA lesions. High concentrations of two flavonoid-enriched fractions were able to break phosphodiester bonds in DNA. In addition, studies using bacterial strains deficient in nucleotide excision repair and base excision repair (BER) enzymes indicated that the flavonoid-enriched fractions generated lesions that were substrates for enzymes belonging to the BER pathway. In addition, in vitro studies indicated that the DNA damage produced by the flavonoid-enriched fractions was also a substrate for exonuclease III and that the phosphodiester breakage was amplified by copper ions. These results indicate that flavonoids from the pepper tree (Schinus terebinthifolius, Raddi) generate lesions on DNA that are potential targets of FPG and MutY glycosylase from the BER pathway. Chromatographic and spectral analyses helped to support the hypothesis that the flavonoids of the Brazilian pepper tree bark are the main factors involved in the fraction's damage potential. The isolated flavonoids from Fraction II were also tested in vitro and support the oxidative damage potential of these flavonoids. (c) 2007 Wiley-Liss, Inc.

  12. Experimental approbation of a new ultrosound contrast agent based on sulfur geksafluoride in diagnostics of focal liver lesions of inflammatory genesis

    Directory of Open Access Journals (Sweden)

    S. V. Fomina

    2017-01-01

    Full Text Available Purpose of the study. Experimental approbation of a new domestic ultrasound contrast agent (UCA based on sulfur hexafluoride in the diagnosis of focal liver lesions of inflammatory genesis.Materials and methods. The investigated ultrasound contrast agent (UCA was a heterogeneous gas-liquid system consisting of micro bubbles of a sparingly soluble gas of sulfur hexafluoride (SF6 surrounded by a flexible mobile membrane of surfactants. Experimental work was carried out on rabbits. The study group included rabbits of males and females with focal liver lesion of inflammatory genesis (n = 12 weighing 1500- 1700 g. UCA was administered to animals in the ear vein. Focal lesions of the liver in animals were created in the experimental laboratory conditions. 14 days after the operation, all animals were subjected to ultrasound examination of the surgical intervention zones by using the Toshiba Aplio 400 scanners (Japan with a 3,5–8 MHz convection sensor. In a natural study, the size, structure and echogenicity of the focus were assessed, the degree of vascularization, the evenness and clarity of the contours were determined. When performing post contrast ultrasound, the time of the onset of contrast enhancement, the total duration of contrast, the changes in the contrast enhancement of the focus in different phases of the study were measured, the dimensions of the focus were measured, and the evenness and acuity of contours were measured. For histological examination, liver fragments and lungs were used. 

  13. Development of an online, publicly accessible naive Bayesian decision support tool for mammographic mass lesions based on the American College of Radiology (ACR) BI-RADS lexicon

    Science.gov (United States)

    Benndorf, Matthias; Kotter, Elmar; Langer, Mathias; Herda, Christoph; Wu, Yirong; Burnside, Elizabeth S.

    2015-01-01

    Purpose To develop and validate a decision support tool for mammographic mass lesions based on a standardized descriptor terminology (BI-RADS lexicon) to reduce variability of practice. Materials and Methods We used separate training data (1276 lesions, 138 malignant) and validation data (1177 lesions, 175 malignant). We created naïve Bayes (NB) classifiers from the training data with 10-fold cross validation. Our “inclusive model” comprised BI-RADS categories, BI-RADS descriptors and age as predictive variables, our “descriptor model” comprised BI-RADS descriptors and age. The resulting NB classifiers were applied to the validation data. We evaluated and compared classifier performance with ROC-analysis. Results In the training data, the inclusive model yields an AUC of 0.959, the descriptor model yields an AUC of 0.910 (PBI-RADS categories alone, PBI-RADS descriptors. We provide our classifier at www.ebm-radiology.com/nbmm/index.html. PMID:25576230

  14. Development of an online, publicly accessible naive Bayesian decision support tool for mammographic mass lesions based on the American College of Radiology (ACR) BI-RADS lexicon

    International Nuclear Information System (INIS)

    Benndorf, Matthias; Kotter, Elmar; Langer, Mathias; Herda, Christoph; Wu, Yirong; Burnside, Elizabeth S.

    2015-01-01

    To develop and validate a decision support tool for mammographic mass lesions based on a standardized descriptor terminology (BI-RADS lexicon) to reduce variability of practice. We used separate training data (1,276 lesions, 138 malignant) and validation data (1,177 lesions, 175 malignant). We created naive Bayes (NB) classifiers from the training data with tenfold cross-validation. Our ''inclusive model'' comprised BI-RADS categories, BI-RADS descriptors, and age as predictive variables; our ''descriptor model'' comprised BI-RADS descriptors and age. The resulting NB classifiers were applied to the validation data. We evaluated and compared classifier performance with ROC-analysis. In the training data, the inclusive model yields an AUC of 0.959; the descriptor model yields an AUC of 0.910 (P < 0.001). The inclusive model is superior to the clinical performance (BI-RADS categories alone, P < 0.001); the descriptor model performs similarly. When applied to the validation data, the inclusive model yields an AUC of 0.935; the descriptor model yields an AUC of 0.876 (P < 0.001). Again, the inclusive model is superior to the clinical performance (P < 0.001); the descriptor model performs similarly. We consider our classifier a step towards a more uniform interpretation of combinations of BI-RADS descriptors. We provide our classifier at www.ebm-radiology.com/nbmm/index.html. (orig.)

  15. Perfusion maps of the whole liver based on high temporal and spatial resolution contrast-enhanced MRI (4D THRIVE): Feasibility and initial results in focal liver lesions

    International Nuclear Information System (INIS)

    Coenegrachts, Kenneth; Ghekiere, Johan; Denolin, Vincent; Gabriele, Beck; Herigault, Gwen; Haspeslagh, Marc; Daled, Peter; Bipat, Shandra; Stoker, Jaap; Rigauts, Hans

    2010-01-01

    Purpose: To prospectively evaluate a new imaging sequence (4D THRIVE) for whole liver perfusion in high temporal and spatial resolution. Feasibility of parametric mapping and its potential for characterizing focal liver lesions (FLLs) are investigated. Materials and methods: Fifteen patients suspected for colorectal liver metastases (LMs) were included. Parametric maps were evaluated qualitatively (ring-enhancement and lesion heterogeneity) and compared to three-phased contrast-enhanced MRI. Quantitative analysis was based on average perfusion values of entire FLLs. Reference standard comprised surgery with histopathology or follow-up imaging. Fisher's exact test was used for qualitative and Kruskal-Wallis test for quantitative analysis. Results: In total 29 LMs, 17 hemangiomas and 4 focal nodular hyperplasias were evaluated. FLLs could be differentiated by qualitative assessment of parametric maps respectively three-phased contrast-enhanced MRI (Fisher's p < 0.001 for comparisons between LMs and hemangiomas and LMs and FNHs for both ring-enhancement and lesion heterogeneity) rather than by quantitative analysis of parametric maps (Chi-square for Kep = 0.33 (p = 0.847) and Chi-square for Kel = 1.35 (p = 0.509)). Conclusion: This preliminary study shows potential of 4D THRIVE for whole liver imaging enabling calculation of parametric maps. Qualitative rather than quantitative analysis was accurate for differentiating malignant and benign FLLs.

  16. Development of an online, publicly accessible naive Bayesian decision support tool for mammographic mass lesions based on the American College of Radiology (ACR) BI-RADS lexicon

    Energy Technology Data Exchange (ETDEWEB)

    Benndorf, Matthias; Kotter, Elmar; Langer, Mathias [University Hospital Freiburg, Department of Radiology, Freiburg (Germany); Herda, Christoph [Kantonsspital Graubuenden, Chur (Switzerland); Wu, Yirong; Burnside, Elizabeth S. [University of Wisconsin-Madison School of Medicine and Public Health, Department of Radiology, Madison, WI (United States)

    2015-06-01

    To develop and validate a decision support tool for mammographic mass lesions based on a standardized descriptor terminology (BI-RADS lexicon) to reduce variability of practice. We used separate training data (1,276 lesions, 138 malignant) and validation data (1,177 lesions, 175 malignant). We created naive Bayes (NB) classifiers from the training data with tenfold cross-validation. Our ''inclusive model'' comprised BI-RADS categories, BI-RADS descriptors, and age as predictive variables; our ''descriptor model'' comprised BI-RADS descriptors and age. The resulting NB classifiers were applied to the validation data. We evaluated and compared classifier performance with ROC-analysis. In the training data, the inclusive model yields an AUC of 0.959; the descriptor model yields an AUC of 0.910 (P < 0.001). The inclusive model is superior to the clinical performance (BI-RADS categories alone, P < 0.001); the descriptor model performs similarly. When applied to the validation data, the inclusive model yields an AUC of 0.935; the descriptor model yields an AUC of 0.876 (P < 0.001). Again, the inclusive model is superior to the clinical performance (P < 0.001); the descriptor model performs similarly. We consider our classifier a step towards a more uniform interpretation of combinations of BI-RADS descriptors. We provide our classifier at www.ebm-radiology.com/nbmm/index.html. (orig.)

  17. Development of an online, publicly accessible naive Bayesian decision support tool for mammographic mass lesions based on the American College of Radiology (ACR) BI-RADS lexicon.

    Science.gov (United States)

    Benndorf, Matthias; Kotter, Elmar; Langer, Mathias; Herda, Christoph; Wu, Yirong; Burnside, Elizabeth S

    2015-06-01

    To develop and validate a decision support tool for mammographic mass lesions based on a standardized descriptor terminology (BI-RADS lexicon) to reduce variability of practice. We used separate training data (1,276 lesions, 138 malignant) and validation data (1,177 lesions, 175 malignant). We created naïve Bayes (NB) classifiers from the training data with tenfold cross-validation. Our "inclusive model" comprised BI-RADS categories, BI-RADS descriptors, and age as predictive variables; our "descriptor model" comprised BI-RADS descriptors and age. The resulting NB classifiers were applied to the validation data. We evaluated and compared classifier performance with ROC-analysis. In the training data, the inclusive model yields an AUC of 0.959; the descriptor model yields an AUC of 0.910 (P BI-RADS categories alone, P BI-RADS descriptors. We provide our classifier at www.ebm-radiology.com/nbmm/index.html . • We provide a decision support tool for mammographic masses at www.ebm-radiology.com/nbmm/index.html . • Our tool may reduce variability of practice in BI-RADS category assignment. • A formal analysis of BI-RADS descriptors may enhance radiologists' diagnostic performance.

  18. Kawasaki disease-associated coronary artery lesions with navigator echo-based. Respiratory-gated three dimensional coronary magnetic resonance angiography compared with echocardiography in young children

    International Nuclear Information System (INIS)

    Amino, Masayuki; Teraoka, Kunihiko; Hirano, Masaharu; Kawashima, Naoshi; Kakizaki, Dai; Ookubo, Yasuo; Sasaki, Kazuyoshi; Katuyama, Hiroaki

    2004-01-01

    Navigator echo-based respiratory-gated three dimensional coronary magnetic resonance angiography (3D-CMRA) was compared with echocardiography, to determine whether 3D-CMRA was useful for the evaluation of Kawasaki disease-associated coronary artery lesions. Sixteen consecutive patients (imaging was performed 17 times in total) who were given a diagnosis of Kawasaki's disease at the pediatric department of our hospital and examined for the precise examination of complicating coronary artery lesions on MRI using a navigator-echo technique because of their incapability of holding their breath during imaging were entered into the present study. A 1.5T MRI system was used. Gd-DOTA was given at a total volume of 0.1 mmol/kg. During imaging, CMRA visualized the left coronary arteries in all 17 cases and the right coronary arteries in 16 cases, but not in one case. The left main coronary trunk segment no.5 was demonstrated in all cases with CMRA, but not in 4 cases with echocardiography. The left anterior descending branch no.6 was visualized in 11 of the 17 cases with CMRA, but only in 5 cases with echocardiography. The left circumflex branch no.11 was observed in 6 cases with CMRA, but only in 2 cases with echocardiography. As for the right coronary arteries, branches no.1 and no.2 were observed in 16 and 9 cases with CMRA, respectively, and in 13 and 3 cases with echocardiography, respectively. Vascular diameters measured on CMRA were almost identical to those on echocardiography, within the range of arteries visualized. 3D-CMRA combined with a navigator echo technique appears to be a useful tool for the observation of coronary artery lesions associated with Kawasaki's disease because it is superior in lesion visualization to echocardiography. (author)

  19. Quantitative Assessment of Degenerative Cartilage and Subchondral Bony Lesions in a Preserved Cadaveric Knee: Propagation-Based Phase-Contrast CT Versus Conventional MRI and CT.

    Science.gov (United States)

    Geith, Tobias; Brun, Emmanuel; Mittone, Alberto; Gasilov, Sergei; Weber, Loriane; Adam-Neumair, Silvia; Bravin, Alberto; Reiser, Maximilian; Coan, Paola; Horng, Annie

    2018-04-09

    The aim of this study was to quantitatively assess hyaline cartilage and subchondral bone conditions in a fully preserved cadaveric human knee joint using high-resolution x-ray propagation-based phase-contrast imaging (PBI) CT and to compare the performance of the new technique with conventional CT and MRI. A cadaveric human knee was examined using an x-ray beam of 60 keV, a detector with a 90-mm 2 FOV, and a pixel size of 46 × 46 μm 2 . PBI CT images were reconstructed with both the filtered back projection algorithm and the equally sloped tomography method. Conventional 3-T MRI and CT were also performed. Measurements of cartilage thickness, cartilage lesions, International Cartilage Repair Society scoring, and detection of subchondral bone changes were evaluated. Visual inspection of the specimen akin to arthroscopy was conducted and served as a standard of reference for lesion detection. Loss of cartilage height was visible on PBI CT and MRI. Quantification of cartilage thickness showed a strong correlation between the two modalities. Cartilage lesions appeared darker than the adjacent cartilage on PBI CT. PBI CT showed similar agreement to MRI for depicting cartilage substance defects or lesions compared with the visual inspection. The assessment of subchondral bone cysts showed moderate to strong agreement between PBI CT and CT. In contrast to the standard clinical methods of MRI and CT, PBI CT is able to simultaneously depict cartilage and bony changes at high resolution. Though still an experimental technique, PBI CT is a promising high-resolution imaging method to evaluate comprehensive changes of osteoarthritic disease in a clinical setting.

  20. A purely functional Imaging based approach for transcortical resection of lesion involving the dominant atrium: Towards safer, imaging-guided, tailored cortico-leucotomies.

    Science.gov (United States)

    Frati, Alessandro; Pesce, Alessandro; D'Andrea, Giancarlo; Fraschetti, Flavia; Salvati, Maurizio; Cimatti, Marco; Esposito, Vincenzo; Raco, Antonino

    2018-04-01

    The Dominant Atrium (DA) is a crossroad of eloquent white matter bundles difficult to preserve with a standard "anatomical" approach. The aim of this work is to evaluate the results of a cohort of patients who underwent surgery with the aid of a purely functional MRI and DTI-based approach. 43 patients suffering from lesions involving the DA have been included in the final cohort and studied in regards to quality of life (KPS); a special attention was lent on the incidence of new or worsening of preexisting neurological deficits, with a focus on motor, visual and speech disturbances after the surgical treatment. Patient, surgery and lesion-related data were recorded to identify the relationships with outcome. Eloquent areas fMRI and the course of Arcuate Fasciculus (AF), Inferior frontooccipital fasciculus (IFOF), Optic radiation (OR) and corticospinal tract (CST) have been investigated with preoperative MRI sequences and DTI reconstruction. The final cohort consisted of 43 patients, 19 males and 24 females; average age was 56.8 years. We recorded 9 transient and 3 permanent postoperative deficits, only one of those was caused by an edema interference with DTI reconstruction. Preoperative functional status, histology and volume of the lesion proved to be independent factors affecting results. A purely functional surgical approach to the DA provided promising preliminary results. A direct DTI-fMRI visualization of the eloquent structures proximal to DA allows surgeon to conceive an ultra-precise and "tailored" cortico-leucotomy for an optimal exposure of the lesion. Copyright © 2018 Elsevier Ltd. All rights reserved.

  1. HER-2, ER, PR status concordance in primary breast cancer and corresponding metastatic lesion in lymph node in Chinese women.

    Science.gov (United States)

    Li, Min Hua; Hou, Chuan Ling; Wang, Cheng; Sun, Ai Jing

    2016-04-01

    To compare the expression of estrogen receptor (ER), progesterone receptor (PR) and human epidermal growth factor receptor 2 (HER-2) in the primary site and the metastatic lesion of lymph nodes in invasive breast cancer for investigating whether the expression of these biomarkers in the primary site could act as a surrogate to the lymphatic metastatic lesion in the same patient. In lymphatic metastatic lesion and corresponding primary lesion of 107 cases of invasive breast cancer, ER and PR statuses were assessed by immunohistochemistry (IHC). HER-2 expression level was evaluated by IHC and/or fluorescence in situ hybridization (FISH). In the primary lesions, 43.9% were ER positive; 46.7% were PR positive; 34.6% were HER-2 positive. In corresponding lymphatic metastatic lesions, the HER-2 status was concordant in 90 patients; 9 patients were diagnosed positive in metastatic lesion while negative in primary lesion; 8 patients were negative in metastatic lesion while positive in primary site (agreement, 84.1%; κ=0.647). A change in ER status was observed in 24 cases: 17 cases positive in metastatic site while negative in primary site; 7 cases negative in metastatic site while positive in primary site (agreement, 77.6%; κ=0.534). PR status discordance between the primary lesion and the metastatic regional lymph nodes was reported in 19 cases (agreement, 82.2%; κ=0.640). This study revealed that there was only a moderate concordance of ER, PR and HER-2 status between primary tumors and metastatic lymph nodes. These results indicate that it was inappropriate to predict the status of ER, PR and HER-2 in metastatic lymph nodes based on the results of evaluation of that in primary lesions. Copyright © 2015 Elsevier GmbH. All rights reserved.

  2. Comparison of megavoltage position verification for prostate irradiation based on bony anatomy and implanted fiducials

    NARCIS (Netherlands)

    Nederveen, Aart J.; Dehnad, Homan; van der Heide, Uulke A.; van Moorselaar, R. Jeroen A.; Hofman, Pieter; Lagendijk, Jan J. W.

    2003-01-01

    PURPOSE: The patient position during radiotherapy treatment of prostate cancer can be verified with the help of portal images acquired during treatment. In this study we quantify the clinical consequences of the use of image-based verification based on the bony anatomy and the prostate target

  3. A Cohort Study on Meniscal Lesions among Airport Baggage Handlers.

    Directory of Open Access Journals (Sweden)

    Sigurd Mikkelsen

    Full Text Available Meniscal lesions are common and may contribute to the development of knee arthrosis. A few case-control and cross-sectional studies have identified knee-straining work as risk factors for meniscal lesions, but exposure-response relations and the role of specific exposures are uncertain, and previous results may be sensitive to reporting and selection bias. We examined the relation between meniscal lesions and cumulative exposure to heavy lifting in a prospective register-based study with complete follow-up and independent information on exposure and outcome. We established a cohort of unskilled men employed at Copenhagen Airport or in other companies in the metropolitan Copenhagen area from 1990 to 2012 (the Copenhagen Airport Cohort. The cohort at risk included 3,307 airport baggage handlers with heavy lifting and kneeling or squatting work tasks and 63,934 referents with a similar socioeconomic background and less knee-straining work. Baggage handlers lifted suitcases with an average weight of approximately 15 kg, in total approximately five tonnes during a 9-hour workday. The cohort was followed in the National Patient Register and Civil Registration System. The outcome was a first time hospital diagnosis or surgery of a meniscal lesion. Baggage handlers had a higher incidence of meniscal lesions than the referents. Within baggage handlers spline regression showed that the incidence rate ratio was 1.91 (95% confidence interval: 1.29-2.84 after five years as a baggage handler and then decreased slowly to reach unity after approximately 30 years, adjusted for effects of potential confounders. This relation between baggage handling and meniscal lesions was present for work on the apron which involves lifting in a kneeling or squatting position, but not in the baggage hall, which only involves lifting in standing positions. The results support that long-term heavy lifting in a kneeling or squatting position is a risk factor for the development of

  4. A Cohort Study on Meniscal Lesions among Airport Baggage Handlers.

    Science.gov (United States)

    Mikkelsen, Sigurd; Brauer, Charlotte; Pedersen, Ellen Bøtker; Alkjær, Tine; Koblauch, Henrik; Simonsen, Erik Bruun; Helweg-Larsen, Karin; Thygesen, Lau Caspar

    2016-01-01

    Meniscal lesions are common and may contribute to the development of knee arthrosis. A few case-control and cross-sectional studies have identified knee-straining work as risk factors for meniscal lesions, but exposure-response relations and the role of specific exposures are uncertain, and previous results may be sensitive to reporting and selection bias. We examined the relation between meniscal lesions and cumulative exposure to heavy lifting in a prospective register-based study with complete follow-up and independent information on exposure and outcome. We established a cohort of unskilled men employed at Copenhagen Airport or in other companies in the metropolitan Copenhagen area from 1990 to 2012 (the Copenhagen Airport Cohort). The cohort at risk included 3,307 airport baggage handlers with heavy lifting and kneeling or squatting work tasks and 63,934 referents with a similar socioeconomic background and less knee-straining work. Baggage handlers lifted suitcases with an average weight of approximately 15 kg, in total approximately five tonnes during a 9-hour workday. The cohort was followed in the National Patient Register and Civil Registration System. The outcome was a first time hospital diagnosis or surgery of a meniscal lesion. Baggage handlers had a higher incidence of meniscal lesions than the referents. Within baggage handlers spline regression showed that the incidence rate ratio was 1.91 (95% confidence interval: 1.29-2.84) after five years as a baggage handler and then decreased slowly to reach unity after approximately 30 years, adjusted for effects of potential confounders. This relation between baggage handling and meniscal lesions was present for work on the apron which involves lifting in a kneeling or squatting position, but not in the baggage hall, which only involves lifting in standing positions. The results support that long-term heavy lifting in a kneeling or squatting position is a risk factor for the development of symptomatic

  5. A mobile indoor positioning system based on iBeacon technology.

    Science.gov (United States)

    Lin, Xin-Yu; Ho, Te-Wei; Fang, Cheng-Chung; Yen, Zui-Shen; Yang, Bey-Jing; Lai, Feipei

    2015-01-01

    To increase the efficiency in the emergency room, the goal of this research is to implement a mobile-based indoor positioning system using mobile applications (APP) with the iBeacon solution based on the Bluetooth Low Energy (BLE) technology. We use the Received Signal Strength (RSS) based localization method to estimate the patients' locations. Our positioning algorithm achieves 97.22% (95% Confidence Interval = 95.90% - 98.55%) accuracy of classification. As the result, our mechanism is reliable enough to satisfy the need for medical staff to track the locations of their patients.

  6. Persuasion Model and Its Evaluation Based on Positive Change Degree of Agent Emotion

    Science.gov (United States)

    Jinghua, Wu; Wenguang, Lu; Hailiang, Meng

    For it can meet needs of negotiation among organizations take place in different time and place, and for it can make its course more rationality and result more ideal, persuasion based on agent can improve cooperation among organizations well. Integrated emotion change in agent persuasion can further bring agent advantage of artificial intelligence into play. Emotion of agent persuasion is classified, and the concept of positive change degree is given. Based on this, persuasion model based on positive change degree of agent emotion is constructed, which is explained clearly through an example. Finally, the method of relative evaluation is given, which is also verified through a calculation example.

  7. An Adaptive Connectivity-based Centroid Algorithm for Node Positioning in Wireless Sensor Networks

    Directory of Open Access Journals (Sweden)

    Aries Pratiarso

    2015-06-01

    Full Text Available In wireless sensor network applications, the position of nodes is randomly distributed following the contour of the observation area. A simple solution without any measurement tools is provided by range-free method. However, this method yields the coarse estimating position of the nodes. In this paper, we propose Adaptive Connectivity-based (ACC algorithm. This algorithm is a combination of Centroid as range-free based algorithm, and hop-based connectivity algorithm. Nodes have a possibility to estimate their own position based on the connectivity level between them and their reference nodes. Each node divides its communication range into several regions where each of them has a certain weight depends on the received signal strength. The weighted value is used to obtain the estimated position of nodes. Simulation result shows that the proposed algorithm has up to 3 meter error of estimated position on 100x100 square meter observation area, and up to 3 hop counts for 80 meters' communication range. The proposed algorithm performs an average error positioning up to 10 meters better than Weighted Centroid algorithm. Keywords: adaptive, connectivity, centroid, range-free.

