C Roy

Hôpital Bichat - Claude-Bernard (Hôpitaux Universitaires Paris Nord Val de Seine), Lutetia Parisorum, Île-de-France, France

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Publications (181)350.41 Total impact

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    ABSTRACT: Dual-energy (DE) brings numerous significant improvements in pulmonary CT angiography (CTPA), but is associated with a 15-50% increase in radiation dose that prevents its widespread use. We hypothesize that thanks to iterative reconstruction (IR), single source DE-CTPA acquired at the same radiation dose that a single-energy examination will maintain an equivalent quantitative and qualitative image quality, allowing a more extensive use of the DE technique in the clinical routine. Fifty patients (58% men, mean age 64.8yo±16.2, mean BMI 25.6±4.5) were prospectively included and underwent single source DE-CTPA with acquisition parameters (275mA fixed tube current, 50% IR) tweaked to target a radiation dose similar to a 100kV single-energy CTPA (SE-CTPA), i.e., a DLP of 260mGycm. Thirty patients (47% men, 64.4yo±18.6, BMI 26.2±4.6) from a previous prospective study on DE-CTPA (375mA fixed tube current, reconstruction with filtered-back projection) were used as the reference group. Thirty-five consecutive patients (57% men, 65.8yo±15.5, BMI 25.7±4.4) who underwent SE-CTPA on the same scanner (automated tube current modulation, 50% IR) served as a comparison. Subjective image quality was scored by two radiologists using a 5-level scale and compared with a Kruskal-Wallis nonparametric test. Density measurements on the 65keV monochromatic reconstructions were used to calculate signal-to-noise (SNR) and contrast-to-noise (CNR) ratios that were compared using a Student's t test. Correlations between image quality, SNR, CNR and BMI were sought using a Pearson's test. p<0.05 was considered significant. All examinations were of diagnostic quality (score ≥3). In comparison with the reference DE-CTPA and the SE-CTPA protocols, the DE-IR group exhibited a non-inferior image quality (p=0.95 and p=0.21, respectively) and a significantly lower mean image noise (p<0.01 and p=0.01) thus slightly improving the SNR (p=0.09 and p=0.47) and the CNR (p=0.12 and p=0.51). There was a strong negative relationship between BMI and SNR/CNR (ρ=-0.59 and -0.55 respectively), but only a moderate negative relationship between BMI and image quality (ρ=-0.27). With iterative reconstruction, objective and subjective image quality of single source DE-CTPA are preserved even though the radiation dose is lowered to that of a single-energy examination, overcoming a major limitation of the DE technique and allowing a widespread use in the clinical routine. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.
    European journal of radiology 07/2015; DOI:10.1016/j.ejrad.2015.07.010 · 2.16 Impact Factor
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    ABSTRACT: Excess adipose tissue in obese individuals may have immunomodulating properties and pharmacokinetics consequences. Previous studies have suggested that obesity could negatively affect the response to anti-TNF-α agents, notably infliximab (IFX). We aimed to determine whether body mass index (BMI) is involved in the response to IFX in rheumatoid arthritis (RA). We retrospectively examined data for 76 RA patients receiving IFX. BMI was calculated before treatment, and change from baseline in DAS28, pain on a visual analog scale, erythrocyte sedimentation rate, C-reactive protein level, tender and swollen joint count was analysed at 6 months after treatment. The primary outcome was decrease in DAS28 ≥1.2. Secondary outcomes were good response and remission according to EULAR. At baseline, the median [interquartile range] BMI was 26.6 [22.6-30.6] kg/m2. The number of patients with normal weight, overweight and obesity was 25, 29 and 22. In multivariable analyses, IFX treated patients with lower BMI showed a more frequent DAS28 decrease ≥1.2 (25.5 [22.3-28.3] vs. 28.0 [23.2-32.5], p=0.02, odds ratio [OR] 0.88 [95% confidence interval 0.79-0.98]), EULAR good response (25.3 [21.9-27.5] vs. 27.5 [24.3-31.2], p=0.03, OR 0.87 [0.76-0.99]) and EULAR remission, although not significant (25.3 [21.9-26.4] vs. 27.5 [23.2-30.9], p=0.14, OR 0.88 [0.75-1.04]). Obesity may negatively influence the response to IFX in RA. These data could help physicians to choose biologic agents for obese RA patients.