  8. A positioning system for forest diseases and pests based on GIS and PTZ camera

    International Nuclear Information System (INIS)

    Wang, Z B; Zhao, F F; Wang, C B; Wang, L L

    2014-01-01

    Forest diseases and pests cause enormous economic losses and ecological damage every year in China. To prevent and control forest diseases and pests, the key is to get accurate information timely. In order to improve monitoring coverage rate and economize on manpower, a cooperative investigation model for forest diseases and pests is put forward. It is composed of video positioning system and manual labor reconnaissance with mobile GIS embedded in PDA. Video system is used to scan the disaster area, and is particularly effective on where trees are withered. Forest diseases prevention and control workers can check disaster area with PDA system. To support this investigation model, we developed a positioning algorithm and a positioning system. The positioning algorithm is based on DEM and PTZ camera. Moreover, the algorithm accuracy is validated. The software consists of 3D GIS subsystem, 2D GIS subsystem, video control subsystem and disaster positioning subsystem. 3D GIS subsystem makes positioning visual, and practically easy to operate. 2D GIS subsystem can output disaster thematic map. Video control subsystem can change Pan/Tilt/Zoom of a digital camera remotely, to focus on the suspected area. Disaster positioning subsystem implements the positioning algorithm. It is proved that the positioning system can observe forest diseases and pests in practical application for forest departments

  9. Magnetic resonance imaging-based measures of atlas position: Relationship to canine atlantooccipital overlapping, syringomyelia and clinical signs.

    Science.gov (United States)

    Cerda-Gonzalez, S; Bibi, K F; Gifford, A T; Mudrak, E L; Scrivani, P V

    2016-03-01

    Canine atlantooccipital overlapping (AOO) is characterized by a decreased distance between the dorsal arch of the atlas and the supraoccipital bone. Current diagnostic criteria for this condition are subjective and clinician-dependent; objective criteria are needed to allow a reliable and reproducible diagnosis in clinical and research settings and assess clinical significance. We propose four standardized MRI-based measurements to objectively assess the proximity of the atlas to the foramen magnum. Inclusion criteria for dogs in this study were bodyweight 5 months, and availability of a complete MRI study performed with the craniocervical junction in extension. Exclusion criteria were space-occupying lesions and poor image quality (i.e. unclear bony margins). Measurements also included blinded determinations of skull type, presence of craniocervical junction anomalies and presence and severity of syringomyelia. Clinical status at the time of imaging was noted. Measurements were obtained in 271 dogs; these were reproducible and reliable. Findings varied by skull type: dolichocephalic dogs had smaller foramen magnum, whereas brachycephalic dogs had more cranially and dorsally positioned atlas bodies in comparison to the other skull types. Measurements also increased with increases in bodyweight. This study demonstrated a close association between AOO, syringomyelia and clinical signs. Toy and small breed dogs (including Cavalier King Charles spaniels) showed higher than previously reported prevalence of AOO; its occurrence was also associated with lower bodyweights within the study population of <15 kg toy/small breed dogs. Copyright © 2016 Elsevier Ltd. All rights reserved.

  10. Surgical neuro navigator guided by preoperative magnetic resonance images, based on a magnetic position sensor

    International Nuclear Information System (INIS)

    Perini, Ana Paula; Siqueira, Rogerio Bulha; Carneiro, Antonio Adilton Oliveira; Oliveira, Lucas Ferrari de; Machado, Helio Rubens

    2009-01-01

    Image guided neurosurgery enables the neurosurgeon to navigate inside the patient's brain using pre-operative images as a guide and a tracking system, during a surgery. Following a calibration procedure, three-dimensional position and orientation of surgical instruments may be transmitted to computer. The spatial information is used to access a region of interest, in the pre-operative images, displaying them to the neurosurgeon during the surgical procedure. However, when a craniotomy is involved and the lesion is removed, movements of brain tissue can be a significant source of error in these conventional navigation systems. The architecture implemented in this work intends the development of a system to surgical planning and orientation guided by ultrasound image. For surgical orientation, the software developed allows the extraction of slices from the volume of the magnetic resonance images (MRI) with orientation supplied by a magnetic position sensor (Polhemus R ). The slices extracted with this software are important because they show the cerebral area that the neurosurgeon is observing during the surgery, and besides they can be correlated with the intra-operative ultrasound images to detect and to correct the deformation of brain tissue during the surgery. Also, a tool for per-operative navigation was developed, providing three orthogonal planes through the image volume. In the methodology used for the software implementation, the Python tm programming language and the Visualization Toolkit (VTK) graphics library were used. The program to extract slices of the MRI volume allowed the application of transformations in the volume, using coordinates supplied by the position sensor. (author)

  11. Predictors of positive health in disability pensioners: a population-based questionnaire study using Positive Odds Ratio

    Directory of Open Access Journals (Sweden)

    Edén Lena

    2002-09-01

    Full Text Available Abstract Background Determinants of ill-health have been studied far more than determinants of good and improving health. Health promotion measures are important even among individuals with chronic diseases. The aim of this study was to find predictors of positive subjective health among disability pensioners (DPs with musculoskeletal disorders. Methods Two questionnaire surveys were performed among 352 DPs with musculoskeletal disorders. Two groups were defined: DPs with positive health and negative health, respectively. In consequence with the health perspective in this study the conception Positive Odds Ratio was defined and used in the logistic regression analyses instead of the commonly used odds ratio. Results Positive health was associated with age ≥ 55 years, not being an immigrant, not having fibromyalgia as the main diagnosis for granting an early retirement, no regular use of analgesics, a high ADL capacity, a positive subjective health preceding the study period, and good quality of life. Conclusion Positive odds ratio is a concept well adapted to theories of health promotion. It can be used in relation to positive outcomes instead of risks. Suggested health promotion and secondary prevention efforts among individuals with musculoskeletal disorders are 1 to avoid a disability pension for individuals

  12. Predicting high grade lesions of sinusoidal obstruction syndrome related to oxaliplatin-based chemotherapy for colorectal liver metastases: correlation with post-hepatectomy outcome.

    Science.gov (United States)

    Soubrane, Olivier; Brouquet, Antoine; Zalinski, Stéphane; Terris, Benoît; Brézault, Catherine; Mallet, Vincent; Goldwasser, François; Scatton, Olivier

    2010-03-01

    Oxaliplatin-based chemotherapy induces sinusoidal obstruction syndrome (SOS) lesions in the nontumorous liver parenchyma, which may increase the risk of liver resection for colorectal liver metastases. The objective of this study was to evaluate the accuracy of aspartate aminotransferase to platelet ratio index (APRI) and FIB-4 scoring systems to predict chemotherapy-associated liver injury and to correlate the severity of sinusoidal injury with postoperative outcome. Between 1998 and 2007, 78 patients were operated for colorectal liver metastases after preoperative oxaliplatin-based chemotherapy. Grading of steatosis and SOS in the nontumorous liver parenchyma was obtained in these patients. Univariate analysis of 18 preoperative factors to predict SOS occurrence was performed as well as multivariate analysis. Relevance of preoperative platelet count level, transaminase levels, and fibrosis scoring systems were evaluated to predict high grade lesions of SOS using a receiving operative curve analysis. Ninety-day mortality and morbidity were studied according to SOS severity in 51 patients who underwent major liver resection. Overall, pathologic examination showed high-grade lesions of SOS (SOS 2/3) in 46 (59%) patients. Univariate analysis showed that a low preoperative platelet count, elevated preoperative aspartate aminotransferase, short interval between chemotherapy and surgery were significant factors associated with high-grade lesions of SOS. Multivariate analysis showed that only the APRI score was an independent predictive factor for severe SOS. Receiving operative curve analysis revealed that the cut-off value predicting high-grade lesions of SOS with the best accuracy was an APRI score of 0.36 (area under the curve, 0.85; sensitivity, 87%; specificity, 69%). After major liver resection (n = 51), SOS 2/3 (n = 38) was associated with postoperative hepatic dysfunction (26/38 in SOS 2/3 vs. 3/13 in SOS 0/1; P = 0.004) and ascites (P = 0.03). A low

  13. Role of diffusion MRI in characterizing benign and malignant breast lesions

    Directory of Open Access Journals (Sweden)

    Palle Lalitha

    2009-01-01

    Full Text Available Aims: The aim of this study was to evaluate the role of MRI based diffusion-weighted imaging (DWI and the apparent diffusion coefficient (ADC for characterizing breast lesions in Indian patients. Materials and Methods : This prospective analysis was performed between October 2006 and June 2008. It includes 200 patients between the ages of 16 and 80 years with solid breast lesions greater than 1 cm in diameter. Of these 200 patients, 80 underwent breast MRI with contrast and DWI. One hundred and twenty patients had only DWI as they had come only for sonomammography. A total of 280 lesions were detected. ADC values were calculated for all the lesions and the highest and lowest values of ADC for benign and malignant lesions were identified. Finally, we compared our findings with those of previous studies. Results : Two hundred and eight lesions were categorized as benign and 72 lesions were categorized as malignant based on the ADC values. Based on previous data, lesions with ADC values from 1.3 to 1.5 mm 2 /s were considered benign where as lesions with ADC values ranging between 0.85 and1.1 mm 2 /s were considered malignant. Two lesions whose ADC values were in the benign range were proven to be malignant tumors after surgery. This method of using ADC values for the detection of malignant lesions showed a sensitivity of 97.22% and a specificity of 100%. The positive predictive value was 100%. Conclusion : DWI is a useful technique for characterizing breast tumors, especially for lesions that cannot be adequately characterized by ultrasonography and routine magnetic resonance imaging.

  14. The propagation of inventory-based positional errors into statistical landslide susceptibility models

    Science.gov (United States)

    Steger, Stefan; Brenning, Alexander; Bell, Rainer; Glade, Thomas

    2016-12-01

    There is unanimous agreement that a precise spatial representation of past landslide occurrences is a prerequisite to produce high quality statistical landslide susceptibility models. Even though perfectly accurate landslide inventories rarely exist, investigations of how landslide inventory-based errors propagate into subsequent statistical landslide susceptibility models are scarce. The main objective of this research was to systematically examine whether and how inventory-based positional inaccuracies of different magnitudes influence modelled relationships, validation results, variable importance and the visual appearance of landslide susceptibility maps. The study was conducted for a landslide-prone site located in the districts of Amstetten and Waidhofen an der Ybbs, eastern Austria, where an earth-slide point inventory was available. The methodological approach comprised an artificial introduction of inventory-based positional errors into the present landslide data set and an in-depth evaluation of subsequent modelling results. Positional errors were introduced by artificially changing the original landslide position by a mean distance of 5, 10, 20, 50 and 120 m. The resulting differently precise response variables were separately used to train logistic regression models. Odds ratios of predictor variables provided insights into modelled relationships. Cross-validation and spatial cross-validation enabled an assessment of predictive performances and permutation-based variable importance. All analyses were additionally carried out with synthetically generated data sets to further verify the findings under rather controlled conditions. The results revealed that an increasing positional inventory-based error was generally related to increasing distortions of modelling and validation results. However, the findings also highlighted that interdependencies between inventory-based spatial inaccuracies and statistical landslide susceptibility models are complex. The

  15. Reporting of Positive Results in Randomized Controlled Trials of Mindfulness-Based Mental Health Interventions.

    Directory of Open Access Journals (Sweden)

    Stephanie Coronado-Montoya

    Full Text Available A large proportion of mindfulness-based therapy trials report statistically significant results, even in the context of very low statistical power. The objective of the present study was to characterize the reporting of "positive" results in randomized controlled trials of mindfulness-based therapy. We also assessed mindfulness-based therapy trial registrations for indications of possible reporting bias and reviewed recent systematic reviews and meta-analyses to determine whether reporting biases were identified.CINAHL, Cochrane CENTRAL, EMBASE, ISI, MEDLINE, PsycInfo, and SCOPUS databases were searched for randomized controlled trials of mindfulness-based therapy. The number of positive trials was described and compared to the number that might be expected if mindfulness-based therapy were similarly effective compared to individual therapy for depression. Trial registries were searched for mindfulness-based therapy registrations. CINAHL, Cochrane CENTRAL, EMBASE, ISI, MEDLINE, PsycInfo, and SCOPUS were also searched for mindfulness-based therapy systematic reviews and meta-analyses.108 (87% of 124 published trials reported ≥1 positive outcome in the abstract, and 109 (88% concluded that mindfulness-based therapy was effective, 1.6 times greater than the expected number of positive trials based on effect size d = 0.55 (expected number positive trials = 65.7. Of 21 trial registrations, 13 (62% remained unpublished 30 months post-trial completion. No trial registrations adequately specified a single primary outcome measure with time of assessment. None of 36 systematic reviews and meta-analyses concluded that effect estimates were overestimated due to reporting biases.The proportion of mindfulness-based therapy trials with statistically significant results may overstate what would occur in practice.

  16. Reporting of Positive Results in Randomized Controlled Trials of Mindfulness-Based Mental Health Interventions.

    Science.gov (United States)

    Coronado-Montoya, Stephanie; Levis, Alexander W; Kwakkenbos, Linda; Steele, Russell J; Turner, Erick H; Thombs, Brett D

    2016-01-01

    A large proportion of mindfulness-based therapy trials report statistically significant results, even in the context of very low statistical power. The objective of the present study was to characterize the reporting of "positive" results in randomized controlled trials of mindfulness-based therapy. We also assessed mindfulness-based therapy trial registrations for indications of possible reporting bias and reviewed recent systematic reviews and meta-analyses to determine whether reporting biases were identified. CINAHL, Cochrane CENTRAL, EMBASE, ISI, MEDLINE, PsycInfo, and SCOPUS databases were searched for randomized controlled trials of mindfulness-based therapy. The number of positive trials was described and compared to the number that might be expected if mindfulness-based therapy were similarly effective compared to individual therapy for depression. Trial registries were searched for mindfulness-based therapy registrations. CINAHL, Cochrane CENTRAL, EMBASE, ISI, MEDLINE, PsycInfo, and SCOPUS were also searched for mindfulness-based therapy systematic reviews and meta-analyses. 108 (87%) of 124 published trials reported ≥1 positive outcome in the abstract, and 109 (88%) concluded that mindfulness-based therapy was effective, 1.6 times greater than the expected number of positive trials based on effect size d = 0.55 (expected number positive trials = 65.7). Of 21 trial registrations, 13 (62%) remained unpublished 30 months post-trial completion. No trial registrations adequately specified a single primary outcome measure with time of assessment. None of 36 systematic reviews and meta-analyses concluded that effect estimates were overestimated due to reporting biases. The proportion of mindfulness-based therapy trials with statistically significant results may overstate what would occur in practice.

  17. Influence of 2 caries-detecting devices on clinical decision making and lesion depth for suspicious occlusal lesions: A The National Dental Practice-Based Research Network randomized trial.

    Science.gov (United States)

    Makhija, Sonia K; Bader, James D; Shugars, Daniel A; Litaker, Mark S; Nagarkar, Sanket; Gordan, Valeria V; Rindal, D Brad; Pihlstrom, Daniel J; Mungia, Rahma; Meyerowitz, Cyril; Gilbert, Gregg H

    2018-02-20

    A suspicious occlusal carious lesion (SOCL) can be defined as a lesion with no cavitation and no radiographic radiolucency but for which caries is suspected. The authors evaluated whether using a device changed the percentage of SOCLs that were opened surgically and, among those SOCLs that were opened, the proportion that had penetrated into dentin. Eighty-two dentists participated. In phase 1 of the study, dentists identified approximately 20 SOCLs, obtained patient consent, and recorded information about the lesion, treatment or treatments, and depth, if opened. Dentists were then randomly assigned into 1 of 3 groups: no device, DIAGNOdent (KaVo), and Spectra (Air Techniques). In phase 2, dentists enrolled approximately 20 additional patients and recorded the same phase 1 information while using the assigned device to help make their treatment decisions. A mixed-model logistic regression was used to determine any differences after randomization in the proportion of lesions opened and, if opened, the proportion of lesions that penetrated into dentin. A total of 1,500 SOCLs were enrolled in each phase. No statistically significant difference was found in the change in proportion of lesions receiving invasive treatment from phase 1 to phase 2 across the 3 groups (P = .33) or in the change in proportion of percentage of opened lesions that extended into dentin (P = .31). Caries-detecting devices in the study did not change substantially dentists' decisions to intervene or the accuracy of the intervention decision in predicting lesion penetration into dentin. The caries-detecting devices tested may not improve dentists' clinical decision making for SOCLs. Copyright © 2018 American Dental Association. Published by Elsevier Inc. All rights reserved.

  18. Robust Operation of Tendon-Driven Robot Fingers Using Force and Position-Based Control Laws

    Science.gov (United States)

    Abdallah, Muhammad E (Inventor); Platt, Jr., Robert J. (Inventor); Reiland, Matthew J (Inventor); Hargrave, Brian (Inventor); Diftler, Myron A (Inventor); Strawser, Philip A (Inventor); Ihrke, Chris A. (Inventor)

    2013-01-01

    A robotic system includes a tendon-driven finger and a control system. The system controls the finger via a force-based control law when a tension sensor is available, and via a position-based control law when a sensor is not available. Multiple tendons may each have a corresponding sensor. The system selectively injects a compliance value into the position-based control law when only some sensors are available. A control system includes a host machine and a non-transitory computer-readable medium having a control process, which is executed by the host machine to control the finger via the force- or position-based control law. A method for controlling the finger includes determining the availability of a tension sensor(s), and selectively controlling the finger, using the control system, via the force or position-based control law. The position control law allows the control system to resist disturbances while nominally maintaining the initial state of internal tendon tensions.

  19. Mitigating Errors in External Respiratory Surrogate-Based Models of Tumor Position

    International Nuclear Information System (INIS)

    Malinowski, Kathleen T.; McAvoy, Thomas J.; George, Rohini; Dieterich, Sonja; D'Souza, Warren D.

    2012-01-01

    Purpose: To investigate the effect of tumor site, measurement precision, tumor–surrogate correlation, training data selection, model design, and interpatient and interfraction variations on the accuracy of external marker-based models of tumor position. Methods and Materials: Cyberknife Synchrony system log files comprising synchronously acquired positions of external markers and the tumor from 167 treatment fractions were analyzed. The accuracy of Synchrony, ordinary-least-squares regression, and partial-least-squares regression models for predicting the tumor position from the external markers was evaluated. The quantity and timing of the data used to build the predictive model were varied. The effects of tumor–surrogate correlation and the precision in both the tumor and the external surrogate position measurements were explored by adding noise to the data. Results: The tumor position prediction errors increased during the duration of a fraction. Increasing the training data quantities did not always lead to more accurate models. Adding uncorrelated noise to the external marker-based inputs degraded the tumor–surrogate correlation models by 16% for partial-least-squares and 57% for ordinary-least-squares. External marker and tumor position measurement errors led to tumor position prediction changes 0.3–3.6 times the magnitude of the measurement errors, varying widely with model algorithm. The tumor position prediction errors were significantly associated with the patient index but not with the fraction index or tumor site. Partial-least-squares was as accurate as Synchrony and more accurate than ordinary-least-squares. Conclusions: The accuracy of surrogate-based inferential models of tumor position was affected by all the investigated factors, except for the tumor site and fraction index.

  20. Computerized detection of mass lesions in digital mammograms

    International Nuclear Information System (INIS)

    Yin, F.F.; Giger, M.L.; Doi, K.; Metz, C.E.; Vyborny, C.J.; Schmidt, R.A.

    1989-01-01

    Early detection of breast cancer from the periodic screening of asymptomatic women could reduce breast cancer mortality by at least 40%. The authors are developing a computerized scheme for the detection of mass lesions in digital mammograms as an aid to radiologists in such high volume screening programs. Based on left-right architectural symmetry and gray-level histogram analysis, bilateral subtraction of left and right breast images is performed. False-positive detections included in bilateral-difference images are reduced with various images feature-extraction techniques. The database involves clinical film mammograms digitized by a TV camera and analyzed on a Micro-VAX workstation. Among five different bilateral subtraction techniques investigated, a nonlinear approach provided superior lesion enhancement. Feature-extraction techniques reduced substantially the remaining false-positives. Preliminary results, for 32 pairs of clinical mammograms, yielded a true-positive rate of approximately 95% with a false-positive rate of about 2 per image

  1. Electronic Track Map Building for Satellite-based High Integrity Railway Train Positioning

    OpenAIRE

    Jiang, Liu; Baigen, Cai; Jian, Wang

    2013-01-01

    The concept of electronic track map has been introduced and researched in many satellite-based railway train positioning and location-based railway systems. It should characterize the railway tracks and their key objects and facilities with a satisfied accuracy and completeness. Based on the application requirements, design and building of the electronic track maps should be in accordance with the map matching approach, and moreover, considering the integrity effect that is decisive to safety...

  2. Female users of internet-based screening for rectal STIs: descriptive statistics and correlates of positivity.

    Science.gov (United States)

    Ladd, Jessica; Hsieh, Yu-Hsiang; Barnes, Mathilda; Quinn, Nicole; Jett-Goheen, Mary; Gaydos, Charlotte A

    2014-09-01

    Internet-based screening for vaginal sexually transmitted infections (STI) has been shown to reach high-risk populations. Published studies of internet-based screening for rectal STIs in women are needed. Our objectives were to describe the female users of a rectal internet-based screening intervention and assess what factors correlated with rectal positivity for STIs. The website http://www.iwantthekit.org offers free STI testing via home self-sampling kits. Women could order vaginal and rectal kits, both containing questionnaires. Rectal and vaginal swabs were tested for Chlamydia trachomatis, Neisseria gonorrhoeae and Trichomonas vaginalis using nucleic acid amplification tests. Data were analysed from 205 rectal kits from January 2009 through February 2011. Self-reported characteristics of participants were examined, and correlates of rectal STI positivity were analysed. Of the 205 rectal samples returned and eligible for testing, 38 (18.5%) were positive for at least one STI. The women were young (mean age 25.8 years), mostly African-American (50.0%), and only 14.0% always used condoms. After adjusting for age and race, Black race (AOR=3.06) and vaginal STI positivity (AOR=40.6) were significantly correlated with rectal STI positivity. Of women testing positive for rectal STIs who also submitted vaginal swabs, 29.4% were negative in the vaginal sample. Internet-based rectal screening can reach populations that appear to be at high risk for rectal STIs (18.5% prevalence) and led to the diagnosis of STIs in women who would not have been diagnosed vaginally. Black race and vaginal STI positivity were highly correlated with rectal STI positivity. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

  3. Methodological Approach to Company Cash Flows Target-Oriented Forecasting Based on Financial Position Analysis

    OpenAIRE

    Sergey Krylov

    2012-01-01

    The article treats a new methodological approach to the company cash flows target-oriented forecasting based on its financial position analysis. The approach is featured to be universal and presumes application of the following techniques developed by the author: financial ratio values correction techniques and correcting cash flows techniques. The financial ratio values correction technique assumes to analyze and forecast company financial position while the correcting cash flows technique i...

  4. Research on Algorithm of Indoor Positioning System Based on Low Energy Bluetooth 4.0

    OpenAIRE

    Zhang De-Yi; Wang Wen-Yue; Lv Lian-Rong

    2017-01-01

    This paper mainly analyzes and compares several well-known algorithms for indoor positioning. By many nodes jump tests, relation between RSSI and distance and relation between LQI and packet error rate can be obtained. Then based on the relations, LQI confidence coefficient is classified. By comparing these different kinds of algorithms, this paper perfects the algorithm of fuzzy fingerprint indoor positioning, which can shorten the time required to process off-line data. At last, this algori...

  5. Research on Algorithm of Indoor Positioning System Based on Low Energy Bluetooth 4.0

    Directory of Open Access Journals (Sweden)

    Zhang De-Yi

    2017-01-01

    Full Text Available This paper mainly analyzes and compares several well-known algorithms for indoor positioning. By many nodes jump tests, relation between RSSI and distance and relation between LQI and packet error rate can be obtained. Then based on the relations, LQI confidence coefficient is classified. By comparing these different kinds of algorithms, this paper perfects the algorithm of fuzzy fingerprint indoor positioning, which can shorten the time required to process off-line data. At last, this algorithm was verified by indoor and outdoor experiments, by which we can know that this algorithm greatly lower RSSI error. And it is concluded that this algorithm has a better positioning accuracy.

  6. Visible light communication based vehicle positioning using LED street light and rolling shutter CMOS sensors

    Science.gov (United States)

    Do, Trong Hop; Yoo, Myungsik

    2018-01-01

    This paper proposes a vehicle positioning system using LED street lights and two rolling shutter CMOS sensor cameras. In this system, identification codes for the LED street lights are transmitted to camera-equipped vehicles through a visible light communication (VLC) channel. Given that the camera parameters are known, the positions of the vehicles are determined based on the geometric relationship between the coordinates of the LEDs in the images and their real world coordinates, which are obtained through the LED identification codes. The main contributions of the paper are twofold. First, the collinear arrangement of the LED street lights makes traditional camera-based positioning algorithms fail to determine the position of the vehicles. In this paper, an algorithm is proposed to fuse data received from the two cameras attached to the vehicles in order to solve the collinearity problem of the LEDs. Second, the rolling shutter mechanism of the CMOS sensors combined with the movement of the vehicles creates image artifacts that may severely degrade the positioning accuracy. This paper also proposes a method to compensate for the rolling shutter artifact, and a high positioning accuracy can be achieved even when the vehicle is moving at high speeds. The performance of the proposed positioning system corresponding to different system parameters is examined by conducting Matlab simulations. Small-scale experiments are also conducted to study the performance of the proposed algorithm in real applications.

  7. Phase-Inductance-Based Position Estimation Method for Interior Permanent Magnet Synchronous Motors

    Directory of Open Access Journals (Sweden)

    Xin Qiu

    2017-12-01

    Full Text Available This paper presents a phase-inductance-based position estimation method for interior permanent magnet synchronous motors (IPMSMs. According to the characteristics of phase induction of IPMSMs, the corresponding relationship of the rotor position and the phase inductance is obtained. In order to eliminate the effect of the zero-sequence component of phase inductance and reduce the rotor position estimation error, the phase inductance difference is employed. With the iterative computation of inductance vectors, the position plane is further subdivided, and the rotor position is extracted by comparing the amplitudes of inductance vectors. To decrease the consumption of computer resources and increase the practicability, a simplified implementation is also investigated. In this method, the rotor position information is achieved easily, with several basic math operations and logical comparisons of phase inductances, without any coordinate transformation or trigonometric function calculation. Based on this position estimation method, the field orientated control (FOC strategy is established, and the detailed implementation is also provided. A series of experiment results from a prototype demonstrate the correctness and feasibility of the proposed method.

  8. GNSS-based train positioning experiments with local and wide area augmentation

    Energy Technology Data Exchange (ETDEWEB)

    Gu, X.; Schmidt, M.; Winter, J. [DaimlerChrysler Rail Systems (Signals) GmbH, Ulm (Germany)

    1999-07-01

    Within the frame of the MAGNET Project ('Multimodal Approach for GNSS 1 in European Transport') of the Telematics Applications programme of the 4{sup th} Research Framework of the European Community (1994-1998), a GNSS-based Train Positioning Platform (TPP) has been developed and tested with the wide area augmentation system pre-EGNOS and a local differential GNSS system using a reference station. This paper presents the principle and the system architecture of the developed GNSS-based train positioning system and highlights the system performance achieved in field tests. The TPP consists of a GNSS core module with an EGNOS (European Geostationary Navigation Overlay Service) decoding function, a GSM (Global System for Mobile Communication) data link for local GPS and GLONASS differential corrections, a digital route map and an interface to odometer. The first step to calculate the train position is to select either wide area or local area differential corrections depending on which are available. The position and velocity are then calculated and matched to the track by using the digital route map. Finally, the GNSS position and velocity data is integrated with odometer data in a sensor data fusion model. The integrated solution avoids the masking problem of GNSS signals and reduces odometer errors like drift and braking slip, so that a continuous positioning availability can be reached and the positioning accuracy can be improved to meter level. The achieved performance is being exploited for industrial applications. (orig.)

  9. Impact of model-based iterative reconstruction on low-contrast lesion detection and image quality in abdominal CT: a 12-reader-based comparative phantom study with filtered back projection at different tube voltages

    Energy Technology Data Exchange (ETDEWEB)

    Euler, Andre; Stieltjes, Bram; Eichenberger, Reto; Reisinger, Clemens; Hirschmann, Anna; Zaehringer, Caroline; Kircher, Achim; Streif, Matthias; Bucher, Sabine; Buergler, David; D' Errico, Luigia; Kopp, Sebastien; Wilhelm, Markus [University Hospital Basel, Clinic of Radiology and Nuclear Medicine, Basel (Switzerland); Szucs-Farkas, Zsolt [Hospital Centre of Biel, Institute of Radiology, Biel (Switzerland); Schindera, Sebastian T. [University Hospital Basel, Clinic of Radiology and Nuclear Medicine, Basel (Switzerland); Cantonal Hospital Aarau, Institute of Radiology, Aarau (Switzerland)

    2017-12-15

    To evaluate the impact of model-based iterative reconstruction (MBIR) on image quality and low-contrast lesion detection compared with filtered back projection (FBP) in abdominal computed tomography (CT) of simulated medium and large patients at different tube voltages. A phantom with 45 hypoattenuating lesions was placed in two water containers and scanned at 70, 80, 100, and 120 kVp. The 120-kVp protocol served as reference, and the volume CT dose index (CTDI{sub vol}) was kept constant for all protocols. The datasets were reconstructed with MBIR and FBP. Image noise and contrast-to-noise-ratio (CNR) were assessed. Low-contrast lesion detectability was evaluated by 12 radiologists. MBIR decreased the image noise by 24% and 27%, and increased the CNR by 30% and 29% for the medium and large phantoms, respectively. Lower tube voltages increased the CNR by 58%, 46%, and 16% at 70, 80, and 100 kVp, respectively, compared with 120 kVp in the medium phantom and by 9%, 18% and 12% in the large phantom. No significant difference in lesion detection rate was observed (medium: 79-82%; large: 57-65%; P > 0.37). Although MBIR improved quantitative image quality compared with FBP, it did not result in increased low-contrast lesion detection in abdominal CT at different tube voltages in simulated medium and large patients. (orig.)

  10. Columnar cell lesions of the canine mammary gland: pathological features and immunophenotypic analysis

    Directory of Open Access Journals (Sweden)

    Cassali Geovanni D

    2010-02-01

    Full Text Available Abstract Background It has been suggested that columnar cell lesions indicate an alteration of the human mammary gland involved in the development of breast cancer. They have not previously been described in canine mammary gland. The aim of this paper is describe the morphologic spectrum of columnar cell lesions in canine mammary gland specimens and their association with other breast lesions. Methods A total of 126 lesions were subjected to a comprehensive morphological review based upon the human breast classification system for columnar cell lesions. The presence of preinvasive (epithelial hyperplasia and in situ carcinoma and invasive lesions was determined and immunophenotypic analysis (estrogen receptor (ER, progesterone receptor (PgR, high molecular weight cytokeratin (34βE-12, E-cadherin, Ki-67, HER-2 and P53 was perfomed. Results Columnar cell lesions were identified in 67 (53.1% of the 126 canine mammary glands with intraepithelial alterations. They were observed in the terminal duct lobular units and characterized at dilated acini may be lined by several layers of columnar epithelial cells with elongated nuclei. Of the columnar cell lesions identified, 41 (61.2% were without and 26 (38.8% with atypia. Association with ductal hyperplasia was observed in 45/67 (67.1%. Sixty (89.5% of the columnar cell lesions coexisted with neoplastic lesions (20 in situ carcinomas, 19 invasive carcinomas and 21 benign tumors. The columnar cells were ER, PgR and E-cadherin positive but negative for cytokeratin 34βE-12, HER-2 and P53. The proliferation rate as measured by Ki-67 appeared higher in the lesions analyzed than in normal TDLUs. Conclusions Columnar cell lesions in canine mammary gland are pathologically and immunophenotypically similar to those in human breast. This may suggest that dogs are a suitable model for the comparative study of noninvasive breast lesions.

  11. Single-Step Arthroscopic Repair With Cell-Free Polymer-Based Scaffold in Osteochondral Lesions of the Talus: Clinical and Radiological Results.

    Science.gov (United States)

    Kanatlı, Ulunay; Eren, Ali; Eren, Toygun Kağan; Vural, Abdurrahman; Geylan, Dilan Ece; Öner, Ali Yusuf

    2017-09-01

    To report the clinical and radiological results of patients with talar osteochondral lesions who were treated by microfracture and cell-free scaffold implantation in a single-step arthroscopic surgery. Forty patients, treated with a single-step arthroscopic surgery, were evaluated in this single-center-based retrospective study. Patients with degenerative arthritis (n = 1), history of ankle fracture (n = 1), kissing lesions (n = 1), lower extremity deformity (n = 1), and lesions 10 mm depth) bone cysts were additionally treated with bone graft. Patients were evaluated clinically, using the American Orthopedic Foot and Ankle Society (AOFAS) hindfoot score. Radiological assessment was performed with magnetic resonance imaging, using the magnetic resonance observation of cartilage repair tissue (MOCART) score. Thirty-two patients with a mean age of 38 ± 12 years were evaluated. The mean defect size was 2.5 ± 0.8 cm 2 and the mean defect volume was 2.4 ± 1.9 cm 3 . The mean preoperative AOFAS score was 52.8 ± 13.9 and increased to 87.1 ± 11.1 postoperatively at the mean follow-up of 33.8 ± 14.0 months (P = .0001). A total of 84.4% of patients had good to excellent clinical scores. Clinical scores had no significant relation with age, lesion size, depth, or body mass index. The mean MOCART score was 64.2 ± 12.0. There was no significant correlation between the total MOCART and AOFAS scores (P = .123). A significant relation was found between the defect filling (the subgroup of the MOCART score) and the clinical outcomes (P = .0001, rho = 0.731). The arthroscopic scaffold implantation technique is a single-step, safe, and effective method for the treatment of talar osteochondral lesions with satisfactory clinical and radiological outcomes. Level IV, therapeutic case series. Copyright © 2017 Arthroscopy Association of North America. Published by Elsevier Inc. All rights reserved.

  12. Presence of High-Risk HPV mRNA in Relation to Future High-Grade Lesions among High-Risk HPV DNA Positive Women with Minor Cytological Abnormalities.

    Directory of Open Access Journals (Sweden)

    Hanna Johansson

    Full Text Available Continuous expression of E6- and E7-oncogenes of high-risk human papillomavirus (HPV types is necessary for the development and maintenance of the dysplastic phenotype. The aim of the study was to determine the sensitivity and specificity of the APTIMA HPV mRNA assay (Hologic in predicting future development of high-grade cervical intraepithelial neoplasia (CIN among high-risk HPV-DNA-positive women with atypical squamous cells of undetermined significance (ASCUS or low-grade squamous epithelial lesion (LSIL cytology.Archived SurePath cervical samples of women ≥ 35 years of age with high-risk HPV DNA-positive ASCUS (n = 211 or LSIL, (n = 131 were tested for the presence of high-risk HPV E6/E7 mRNA using the APTIMA HPV assay, and the women were monitored for development of histopathologically verified CIN2+.Twenty-nine percent (61/211 of the women in the ASCUS group, and 34.3% (45/131 in the LSIL group developed CIN2+ within 4.5 years of follow-up. The prevalence of HPV mRNA was 90.0% (95% CI 85.9-94.0 among women with ASCUS and 95.4% (95% CI 91.8-99.0 among women with LSIL. The presence of HPV E6/E7 mRNA was associated with future development of CIN2+ among women with ASCUS and LSIL (p=0.02. The mRNA assay demonstrated high sensitivity in predicting future CIN2+ and CIN3 for index ASCUS (96.7%; 95% CI 87.6-99.4 and 100%; 95% CI 82.2-100, respectively and LSIL (97.8%, 95% CI 86.8-99.9 and 100%, 95% CI 79.9-100, respectively. The corresponding specificity was low, 12.7% (95% CI 7.9-19.3 and 5.8% (95% CI 2.2-13.6, for future CIN2+, respectively. The negative predictive value of the HPV mRNA assay for detecting future CIN3 was 100%, since no mRNA-negative woman developed CIN3 (0/27 as compared to 13.6% (43/315 of the mRNA-positive women (p = 0.03.The APTIMA mRNA assay demonstrated high sensitivity but low specificity in predicting future CIN2+ among women with minor cytological abnormalities. The assay had high negative predictive value for future

  13. Acute periodontal lesions.

    Science.gov (United States)

    Herrera, David; Alonso, Bettina; de Arriba, Lorenzo; Santa Cruz, Isabel; Serrano, Cristina; Sanz, Mariano

    2014-06-01

    This review provides updates on acute conditions affecting the periodontal tissues, including abscesses in the periodontium, necrotizing periodontal diseases and other acute conditions that cause gingival lesions with acute presentation, such as infectious processes not associated with oral bacterial biofilms, mucocutaneous disorders and traumatic and allergic lesions. A periodontal abscess is clinically important because it is a relatively frequent dental emergency, it can compromise the periodontal prognosis of the affected tooth and bacteria within the abscess can spread and cause infections in other body sites. Different types of abscesses have been identified, mainly classified by their etiology, and there are clear differences between those affecting a pre-existing periodontal pocket and those affecting healthy sites. Therapy for this acute condition consists of drainage and tissue debridement, while an evaluation of the need for systemic antimicrobial therapy will be made for each case, based on local and systemic factors. The definitive treatment of the pre-existing condition should be accomplished after the acute phase is controlled. Necrotizing periodontal diseases present three typical clinical features: papilla necrosis, gingival bleeding and pain. Although the prevalence of these diseases is not high, their importance is clear because they represent the most severe conditions associated with the dental biofilm, with very rapid tissue destruction. In addition to bacteria, the etiology of necrotizing periodontal disease includes numerous factors that alter the host response and predispose to these diseases, namely HIV infection, malnutrition, stress or tobacco smoking. The treatment consists of superficial debridement, careful mechanical oral hygiene, rinsing with chlorhexidine and daily re-evaluation. Systemic antimicrobials may be used adjunctively in severe cases or in nonresponding conditions, being the first option metronidazole. Once the acute

  14. An online x-ray based position validation system for prostate hypofractionated radiotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Arumugam, Sankar, E-mail: Sankar.Arumugam@sswahs.nsw.gov.au; Xing, Aitang [Department of Medical Physics, Liverpool and Macarthur Cancer Therapy Centres and Ingham Institute, New South Wales 2170 (Australia); Sidhom, Mark [Department of Radiation Oncology, Liverpool and Macarthur Cancer Therapy Centres, New South Wales 2170 (Australia); Holloway, Lois [Department of Medical Physics, Liverpool and Macarthur Cancer Therapy Centres and Ingham Institute, New South Wales 2170 (Australia); Centre for Medical Radiation Physics, University of Wollongong, Wollongong, New South Wales 2522 (Australia); South Western Clinical School, University of New South Wales, Sydney, New South Wales 2052 (Australia); Institute of Medical Physics, School of Physics, University of Sydney, Sydney, New South Wales 2006 (Australia)

    2016-02-15

    Purpose: Accurate positioning of the target volume during treatment is paramount for stereotactic body radiation therapy (SBRT). In this work, the authors present the development of an in-house software tool to verify target position with an Elekta-Synergy linear accelerator using kV planar images acquired during treatment delivery. Methods: In-house software, SeedTracker, was developed in MATLAB to perform the following three functions: 1. predict intended seed positions in a planar view perpendicular to any gantry angle, simulating a portal imaging device, from the 3D seed co-ordinates derived from the treatment planning system; 2. autosegment seed positions in kV planar images; and 3. report the position shift based on the seed positions in the projection images. The performance of SeedTracker was verified using a CIRS humanoid phantom (CIRS, VA, USA) implanted with three Civco gold seed markers (Civco, IA, USA) in the prostate. The true positive rate of autosegmentation (TPR{sub seg}) and the accuracy of the software in alerting the user when the isocenter position was outside the tolerance (TPR{sub trig}) were studied. Two-dimensional and 3D static position offsets introduced to the humanoid phantom and 3D dynamic offsets introduced to a gel phantom containing gold seeds were used for evaluation of the system. Results: SeedTracker showed a TPR{sub seg} of 100% in the humanoid phantom for projection images acquired at all angles except in the ranges of 80°–100° and 260°–280° where seeds are obscured by anatomy. This resulted in a TPR{sub trig} of 88% over the entire treatment range for considered 3D static offsets introduced to the phantom. For 2D static offsets where the position offsets were only introduced in the anterior–posterior and lateral directions, the TPR{sub trig} of SeedTracker was limited by both seed detectability and positional offset. SeedTracker showed a false positive trigger in the projection angle range between 130°–170° and

  15. Rapid evaluation of machine tools with position-dependent milling stability based on response surface model

    Directory of Open Access Journals (Sweden)

    Li Zhang

    2016-03-01

    Full Text Available The milling stability is one of the important evaluation criterions of dynamic characteristics of machine tools, and it is of great importance for machine tools’ design and manufacturing. The milling stability of machine tools generally varies with the position combinations of moving parts. The traditional milling stability analysis of machine tools is based on some specific positions in the whole workspace of machine tools, and the results are not comprehensive. Furthermore, it is very time-consuming for operation and calculation to complete analysis of multiple positions. A new method to rapidly evaluate the stability of machine tools with position dependence is developed in this article. In this method, the key position combinations of moving parts are set as the samples of calculation to calculate the dynamic characteristics of machine tools with SAMCEF finite element simulation analysis software. Then the minimum critical axial cutting depth of each sample is obtained. The relationship between the position and the value of minimum critical axial cutting depth at any position in the whole workspace can be obtained through established response surface model. The precision of the response surface model is evaluated and the model could be used to rapidly evaluate the milling stability of machine tools with position dependence. With a precision horizontal machining center with box-in-box structure as an example, the value of minimum critical axial cutting depth at any position is shown. This method of rapid evaluation of machine tools with position-dependent stability avoids complicated theoretical calculation, so it can be easily adopted by engineers and technicians in the phase of design process of machine tools.

  16. Mesenchymal breast lesions

    International Nuclear Information System (INIS)

    Schickman, R.; Leibman, A.J.; Handa, P.; Kornmehl, A.; Abadi, M.

    2015-01-01

    Mesenchymal breast lesions encompass a variety of breast diseases. Many of these lesions are rare with only a few case reports in the literature. This article reviews the imaging findings of selected mesenchymal breast lesions, their clinical presentations and method of diagnosis. Mesenchymal lesions are diverse and include haemangioma, granular cell tumour, myofibroblastoma, fibromatosis, pseudoangiomatous stromal hyperplasia, and malignant fibrous histiocytoma. It is important for radiologists to be aware of these lesions as some of them may have malignant potential or demonstrate imaging features that overlap with other malignant lesions

  17. Vehicle Position Estimation Based on Magnetic Markers: Enhanced Accuracy by Compensation of Time Delays

    Directory of Open Access Journals (Sweden)

    Yeun-Sub Byun

    2015-11-01

    Full Text Available The real-time recognition of absolute (or relative position and orientation on a network of roads is a core technology for fully automated or driving-assisted vehicles. This paper presents an empirical investigation of the design, implementation, and evaluation of a self-positioning system based on a magnetic marker reference sensing method for an autonomous vehicle. Specifically, the estimation accuracy of the magnetic sensing ruler (MSR in the up-to-date estimation of the actual position was successfully enhanced by compensating for time delays in signal processing when detecting the vertical magnetic field (VMF in an array of signals. In this study, the signal processing scheme was developed to minimize the effects of the distortion of measured signals when estimating the relative positional information based on magnetic signals obtained using the MSR. In other words, the center point in a 2D magnetic field contour plot corresponding to the actual position of magnetic markers was estimated by tracking the errors between pre-defined reference models and measured magnetic signals. The algorithm proposed in this study was validated by experimental measurements using a test vehicle on a pilot network of roads. From the results, the positioning error was found to be less than 0.04 m on average in an operational test.

  18. DIFFERENCES BETWEEN FOOTBALL PLAYERS OF DIFFERENT GAMING POSITIONS BASED ON SOME BASIC AND SPECIFIC MOTOR ABILITIES

    Directory of Open Access Journals (Sweden)

    Bogdan Tomić

    2011-09-01

    Full Text Available Based on the structure competition activities, and its character can be defined as a hypothetical model of the anthropological characteristics of football players of different gaming positions. Based on hypothetical models of different football players' position can make a division into two groups of players based on game systems that are commonly used in modern football, which is 4-4-2, and the common anthropological characteristics, structure and nature of activities carried out by during the game, so the first group consists of players with smaller volumes of engagement in the game (goalkeeper, two central defenders and two strikers and the second group 190 CRNOGORSKA SPORTSKA AKADEMIJA, „Sport Mont“ časopis br. 31,32,33. consists of players with greater scope to engage in the game (two foreign players and four defensive midfielder (midfielder . The aim is to determine the difference between players of different players' positions on the basis of some basic and specific motor abilities. The sample of 206 football players aged 18 ± 0.5 years is divided into 5 subsamples according to examinees gaming position: forwarders (45, midfield players (47, defenders (41, central defenders (44 and goalkeepers (29. The battery of 16 tests (in which the results are expressed in distance and time - metric. It can be concluded that there are differences between players of different players' positions on the team in relation to the basic and specific motor skills.

  19. High-precision positioning system of four-quadrant detector based on the database query

    Science.gov (United States)

    Zhang, Xin; Deng, Xiao-guo; Su, Xiu-qin; Zheng, Xiao-qiang

    2015-02-01

    The fine pointing mechanism of the Acquisition, Pointing and Tracking (APT) system in free space laser communication usually use four-quadrant detector (QD) to point and track the laser beam accurately. The positioning precision of QD is one of the key factors of the pointing accuracy to APT system. A positioning system is designed based on FPGA and DSP in this paper, which can realize the sampling of AD, the positioning algorithm and the control of the fast swing mirror. We analyze the positioning error of facular center calculated by universal algorithm when the facular energy obeys Gauss distribution from the working principle of QD. A database is built by calculation and simulation with MatLab software, in which the facular center calculated by universal algorithm is corresponded with the facular center of Gaussian beam, and the database is stored in two pieces of E2PROM as the external memory of DSP. The facular center of Gaussian beam is inquiry in the database on the basis of the facular center calculated by universal algorithm in DSP. The experiment results show that the positioning accuracy of the high-precision positioning system is much better than the positioning accuracy calculated by universal algorithm.

  20. A Position Sensorless Control Method for SRM Based on Variation of Phase Inductance

    Science.gov (United States)

    Komatsuzaki, Akitomo; Miki, Ichiro

    Switched reluctance motor (SRM) drives are suitable for variable speed industrial applications because of the simple structure and high-speed capability. However, it is necessary to detect the rotor position with a position sensor attached to the motor shaft. The use of the sensor increases the cost of the drive system and machine size, and furthermore the reliability of the system is reduced. Therefore, several approaches to eliminate the position sensor have already been reported. In this paper, a position sensorless control method based on the variation of the phase inductance is described. The phase inductance regularly varies with the rotor position. The SRM is controlled without the position sensor using the de-fluxing period and the phase inductance. The turn-off timing is determined by computing the difference of angle between the sampling point and the aligned point and the variation of angle during the de-fluxing period. In the magnetic saturation region, the phase inductance at the current when the effect of the saturation starts is computed and the sensorless control can be carried out using this inductance. Experimental results show that the SRM is well controlled without the position sensor using the proposed method.