    Clinical and experimental rheumatology 05/2015; DOI:10.1016/j.jbspin.2015.02.011 · 2.97 Impact Factor
  • Revue d Épidémiologie et de Santé Publique 05/2015; 63:S76-S77. DOI:10.1016/j.respe.2015.03.089 · 0.66 Impact Factor
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    ABSTRACT: To analyse the treatment and control of dyslipidaemia in patients at high and very high cardiovascular risk being treated for the primary prevention of cardiovascular disease (CVD) in Europe. Data were assessed from the European Study on Cardiovascular Risk Prevention and Management in Usual Daily Practice (EURIKA, ClinicalTrials.gov identifier: NCT00882336), which included a randomly sampled population of primary CVD prevention patients from 12 European countries (n = 7641). Patients' 10-year risk of CVD-related mortality was calculated using the Systematic Coronary Risk Evaluation (SCORE) algorithm, identifying 5019 patients at high cardiovascular risk (SCORE ≥5% and/or receiving lipid-lowering therapy), and 2970 patients at very high cardiovascular risk (SCORE ≥10% or with diabetes mellitus). Among high-risk individuals, 65.3% were receiving lipid-lowering therapy, and 61.3% of treated patients had uncontrolled low-density lipoprotein cholesterol (LDL-C) levels (≥2.5 mmol/L). For very-high-risk patients (uncontrolled LDL-C levels defined as ≥1.8 mmol/L) these figures were 49.5% and 82.9%, respectively. Excess 10-year risk of CVD-related mortality (according to SCORE) attributable to lack of control of dyslipidaemia was estimated to be 0.72% and 1.61% among high-risk and very-high-risk patients, respectively. Among high-risk individuals with uncontrolled LDL-C levels, only 8.7% were receiving a high-intensity statin (atorvastatin ≥40 mg/day or rosuvastatin ≥20 mg/day). Among very-high-risk patients, this figure was 8.4%. There is a considerable opportunity for improvement in rates of lipid-lowering therapy use and achievement of lipid-level targets in high-risk and very-high-risk patients being treated for primary CVD prevention in Europe.
    PLoS ONE 02/2015; 10(2):e0115270. DOI:10.1371/journal.pone.0115270 · 3.23 Impact Factor
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    ABSTRACT: OBJECTIVE Healthcare workers (HCWs), especially those caring for patients with tuberculosis (TB), are at high risk of acquiring that disease. The poor specificity of tuberculin skin testing (TST) prompted us to evaluate the effectiveness of the interferon-γ release assay (IGRA) in comparison with TST in a large prospective, multicenter, 1-year study of HCWs with occupational exposure to TB. METHODS HCWs from high-risk units at 14 university hospitals were invited to participate and underwent both TST and IGRA (first Quantiferon TB Gold-IT®, QFT-G, then T-SPOT.TB® if QFT-G was indeterminate) at baseline and after 1 year. We collected demographic characteristics, country of birth, history of TB, immunosuppression, past exposure to TB, history of BCG vaccination, results of most recent TST, job category, and duration of current function. RESULTS Among 807 HCWs enrolled, current or past TST at baseline was positive (≥15 mm) in 282 (34.9%); the IGRA was positive in 113 (14.0%) and indeterminate in 3 (0.4%). After 1 year, 594 HCWs had both an IGRA and TST (or prior TST≥15 mm) at baseline and an IGRA and TST (if indicated). The conversion rate was 2.5% (9 of 367) with TST and 7.6% (45 of 594) with IGRA, with poor agreement between the 2 tests. Using only QFT-G, conversion (9.9%) and reversion (17.8%) rates were higher for baseline QFT-G positive quantitative values <1 IU/mL. CONCLUSION TST and the IGRA yielded discordant results. The value of IGRA in addition to TST remains undetermined; the two should be jointly interpreted in decision-making (clinical trial registration NCT00797836). Infect Control Hosp Epidemiol 2015;00(0): 1-6.