  1. AUV Underwater Positioning Algorithm Based on Interactive Assistance of SINS and LBL

    Directory of Open Access Journals (Sweden)

    Tao Zhang

    2015-12-01

    Full Text Available This paper studies an underwater positioning algorithm based on the interactive assistance of a strapdown inertial navigation system (SINS and LBL, and this algorithm mainly includes an optimal correlation algorithm with aided tracking of an SINS/Doppler velocity log (DVL/magnetic compass pilot (MCP, a three-dimensional TDOA positioning algorithm of Taylor series expansion and a multi-sensor information fusion algorithm. The final simulation results show that compared to traditional underwater positioning algorithms, this scheme can not only directly correct accumulative errors caused by a dead reckoning algorithm, but also solves the problem of ambiguous correlation peaks caused by multipath transmission of underwater acoustic signals. The proposed method can calibrate the accumulative error of the AUV position more directly and effectively, which prolongs the underwater operating duration of the AUV.

  2. AUV Underwater Positioning Algorithm Based on Interactive Assistance of SINS and LBL

    Science.gov (United States)

    Zhang, Tao; Chen, Liping; Li, Yao

    2015-01-01

    This paper studies an underwater positioning algorithm based on the interactive assistance of a strapdown inertial navigation system (SINS) and LBL, and this algorithm mainly includes an optimal correlation algorithm with aided tracking of an SINS/Doppler velocity log (DVL)/magnetic compass pilot (MCP), a three-dimensional TDOA positioning algorithm of Taylor series expansion and a multi-sensor information fusion algorithm. The final simulation results show that compared to traditional underwater positioning algorithms, this scheme can not only directly correct accumulative errors caused by a dead reckoning algorithm, but also solves the problem of ambiguous correlation peaks caused by multipath transmission of underwater acoustic signals. The proposed method can calibrate the accumulative error of the AUV position more directly and effectively, which prolongs the underwater operating duration of the AUV. PMID:26729120

  3. A laser interferometer for measuring straightness and its position based on heterodyne interferometry

    International Nuclear Information System (INIS)

    Chen Benyong; Zhang Enzheng; Yan Liping; Li Chaorong; Tang Wuhua; Feng Qibo

    2009-01-01

    Not only the magnitude but also the position of straightness errors are of concern to users. However, current laser interferometers used for measuring straightness seldom give the relative position of the straightness error. To solve this problem, a laser interferometer for measuring straightness and its position based on heterodyne interferometry is proposed. The optical configuration of the interferometer is designed and the measurement principle is analyzed theoretically. Two experiments were carried out. The first experiment verifies the validity and repeatability of the interferometer by measuring a linear stage. Also, the second one for measuring a flexure-hinge stage demonstrates that the interferometer is capable of nanometer measurement accuracy. These results show that this interferometer has advantages of simultaneously measuring straightness error and the relative position with high precision, and a compact structure.

  4. AUV Underwater Positioning Algorithm Based on Interactive Assistance of SINS and LBL.

    Science.gov (United States)

    Zhang, Tao; Chen, Liping; Li, Yao

    2015-12-30

    This paper studies an underwater positioning algorithm based on the interactive assistance of a strapdown inertial navigation system (SINS) and LBL, and this algorithm mainly includes an optimal correlation algorithm with aided tracking of an SINS/Doppler velocity log (DVL)/magnetic compass pilot (MCP), a three-dimensional TDOA positioning algorithm of Taylor series expansion and a multi-sensor information fusion algorithm. The final simulation results show that compared to traditional underwater positioning algorithms, this scheme can not only directly correct accumulative errors caused by a dead reckoning algorithm, but also solves the problem of ambiguous correlation peaks caused by multipath transmission of underwater acoustic signals. The proposed method can calibrate the accumulative error of the AUV position more directly and effectively, which prolongs the underwater operating duration of the AUV.

  5. Teleoperation environment based on virtual reality. Application of two-planes method for position measurement

    International Nuclear Information System (INIS)

    Yoshikawa, Hidekazu; Tezuka, Tetsuo; Inoue, Ryuji

    1998-01-01

    A teleoperation system based on virtual environment (VE) is an emergent technology for operating a robot in remote or hazardous environment. We have developed a VE-based teleoperation system for robot-arm manipulation in a simplified real world. The VE for manipulating the robot arm is constructed by measuring the 3D positions of the objects around the robot arm by motion-stereo method. The 3D position is estimated by using two-(calibration) planes method based on images captured by the CCD camera on the robot-arm, since the two-planes method does not need pin-hole-model assumption to the camera system. The precision of this 3D-measurement is evaluated through experiments and then derived is the theoretical model to the error in the measurement. This measurement system is applied to VE-based teleoperation experiment for Peg-in-hole practice by the robot arm. (author)

  6. Indoor anti-occlusion visible light positioning systems based on particle filtering

    Science.gov (United States)

    Jiang, Meng; Huang, Zhitong; Li, Jianfeng; Zhang, Ruqi; Ji, Yuefeng

    2015-04-01

    As one of the most popular categories of mobile services, a rapid growth of indoor location-based services has been witnessed over the past decades. Indoor positioning methods based on Wi-Fi, radio-frequency identification or Bluetooth are widely commercialized; however, they have disadvantages such as low accuracy or high cost. An emerging method using visible light is under research recently. The existed visible light positioning (VLP) schemes using carrier allocation, time allocation and multiple receivers all have limitations. This paper presents a novel mechanism using particle filtering in VLP system. By this method no additional devices are needed and the occlusion problem in visible light would be alleviated which will effectively enhance the flexibility for indoor positioning.

  7. Restoring the lattice of Si-based atom probe reconstructions for enhanced information on dopant positioning.

    Science.gov (United States)

    Breen, Andrew J; Moody, Michael P; Ceguerra, Anna V; Gault, Baptiste; Araullo-Peters, Vicente J; Ringer, Simon P

    2015-12-01

    The following manuscript presents a novel approach for creating lattice based models of Sb-doped Si directly from atom probe reconstructions for the purposes of improving information on dopant positioning and directly informing quantum mechanics based materials modeling approaches. Sophisticated crystallographic analysis techniques are used to detect latent crystal structure within the atom probe reconstructions with unprecedented accuracy. A distortion correction algorithm is then developed to precisely calibrate the detected crystal structure to the theoretically known diamond cubic lattice. The reconstructed atoms are then positioned on their most likely lattice positions. Simulations are then used to determine the accuracy of such an approach and show that improvements to short-range order measurements are possible for noise levels and detector efficiencies comparable with experimentally collected atom probe data. Copyright © 2015 Elsevier B.V. All rights reserved.

  8. IWKNN: An Effective Bluetooth Positioning Method Based on Isomap and WKNN

    Directory of Open Access Journals (Sweden)

    Qi Wang

    2016-01-01

    Full Text Available Recently, Bluetooth-based indoor positioning has become a hot research topic. However, the instability of Bluetooth RSSI (Received Signal Strength Indicator promotes a huge challenge in localization accuracy. To improve the localization accuracy, this paper measures the distance of RSSI vectors on their low-dimensional manifold and proposes a novel positioning method IWKNN (Isomap-based Weighted K-Nearest Neighbor. The proposed method firstly uses Isomap to generate low-dimensional embedding for RSSI vectors. Then, the distance of two given RSSI vectors is measured by Euclidean distance of their low-dimensional embeddings. Finally, the position is calculated by WKNN. Experiment indicates that the proposed approach is more robust and accurate.

  9. Position-momentum uncertainty relations based on moments of arbitrary order

    International Nuclear Information System (INIS)

    Zozor, Steeve; Portesi, Mariela; Sanchez-Moreno, Pablo; Dehesa, Jesus S.

    2011-01-01

    The position-momentum uncertainty-like inequality based on moments of arbitrary order for d-dimensional quantum systems, which is a generalization of the celebrated Heisenberg formulation of the uncertainty principle, is improved here by use of the Renyi-entropy-based uncertainty relation. The accuracy of the resulting lower bound is physico-computationally analyzed for the two main prototypes in d-dimensional physics: the hydrogenic and oscillator-like systems.

  10. Control Information and Data Processing of Vehicle based on Global Position System

    OpenAIRE

    Shupeng Zhao; Miao Tian; Shifang Zhang; Jiuxi Li

    2013-01-01

    A testing system based on Data Stream function of vehicle electronic control system was developed to test the city bus driving cycle. A mufti-function Vehicle Traveling Data Recorder based on GPS which can realize the vehicles positioning and navigating was investigated. The system included data acquisition module, display module, print module, GPS module, communication module and so on. This system adopts the FRAM memory as the storing equipment in which the automobile realized the real-time...

  11. Use of ICDAS-II, Fluorescence-Based Methods, and Radiography in Detection and Treatment Decision of Occlusal Caries Lesions: An In Vitro Study

    Directory of Open Access Journals (Sweden)

    Anahita Jablonski-Momeni

    2012-01-01

    Full Text Available Aim. To use visual inspection (ICDAS-II, laser fluorescence (LF, fluorescence based camera (FC and radiographic examination (BW for detection of caries and for treatment decision. Methods. The occlusal sites of 84 extracted permanent teeth were examined using all methods and treatment decisions (preventive or operative care were recorded based on each method independently. For validation of the findings, fissures were opened with rotating instruments and clinical depth was determined as gold standard. Correlations (, sensitivity, specificity and AUC were calculated. McNemar test was used to show whether different methods led to significant changes in treatment decisions. Results. Highest correlation was found between ICDAS-II and FC ( 0.84, ICDAS-II and gold standard (0.82 and FC and gold standard (0.81. ICDAS-II provided the highest performance (AUC 1.0, followed by FC (0.95 and LF (0.88. The greatest difference was found for treatment planning of dentine lesions, where the use of FC (cut-offs according to the literature had the greatest agreement between operative treatment and dentine lesions, followed by use of ICDAS-II. Conclusion. ICDAS-II may have high potential for detection and treatment planning, and other devices, especially the fluorescence camera, can add substantial information to the visual examination, enabling examiners plan treatment more accurately.

  12. Embodied positioning/discourse analysis of a research based leadership development forum

    DEFF Research Database (Denmark)

    Bager, Ann

    2018-01-01

    The present article engages a discourse analysis of identity work as it is accomplished in a research and dialogue based leadership development forum in a university setting. It displays how different interactional setups in a positioning exercise prompt diverse spaces of possibilities that shape...

  13. What does it cost to deliver information using position-based beaconless forwarding protocols?

    KAUST Repository

    Bader, Ahmed

    2012-04-01

    Beaconless position-based forwarding protocols have recently evolved as a promising solution for packet forwarding in wireless sensor networks. Quite a few variants of this class of forwarding protocols have been proposed over the years. One common observation is that they have all been evaluated from the perspective of a single node. Although useful, but a solid understanding of the end-to-end performance is still necessary. In this paper, we shed light on the end-to-end performance of beaconless position-based protocols along three distinct dimensions: energy, latency, and back-off probability. The latter is used as a direct indicator of the network\\'s transport capacity. Consequently, we are able to provide an elaborate response to the question: what does it really cost to deliver a packet in a wireless sensor network using position-based beaconless forwarding protocols? In responding to this question, we highlighted the different performance tradeoffs inherent to beaconless position-based protocols. Furthermore, some operational recommendations are also provided. © 2012 IEEE.

  14. High-Accuracy Positioning of an Industrial Robot Using Image/PSD-Based Hybrid Servo Control

    Science.gov (United States)

    Liu, Yong; Xi, Ning; Shen, Yantao

    2011-04-01

    This article presents a new and effective multi-sensor-based control strategy for high-accuracy/precision and high-efficiency automatic robot positioning in the field of industrial robot calibration. The strategy combines both coarsely visual servo and fine position-sensitive detector (PSD) servo control methods. In a large field of view, an image-based visual servo control system is employed to roughly guide the laser spot, which is from a single laser pointer attached to the end-effector of a robot to project to the segmented PSDs with a resolution of better than 0.1 µm. Once the laser spot is projected onto the active area of the PSD surface, the control will automatically be switched to the PSD feedback and servoing for fine positioning. An image/PSD-based servoing system has been presented. Based on the system, the controller design and switch logic of the hybrid servoing are given. The experimental results conducted on an ABB industrial robot IRB1600 verified the effectiveness of the developed visual/PSD hybrid servo controllers, as well as demonstrated that the high accuracy of 30 µm of robot positioning can be approached. The development of the hybrid control method and system has played a major role in achieving high-performance automatic robot calibration.

  15. Improving Wi-Fi Based Indoor Positioning Using Bluetooth Add-Ons

    DEFF Research Database (Denmark)

    Baniukevic, Artur; Sabonis, Dovydas; Jensen, Christian S.

    2011-01-01

    Location-Based Services (LBSs) constitutes one of the most popular classes of mobile services. However, while current LBSs typically target outdoor settings, we lead large parts of our lives indoors. The availability of easy-to-use and low-cost indoor positioning services is essential in also ena...

  16. Seamless Indoor/Outdoor Positioning Handover for Location-Based Services in Streamspin

    DEFF Research Database (Denmark)

    Hansen, Rene; Wind, Rico; Jensen, Christian Søndergaard

    2009-01-01

    the delivery of truly ubiquitous location-based services by integrating GPS and Wi-Fi location fingerprinting. The paper puts focus on key aspects of the seamless handover between outdoor to indoor positioning. Several different handover solutions are presented,and their applicability is evaluated with respect...

  17. Production of verbs in base position by Dutch agrammatic speakers : Inflection versus finiteness

    NARCIS (Netherlands)

    Bastiaanse, Y.R.M.

    Several hypotheses have been formulated to predict the pattern of performance on finite verbs by agrammatic speakers. The present study is focused on finite and nonfinite verbs in base-position. Three finite verb forms (third person singular in past and present tense and third person plural in

  18. Kinetic scrolling-based position mapping for haptic teleoperation of unmanned aerial vehicles

    NARCIS (Netherlands)

    Ruesch, A.; Mersha, A.Y.; Stramigioli, Stefano; Carloni, Raffaella

    In this paper, we present a haptic teleoperation control algorithm for unmanned aerial vehicles, applying a kinetic scrolling-based position mapping. The proposed algorithm overcomes the master workspace limitations and enables to teleoperate the aerial vehicle in unbounded workspace in a fast and

  19. Individual and ecological assets and positive developmental trajectories among gang and community-based organization youth.

    Science.gov (United States)

    Taylor, Carl S; Lerner, Richard M; von Eye, Alexander; Balsano, Aida Bilalbegovic; Dowling, Elizabeth M; Anderson, Pamela M; Bobek, Deborah L; Bjelobrk, Dragana

    2002-01-01

    The Search Institute framework for conceptualizing developmental assets was used in a longitudinal study of African American male youth involved in gangs or in community-based organizations (CBOs) serving youth. Analyses of intraindividual change indicated that individual and ecological assets are linked to positive developmental trajectories among these youth.

  20. Reporting of positive results in randomized controlled trials of mindfulness-based mental health interventions

    NARCIS (Netherlands)

    Coronado-Montoya, S.; Levis, A.W.; Kwakkenbos, C.M.C.; Steele, R.J.; Turner, E.H.; Thombs, B.D.

    2016-01-01

    Background A large proportion of mindfulness-based therapy trials report statistically significant results, even in the context of very low statistical power. The objective of the present study was to characterize the reporting of "positive" results in randomized controlled trials of

  1. Training data representation in a neural based robot position estimation system

    International Nuclear Information System (INIS)

    Taraglio, S.; Di Fonzo, F.; Burrascano, P.

    1997-03-01

    The vision subsystem of an autonomous vehicle is studies. It is based on a multi layer perceptron that uses TV images to estimate the position of the vehicle. A comparative study of the effects of output data representation and input data processing is presented and discussed

  2. Can School-Wide Positive Behavior Support Be an Evidence-Based Practice?

    Science.gov (United States)

    Renshaw, Tyler L.; Young, K. Richard; Caldarella, Paul; Christensen, Lynnette

    2008-01-01

    Researchers invested in school-wide positive behavior support (SWPBS) have been attempting to answer an important question: Is SWPBS an evidence-based practice (EBP; e.g., Sugai & Horner, 2007)? Given the context of educational policy, this question appears to be reasonable, as its answer could significantly influence funding and adoption of SWPBS…

  3. Prevent-Teach-Reinforce: The School-Based Model of Individualized Positive Behavior Support

    Science.gov (United States)

    Dunlap, Glen; Iovannone, Rose; Kincaid, Donald; Wilson, Kelly; Christiansen, Kathy; Strain, Phillip; English, Carie

    2010-01-01

    Solve serious behavior challenges in K-8 classrooms with this easy-to-use book, the first practical guide to the research-proven Prevent-Teach-Reinforce (PTR) model. Developed by some of the most respected authorities on positive behavior support, this innovative model gives school-based teams a five-step plan for reducing problems unresolved by…

  4. Identification of Malassezia species in the facial lesions of Chinese seborrhoeic dermatitis patients based on DNA sequencing.

    Science.gov (United States)

    Lian, C-h; Shen, L-l; Gao, Q-y; Jiang, M; Zhao, Z-j; Zhao, J-j

    2014-12-01

    The genus Malassezia is important in the aetiology of facial seborrhoeic dermatitis (FSD), which is the most common clinical type. The purpose of this study was to analyse the distribution of Malassezia species in the facial lesions of Chinese seborrhoeic dermatitis (SD) patients and healthy individuals. Sixty-four isolates of Malassezia were isolated from FSD patients and 60 isolates from healthy individuals. Sequence analysis of the internal transcribed spacer (ITS) region was used to identify the isolates. The most frequently identified Malassezia species associated with FSD was M. furfur (76.56%), followed by M. sympodialis (12.50%) and M. japonica (9.38%). The most frequently isolated species in healthy individuals were M. furfur (61.67%), followed by M. sympodialis (25.00%), M. japonica (6.67%), M. globosa (3.33%), and M. obtusa (3.33%). Overall, our study revealed that while M. furfur is the predominant Malassezia species in Chinese SD patients, there is no significant difference in the distribution of Malassezia species between Chinese SD patients and healthy individuals. © 2014 Blackwell Verlag GmbH.

  5. Comparison of SPECT/CT and MRI in diagnosing symptomatic lesions in ankle and foot pain patients: diagnostic performance and relation to lesion type.

    Science.gov (United States)

    Ha, Seunggyun; Hong, Sung Hwan; Paeng, Jin Chul; Lee, Dong Yeon; Cheon, Gi Jeong; Arya, Amitabh; Chung, June-Key; Lee, Dong Soo; Kang, Keon Wook

    2015-01-01

    The purpose of this study was to compare the diagnostic performance of SPECT/CT and MRI in patients with ankle and foot pain, with regard to the lesion types. Fifty consecutive patients with ankle and foot pain, who underwent 99mTc-MDP SPECT/CT and MRI, were retrospectively enrolled in this study. Symptomatic lesions were determined based on clinical examination and response to treatment. On MRI and SPECT/CT, detected lesions were classified as bone, ligament/tendon, and joint lesions. Uptake on SPECT/CT was assessed using a 4-grade system. Sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of SPECT/CT and MRI were evaluated in all detected lesions and each lesion type. Diagnostic value of uptake grade was analyzed using receiver-operating characteristics (ROC) curve analysis, and diagnostic performance was compared using Chi-square or McNemar tests. In overall lesions, the sensitivity, PPV and NPV of SPECT/CT for symptomatic lesions were 93%, 56%, 91%, and they were 98%, 48%, 95% for MRI. There was no significant difference between SPECT/CT and MRI. However, the specificity of SPECT/CT was significantly higher than that of MRI (48% versus 24%, P = 0.016). Uptake grade on SPECT/CT was significantly higher in symptomatic lesions (P diagnostic performance for symptomatic lesions in ankle and foot pain patients. SPECT/CT and MRI exhibit different diagnostic specificity in different lesion types. SPECT/CT may be used as a complementary imaging method to MRI for enhancing diagnostic specificity.

  6. A novel capacitive absolute positioning sensor based on time grating with nanometer resolution

    Science.gov (United States)

    Pu, Hongji; Liu, Hongzhong; Liu, Xiaokang; Peng, Kai; Yu, Zhicheng

    2018-05-01

    The present work proposes a novel capacitive absolute positioning sensor based on time grating. The sensor includes a fine incremental-displacement measurement component combined with a coarse absolute-position measurement component to obtain high-resolution absolute positioning measurements. A single row type sensor was proposed to achieve fine displacement measurement, which combines the two electrode rows of a previously proposed double-row type capacitive displacement sensor based on time grating into a single row. To achieve absolute positioning measurement, the coarse measurement component is designed as a single-row type displacement sensor employing a single spatial period over the entire measurement range. In addition, this component employs a rectangular induction electrode and four groups of orthogonal discrete excitation electrodes with half-sinusoidal envelope shapes, which were formed by alternately extending the rectangular electrodes of the fine measurement component. The fine and coarse measurement components are tightly integrated to form a compact absolute positioning sensor. A prototype sensor was manufactured using printed circuit board technology for testing and optimization of the design in conjunction with simulations. Experimental results show that the prototype sensor achieves a ±300 nm measurement accuracy with a 1 nm resolution over a displacement range of 200 mm when employing error compensation. The proposed sensor is an excellent alternative to presently available long-range absolute nanometrology sensors owing to its low cost, simple structure, and ease of manufacturing.

  7. A Heterogeneous Sensing System-Based Method for Unmanned Aerial Vehicle Indoor Positioning.

    Science.gov (United States)

    Wang, Can; Li, Kang; Liang, Guoyuan; Chen, Haoyao; Huang, Sheng; Wu, Xinyu

    2017-08-10

    The indoor environment has brought new challenges for micro Unmanned Aerial Vehicles (UAVs) in terms of their being able to execute tasks with high positioning accuracy. Conventional positioning methods based on GPS are unreliable, although certain circumstances of limited space make it possible to apply new technologies. In this paper, we propose a novel indoor self-positioning system of UAV based on a heterogeneous sensing system, which integrates data from a structured light scanner, ultra-wideband (UWB), and an inertial navigation system (INS). We made the structured light scanner, which is composed of a low-cost structured light and camera, ourselves to improve the positioning accuracy at a specified area. We applied adaptive Kalman filtering to fuse the data from the INS and UWB while the vehicle was moving, as well as Gauss filtering to fuse the data from the UWB and the structured light scanner in a hovering state. The results of our simulations and experiments demonstrate that the proposed strategy significantly improves positioning accuracy in motion and also in the hovering state, as compared to using a single sensor.

  8. Impedance-based real-time position sensor for lab-on-a-chip devices.

    Science.gov (United States)

    Brazey, B; Cottet, J; Bolopion, A; Van Lintel, H; Renaud, P; Gauthier, M

    2018-02-27

    This paper presents the theoretical and experimental development of an integrated position sensor for lab-on-a-chip devices. The interest for single cell analysis is growing. However, this requires monitoring and controlling cell displacements in real time during their journey in the chip. Due to the high number of cells that must be monitored at the same time, classical vision-based sensors are not suitable. This paper aims to present an alternative based on impedance measurement. The position of the cells is obtained from the variation of impedance measured between two electrodes. This technique presents several advantages: the sensor is integrated into the chip, the measurement electrodes are compatible with the fabrication process of actuation electrodes for dielectrophoresis, the sampling time of the sensor is high and the position of the cells can be obtained in real time. This article highlights the concept of position-sensitive impedance sensing. The design of the chip, and in particular of the electrodes, is discussed to improve the sensitivity and repeatability of the measurement. The issue of real-time detection in a noisy environment is solved by using an extended Kalman filter. As a first proof of concept, this article presents experimental validation on a 1D case to determine the longitudinal position of 8.7 μm diameter beads in a channel.

  9. Design and performance analysis of position-based impedance control for an electrohydrostatic actuation system

    Directory of Open Access Journals (Sweden)

    Yongling FU

    2018-03-01

    Full Text Available Electrohydrostatic actuator (EHA is a type of power-by-wire actuator that is widely implemented in the aerospace industry for flight control, landing gears, thrust reversers, thrust vector control, and space robots. This paper presents the development and evaluation of position-based impedance control (PBIC for an EHA. Impedance control provides the actuator with compliance and facilitates the interaction with the environment. Most impedance control applications utilize electrical or valve-controlled hydraulic actuators, whereas this work realizes impedance control via a compact and efficient EHA. The structures of the EHA and PBIC are firstly introduced. A mathematical model of the actuation system is established, and values of its coefficients are identified by particle swarm optimization. This model facilitates the development of a position controller and the selection of target impedance parameters. A nonlinear proportional-integral position controller is developed for the EHA to achieve the accurate positioning requirement of PBIC. The controller compensates for the adverse effect of stiction, and a position accuracy of 0.08 mm is attained. Various experimental results are presented to verify the applicability of PBIC to the EHA. The compliance of the actuator is demonstrated in an impact test. Keywords: Actuation system, Aerospace, Electrohydrostatic actuator, Force control, Nonlinear dynamics, Particle swarm optimization, Position control

  10. Understanding positional cues in salamander limb regeneration: implications for optimizing cell-based regenerative therapies

    Directory of Open Access Journals (Sweden)

    Catherine D. McCusker

    2014-06-01

    Full Text Available Regenerative medicine has reached the point where we are performing clinical trials with stem-cell-derived cell populations in an effort to treat numerous human pathologies. However, many of these efforts have been challenged by the inability of the engrafted populations to properly integrate into the host environment to make a functional biological unit. It is apparent that we must understand the basic biology of tissue integration in order to apply these principles to the development of regenerative therapies in humans. Studying tissue integration in model organisms, where the process of integration between the newly regenerated tissues and the ‘old’ existing structures can be observed and manipulated, can provide valuable insights. Embryonic and adult cells have a memory of their original position, and this positional information can modify surrounding tissues and drive the formation of new structures. In this Review, we discuss the positional interactions that control the ability of grafted cells to integrate into existing tissues during the process of salamander limb regeneration, and discuss how these insights could explain the integration defects observed in current cell-based regenerative therapies. Additionally, we describe potential molecular tools that can be used to manipulate the positional information in grafted cell populations, and to promote the communication of positional cues in the host environment to facilitate the integration of engrafted cells. Lastly, we explain how studying positional information in current cell-based therapies and in regenerating limbs could provide key insights to improve the integration of cell-based regenerative therapies in the future.

  11. Facial Position and Expression-Based Human-Computer Interface for Persons With Tetraplegia.

    Science.gov (United States)

    Bian, Zhen-Peng; Hou, Junhui; Chau, Lap-Pui; Magnenat-Thalmann, Nadia

    2016-05-01

    A human-computer interface (namely Facial position and expression Mouse system, FM) for the persons with tetraplegia based on a monocular infrared depth camera is presented in this paper. The nose position along with the mouth status (close/open) is detected by the proposed algorithm to control and navigate the cursor as computer user input. The algorithm is based on an improved Randomized Decision Tree, which is capable of detecting the facial information efficiently and accurately. A more comfortable user experience is achieved by mapping the nose motion to the cursor motion via a nonlinear function. The infrared depth camera enables the system to be independent of illumination and color changes both from the background and on human face, which is a critical advantage over RGB camera-based options. Extensive experimental results show that the proposed system outperforms existing assistive technologies in terms of quantitative and qualitative assessments.

  12. Cultural bases for self-evaluation: seeing oneself positively in different cultural contexts.

    Science.gov (United States)

    Becker, Maja; Vignoles, Vivian L; Owe, Ellinor; Easterbrook, Matthew J; Brown, Rupert; Smith, Peter B; Bond, Michael Harris; Regalia, Camillo; Manzi, Claudia; Brambilla, Maria; Aldhafri, Said; González, Roberto; Carrasco, Diego; Paz Cadena, Maria; Lay, Siugmin; Schweiger Gallo, Inge; Torres, Ana; Camino, Leoncio; Özgen, Emre; Güner, Ülkü E; Yamakoğlu, Nil; Silveira Lemos, Flávia Cristina; Trujillo, Elvia Vargas; Balanta, Paola; Macapagal, Ma Elizabeth J; Cristina Ferreira, M; Herman, Ginette; de Sauvage, Isabelle; Bourguignon, David; Wang, Qian; Fülöp, Márta; Harb, Charles; Chybicka, Aneta; Mekonnen, Kassahun Habtamu; Martin, Mariana; Nizharadze, George; Gavreliuc, Alin; Buitendach, Johanna; Valk, Aune; Koller, Silvia H

    2014-05-01

    Several theories propose that self-esteem, or positive self-regard, results from fulfilling the value priorities of one's surrounding culture. Yet, surprisingly little evidence exists for this assertion, and theories differ about whether individuals must personally endorse the value priorities involved. We compared the influence of four bases for self-evaluation (controlling one's life, doing one's duty, benefitting others, achieving social status) among 4,852 adolescents across 20 cultural samples, using an implicit, within-person measurement technique to avoid cultural response biases. Cross-sectional and longitudinal analyses showed that participants generally derived feelings of self-esteem from all four bases, but especially from those that were most consistent with the value priorities of others in their cultural context. Multilevel analyses confirmed that the bases of positive self-regard are sustained collectively: They are predictably moderated by culturally normative values but show little systematic variation with personally endorsed values.

  13. Effect of genioglossus, geniohyoid, and digastric advancement on tongue base and hyoid position.

    Science.gov (United States)

    Kutzner, Emily A; Miot, Christelle; Liu, Yuan; Renk, Elizabeth; Park, Joshua S; Inman, Jared C

    2017-08-01

    To assess the effect of genioglossus, geniohyoid, and anterior digastric muscle advancement on base of tongue and hyoid position. Cadaver experiments. In fresh cadavers, the mandibular attachments of the genioglossus, geniohyoid, and anterior digastric muscles were advanced anteriorly by 6, 10, or 14 mm, and the anterior displacement of the base of tongue and hyoid was measured. The degrees of displacement of the tongue base and hyoid by the individual muscles and combinations of muscles were compared to one another. In 11 cadavers, 462 measurements were taken. Genioglossus advancement alone produced significantly greater tongue base advancement than any other muscle (P tongue base advancement than the genioglossus alone. Geniohyoid (P tongue advancement. Geniohyoid or anterior digastric muscle advancement produces the greatest hyoid advancement. Advancement of neither base of tongue nor hyoid was superior when combinations of muscles were moved. NA Laryngoscope, 127:1938-1942, 2017. © 2016 The American Laryngological, Rhinological and Otological Society, Inc.

  14. Incidental enhancing lesions found on preoperative breast MRI: management and role of second-look ultrasound.

    Science.gov (United States)

    Luciani, M L; Pediconi, F; Telesca, M; Vasselli, F; Casali, V; Miglio, E; Passariello, R; Catalano, C

    2011-09-01

    This study prospectively assessed second-look ultrasound (US) for the evaluation of incidental enhancing lesions identified on preoperative breast magnetic resonance imaging (MRI). Between 2004 and 2007, 182 patients with malignant breast lesions detected on US and/or X-ray mammography and confirmed by cytology/histology underwent preoperative breast contrast-enhanced (CE)-MRI. Patients with incidental lesions on breast MRI underwent second-look high-resolution US directed at the site of the incidental finding. Diagnosis of incidental lesions was based on biopsy or 24-month follow-up. Breast MRI detected 55 additional lesions in 46/182 (25.2%) patients. Forty-two of 55 (76.3%) lesions were detected on second-look US in 38/46 (82.6%) patients. Malignancy was confirmed for 24/42 (57.1%) correlate lesions compared with 7/13 (53.8%) noncorrelate lesions. Second-look US depicted 8/9 (88.8%) Breast Imaging Reporting and Data System (BI-RADS) 5, 16/22 (72.7%) BI-RADS 4 and 18/24 (75%) BI-RADS 3 lesions. Sensitivity, specificity, accuracy and positive and negative predictive values for lesion detection/diagnosis was 100%, 88.9%, 94.6%, 90.3% and 100% for MRI and 64.3%, 70.4%, 67.3%, 69.2% and 65.5% for second-look US. Improved performance for US was obtained when masslike lesions only were considered. Second-look US is a confirmatory method for incidental findings on breast MRI, particularly for mass-like lesions.

  15. A Foot-Mounted Inertial Measurement Unit (IMU) Positioning Algorithm Based on Magnetic Constraint.

    Science.gov (United States)

    Wang, Yan; Li, Xin; Zou, Jiaheng

    2018-03-01

    With the development of related applications, indoor positioning techniques have been more and more widely developed. Based on Wi-Fi, Bluetooth low energy (BLE) and geomagnetism, indoor positioning techniques often rely on the physical location of fingerprint information. The focus and difficulty of establishing the fingerprint database are in obtaining a relatively accurate physical location with as little given information as possible. This paper presents a foot-mounted inertial measurement unit (IMU) positioning algorithm under the loop closure constraint based on magnetic information. It can provide relatively reliable position information without maps and geomagnetic information and provides a relatively accurate coordinate for the collection of a fingerprint database. In the experiment, the features extracted by the multi-level Fourier transform method proposed in this paper are validated and the validity of loop closure matching is tested with a RANSAC-based method. Moreover, the loop closure detection results show that the cumulative error of the trajectory processed by the graph optimization algorithm is significantly suppressed, presenting a good accuracy. The average error of the trajectory under loop closure constraint is controlled below 2.15 m.

  16. A Foot-Mounted Inertial Measurement Unit (IMU Positioning Algorithm Based on Magnetic Constraint

    Directory of Open Access Journals (Sweden)

    Yan Wang

    2018-03-01

    Full Text Available With the development of related applications, indoor positioning techniques have been more and more widely developed. Based on Wi-Fi, Bluetooth low energy (BLE and geomagnetism, indoor positioning techniques often rely on the physical location of fingerprint information. The focus and difficulty of establishing the fingerprint database are in obtaining a relatively accurate physical location with as little given information as possible. This paper presents a foot-mounted inertial measurement unit (IMU positioning algorithm under the loop closure constraint based on magnetic information. It can provide relatively reliable position information without maps and geomagnetic information and provides a relatively accurate coordinate for the collection of a fingerprint database. In the experiment, the features extracted by the multi-level Fourier transform method proposed in this paper are validated and the validity of loop closure matching is tested with a RANSAC-based method. Moreover, the loop closure detection results show that the cumulative error of the trajectory processed by the graph optimization algorithm is significantly suppressed, presenting a good accuracy. The average error of the trajectory under loop closure constraint is controlled below 2.15 m.

  17. A solution of High-precision WLAN positioning based on TDOA and PTP

    Directory of Open Access Journals (Sweden)

    Zhou Junjie

    2016-01-01

    Full Text Available For indoor WLAN positioning it is difficult to achieve decimeter or centimeter-level precision questions, to IEEE1588v2 (PTP precision network clock synchronization technology and the arrival time difference principle (TDOA, combined with non line of sight (NLOS error mitigation techniques ranging research and design a set based on the existing WLAN (IEEE802.11x series of standards device with high precision realtime location solutions. First, build a high-performance software-defined radio network communications platform, for accurate measurement of the radio signal arrival time and is calculated based on TDOA location. Secondly, the use of high-precision clock IEEE1588v2 standard equipment PTPGrand-2100 as a network clock source, through the integrated application of multi-hop latency compensation and asymmetric compensation algorithm to ensure nanosecond clock synchronization between the various WLAN access points (AP accuracy(Experiments show that 1 nanosecond time synchronization error is equivalent to 10 to 30 cm of positioning error. Finally, based NLOS error becomes stability principle, filtered NLOS error and pre-positioned before the data, eliminate the influence of the greatest degree of NLOS error, the time domain error control in wireless ranging 5ns or less to achieve decimeter or more accurately estimate the position. The case can be widely used in mobile Internet, logistics management, mineral exploration, health and other needs of the precise location services (LBS in other industry sectors.

  18. Hui Malama O Ke Kai: A Positive Prevention-Based Youth Development Program Based on Native Hawaiian Values and Activities

    Science.gov (United States)

    Hishinuma, Earl S.; Chang, Janice Y.; Sy, Angela; Greaney, Malia F.; Morris, Katherine A.; Scronce, Ami C.; Rehuher, Davis; Nishimura, Stephanie T.

    2009-01-01

    Evaluation of after-school programs that are culturally and place-based and promote positive youth development among minority and indigenous youths has not been widely published. The present evaluation is the first of its kind of an after-school, youth-risk prevention program called Hui Malama O Ke Kai (HMK), that emphasizes Native Hawaiian values…

  19. Tumefactive demyelinating lesions

    International Nuclear Information System (INIS)

    Dagher, A.P.; Smirniotopoulos, J.; Armed Forces Inst. of Pathology, Washington, DC

    1996-01-01

    We studied 21 cases of pathologically confirmed tumefactive demyelinating lesions and reviewed the spectrum of tumefactive demyelinating lesions in the literature. Radiological features and clinical data were reviewed to characterize the lesions as consistent with a known demyelinating disease, most notably multiple sclerosis. Atypical clinical or radiological features (other than tumefaction) were noted. Most lesions were part of a clinical and/or radiological picture consistent with multiple sclerosis. No case strongly suggestive of variants or related diseases, such as Schilder's disease or Balo's concentric sclerosis, were found. There was one case suggestive of acute disseminated encephalomyelitis. Features which help distinguish the lesions from tumour are discussed. (orig.)

  20. Benign Jaw Lesions.

    Science.gov (United States)

    Gohel, Anita; Villa, Alessandro; Sakai, Osamu

    2016-01-01

    There are both odontogenic and nonodontogenic benign lesions in the maxilla and mandible. These lesions may have similar imaging features, and the key radiographic features are presented to help the clinician narrow the differential diagnosis and plan patient treatment. Both intraoral and panoramic radiographs and advanced imaging features are useful in assessing the benign lesions of the jaws. The location, margins, internal contents, and effects of the lesions on adjacent structures are important features in diagnosing the lesions. Copyright © 2016 Elsevier Inc. All rights reserved.

  1. Tumefactive demyelinating lesions

    Energy Technology Data Exchange (ETDEWEB)

    Dagher, A.P. [Thomas Jefferson Univ. Hospital, Philadelphia, PA (United States). Div. of Neuroradiology; Smirniotopoulos, J. [Thomas Jefferson Univ. Hospital, Philadelphia, PA (United States). Div. of Neuroradiology]|[Armed Forces Inst. of Pathology, Washington, DC (United States). Dept. of Radiological Pathology

    1996-08-01

    We studied 21 cases of pathologically confirmed tumefactive demyelinating lesions and reviewed the spectrum of tumefactive demyelinating lesions in the literature. Radiological features and clinical data were reviewed to characterize the lesions as consistent with a known demyelinating disease, most notably multiple sclerosis. Atypical clinical or radiological features (other than tumefaction) were noted. Most lesions were part of a clinical and/or radiological picture consistent with multiple sclerosis. No case strongly suggestive of variants or related diseases, such as Schilder`s disease or Balo`s concentric sclerosis, were found. There was one case suggestive of acute disseminated encephalomyelitis. Features which help distinguish the lesions from tumour are discussed. (orig.)

  2. Periodontal bone lesions

    International Nuclear Information System (INIS)

    Linden, L.W.J. van der.

    1985-01-01

    In the course of life the periodontum is subject to changes which may be physiological or pathological. Intraoral radiographs give insight into the hard structures of the dentomaxillar region and provides information on lesions in the bone of the periodontum in that they show radiopacities and radiolucencies caused by such lesions. In this thesis the relation is investigated between the true shape and dimensions of periodontal bone lesions and their radiographic images. A method is developed and tested of making standardized and reproducible radiographs suitable for longitudinal studies of periodontal lesions. Also the possibility is demonstrated of an objective and reproducible interpretation of radiographic characteristics of periodontal bone lesions. (Auth.)

  3. A Model of Market Positioning of Destinations Based on Online Customer Reviews of Lodgings

    Directory of Open Access Journals (Sweden)

    Manuel Rodríguez-Díaz

    2017-12-01

    Full Text Available The aim of this study is to develop a methodology to determine the competitive online positioning of lodging companies in different tourist destinations. The rise of the digital age has allowed many customers to share their opinions through specialized websites, providing a dynamic and constantly updated evaluation of the market. In this context, competitiveness is an essential factor in the economic sustainability of destinations. The competitive positioning of destinations is determined by the scale of variables used by Booking.com. The price and lodging category variables are also used, as well as three new variables derived from the initial scale: the quality average, value and added value. This methodology provides a tool to determine the level of competitiveness of the lodging offered in tourist destinations, based on which, actions can be taken to improve destinations’ positioning.

  4. Distributed Position-Based Consensus of Second-Order Multiagent Systems With Continuous/Intermittent Communication.

    Science.gov (United States)

    Song, Qiang; Liu, Fang; Wen, Guanghui; Cao, Jinde; Yang, Xinsong

    2017-04-24

    This paper considers the position-based consensus in a network of agents with double-integrator dynamics and directed topology. Two types of distributed observer algorithms are proposed to solve the consensus problem by utilizing continuous and intermittent position measurements, respectively, where each observer does not interact with any other observers. For the case of continuous communication between network agents, some convergence conditions are derived for reaching consensus in the network with a single constant delay or multiple time-varying delays on the basis of the eigenvalue analysis and the descriptor method. When the network agents can only obtain intermittent position data from local neighbors at discrete time instants, the consensus in the network without time delay or with nonuniform delays is investigated by using the Wirtinger's inequality and the delayed-input approach. Numerical examples are given to illustrate the theoretical analysis.

  5. Developing and implementing a positive behavioral reinforcement intervention in prison-based drug treatment: Project BRITE.

    Science.gov (United States)

    Burdon, William M; St De Lore, Jef; Prendergast, Michael L

    2011-09-01

    Within prison settings, the reliance on punishment for controlling inappropriate or noncompliant behavior is self-evident. What is not so evident is the similarity between this reliance on punishment and the use of positive reinforcements to increase desired behaviors. However, seldom do inmates receive positive reinforcement for engaging in prosocial behaviors or, for inmates receiving drug treatment, behaviors that are consistent with or support their recovery. This study provides an overview of the development and implementation of a positive behavioral reinforcement intervention in male and female prison-based drug treatment programs. The active involvement of institutional staff, treatment staff, and inmates enrolled in the treatment programs in the development of the intervention along with the successful branding of the intervention were effective at promoting support and participation. However, these factors may also have ultimately impacted the ability of the randomized design to reliably demonstrate the effectiveness of the intervention.

  6. The effects of shallow traps on the positive streamer electrodynamics in transformer oil based nanofluids

    Science.gov (United States)

    Zhou, You; Sui, Sanyi; Li, Jie; Ouyang, Zigui; Lv, Yuzhen; Li, Chengrong; Lu, Wu

    2018-03-01

    Nanotechnology provides a new way to improve the insulating properties of traditional dielectric materials. In this study, three types of mineral oil based nanofluids were prepared by suspending Fe3O4, TiO2 and Al2O3 nanoparticles all of which were surface modified by oleic acid. The inception voltage, stopping length and propagating velocity of streamers in the nanofluids under positive lightning impulse voltage were experimentally studied. It is found that nanoparticles can restrain the initiation and propagation processes of positive streamers in transformer oil depending on the types of nanoparticles. In addition, the trap characteristics in pure oil and nanofluids were comparably studied. The relationship between the trap characteristics and mobility of charge carriers in oil samples were then established. The increased trap density in nanofluids diffuses kinetic energy of ionized electrons and converts them into negative ions, resulting in the reduced electrical field strength in front of positive streamer and increased breakdown strength of nanofluids.

  7. Positive Orientation-a Common Base for Hedonistic and Eudemonistic Happiness?

    Science.gov (United States)

    Oleś, Piotr; Jankowski, Tomasz

    2018-01-01

    Positive orientation (PO) is proposed as a common base for hedonistic and eudemonistic senses of happiness. PO involves a tendency to formulate positive judgments concerning the self, one's personal life, and the future. Previously, PO had been investigated in the context of the hedonistic approach to well-being. In this article, we tested a broader understanding of PO, which is conceptualized, here, as a latent factor underlying variables that exemplify hedonistic and eudemonistic view on happiness. Using two samples ( N  = 159 and N  = 200), we tested three models of PO extended to include various measures of meaning of life. The extended models fitted the data well. Results suggest that PO can be a general factor that is the basis for integrating two aspects of well-being: searching for positivity and pleasure, as well as striving for meaning.

  8. Flocking in Multi-Agent Systems with Multiple Virtual Leaders Based Only on Position Measurements

    International Nuclear Information System (INIS)

    Su Housheng

    2012-01-01

    Most existing flocking algorithms assume one single virtual leader and rely on information on both relative positions and relative velocities among neighboring agents. In this paper, the problem of controlling a flock of mobile autonomous agents to follow multiple virtual leaders is investigated by using only position information in the sense that agents with the same virtual leader asymptotically attain the same velocity and track the corresponding virtual leader based on only position measurements. A flocking algorithm is proposed under which every agent asymptotically attains its desired velocity, collision between agents can be avoided, and the final tight formation minimizes all agents' global potentials. A simulation example is presented to verify and illustrate the theoretical results. (general)

  9. Hybrid organic/inorganic position-sensitive detectors based on PEDOT:PSS/n-Si

    Science.gov (United States)

    Javadi, Mohammad; Gholami, Mahdiyeh; Torbatiyan, Hadis; Abdi, Yaser

    2018-03-01

    Various configurations like p-n junctions, metal-semiconductor Schottky barriers, and metal-oxide-semiconductor structures have been widely used in position-sensitive detectors. In this report, we propose a PEDOT:PSS/n-Si heterojunction as a hybrid organic/inorganic configuration for position-sensitive detectors. The influence of the thickness of the PEDOT:PSS layer, the wavelength of incident light, and the intensity of illumination on the device performance are investigated. The hybrid PSD exhibits very high sensitivity (>100 mV/mm), excellent nonlinearity (0.995) with a response time of PEDOT:PSS/n-Si heterojunction are very promising for developing a new class of position-sensitive detectors based on the hybrid organic/inorganic junctions.

  10. RELATIVE PANORAMIC CAMERA POSITION ESTIMATION FOR IMAGE-BASED VIRTUAL REALITY NETWORKS IN INDOOR ENVIRONMENTS

    Directory of Open Access Journals (Sweden)

    M. Nakagawa

    2017-09-01

    Full Text Available Image-based virtual reality (VR is a virtual space generated with panoramic images projected onto a primitive model. In imagebased VR, realistic VR scenes can be generated with lower rendering cost, and network data can be described as relationships among VR scenes. The camera network data are generated manually or by an automated procedure using camera position and rotation data. When panoramic images are acquired in indoor environments, network data should be generated without Global Navigation Satellite Systems (GNSS positioning data. Thus, we focused on image-based VR generation using a panoramic camera in indoor environments. We propose a methodology to automate network data generation using panoramic images for an image-based VR space. We verified and evaluated our methodology through five experiments in indoor environments, including a corridor, elevator hall, room, and stairs. We confirmed that our methodology can automatically reconstruct network data using panoramic images for image-based VR in indoor environments without GNSS position data.

  11. The Post-Ureteroscopic Lesion Scale (PULS)

    DEFF Research Database (Denmark)

    Schoenthaler, Martin; Buchholz, Noor; Farin, Erik

    2014-01-01

    The Post-Ureteroscopic Lesion Scale (PULS) offers a simple grading system for the description of ureteral lesions after ureteroscopy. In this article, we present the results of a video-based multicenter evaluation of the inter-rater reliability of clinically important PULS grades 0-3.......The Post-Ureteroscopic Lesion Scale (PULS) offers a simple grading system for the description of ureteral lesions after ureteroscopy. In this article, we present the results of a video-based multicenter evaluation of the inter-rater reliability of clinically important PULS grades 0-3....

  12. [Color Doppler sonography of focal abdominal lesions].