    Infection Control and Hospital Epidemiology 02/2015; 36(05):1-6. DOI:10.1017/ice.2015.19 · 3.94 Impact Factor
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    ABSTRACT: Des études antérieures ont montré que la positivité des anticorps anti-CCP était prédictive d’une bonne réponse au rituximab (RTX) au cours de la polyarthrite rhumatoïde (PR). Une approche quantitative de cette hypothèse pourrait constituer une méthode de choix pour définir un sous-groupe de patients ayant le plus de chance de répondre au RTX. Nous avons donc étudié si le taux sérique des anticorps anti-CCP était prédictif de la réponse au MTX chez les patients atteints de PR.
    Revue du Rhumatisme 02/2015; 82(2). DOI:10.1016/j.rhum.2014.12.006
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    ABSTRACT: The goal of this prospective study was to compare the efficiency of two types of MRU after diuretic administration to identify the non-dilated ureter.
    12/2014; 1. DOI:10.1016/j.ejro.2014.08.001
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    ABSTRACT: Imaging plays a central role in the management of Peripheral Arterial Diseases (PAD), emphasized by the continuously increasing use of modern cross--sectional imaging and the corresponding decline of Digital Subtraction Angiography (DSA) in the diagnostic setting. Imaging is sometimes used as a screening tool in high--risk individuals. In symptomatic patients, imaging is mandatory to make an accurate positive diagnosis, grade the severity and the extent of the abnormalities, carefully choose and plan the best therapeutic option and provide adequate follow--up. Non--invasive diagnosis of PAD can be made by Doppler Ultrasonography, Magnetic Resonance Angiography (MRA) and Computed Tomography Angiography (CTA). Given the major technological breakouts over the last decade, MRA and especially CTA are nowadays mature and precise enough to properly answer all the questions raised in symptomatic patients. This review article aims at describing state--of--the--art non--invasive imaging of PAD, its involvement in the decision making for the vascular surgeon and the future trends and developments expected in the coming years.
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    ABSTRACT: La pneumatose intestinale est le reflet de pathologies diverses, allant des plus anodines aux plus graves. En imagerie, l’examen de référence est le scanner. Le type de pneumatose kystique ou linéaire ne préjuge pas de la sévérité de la maladie. Les données cliniques et biologiques doivent orienter le radiologue vers l’une ou l’autre cause, afin de ne pas mettre en jeu le pronostic vital du patient. La pneumatose kystique chronique intestinale ne doit pas être confondue avec les images gazeuses observées lors des tableaux abdominaux aigus. Elle peut être associée à un pneumopéritoine bénin qui ne nécessite pas de traitement.
    Feuillets de Radiologie 11/2014; 55(2). DOI:10.1016/j.frad.2014.10.001 · 0.05 Impact Factor
  • Feuillets de Radiologie 11/2014; 55(2). DOI:10.1016/j.frad.2014.10.003 · 0.05 Impact Factor
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    ABSTRACT: Background Quinolone resistance is a major global clinical problem. It primarily emerges in microbiota under selective pressure. Studies evaluating the incidence and risk factors for carrying quinolone-resistant bacteria in hospitalized patients treated with fluoroquinolones (FQs) are lacking.
    Journal of Antimicrobial Chemotherapy 07/2014; 69(12). DOI:10.1093/jac/dku283 · 5.44 Impact Factor
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    ABSTRACT: Aim: (i) evaluate carotid artery strain derived from speckle tracking ultrasound imaging (CAS) in subjects with coronary artery disease (CAD) and without coronary artery disease (N-CAD), (ii) compare CAS, to global aortic stiffness using carotid-femoral pulse wave velocity (c-f PWV) and to endothelial function using brachial flow-mediated dilatation (FMD) in subjects with CAD. Methods: 100 subjects were prospectively included, and classified into 2 groups: subjects with CAD (CAD, n=49), subjects N-CAD (N-CAD, n=51). The CAS on the common carotid artery using speckle-tracking ultrasound imaging (Vivid 7, General Electric) was measured. In the CAD, c-f PWV and FMD were evaluated and compared to CS. Results: Age of the population was 65±1.7 years. The proportion of males, diabetes and obesity in CAD was higher than N-CMD group (p=0.0005, p=0.0002, 0.0004 respectively). There was no significant difference in age and hypertension. In a multivariate analysis, age and CAD were the sole independent predictors of CAS (r=−0.6, p<0.0001; r=-0.5, p<0.0001 respectively). The CAS was significantly lower in CAD as compared to N-CAD (2.41% vs 4.48%, p<0.0001). In CAD group, 41% presented stable angina and 59 % acute coronary syndrome (ACS). The CAS was lower in stable angina vs ACS (1.85% vs 2.92%, p=0.02). In the CAD group, CAS was inversely correlated to c-f PWV (r=−0.7, p=0.0001), and correlated with endothelial dysfunction (r=0.45, p=0.003). Conclusion: Speckle-tracking ultrasound imaging is a non-invasive technique useful for the evaluation of local carotid artery stiffness. Carotid artery stiffness was higher in coronary artery disease. In CAD, carotid artery stiffness measured by speckle-tracking is associated with global aortic stiffness and endothelial dysfunction.