    Science.gov (United States)

    Licanin, Zoran; Lincender, Lidija; Djurović, V; Salihefendić, Nizama; Smajlović, Fahrudin

    2004-01-01

    Color Doppler sonography (CDS--spectral, color and power), harmonic imaging techniques (THI, PHI), possibility of 3D analysis of picture, usage of contrast agents, have raised the values of ultrasound as a diagnostic method to a very high level. THI--non-linear gray scale modality, is based on the processing of higher reflected frequencies, that has improved a picture resolution, which is presented with less artifacts and limiting effects of obesity and gases. Ultrasound contrast agents improve analysis of micro and macro circulation of the examined area, and with the assessment of velocity of supply in ROI (wash in), distribution and time of signal weakening (wash out), are significantly increasing diagnostic value of ultrasound. Besides the anatomical and topographic presentation of examined region (color, power), Color Doppler sonography gives us haemodynamic-functional information on vascularisation of that region, as well as on pathologic vascularisation if present. Avascular aspect of a focal pathologic lesion corresponds to a cyst or haematoma, while coloration and positive spectral curve discover that anechogenic lesions actually represents aneurysms, pseudoaneurysms or AVF. In local inflammatory lesion, abscess in an acute phase, CDS shows first increased, and then decreased central perfusion, while in a chronic phase, a pericapsular vascularisation is present. Contribution of CDS in differentiation of hepatic tumors (hemangioma, HCC and metastasis) is very significant. Central color dots along the peripheral blood vessels and the blush phenomenon are characteristics of capillary hemangioma, peritumoral vascular ring "basket" of HCC, and "detour" sign of metastasis. The central artery, RI from 0.45 to 0.60 and radial spreading characterize FNH. Hepatic adenoma is characterized by an intratumoral vein, and rarely by a vascular hallo. Further on, blood velocity in tumor defined by Color Doppler, distinguishes malignant from benign lesion, where 40 cm/s is a

  13. Self-positioned thin Pb-alloy base electrode Josephson junction

    International Nuclear Information System (INIS)

    Kuroda, K.; Sato, K.

    1986-01-01

    A self-positioned thin (SPOT) Pb-alloy base electrode Josephson junction is developed. In this junction, a 50-nm thick Pb-alloy base electrode is restricted within the junction region on an Nb underlayer using a self-alignment technique. The grain size reduction and the base electrode area restriction greatly improve thermal cycling stability, where the thermal cycling tests of 4000 proposed junctions (5 x 5 μm 2 ) showed no failures after 4000 cycles. In addition, the elimination of insulator layer stress on the Pb-alloy base electrode rectifies the problem of size effect on current density. The Nb underlayers also serve to isolate the Pb-alloy base electrodes from the resistors

  14. A Smartphone-Based Approach for Triage of Human Papillomavirus-Positive Sub-Saharan African Women: A Prospective Study.

    Science.gov (United States)

    Urner, Esther; Delavy, Martine; Catarino, Rosa; Viviano, Manuela; Meyer-Hamme, Ulrike; Benski, Anne-Caroline; Jinoro, Jeromine; Heriniainasolo, Josea Lea; Undurraga, Manuela; De Vuyst, Hugo; Combescure, Christophe; Vassilakos, Pierre; Petignat, Patrick

    2017-05-29

    Sub-Saharan African countries are marked by a high incidence of cervical cancer. Madagascar ranks 11th among the countries with the highest cervical cancer incidence worldwide. The aim of the study was to evaluate the performances of digital smartphone-based visual inspection with acetic acid (D-VIA) and Lugol's iodine (D-VILI) for diagnosing cervical precancer and cancer. Human papillomavirus (HPV)-positive women recruited through a cervical screening campaign had D-VIA and D-VILI examinations with endocervical curettage (ECC) and cervical biopsy. Three images were captured for each woman (native, D-VIA, D-VILI) using a smartphone camera. The images were randomly coded and distributed on 2 online databases (Google Forms). The D-VIA form included native and D-VIA images, and the D-VILI form included native and D-VILI images. Pathological cases were defined as cervical intraepithelial neoplasia grade 2 or worse (CIN2+). Physicians rated the images as non-pathological or pathological. Using the ECC and cervical biopsy results as references, the sensitivity and specificity of D-VIA and D-VILI examinations for each and all physicians were calculated. Altogether, 15 clinicians assessed 240 images. Sensitivity was higher for the D-VIA interpretations (94.1%; 95% CI 81.6-98.3) than for the D-VILI interpretations (78.8%; 95% CI 54.1-92.1; P=.009). In contrast, the specificity was higher for the D-VILI interpretations (56.4%; 95% CI 38.3-72.9) than for the D-VIA interpretations (50.4%; 95% CI 35.9-64.8; P=.005). Smartphone-based image for triage of HPV-positive women is more accurate for detecting CIN2+ lesions with D-VIA than D-VILI, although with a small loss of specificity. ©Esther Urner, Martine Delavy, Rosa Catarino, Manuela Viviano, Ulrike Meyer-Hamme, Anne-Caroline Benski, Jeromine Jinoro, Josea Lea Heriniainasolo, Manuela Undurraga, Hugo De Vuyst, Christophe Combescure, Pierre Vassilakos, Patrick Petignat. Originally published in JMIR Mhealth and Uhealth (http

  15. Cherenkoscopy based patient positioning validation and movement tracking during post-lumpectomy whole breast radiation therapy.

    Science.gov (United States)

    Zhang, Rongxiao; Andreozzi, Jacqueline M; Gladstone, David J; Hitchcock, Whitney L; Glaser, Adam K; Jiang, Shudong; Pogue, Brian W; Jarvis, Lesley A

    2015-01-07

    To investigate Cherenkov imaging (Cherenkoscopy) based patient positioning and movement tracking during external beam radiation therapy (EBRT). In a phase 1 clinical trial, including 12 patients undergoing post-lumpectomy whole breast irradiation, Cherenkov emission was imaged with a time-gated ICCD camera synchronized to the LINAC pulse output, during different fractions of the treatment. Patients were positioned with the aid of the AlignRT system in the beginning of each treatment session. Inter-fraction setup variation was studied by rigid image registrations between images acquired at individual treatments to the average image from all imaged treatment fractions. The amplitude of respiratory motion was calculated from the registration of each frame of Cherenkov images to the reference. A Canny edge detection algorithm was utilized to highlight the beam field edges and biological features provided by major blood vessels apparent in the images. Real-time Cherenkoscopy can monitor the treatment delivery, patient motion and alignment of the beam edge to the treatment region simultaneously. For all the imaged fractions, the patient positioning discrepancies were within our clinical tolerances (3 mm in shifts and 3 degree in pitch angle rotation), with 4.6% exceeding 3 mm but still within 4 mm in shifts. The average discrepancy of repetitive patient positioning was 1.22 mm in linear shift and 0.34 degrees in rotational pitch, consistent with the accuracy reported by the AlignRT system. The edge detection algorithm enhanced features such as field edges and blood vessels. Patient positioning discrepancies and respiratory motion retrieved from rigid image registration were consistent with the edge enhanced images. Besides positioning discrepancies caused by globally inaccurate setups, edge enhanced blood vessels indicate the existence of deformations within the treatment region, especially for large patients. Real-time Cherenkoscopy imaging during EBRT is a

  16. Context-based advocacy for HIV-positive women making reproductive decisions.

    Science.gov (United States)

    McCreary, Linda L; Ferrer, Lilian M; Ilagan, Perla R; Ungerleider, Linda S

    2003-01-01

    As the number of HIV-positive women of childbearing age continues to rise, and treatments available to manage HIV become more accessible, the issue of HIV-positive women's reproductive decision making is gaining importance for nurses in AIDS care. Nurses and other health professionals care for these women as they decide whether to bear children. The decision whether to have children is complex and influenced by a number of individual and societal factors, creating an ethical tension between the interests of HIV-positive women and those of society. This article proposes a six-step, context-based advocacy process for nurses and other health professionals who interact with HIV-positive women of childbearing age. The advocacy process described is grounded in a review of literature on HIV/AIDS, factors influencing HIV-positive women's reproductive choices, and nursing advocacy. The proposed advocacy process enables nurses to support women's self-determination and decision making in a way that is informative and empowering.

  17. Improvement of Gaofen-3 Absolute Positioning Accuracy Based on Cross-Calibration

    Directory of Open Access Journals (Sweden)

    Mingjun Deng

    2017-12-01

    Full Text Available The Chinese Gaofen-3 (GF-3 mission was launched in August 2016, equipped with a full polarimetric synthetic aperture radar (SAR sensor in the C-band, with a resolution of up to 1 m. The absolute positioning accuracy of GF-3 is of great importance, and in-orbit geometric calibration is a key technology for improving absolute positioning accuracy. Conventional geometric calibration is used to accurately calibrate the geometric calibration parameters of the image (internal delay and azimuth shifts using high-precision ground control data, which are highly dependent on the control data of the calibration field, but it remains costly and labor-intensive to monitor changes in GF-3’s geometric calibration parameters. Based on the positioning consistency constraint of the conjugate points, this study presents a geometric cross-calibration method for the rapid and accurate calibration of GF-3. The proposed method can accurately calibrate geometric calibration parameters without using corner reflectors and high-precision digital elevation models, thus improving absolute positioning accuracy of the GF-3 image. GF-3 images from multiple regions were collected to verify the absolute positioning accuracy after cross-calibration. The results show that this method can achieve a calibration accuracy as high as that achieved by the conventional field calibration method.

  18. Photoelectric scanning-based method for positioning omnidirectional automatic guided vehicle

    Science.gov (United States)

    Huang, Zhe; Yang, Linghui; Zhang, Yunzhi; Guo, Yin; Ren, Yongjie; Lin, Jiarui; Zhu, Jigui

    2016-03-01

    Automatic guided vehicle (AGV) as a kind of mobile robot has been widely used in many applications. For better adapting to the complex working environment, more and more AGVs are designed to be omnidirectional by being equipped with Mecanum wheels for increasing their flexibility and maneuverability. However, as the AGV with this kind of wheels suffers from the position errors mainly because of the frequent slipping property, how to measure its position accurately in real time is an extremely important issue. Among the ways of achieving it, the photoelectric scanning methodology based on angle measurement is efficient. Hence, we propose a feasible method to ameliorate the positioning process, which mainly integrates four photoelectric receivers and one laser transmitter. To verify the practicality and accuracy, actual experiments and computer simulations have been conducted. In the simulation, the theoretical positioning error is less than 0.28 mm in a 10 m×10 m space. In the actual experiment, the performances about the stability, accuracy, and dynamic capability of this method were inspected. It demonstrates that the system works well and the performance of the position measurement is high enough to fulfill the mainstream tasks.

  19. Research on position and orientation measurement method for roadheader based on vision/INS

    Science.gov (United States)

    Yang, Jinyong; Zhang, Guanqin; Huang, Zhe; Ye, Yaozhong; Ma, Bowen; Wang, Yizhong

    2018-01-01

    Roadheader which is a kind of special equipment for large tunnel excavation has been widely used in Coal Mine. It is one of the main mechanical-electrical equipment for mine production and also has been regarded as the core equipment for underground tunnel driving construction. With the deep application of the rapid driving system, underground tunnel driving methods with higher automation level are required. In this respect, the real-time position and orientation measurement technique for roadheader is one of the most important research contents. For solving the problem of position and orientation measurement automatically in real time for roadheaders, this paper analyses and compares the features of several existing measuring methods. Then a new method based on the combination of monocular vision and strap down inertial navigation system (SINS) would be proposed. By realizing five degree-of-freedom (DOF) measurement of real-time position and orientation of roadheader, this method has been verified by the rapid excavation equipment in Daliuta coal mine. Experiment results show that the accuracy of orientation measurement is better than 0.1°, the standard deviation of static drift is better than 0.25° and the accuracy of position measurement is better than 1cm. It is proved that this method can be used in real-time position and orientation measurement application for roadheader which has a broad prospect in coal mine engineering.

  20. Hausdorff-Based RC and IESIL Combined Positioning Algorithm for Underwater Geomagnetic Navigation

    Directory of Open Access Journals (Sweden)

    Lin Yi

    2010-01-01

    Full Text Available This paper presents a primitive solution with novel scheme and algorithm for Underwater geoMagnetic Navigation (UMN, which now occurs as the hot-point in the research field of navigation. UMN as an independent or supplementary technique can theoretically supply accurate locations for marine vehicles, but in practice there are plenty of restrictions for UMN's application (e.g., geomagnetic daily variation. After analysis of the theoretical model of geomagnetic positioning in the correlation-matching mode from the viewpoint of pattern recognition, this paper proposed an appropriate matching scenario and a combined positioning algorithm for UMN. The subalgorithm of Hausdorff-based Relative Correlation (RC corresponding to the pattern classification module implements the coarse positioning, and the subalgorithm of Isograms Equidistance-Segmenting theIntersection Lines (IESILs associated with the module of feature extraction continues the fine positioning. The experiments based on the simulation platform and the real-surveyed data both validate the new algorithm, and its efficiency and accuracy are also discussed. It can be concluded that the work introduced in this paper gives an initial and real validation of UMN's potentiality.

  1. Multi-criterial patient positioning based on dose recalculation on scatter-corrected CBCT images.

    Science.gov (United States)

    Hofmaier, Jan; Haehnle, Jonas; Kurz, Christopher; Landry, Guillaume; Maihoefer, Cornelius; Schüttrumpf, Lars; Süss, Philipp; Teichert, Katrin; Söhn, Matthias; Spahr, Nadine; Brachmann, Christoph; Weiler, Florian; Thieke, Christian; Küfer, Karl-Heinz; Belka, Claus; Parodi, Katia; Kamp, Florian

    2017-12-01

    Our aim was to evaluate the feasibility and potential advantages of dose guided patient positioning based on dose recalculation on scatter corrected cone beam computed tomography (CBCT) image data. A scatter correction approach has been employed to enable dose calculations on CBCT images. A recently proposed tool for interactive multicriterial dose-guided patient positioning which uses interpolation between pre-calculated sample doses has been utilized. The workflow was retrospectively evaluated for two head and neck patients with a total of 39 CBCTs. Dose-volume histogram (DVH) parameters were compared to rigid image registration based isocenter corrections (clinical scenario). The accuracy of the dose interpolation was found sufficient, facilitating the implementation of dose guided patient positioning. Compared to the clinical scenario, the mean dose to the parotid glands could be improved for 2 out of 5 fractions for the first patient while other parameters were preserved. For the second patient, the mean coverage over all fractions of the high dose PTV could be improved by 4%. For this patient, coverage improvements had to be traded against organ at risk (OAR) doses within their clinical tolerance limits. Dose guided patient positioning using in-room CBCT data is feasible and offers increased control over target coverage and doses to OARs. Copyright © 2017 Elsevier B.V. All rights reserved.

  2. A fully automatic, threshold-based segmentation method for the estimation of the Metabolic Tumor Volume from PET images: validation on 3D printed anthropomorphic oncological lesions

    International Nuclear Information System (INIS)

    Gallivanone, F.; Interlenghi, M.; Castiglioni, I.; Canervari, C.

    2016-01-01

    18F-Fluorodeoxyglucose (18F-FDG) Positron Emission Tomography (PET) is a standard functional diagnostic technique to in vivo image cancer. Different quantitative paramters can be extracted from PET images and used as in vivo cancer biomarkers. Between PET biomarkers Metabolic Tumor Volume (MTV) has gained an important role in particular considering the development of patient-personalized radiotherapy treatment for non-homogeneous dose delivery. Different imaging processing methods have been developed to define MTV. The different proposed PET segmentation strategies were validated in ideal condition (e.g. in spherical objects with uniform radioactivity concentration), while the majority of cancer lesions doesn't fulfill these requirements. In this context, this work has a twofold objective: 1) to implement and optimize a fully automatic, threshold-based segmentation method for the estimation of MTV, feasible in clinical practice 2) to develop a strategy to obtain anthropomorphic phantoms, including non-spherical and non-uniform objects, miming realistic oncological patient conditions. The developed PET segmentation algorithm combines an automatic threshold-based algorithm for the definition of MTV and a k-means clustering algorithm for the estimation of the background. The method is based on parameters always available in clinical studies and was calibrated using NEMA IQ Phantom. Validation of the method was performed both in ideal (e.g. in spherical objects with uniform radioactivity concentration) and non-ideal (e.g. in non-spherical objects with a non-uniform radioactivity concentration) conditions. The strategy to obtain a phantom with synthetic realistic lesions (e.g. with irregular shape and a non-homogeneous uptake) consisted into the combined use of standard anthropomorphic phantoms commercially and irregular molds generated using 3D printer technology and filled with a radioactive chromatic alginate. The proposed segmentation algorithm was feasible in

  3. Trans-zygomatic middle cranial fossa approach to access lesions around the cavernous sinus and anterior parahippocampus: a minimally invasive skull base approach.

    Science.gov (United States)

    Melamed, Itay; Tubbs, R Shane; Payner, Troy D; Cohen-Gadol, Aaron A

    2009-08-01

    Exposure of the cavernous sinus or anterior parahippocampus often involves a wide exposure of the temporal lobe and mobilization of the temporalis muscle associated with temporal lobe retraction. The authors present a cadaveric study to illustrate the feasibility, advantages and landmarks necessary to perform a trans-zygomatic middle fossa approach to lesions around the cavernous sinus and anterior parahippocampus. The authors performed bilateral trans-zygomatic middle fossae exposures to reach the cavernous sinus and parahippocampus in five cadavers (10 sides). We assessed the morbidity associated with this procedure and compared the indications, advantages, and disadvantages of this method versus more extensive skull base approaches. A vertical linear incision along the middle portion of the zygomatic arch was extended one finger breadth inferior to the inferior edge of the zygomatic arch. Careful dissection inferior to the arch allowed preservation of facial nerve branches. A zygomatic osteotomy was followed via a linear incision through the temporalis muscle and exposure of the middle cranial fossa floor. A craniotomy along the inferolateral temporal bone and middle fossa floor allowed extradural dissection along the middle fossa floor and exposure of the cavernous sinus including all three divisions of the trigeminal nerve. Intradural inspection demonstrated adequate exposure of the parahippocampus. Exposure of the latter required minimal or no retraction of the temporal lobe. The trans-zygomatic middle fossa approach is a simplified skull base exposure using a linear incision, which may avoid the invasivity of more extensive skull base approaches while providing an adequate corridor for resection of cavernous sinus and parahippocampus lesions. The advantages of this approach include its efficiency, ease, minimalism, preservation of the temporalis muscle, and minimal retraction of the temporal lobe.

  4. Recidiva de lesões associadas ao HPV em pacientes HIV positivos após tratamento cirúrgico Recurrence of HPV lesions after surgical treatment in HIV-positive patients

    Directory of Open Access Journals (Sweden)

    André Luigi Pincinato

    2009-06-01

    Full Text Available O HPV é a doença anal sexualmente transmissível mais diagnosticada em pacientes HIV positivos. Neste estudo investigamos a taxa de recidiva após tratamento cirúrgico do HPV em pacientes HIV positivos. Foi realizado um estudo retrospectivo em 74 pacientes que foram submetidos a tratamento cirúrgico de lesões remanescentes após tratamento clínico do HPV, no Hospital Heliópolis, São Paulo, Brasil, de julho de 2004 até junho de 2007. A maioria dos pacientes eram homens (91,9%, idade variando de 22 a 57 anos (média de 36 anos. Carga viral variou de indetectável até 488.000 cópias/mm³, células T CD4 de 19 a 900 céls/mm³. Observamos neoplasia intraepitelial de alto grau em 12,2% e recorrência das lesões em 58,1% dos pacientes. A recorrência foi significantemente menor em pacientes com células T CD4 =200 cells/mm³ e carga viral indetectável.HPV is the commonest anal disease in HIV-infected patients. In the present study we investigated the recurrence rates after surgical treatment of HPV in HIV-positive patients. A retrospective review was performed on 74 patients who underwent surgical intervention for medically intractable anal condyloma at Hospital Heliópolis, São Paulo, Brazil, from July 2004 to June 2007. The majority of the patients were male (91,9%, ranged in age from 22 to 57 years (mean 36 years. Viral load ranged from undetectable to 488.000 copies/mm³, T CD4 cells counts from 19 to 900 cells/mm³. We observed high grade anal squamous intraepithelial lesions in 12,2% and anal condyloma recurred in 58,1%. A significantly lower recurrence was observed in patients with T CD4 cells counts =200 cells/mm³ and viral load undetectable.

  5. Life review based on remembering specific positive events in active aging.

    Science.gov (United States)

    Latorre, José M; Serrano, Juan P; Ricarte, Jorge; Bonete, Beatriz; Ros, Laura; Sitges, Esther

    2015-02-01

    The aim of this study is to evaluate the effectiveness of life review (LR) based on specific positive events in non-depressed older adults taking part in an active aging program. Fifty-five older adults were randomly assigned to an experimental group or an active control (AC) group. A six-session individual training of LR based on specific positive events was carried out with the experimental group. The AC group undertook a "media workshop" of six sessions focused on learning journalistic techniques. Pre-test and post-test measures included life satisfaction, depressive symptoms, experiencing the environment as rewarding, and autobiographical memory (AM) scales. LR intervention decreased depressive symptomatology, improved life satisfaction, and increased specific memories. The findings suggest that practice in AM for specific events is an effective component of LR that could be a useful tool in enhancing emotional well-being in active aging programs, thus reducing depressive symptoms. © The Author(s) 2014.

  6. Insecurity of position-based quantum-cryptography protocols against entanglement attacks

    International Nuclear Information System (INIS)

    Lau, Hoi-Kwan; Lo, Hoi-Kwong

    2011-01-01

    Recently, position-based quantum cryptography has been claimed to be unconditionally secure. On the contrary, here we show that the existing proposals for position-based quantum cryptography are, in fact, insecure if entanglement is shared among two adversaries. Specifically, we demonstrate how the adversaries can incorporate ideas of quantum teleportation and quantum secret sharing to compromise the security with certainty. The common flaw to all current protocols is that the Pauli operators always map a codeword to a codeword (up to an irrelevant overall phase). We propose a modified scheme lacking this property in which the same cheating strategy used to undermine the previous protocols can succeed with a rate of at most 85%. We prove the modified protocol is secure when the shared quantum resource between the adversaries is a two- or three-level system.

  7. Loosen Couple Workflow Mode of Lean Operator Improvement Based on Positive Feedback

    Directory of Open Access Journals (Sweden)

    Yao Li

    2013-04-01

    Full Text Available In order to promote the core competitive power for telecom operating enterprises to face market fine operation, this article compares the ECTA mode (Extension Case Transmission Mode and the LCA mode (Loosen Couple Mode, both of which are promoted by WfMC. By comparing these two modes, the suitable situations for these two modes are determined. We also carry out empirical analysis based on the customization mode of mobile phones between China telecom and mobile phone manufacturers and to expound the ascension effect of mechanism based on the agile telecom loose coupling workflow with positive feedback to the telecom enterprises. Finally, on the basis of positive feedback system, the task complexity and information transparency of LCA mode are improved, so that the semantics of public flow mode is kept unchanged and the sub workflow is optimized when modifying the sub workflow.

  8. Systematic error mitigation in multi-GNSS positioning based on semiparametric estimation

    Science.gov (United States)

    Yu, Wenkun; Ding, Xiaoli; Dai, Wujiao; Chen, Wu

    2017-12-01

    Joint use of observations from multiple global navigation satellite systems (GNSS) is advantageous in high-accuracy positioning. However, systematic errors in the observations can significantly impact on the positioning accuracy if such errors cannot be properly mitigated. The errors can distort least squares estimations and also affect the results of variance component estimation that is frequently used to determine the stochastic model when observations from multiple GNSS are used. We present an approach that is based on the concept of semiparametric estimation for mitigating the effects of the systematic errors. Experimental results based on both simulated and real GNSS datasets show that the approach is effective, especially when applied before carrying out variance component estimation.

  9. Benign Paroxysmal Positional Vertigo after Dental Procedures: A Population-Based Case-Control Study

    OpenAIRE

    Chang, Tzu-Pu; Lin, Yueh-Wen; Sung, Pi-Yu; Chuang, Hsun-Yang; Chung, Hsien-Yang; Liao, Wen-Ling

    2016-01-01

    Background Benign paroxysmal positional vertigo (BPPV), the most common type of vertigo in the general population, is thought to be caused by dislodgement of otoliths from otolithic organs into the semicircular canals. In most cases, however, the cause behind the otolith dislodgement is unknown. Dental procedures, one of the most common medical treatments, are considered to be a possible cause of BPPV, although this has yet to be proven. This study is the first nationwide population-based cas...

  10. A Web-Based Adolescent Positive Psychology Program in Schools: Randomized Controlled Trial

    OpenAIRE

    Burckhardt, Rowan; Manicavasagar, Vijaya; Batterham, Philip J; Miller, Leonie M; Talbot, Elizabeth; Lum, Alistair

    2015-01-01

    Background Adolescent mental health is characterized by relatively high rates of psychiatric disorders and low levels of help-seeking behaviors. Existing mental health programs aimed at addressing these issues in adolescents have repeated inconsistent results. Such programs have generally been based on techniques derived from cognitive behavioral therapy, which may not be ideally suited to early intervention among adolescent samples. Positive psychology, which seeks to improve well-being rath...

  11. Artificial Bee Colony-based Adaptive Position Control of Electrohydraulic Servo Systems with Parameter Uncertainty

    OpenAIRE

    Ayinde, Babajide O.; El-Ferik, Sami

    2017-01-01

    In this paper, a robust adaptive backstepping-based controller is developed for positioning the spool valve of Electro-Hydraulic Servo System (EHSS) with parameter fluctuations. Artificial Bee Colony (ABC) algorithm is utilized to drive the parameters of the proposed controller to a good neighbourhood of the solution space. The optimization problem is formulated such that both the tracking error and control signal are minimized concurrently. The results show that the proposed controller guara...

  12. Method for determining the spatial position of the shoulder with ultrasound-based motion analyzer.

    Science.gov (United States)

    Illyés, Arpád; Kiss, Rita M

    2006-02-01

    Several methods have been developed recently for the analysis of the spatial motion of the scapula and the arm, whereby the spatial position of shoulder bones is determined in static conditions by interrupting motion. The authors have developed a 3D motion analysis method recording scapular motion in progress with appropriate accuracy in the course of arm movements of various degrees. The objective of this study is to explore the applicability of the method developed, as well as to compare it with and verify it by other methods developed earlier. The position and displacements of shoulder bones were determined on 30 shoulders of 15 healthy people. The newly developed measurement method is based on the mechanical basic principle stating that the position and motion of a rigid body -- in this case, the bones (segments) forming the shoulder joint -- can be calculated at any moment from the spatial coordinates of three points of a segment and any changes thereof in the course of motion. Ultrasound-based triplets providing the three points (fundamental points) by a segment as required for measurement were fixed on the sternum (modeling the trunk), the clavicle, the acromion (modeling the scapula), the upper arm, and the lower arm. The position of the sixteen anatomical points involved in the study were determined by an ultrasound-based pointer in the local coordinate system specified by the fundamental points before starting measurements. The ZEBRIS ultrasound-based motion analysis system was used for measuring the spatial coordinates of triplets in the course of continuous motion. The spatial coordinates of the designated anatomical points can be calculated by the method of triangulation. The method was calibrated by a ZEBRIS mapping (3DCAD) software commercially available, and the measurement error rate of the method was determined by statistical calculations. On the basis of calibration and error calculations it could be established that the accuracy and the

  13. An efficient multi-carrier position-based packet forwarding protocol for wireless sensor networks

    KAUST Repository

    Bader, Ahmed

    2012-01-01

    Beaconless position-based forwarding protocols have recently evolved as a promising solution for packet forwarding in wireless sensor networks. However, as the node density grows, the overhead incurred in the process of relay selection grows significantly. As such, end-to-end performance in terms of energy and latency is adversely impacted. With the motivation of developing a packet forwarding mechanism that is tolerant to variation in node density, an alternative position-based protocol is proposed in this paper. In contrast to existing beaconless protocols, the proposed protocol is designed such that it eliminates the need for potential relays to undergo a relay selection process. Rather, any eligible relay may decide to forward the packet ahead, thus significantly reducing the underlying overhead. The operation of the proposed protocol is empowered by exploiting favorable features of orthogonal frequency division multiplexing (OFDM) at the physical layer. The end-to-end performance of the proposed protocol is evaluated against existing beaconless position-based protocols analytically and as well by means of simulations. The proposed protocol is demonstrated in this paper to be more efficient. In particular, it is shown that for the same amount of energy the proposed protocol transports one bit from source to destination much quicker. © 2012 IEEE.

  14. An Indoor Positioning System Based on Wearables for Ambient-Assisted Living

    Directory of Open Access Journals (Sweden)

    Óscar Belmonte-Fernández

    2016-12-01

    Full Text Available The urban population is growing at such a rate that by 2050 it is estimated that 84% of the world’s population will live in cities, with flats being the most common living place. Moreover, WiFi technology is present in most developed country urban areas, with a quick growth in developing countries. New Ambient-Assisted Living applications will be developed in the near future having user positioning as ground technology: elderly tele-care, energy consumption, security and the like are strongly based on indoor positioning information. We present an Indoor Positioning System for wearable devices based on WiFi fingerprinting. Smart-watch wearable devices are used to acquire the WiFi strength signals of the surrounding Wireless Access Points used to build an ensemble of Machine Learning classification algorithms. Once built, the ensemble algorithm is used to locate a user based on the WiFi strength signals provided by the wearable device. Experimental results for five different urban flats are reported, showing that the system is robust and reliable enough for locating a user at room level into his/her home. Another interesting characteristic of the presented system is that it does not require deployment of any infrastructure, and it is unobtrusive, the only device required for it to work is a smart-watch.

  15. An Indoor Positioning System Based on Wearables for Ambient-Assisted Living.

    Science.gov (United States)

    Belmonte-Fernández, Óscar; Puertas-Cabedo, Adrian; Torres-Sospedra, Joaquín; Montoliu-Colás, Raúl; Trilles-Oliver, Sergi

    2016-12-25

    The urban population is growing at such a rate that by 2050 it is estimated that 84% of the world's population will live in cities, with flats being the most common living place. Moreover, WiFi technology is present in most developed country urban areas, with a quick growth in developing countries. New Ambient-Assisted Living applications will be developed in the near future having user positioning as ground technology: elderly tele-care, energy consumption, security and the like are strongly based on indoor positioning information. We present an Indoor Positioning System for wearable devices based on WiFi fingerprinting. Smart-watch wearable devices are used to acquire the WiFi strength signals of the surrounding Wireless Access Points used to build an ensemble of Machine Learning classification algorithms. Once built, the ensemble algorithm is used to locate a user based on the WiFi strength signals provided by the wearable device. Experimental results for five different urban flats are reported, showing that the system is robust and reliable enough for locating a user at room level into his/her home. Another interesting characteristic of the presented system is that it does not require deployment of any infrastructure, and it is unobtrusive, the only device required for it to work is a smart-watch.

  16. A RSSI-based parameter tracking strategy for constrained position localization

    Science.gov (United States)

    Du, Jinze; Diouris, Jean-François; Wang, Yide

    2017-12-01

    In this paper, a received signal strength indicator (RSSI)-based parameter tracking strategy for constrained position localization is proposed. To estimate channel model parameters, least mean squares method (LMS) is associated with the trilateration method. In the context of applications where the positions are constrained on a grid, a novel tracking strategy is proposed to determine the real position and obtain the actual parameters in the monitored region. Based on practical data acquired from a real localization system, an experimental channel model is constructed to provide RSSI values and verify the proposed tracking strategy. Quantitative criteria are given to guarantee the efficiency of the proposed tracking strategy by providing a trade-off between the grid resolution and parameter variation. The simulation results show a good behavior of the proposed tracking strategy in the presence of space-time variation of the propagation channel. Compared with the existing RSSI-based algorithms, the proposed tracking strategy exhibits better localization accuracy but consumes more calculation time. In addition, a tracking test is performed to validate the effectiveness of the proposed tracking strategy.

  17. Parallel effects of processing fluency and positive affect on familiarity-based recognition decisions for faces

    Directory of Open Access Journals (Sweden)

    Devin eDuke

    2014-04-01

    Full Text Available According to attribution models of familiarity assessment, people can use a heuristic in recognition-memory decisions, in which they attribute the subjective ease of processing of a memory probe to a prior encounter with the stimulus in question. Research in social cognition suggests that experienced positive affect may be the proximal cue that signals fluency in various experimental contexts. In the present study, we compared the effects of positive affect and fluency on recognition-memory judgments for faces with neutral emotional expression. We predicted that if positive affect is indeed the critical cue that signals processing fluency at retrieval, then its manipulation should produce effects that closely mirror those produced by manipulations of processing fluency. In two experiments, we employed a masked-priming procedure in combination with a Remember-Know paradigm that aimed to separate familiarity- from recollection-based memory decisions. In addition, participants performed a prime-discrimination task that allowed us to take inter-individual differences in prime awareness into account. We found highly similar effects of our priming manipulations of processing fluency and of positive affect. In both cases, the critical effect was specific to familiarity-based recognition responses. Moreover, in both experiments it was reflected in a shift towards a more liberal response bias, rather than in changed discrimination. Finally, in both experiments, the effect was found to be related to prime awareness; it was present only in participants who reported a lack of such awareness on the prime-discrimination task. These findings add to a growing body of evidence that points not only to a role of fluency, but also of positive affect in familiarity assessment. As such they are consistent with the idea that fluency itself may be hedonically marked.

  18. Immunoreactivity of granular cell lesions of skin, mucosa, and jaw.

    Science.gov (United States)

    Regezi, J A; Zarbo, R J; Courtney, R M; Crissman, J D

    1989-10-01

    Granular cell lesions from many different sites share similar light and electron microscopic features. Immunologically, however, these lesions do not appear to be a homogenous group. This study determines the extent of immunologic heterogeneity of granular cell lesions from a wide variety of sites in skin, mucosa, and jaw. Thirty-one granular cell lesions (26 granular cell tumors [GCT] and five other granular cell lesions) from 18 different sites were evaluated immunohistochemically for keratins, vimentin, desmin, muscle actin, ACT, HLA-DR, and S-100 protein. Paraffin-embedded sections were utilized with an avidin-biotin complex immunoperoxidase technique. Except for ameloblastomas, all lesions were negative for keratin and positive for vimentin. All lesions were negative for desmin and actin. Positive ACT reactivity was found in one of seven GCT of tongue, a colonic lesion, a nose lesion, and a granular cell ameloblastic fibroma. All lesions were positive for HLA-DR except a few in which fixation appeared inadequate. S-100 immunoreactivity was found in all lesions except the congenital epulis, a GCT of the skin of the nose, a colonic lesion, and the odontogenic tumors. The antigenic profile of GCT of skin and mucosa is consistent with Schwann cell origin. However, some GCT and other granular cell lesions appear to be derived from macrophages, epithelial cells, or other cells. The expression of HLA-DR by granular cells is believed to be unrelated to cellular origin but rather to some common immunologic function.

  19. Path duplication using GPS carrier based relative position for automated ground vehicle convoys

    Science.gov (United States)

    Travis, William E., III

    A GPS based automated convoy strategy to duplicate the path of a lead vehicle is presented in this dissertation. Laser scanners and cameras are not used; all information available comes from GPS or inertial systems. An algorithm is detailed that uses GPS carrier phase measurements to determine relative position between two moving ground vehicles. Error analysis shows the accuracy is centimeter level. It is shown that the time to the first solution fix is dependent upon initial relative position accuracy, and that near instantaneous fixes can be realized if that accuracy is less than 20 centimeters. The relative positioning algorithm is then augmented with inertial measurement units to dead reckon through brief outages. Performance analysis of automotive and tactical grade units shows the twenty centimeter threshold can be maintained for only a few seconds with the automotive grade unit and for 14 seconds with the tactical unit. Next, techniques to determine odometry information in vector form are discussed. Three methods are outlined: dead reckoning of inertial sensors, time differencing GPS carrier measurements to determine change in platform position, and aiding the time differenced carrier measurements with inertial measurements. Partial integration of a tactical grade inertial measurement unit provided the lowest error drift for the scenarios investigated, but the time differenced carrier phase approach provided the most cost feasible approach with similar accuracy. Finally, the relative position and odometry algorithms are used to generate a reference by which an automated following vehicle can replicate a lead vehicle's path of travel. The first method presented uses only the relative position information to determine a relative angle to the leader. Using the relative angle as a heading reference for a steering control causes the follower to drive at the lead vehicle, thereby creating a towing effect on the follower when both vehicles are in motion. Effective

  20. MRI of the stener lesion

    International Nuclear Information System (INIS)

    Haramati, N.; Hiller, N.; Dowdle, J.; Jacobson, M.; Barax, C.N.; Lieberfarb, R.I.; Lester, B.; Kulick, R.G.

    1995-01-01

    Six cadaver thumbs had ulnar collateral ligament (UCL) tears created surgically. MR examinations (2D STIR and 3D GRASS) were performed identically on all specimens both before displacement (non-Stener) and after displacement (Stener lesion) of the UCL. The MR images were then randomly numbered. Each image was evaluated separately in blinded fashion by four musculoskeletal radiologists for the presence or absence of a Stener lesion. Each radiologist reinterpreted the images after an interval of several days. The interpretation was based on previously published criteria for Stener lesion diagnosis by MR. The sensitivity of GRASS ranged from 0.17 to 0.67 with the most experienced reader scoring the lowest. The specificity of GRASS ranged from 0.33 to 1.0 (most experienced reader 0.67, 0.83). STIR had a sensitivity of 0.00-0.17 and a specificity of 0.53-0.83. The K values for inter- and intraobserver agreement were measured. The intraobserver K for GRASS was 0.27-0.75 (most experienced reader 0.75). 2D imaging is probably inadequate for the evaluation of Stener lesions. The most likely reason is that the STIR slice thickness of 3 mm limits resolution of small UCLs. The poor sensitivity and specificity of GRASS as well as poor interobserver agreement suggest that MR may not be sufficiently accurate for Stener lesion evaluation. (orig./MG)

  1. A Police and Insurance Joint Management System Based on High Precision BDS/GPS Positioning

    Directory of Open Access Journals (Sweden)

    Wenwei Zuo

    2018-01-01

    Full Text Available Car ownership in China reached 194 million vehicles at the end of 2016. The traffic congestion index (TCI exceeds 2.0 during rush hour in some cities. Inefficient processing for minor traffic accidents is considered to be one of the leading causes for road traffic jams. Meanwhile, the process after an accident is quite troublesome. The main reason is that it is almost always impossible to get the complete chain of evidence when the accident happens. Accordingly, a police and insurance joint management system is developed which is based on high precision BeiDou Navigation Satellite System (BDS/Global Positioning System (GPS positioning to process traffic accidents. First of all, an intelligent vehicle rearview mirror terminal is developed. The terminal applies a commonly used consumer electronic device with single frequency navigation. Based on the high precision BDS/GPS positioning algorithm, its accuracy can reach sub-meter level in the urban areas. More specifically, a kernel driver is built to realize the high precision positioning algorithm in an Android HAL layer. Thus the third-party application developers can call the general location Application Programming Interface (API of the original standard Global Navigation Satellite System (GNSS to get high precision positioning results. Therefore, the terminal can provide lane level positioning service for car users. Next, a remote traffic accident processing platform is built to provide big data analysis and management. According to the big data analysis of information collected by BDS high precision intelligent sense service, vehicle behaviors can be obtained. The platform can also automatically match and screen the data that uploads after an accident to achieve accurate reproduction of the scene. Thus, it helps traffic police and insurance personnel to complete remote responsibility identification and survey for the accident. Thirdly, a rapid processing flow is established in this article to

  2. A Police and Insurance Joint Management System Based on High Precision BDS/GPS Positioning.

    Science.gov (United States)

    Zuo, Wenwei; Guo, Chi; Liu, Jingnan; Peng, Xuan; Yang, Min

    2018-01-10

    Car ownership in China reached 194 million vehicles at the end of 2016. The traffic congestion index (TCI) exceeds 2.0 during rush hour in some cities. Inefficient processing for minor traffic accidents is considered to be one of the leading causes for road traffic jams. Meanwhile, the process after an accident is quite troublesome. The main reason is that it is almost always impossible to get the complete chain of evidence when the accident happens. Accordingly, a police and insurance joint management system is developed which is based on high precision BeiDou Navigation Satellite System (BDS)/Global Positioning System (GPS) positioning to process traffic accidents. First of all, an intelligent vehicle rearview mirror terminal is developed. The terminal applies a commonly used consumer electronic device with single frequency navigation. Based on the high precision BDS/GPS positioning algorithm, its accuracy can reach sub-meter level in the urban areas. More specifically, a kernel driver is built to realize the high precision positioning algorithm in an Android HAL layer. Thus the third-party application developers can call the general location Application Programming Interface (API) of the original standard Global Navigation Satellite System (GNSS) to get high precision positioning results. Therefore, the terminal can provide lane level positioning service for car users. Next, a remote traffic accident processing platform is built to provide big data analysis and management. According to the big data analysis of information collected by BDS high precision intelligent sense service, vehicle behaviors can be obtained. The platform can also automatically match and screen the data that uploads after an accident to achieve accurate reproduction of the scene. Thus, it helps traffic police and insurance personnel to complete remote responsibility identification and survey for the accident. Thirdly, a rapid processing flow is established in this article to meet the

  3. POSITIVE PSYCHOLOGY AND ITS ENEMIES: A REPLY BASED ON SCIENTIFIC EVIDENCE

    Directory of Open Access Journals (Sweden)

    Carmelo Vázquez

    2013-05-01

    Full Text Available Positive psychology has been the subject of passionate attacks. Its novelty, its scientific scope, its intentions and even the honesty of its followers have been questioned. Furthermore, by extension, the concern of psychology on a whole with human well-being has been placed in doubt. In this review, we offer an answer to some disproportionate criticism and make an overview of the existing overwhelming evidence derived from the active, robust research agenda on positive emotions and cognitions (e.g., optimism and their relationship to health and psychological wellness. Psychology cannot ignore a growing general movement in social sciences and in political and economic discussion that places psychological well-being in the legitimate focus of attention. In this regard, positive psychology is contributing, with the best standard tools psychological research, to articulate and support a good part of the research in and promotion of those crucial issues. Finally, it is argued that, based on a true and respectful academic dialogue, psychology must inevitably and fluently integrate the focus on positive functioning for a more inclusive explanation of human nature.

  4. A New Three-Dimensional Indoor Positioning Mechanism Based on Wireless LAN

    Directory of Open Access Journals (Sweden)

    Jiujun Cheng

    2014-01-01

    Full Text Available The researches on two-dimensional indoor positioning based on wireless LAN and the location fingerprint methods have become mature, but in the actual indoor positioning situation, users are also concerned about the height where they stand. Due to the expansion of the range of three-dimensional indoor positioning, more features must be needed to describe the location fingerprint. Directly using a machine learning algorithm will result in the reduced ability of classification. To solve this problem, in this paper, a “divide and conquer” strategy is adopted; that is, first through k-medoids algorithm the three-dimensional location space is clustered into a number of service areas, and then a multicategory SVM with less features is created for each service area for further positioning. Our experiment shows that the error distance resolution of the approach with k-medoids algorithm and multicategory SVM is higher than that of the approach only with SVM, and the former can effectively decrease the “crazy prediction.”

  5. Targeting Sindbis virus-based vectors to Fc receptor-positive cell types

    International Nuclear Information System (INIS)

    Klimstra, William B.; Williams, Jacqueline C.; Ryman, Kate D.; Heidner, Hans W.

    2005-01-01

    Some viruses display enhanced infection for Fc receptor (FcR)-positive cell types when complexed with virus-specific immunoglobulin (Ig). This process has been termed antibody-dependent enhancement of viral infection (ADE). We reasoned that the mechanism of ADE could be exploited and adapted to target alphavirus-based vectors to FcR-positive cell types. Towards this goal, recombinant Sindbis viruses were constructed that express 1 to 4 immunoglobulin-binding domains of protein L (PpL) as N-terminal extensions of the E2 glycoprotein. PpL is a bacterial protein that binds the variable region of antibody kappa light chains from a range of mammalian species. The recombinant viruses incorporated PpL/E2 fusion proteins into the virion structure and recapitulated the species-specific Ig-binding phenotypes of native PpL. Virions reacted with non-immune serum or purified IgG displayed enhanced binding and ADE for several species-matched FcR-positive murine and human cell lines. ADE required virus expression of a functional PpL Ig-binding domain, and appeared to be FcγR-mediated. Specifically, ADE did not occur with FcγR-negative cells, did not require active complement proteins, and did not occur on FcγR-positive murine cell lines when virions were bound by murine IgG-derived F(ab') 2 fragments

  6. Compassion-based emotion regulation up-regulates experienced positive affect and associated neural networks

    Science.gov (United States)

    Singer, Tania

    2015-01-01

    Emotion regulation research has primarily focused on techniques that attenuate or modulate the impact of emotional stimuli. Recent evidence suggests that this mode regulation can be problematic in the context of regulation of emotion elicited by the suffering of others, resulting in reduced emotional connectedness. Here, we investigated the effects of an alternative emotion regulation technique based on the up-regulation of positive affect via Compassion-meditation on experiential and neural affective responses to depictions of individuals in distress, and compared these with the established emotion regulation strategy of Reappraisal. Using fMRI, we scanned 15 expert practitioners of Compassion-meditation either passively viewing, or using Compassion-meditation or Reappraisal to modulate their emotional reactions to film clips depicting people in distress. Both strategies effectively, but differentially regulated experienced affect, with Compassion primarily increasing positive and Reappraisal primarily decreasing negative affect. Imaging results showed that Compassion, relative to both passive-viewing and Reappraisal increased activation in regions involved in affiliation, positive affect and reward processing including ventral striatum and medial orbitfrontal cortex. This network was shown to be active prior to stimulus presentation, suggesting that the regulatory mechanism of Compassion is the stimulus-independent endogenous generation of positive affect. PMID:25698699

  7. On Position Sensorless Control for Permanent Magnet Synchronous Motor Based on a New Sliding Mode Observer

    Directory of Open Access Journals (Sweden)

    Qixin Zhu

    2014-10-01

    Full Text Available For the problems of buffeting and phase delay in traditional rotor detection in sensorless vector control of permanent magnet synchronous motor (PMSM, the Sigmoid function is proposed to replace sign function and the approach of piecewise linearization is proposed to compensate phase delay. To the problem that the output of traditional low pass filter contains high- order harmonic, two-stage filter including traditional low-pass filter and Kalman filter is proposed in this paper. Based on the output of traditional first-order low-pass filter, the Kalman filter is used to get modified back-EMF. The phase-locked loop control of rotor position is adopted to estimate motor position and speed. A Matlab/Simulink simulation model of PMSM position servo control system is established. The simulation analysis of the new sliding mode observer’s back-EMF detection, position and speed estimation, load disturbance and dynamic process are carried out respectively. Simulation results verify feasibility of the new sliding mode observer algorithm.

  8. A PID Positioning Controller with a Curve Fitting Model Based on RFID Technology

    Directory of Open Access Journals (Sweden)

    Young-Long Chen

    2013-04-01

    Full Text Available The global positioning system (GPS is an important research topic to solve outdoor positioning problems, but GPS is unable to locate objects accurately and precisely indoors. Some available systems apply ultrasound or optical tracking. This paper presents an efficient proportional-integral-derivative (PID controller with curve fitting model for mobile robot localization and position estimation which adopts passive radio frequency identification (RFID tags in a space. This scheme is based on a mobile robot carries an RFID reader module which reads the installed low-cost passive tags under the floor in a grid-like pattern. The PID controllers increase the efficiency of captured RFID tags and the curve fitting model is used to systematically identify the revolutions per minute (RPM of the motor. We control and monitor the position of the robot from a remote location through a mobile phone via Wi-Fi and Bluetooth network. Experiment results present that the number of captured RFID tags of our proposed scheme outperforms that of the previous scheme.