    Cardiovascular Research 07/2014; 103(suppl 1):S141. DOI:10.1093/cvr/cvu098.186 · 5.81 Impact Factor
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    ABSTRACT: Objective: Previous studies reported that anti-CCP antibody positivity predicts good response to rituximab (RTX) in rheumatoid arthritis (RA). A quantitative approach to such possibility could be a good way to detect the subset of patients most likely to respond. We investigated whether serum anti-CCP antibody titres could predict response to RTX in RA patients. Methods: We retrospectively investigated RA patients who received RTX. The primary criterion was decrease in DAS28 > 1.2 at 6 months (M6). Secondary efficacy criteria included a good response and remission according to EULAR. Predictors of response were investigated by multivariate logistic regression analysis. Results: We included 114 RA patients (81.6% female, median age 53.5 [IQR 45.7-61.2] years, median disease duration 8.5 [4.0-16.0] years). Anti-CCP antibodies were present in 93 patients (81.6%), with median anti-CCP antibody titres 583 [195-1509] U/mL. In all, 44 patients (38.6%) showed decreased DA528 > 1.2 at M6. On univariate analysis, high anti-CCP titres were associated with response rather than non-response to RTX (median 1122 [355-1755] vs. 386 [149-800] U/mL, 13= 0.0191) at M6. On multivariate regression analysis, with a cut-off of 1000 U/mL, anti-CCP antibody titres > 1000 was associated with a decrease in DA528 > 1.2 (OR 5.10 [1.97-13.2], P=0.0002); a EULAR good response (4.26 [1.52-11.95], P=0.0059); and a trend for EULAR remission (2.52 [0.78-8.12], 13= 0.1207). Conclusion: High anti-CCP antibody titres predict response to RTX in RA. This factor, easily assessed in clinical practice, can help with personalized medicine and selecting the best candidates for RTX treatment.
    Joint, bone, spine: revue du rhumatisme 07/2014; 81(5). DOI:10.1016/j.jbspin.2014.06.001 · 3.22 Impact Factor
  • 05/2014; 15 Suppl 1:i12-i33. DOI:10.1093/ehjci/jeu085
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    ABSTRACT: Thanks to a simultaneous acquisition at high and low kilovoltage, dual energy computed tomography (DECT) can achieve material-based decomposition (iodine, water, calcium, etc.) and reconstruct images at different energy levels (40 to 140keV). Post-processing uses this potential to maximise iodine detection, which elicits demonstrated added value for chest imaging in acute and chronic embolic diseases (increases the quality of the examination and identifies perfusion defects), follow-up of aortic endografts and detection of contrast uptake in oncology. In CT angiography, these unique features are taken advantage of to reduce the iodine load by more than half. This review article aims to set out the physical basis for the technology, the acquisition and post-processing protocols used, its proven advantages in chest pathologies, and to present future developments.
    04/2014; 95(11). DOI:10.1016/j.diii.2014.01.001
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    ABSTRACT: Grâce à une acquisition simultanée à haut et bas kilovoltage, la tomodensitométrie double énergie (TDE) permet de séparer les matériaux (iode, eau, calcium…) et de reconstruire des images à différents niveaux d’énergie (40 à 140 keV). Le post-traitement exploite ces possibilités et maximise la détection de l’iode, avec en imagerie thoracique un intérêt démontré dans la pathologie embolique aiguë et chronique (augmentation de la qualité de l’examen et identification des défects de perfusion), le suivi des endoprothèses aortiques et la détection des prises de contraste en oncologie. En angioscanographie, ces particularités sont mises à profit pour réduire de plus de moitié la dose d’iode injectée. Les objectifs de cette mise au point sont d’expliciter les bases physiques, protocoles d’acquisition et post-traitements utilisés en TDE, d’exposer ses avantages démontrés en pathologie thoracique et d’en présenter les développements à venir.