  9. A HISTOPATHOLOGICAL SPECTRUM OF NECK LESIONS IN A RURAL HOSPITAL

    Directory of Open Access Journals (Sweden)

    Shri Lakshmi Surapaneni

    2016-07-01

    Full Text Available BACKGROUND A multitude of lesions occur in the neck and patients come to hospital on account of morbidity associated with these lesions. Therefore a histopathological study of the spectrum of neck lesions was undertaken. MATERIALS AND METHODS All histologically diagnosed lesions of the neck from January 2014 to December 2015 were noted. Details of gender, age, location and diagnosis were recorded. The lesions were classified based on anatomic location, gross and histological features and clinically. Clinically, lesions were classified as congenital, inflammatory/infective and neoplastic. Incidence of age, gender and location of different lesions was calculated using percentage, and median. The findings were compared with other studies. RESULTS A total of 140 neck lesions were included in the current study. Neck lesions were predominant in females with 94 cases. The median age group involved was the 21-30 group. Anterior neck lesions were more common. Anterior midline lesions were 74 and mostly thyroid and thyroglossal duct origin. Lesions of the lymph node were greater in the posterior triangle. 122 lesions were solid and 18 were cystic. Histologically, there were 64 thyroid gland lesions, 40 lymph node lesions, 13 soft tissue tumours, 8 salivary lesions, 10 thyroglossal cysts and 5 skin/adnexal lesions. Clinically, congenital/developmental lesions were 11, inflammatory/infective lesions were 68 and neoplastic lesions were 61. Of the neoplastic lesions, 17 were malignant. CONCLUSION Non-neoplastic lesions of the neck were common in our study in accordance with findings in other studies. The most common malignancy was Papillary carcinoma of thyroid.

  10. ACPA-Negative RA Consists of Two Genetically Distinct Subsets Based on RF Positivity in Japanese

    Science.gov (United States)

    Terao, Chikashi; Ohmura, Koichiro; Ikari, Katsunori; Kochi, Yuta; Maruya, Etsuko; Katayama, Masaki; Yurugi, Kimiko; Shimada, Kota; Murasawa, Akira; Honjo, Shigeru; Takasugi, Kiyoshi; Matsuo, Keitaro; Tajima, Kazuo; Suzuki, Akari; Yamamoto, Kazuhiko; Momohara, Shigeki; Yamanaka, Hisashi; Yamada, Ryo; Saji, Hiroo; Matsuda, Fumihiko; Mimori, Tsuneyo

    2012-01-01

    HLA-DRB1, especially the shared epitope (SE), is strongly associated with rheumatoid arthritis (RA). However, recent studies have shown that SE is at most weakly associated with RA without anti-citrullinated peptide/protein antibody (ACPA). We have recently reported that ACPA-negative RA is associated with specific HLA-DRB1 alleles and diplotypes. Here, we attempted to detect genetically different subsets of ACPA-negative RA by classifying ACPA-negative RA patients into two groups based on their positivity for rheumatoid factor (RF). HLA-DRB1 genotyping data for totally 954 ACPA-negative RA patients and 2,008 healthy individuals in two independent sets were used. HLA-DRB1 allele and diplotype frequencies were compared among the ACPA-negative RF-positive RA patients, ACPA-negative RF-negative RA patients, and controls in each set. Combined results were also analyzed. A similar analysis was performed in 685 ACPA-positive RA patients classified according to their RF positivity. As a result, HLA-DRB1*04:05 and *09:01 showed strong associations with ACPA-negative RF-positive RA in the combined analysis (p = 8.8×10−6 and 0.0011, OR: 1.57 (1.28–1.91) and 1.37 (1.13–1.65), respectively). We also found that HLA-DR14 and the HLA-DR8 homozygote were associated with ACPA-negative RF-negative RA (p = 0.00022 and 0.00013, OR: 1.52 (1.21–1.89) and 3.08 (1.68–5.64), respectively). These association tendencies were found in each set. On the contrary, we could not detect any significant differences between ACPA-positive RA subsets. As a conclusion, ACPA-negative RA includes two genetically distinct subsets according to RF positivity in Japan, which display different associations with HLA-DRB1. ACPA-negative RF-positive RA is strongly associated with HLA-DRB1*04:05 and *09:01. ACPA-negative RF-negative RA is associated with DR14 and the HLA-DR8 homozygote. PMID:22792215

  11. Restoring the lattice of Si-based atom probe reconstructions for enhanced information on dopant positioning

    International Nuclear Information System (INIS)

    Breen, Andrew J.; Moody, Michael P.; Ceguerra, Anna V.; Gault, Baptiste; Araullo-Peters, Vicente J.; Ringer, Simon P.

    2015-01-01

    The following manuscript presents a novel approach for creating lattice based models of Sb-doped Si directly from atom probe reconstructions for the purposes of improving information on dopant positioning and directly informing quantum mechanics based materials modeling approaches. Sophisticated crystallographic analysis techniques are used to detect latent crystal structure within the atom probe reconstructions with unprecedented accuracy. A distortion correction algorithm is then developed to precisely calibrate the detected crystal structure to the theoretically known diamond cubic lattice. The reconstructed atoms are then positioned on their most likely lattice positions. Simulations are then used to determine the accuracy of such an approach and show that improvements to short-range order measurements are possible for noise levels and detector efficiencies comparable with experimentally collected atom probe data. - Highlights: • Atom probe crystallography techniques detect crystal structure within doped Si. • A crystallographic distortion correction algorithm is proposed. • A novel lattice rectification procedure, applicable to doped Si, is proposed. • Lattice rectification is found to improve measurements in short-range order.

  12. Restoring the lattice of Si-based atom probe reconstructions for enhanced information on dopant positioning

    Energy Technology Data Exchange (ETDEWEB)

    Breen, Andrew J., E-mail: andrew.breen@sydney.edu.au [School of Aerospace, Mechanical and Mechatronic Engineering, The University of Sydney, NSW 2006 (Australia); The Australian Centre for Microscopy and Microanalysis, The University of Sydney, NSW 2006 (Australia); Moody, Michael P. [Department of Materials, University of Oxford, Parks Road, OX1 3PH Oxford (United Kingdom); Ceguerra, Anna V. [School of Aerospace, Mechanical and Mechatronic Engineering, The University of Sydney, NSW 2006 (Australia); The Australian Centre for Microscopy and Microanalysis, The University of Sydney, NSW 2006 (Australia); Gault, Baptiste [Department of Materials, University of Oxford, Parks Road, OX1 3PH Oxford (United Kingdom); Araullo-Peters, Vicente J. [Department of Materials Science and Engineering, University of Michigan, Ann Arbor, MI 48109-2136 (United States); Ringer, Simon P., E-mail: simon.ringer@sydney.edu.au [School of Aerospace, Mechanical and Mechatronic Engineering, The University of Sydney, NSW 2006 (Australia); The Australian Centre for Microscopy and Microanalysis, The University of Sydney, NSW 2006 (Australia)

    2015-12-15

    The following manuscript presents a novel approach for creating lattice based models of Sb-doped Si directly from atom probe reconstructions for the purposes of improving information on dopant positioning and directly informing quantum mechanics based materials modeling approaches. Sophisticated crystallographic analysis techniques are used to detect latent crystal structure within the atom probe reconstructions with unprecedented accuracy. A distortion correction algorithm is then developed to precisely calibrate the detected crystal structure to the theoretically known diamond cubic lattice. The reconstructed atoms are then positioned on their most likely lattice positions. Simulations are then used to determine the accuracy of such an approach and show that improvements to short-range order measurements are possible for noise levels and detector efficiencies comparable with experimentally collected atom probe data. - Highlights: • Atom probe crystallography techniques detect crystal structure within doped Si. • A crystallographic distortion correction algorithm is proposed. • A novel lattice rectification procedure, applicable to doped Si, is proposed. • Lattice rectification is found to improve measurements in short-range order.

  13. Markov Jump Linear Systems-Based Position Estimation for Lower Limb Exoskeletons

    Directory of Open Access Journals (Sweden)

    Samuel L. Nogueira

    2014-01-01

    Full Text Available In this paper, we deal with Markov Jump Linear Systems-based filtering applied to robotic rehabilitation. The angular positions of an impedance-controlled exoskeleton, designed to help stroke and spinal cord injured patients during walking rehabilitation, are estimated. Standard position estimate approaches adopt Kalman filters (KF to improve the performance of inertial measurement units (IMUs based on individual link configurations. Consequently, for a multi-body system, like a lower limb exoskeleton, the inertial measurements of one link (e.g., the shank are not taken into account in other link position estimation (e.g., the foot. In this paper, we propose a collective modeling of all inertial sensors attached to the exoskeleton, combining them in a Markovian estimation model in order to get the best information from each sensor. In order to demonstrate the effectiveness of our approach, simulation results regarding a set of human footsteps, with four IMUs and three encoders attached to the lower limb exoskeleton, are presented. A comparative study between the Markovian estimation system and the standard one is performed considering a wide range of parametric uncertainties.

  14. Web-Based Immersive Virtual Patient Simulators: Positive Effect on Clinical Reasoning in Medical Education.

    Science.gov (United States)

    Kleinert, Robert; Heiermann, Nadine; Plum, Patrick Sven; Wahba, Roger; Chang, De-Hua; Maus, Martin; Chon, Seung-Hun; Hoelscher, Arnulf H; Stippel, Dirk Ludger

    2015-11-17

    Clinical reasoning is based on the declarative and procedural knowledge of workflows in clinical medicine. Educational approaches such as problem-based learning or mannequin simulators support learning of procedural knowledge. Immersive patient simulators (IPSs) go one step further as they allow an illusionary immersion into a synthetic world. Students can freely navigate an avatar through a three-dimensional environment, interact with the virtual surroundings, and treat virtual patients. By playful learning with IPS, medical workflows can be repetitively trained and internalized. As there are only a few university-driven IPS with a profound amount of medical knowledge available, we developed a university-based IPS framework. Our simulator is free to use and combines a high degree of immersion with in-depth medical content. By adding disease-specific content modules, the simulator framework can be expanded depending on the curricular demands. However, these new educational tools compete with the traditional teaching It was our aim to develop an educational content module that teaches clinical and therapeutic workflows in surgical oncology. Furthermore, we wanted to examine how the use of this module affects student performance. The new module was based on the declarative and procedural learning targets of the official German medical examination regulations. The module was added to our custom-made IPS named ALICE (Artificial Learning Interface for Clinical Education). ALICE was evaluated on 62 third-year students. Students showed a high degree of motivation when using the simulator as most of them had fun using it. ALICE showed positive impact on clinical reasoning as there was a significant improvement in determining the correct therapy after using the simulator. ALICE positively impacted the rise in declarative knowledge as there was improvement in answering multiple-choice questions before and after simulator use. ALICE has a positive effect on knowledge gain and

  15. Chemical repair activity of free radical scavenger edaravone: reduction reactions with dGMP hydroxyl radical adducts and suppression of base lesions and AP sites on irradiated plasmid DNA.

    Science.gov (United States)

    Hata, Kuniki; Urushibara, Ayumi; Yamashita, Shinichi; Lin, Mingzhang; Muroya, Yusa; Shikazono, Naoya; Yokoya, Akinari; Fu, Haiying; Katsumura, Yosuke

    2015-01-01

    Reactions of edaravone (3-methyl-1-phenyl-2-pyrazolin-5-one) with deoxyguanosine monophosphate (dGMP) hydroxyl radical adducts were investigated by pulse radiolysis technique. Edaravone was found to reduce the dGMP hydroxyl radical adducts through electron transfer reactions. The rate constants of the reactions were greater than 4 × 10(8) dm(3) mol(-1) s(-1) and similar to those of the reactions of ascorbic acid, which is a representative antioxidant. Yields of single-strand breaks, base lesions, and abasic sites produced in pUC18 plasmid DNA by gamma ray irradiation in the presence of low concentrations (10-1000 μmol dm(-3)) of edaravone were also quantified, and the chemical repair activity of edaravone was estimated by a method recently developed by the authors. By comparing suppression efficiencies to the induction of each DNA lesion, it was found that base lesions and abasic sites were suppressed by the chemical repair activity of edaravone, although the suppression of single-strand breaks was not very effective. This phenomenon was attributed to the chemical repair activity of edaravone toward base lesions and abasic sites. However, the chemical repair activity of edaravone for base lesions was lower than that of ascorbic acid. © The Author 2014. Published by Oxford University Press on behalf of The Japan Radiation Research Society and Japanese Society for Radiation Oncology.

  16. The $\\mu$TPC Method: Improving the Position Resolution of Neutron Detectors Based on MPGDs

    CERN Document Server

    Pfeiffer, Dorothea; Birch, Jens; Hall-Wilton, Richard; Höglund, Carina; Hultman, Lars; Iakovidis, George; Oliveri, Eraldo; Oksanen, Esko; Ropelewski, Leszek; Thuiner, Patrik

    2015-01-01

    Due to the Helium-3 crisis, alternatives to the standard neutron detection techniques are becoming urgent. In addition, the instruments of the European Spallation Source (ESS) require advances in the state of the art of neutron detection. The instruments need detectors with excellent neutron detection efficiency, high-rate capabilities and unprecedented spatial resolution. The Macromolecular Crystallography instrument (NMX) requires a position resolution in the order of 200 um over a wide angular range of incoming neutrons. Solid converters in combination with Micro Pattern Gaseous Detectors (MPGDs) are proposed to meet the new requirements. Charged particles rising from the neutron capture have usually ranges larger than several millimetres in gas. This is apparently in contrast with the requirements for the position resolution. In this paper, we present an analysis technique, new in the field of neutron detection, based on the Time Projection Chamber (TPC) concept. Using a standard Single-GEM with the catho...

  17. The error model and experiment of measuring angular position error based on laser collimation

    Science.gov (United States)

    Cai, Yangyang; Yang, Jing; Li, Jiakun; Feng, Qibo

    2018-01-01

    Rotary axis is the reference component of rotation motion. Angular position error is the most critical factor which impair the machining precision among the six degree-of-freedom (DOF) geometric errors of rotary axis. In this paper, the measuring method of angular position error of rotary axis based on laser collimation is thoroughly researched, the error model is established and 360 ° full range measurement is realized by using the high precision servo turntable. The change of space attitude of each moving part is described accurately by the 3×3 transformation matrices and the influences of various factors on the measurement results is analyzed in detail. Experiments results show that the measurement method can achieve high measurement accuracy and large measurement range.

  18. Probabilistic inference for nucleosome positioning with MNase-based or sonicated short-read data.

    Directory of Open Access Journals (Sweden)

    Xuekui Zhang

    Full Text Available We describe a model-based method, PING, for predicting nucleosome positions in MNase-Seq and MNase- or sonicated-ChIP-Seq data. PING compares favorably to NPS and TemplateFilter in scalability, accuracy and robustness to low read density. To demonstrate that PING predictions from widely available sonicated data can have sufficient spatial resolution to be to be useful for biological inference, we use Illumina H3K4me1 ChIP-seq data to detect changes in nucleosome positioning around transcription factor binding sites due to tamoxifen stimulation, to discriminate functional and non-functional transcription factor binding sites more effectively than with enrichment profiles, and to confirm that the pioneer transcription factor Foxa2 associates with the accessible major groove of nucleosomal DNA.

  19. A novel autonomous real-time position method based on polarized light and geomagnetic field.

    Science.gov (United States)

    Wang, Yinlong; Chu, Jinkui; Zhang, Ran; Wang, Lu; Wang, Zhiwen

    2015-04-08

    Many animals exploit polarized light in order to calibrate their magnetic compasses for navigation. For example, some birds are equipped with biological magnetic and celestial compasses enabling them to migrate between the Western and Eastern Hemispheres. The Vikings' ability to derive true direction from polarized light is also widely accepted. However, their amazing navigational capabilities are still not completely clear. Inspired by birds' and Vikings' ancient navigational skills. Here we present a combined real-time position method based on the use of polarized light and geomagnetic field. The new method works independently of any artificial signal source with no accumulation of errors and can obtain the position and the orientation directly. The novel device simply consists of two polarized light sensors, a 3-axis compass and a computer. The field experiments demonstrate device performance.

  20. Evaluation of Vienna’s World Economic Position Based on Global and World City Rankings

    Directory of Open Access Journals (Sweden)

    Andrea Uszkai

    2016-12-01

    Full Text Available Metropolitan areas play a dominant role in today’s economic, social and environmental processes; therefore the scientific interest has also increased related to the global and world cities. They can be considered as key players of the world economy and a very complex competition takes place among them, which crosses the national state borders. Every city tries to reach the most favorable position and this rivalry has helped the birth of several city rankings. This paper has two important aims. Firstly, it explains the term of the world and global city based on the international literature and it is also looking for the answer, whether the Austrian capital belongs to which category. Secondly, it examines the position of Vienna in the different world and global city rankings.

  1. Cystic Lesions in Autoimmune Pancreatitis

    Directory of Open Access Journals (Sweden)

    Macarena Gompertz

    2015-11-01

    Full Text Available Autoimmune pancreatitis (AIP can be chronic or recurrent, but frequently completely reversible after steroid treatment. A cystic lesion in AIP is a rare finding, and it can mimic a pancreatic cystic neoplasm. Difficulties in an exact diagnosis interfere with treatment, and surgery cannot be avoided in some cases. We report the history of a 63-year-old male presenting with jaundice and pruritus. AIP was confirmed by imaging and elevated IgG4 blood levels, and the patient completely recovered after corticosteroid therapy. One year later, he presented with a recurrent episode of AIP with elevated IgG4 levels, accompanied by the appearance of multiple intrapancreatic cystic lesions. All but 1 of these cysts disappeared after steroid treatment, but the remaining cyst in the pancreatic head was even somewhat larger 1 year later. Pancreatoduodenectomy was finally performed. Histology showed the wall of the cystic lesion to be fibrotic; the surrounding pancreatic tissue presented fibrosis, atrophy and lymphoplasmacytic infiltration by IgG4-positive cells, without malignant elements. Our case illustrates the rare possibility that cystic lesions can be part of AIP. These pseudocysts appear in the pancreatic segments involved in the autoimmune disease and can be a consequence of the local inflammation or related to ductal strictures. Steroid treatment should be initiated, after which these cysts can completely disappear with recovery from AIP. Surgical intervention may be necessary in some exceptional cases.

  2. Analysis of web-based online services for GPS relative and precise point positioning techniques

    Directory of Open Access Journals (Sweden)

    Taylan Ocalan

    Full Text Available Nowadays, Global Positioning System (GPS has been used effectively in several engineering applications for the survey purposes by multiple disciplines. Web-based online services developed by several organizations; which are user friendly, unlimited and most of them are free; have become a significant alternative against the high-cost scientific and commercial software on achievement of post processing and analyzing the GPS data. When centimeter (cm or decimeter (dm level accuracies are desired, that can be obtained easily regarding different quality engineering applications through these services. In this paper, a test study was conducted at ISKI-CORS network; Istanbul-Turkey in order to figure out the accuracy analysis of the most used web based online services around the world (namely OPUS, AUSPOS, SCOUT, CSRS-PPP, GAPS, APPS, magicGNSS. These services use relative and precise point positioning (PPP solution approaches. In this test study, the coordinates of eight stations were estimated by using of both online services and Bernese 5.0 scientific GPS processing software from 24-hour GPS data set and then the coordinate differences between the online services and Bernese processing software were computed. From the evaluations, it was seen that the results for each individual differences were less than 10 mm regarding relative online service, and less than 20 mm regarding precise point positioning service. The accuracy analysis was gathered from these coordinate differences and standard deviations of the obtained coordinates from different techniques and then online services were compared to each other. The results show that the position accuracies obtained by associated online services provide high accurate solutions that may be used in many engineering applications and geodetic analysis.

  3. Prediction of lung tumour position based on spirometry and on abdominal displacement: Accuracy and reproducibility

    International Nuclear Information System (INIS)

    Hoisak, Jeremy D.P.; Sixel, Katharina E.; Tirona, Romeo; Cheung, Patrick C.F.; Pignol, Jean-Philippe

    2006-01-01

    Background and purpose: A simulation investigating the accuracy and reproducibility of a tumour motion prediction model over clinical time frames is presented. The model is formed from surrogate and tumour motion measurements, and used to predict the future position of the tumour from surrogate measurements alone. Patients and methods: Data were acquired from five non-small cell lung cancer patients, on 3 days. Measurements of respiratory volume by spirometry and abdominal displacement by a real-time position tracking system were acquired simultaneously with X-ray fluoroscopy measurements of superior-inferior tumour displacement. A model of tumour motion was established and used to predict future tumour position, based on surrogate input data. The calculated position was compared against true tumour motion as seen on fluoroscopy. Three different imaging strategies, pre-treatment, pre-fraction and intrafractional imaging, were employed in establishing the fitting parameters of the prediction model. The impact of each imaging strategy upon accuracy and reproducibility was quantified. Results: When establishing the predictive model using pre-treatment imaging, four of five patients exhibited poor interfractional reproducibility for either surrogate in subsequent sessions. Simulating the formulation of the predictive model prior to each fraction resulted in improved interfractional reproducibility. The accuracy of the prediction model was only improved in one of five patients when intrafractional imaging was used. Conclusions: Employing a prediction model established from measurements acquired at planning resulted in localization errors. Pre-fractional imaging improved the accuracy and reproducibility of the prediction model. Intrafractional imaging was of less value, suggesting that the accuracy limit of a surrogate-based prediction model is reached with once-daily imaging

  4. Evaluating the negative or valuing the positive? Neural mechanisms supporting feedback-based learning across development.

    Science.gov (United States)

    van Duijvenvoorde, Anna C K; Zanolie, Kiki; Rombouts, Serge A R B; Raijmakers, Maartje E J; Crone, Eveline A

    2008-09-17

    How children learn from positive and negative performance feedback lies at the foundation of successful learning and is therefore of great importance for educational practice. In this study, we used functional magnetic resonance imaging (fMRI) to examine the neural developmental changes related to feedback-based learning when performing a rule search and application task. Behavioral results from three age groups (8-9, 11-13, and 18-25 years of age) demonstrated that, compared with adults, 8- to 9-year-old children performed disproportionally more inaccurately after receiving negative feedback relative to positive feedback. Additionally, imaging data pointed toward a qualitative difference in how children and adults use performance feedback. That is, dorsolateral prefrontal cortex and superior parietal cortex were more active after negative feedback for adults, but after positive feedback for children (8-9 years of age). For 11- to 13-year-olds, these regions did not show differential feedback sensitivity, suggesting that the transition occurs around this age. Pre-supplementary motor area/anterior cingulate cortex, in contrast, was more active after negative feedback in both 11- to 13-year-olds and adults, but not 8- to 9-year-olds. Together, the current data show that cognitive control areas are differentially engaged during feedback-based learning across development. Adults engage these regions after signals of response adjustment (i.e., negative feedback). Young children engage these regions after signals of response continuation (i.e., positive feedback). The neural activation patterns found in 11- to 13-year-olds indicate a transition around this age toward an increased influence of negative feedback on performance adjustment. This is the first developmental fMRI study to compare qualitative changes in brain activation during feedback learning across distinct stages of development.

  5. A Web-Based Adolescent Positive Psychology Program in Schools: Randomized Controlled Trial.

    Science.gov (United States)

    Burckhardt, Rowan; Manicavasagar, Vijaya; Batterham, Philip J; Miller, Leonie M; Talbot, Elizabeth; Lum, Alistair

    2015-07-28

    Adolescent mental health is characterized by relatively high rates of psychiatric disorders and low levels of help-seeking behaviors. Existing mental health programs aimed at addressing these issues in adolescents have repeated inconsistent results. Such programs have generally been based on techniques derived from cognitive behavioral therapy, which may not be ideally suited to early intervention among adolescent samples. Positive psychology, which seeks to improve well-being rather than alleviate psychological symptoms, offers an alternative approach. A previous community study of adolescents found that informal engagement in an online positive psychology program for up to 6 weeks yielded significant improvements in both well-being and depression symptoms. However, this approach had not been trialed among adolescents in a structured format and within a school setting. This study examines the feasibility of an online school-based