    04/2014; 95(11). DOI:10.1016/j.jradio.2013.10.016
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    ABSTRACT: Since the late 1980s, lung transplantation has emerged as a valid treatment option for some patients with advanced non-neoplastic lung disease. Long-term survival of lung transplant recipients, however, is lower than that of patients with other types of transplantation, because of numerous specific postoperative complications. Thanks to X-ray and CT, radiologists can guide clinicians, helped in this diagnostic approach by the time between the date of injury and date of transplantation. We will detail in this pictorial review the immediate and late surgical complications, the immunological complications, the infectious complications and other late complications.
    04/2014; 95(4). DOI:10.1016/j.diii.2013.09.005
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    ABSTRACT: La transplantation pulmonaire s’est imposée depuis la fin des années 1980 comme une option thérapeutique valable pour certains patients atteints d’une pathologie pulmonaire avancée non néoplasique. Toutefois, la survie à long terme des greffés pulmonaires reste inférieure à celle des patients ayant bénéficié d’autres types de transplantation, et ce en raison de complications postopératoires spécifiques nombreuses. Grâce au couple radiographie/scanner thoracique, le radiologue va pouvoir orienter le clinicien, en se fondant particulièrement sur le délai entre la survenue des lésions et la date de la transplantation. Seront ainsi détaillées dans cette revue iconographique les complications chirurgicales immédiates et retardées, les complications immunologiques, les complications infectieuses et les complications tardives autres.
    04/2014; DOI:10.1016/j.jradio.2013.08.003
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    Dataset: Halcox 2014
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    ABSTRACT: Elevated C-reactive protein (CRP) levels are associated with high cardiovascular risk, and might identify patients who could benefit from more carefully adapted risk factor management. We have assessed the prevalence of elevated CRP levels in patients with one or more traditional cardiovascular risk factors. Data were analysed from the European Study on Cardiovascular Risk Prevention and Management in Usual Daily Practice (EURIKA, ClinicalTrials.gov Identifier: NCT00882336), which included patients (aged >=50 years) from 12 European countries with at least one traditional cardiovascular risk factor but no history of cardiovascular disease. Analysis was also carried out on the subset of patients without diabetes mellitus who were not receiving statin therapy. In the overall population, CRP levels were positively correlated with body mass index and glycated haemoglobin levels, and were negatively correlated with high-density lipoprotein cholesterol levels. CRP levels were also higher in women, those at higher traditionally estimated cardiovascular risk and those with greater numbers of metabolic syndrome markers. Among patients without diabetes mellitus who were not receiving statin therapy, approximately 30% had CRP levels >=3 mg/L, and approximately 50% had CRP levels >=2 mg/L, including those at intermediate levels of traditionally estimated cardiovascular risk. CRP levels are elevated in a large proportion of patients with at least one cardiovascular risk factor, without diabetes mellitus who are not receiving statin therapy, suggesting a higher level of cardiovascular risk than predicted according to conventional risk estimation systems. Trial registration: ClinicalTrials.gov Identifier: NCT00882336.
    BMC Cardiovascular Disorders 02/2014; 14(1):25. DOI:10.1186/1471-2261-14-25 · 1.50 Impact Factor

Publication Stats

1k Citations
350.41 Total Impact Points

Institutions

  • 2009–2015
    • Hôpital Bichat - Claude-Bernard (Hôpitaux Universitaires Paris Nord Val de Seine)
      • Service de Rhumatologie
      Lutetia Parisorum, Île-de-France, France
    • University of Paris-Est
      La Haye-Descartes, Centre, France
  • 2008–2015
    • Paris Diderot University
      Lutetia Parisorum, Île-de-France, France
  • 2006–2015
    • Assistance Publique – Hôpitaux de Paris
      Lutetia Parisorum, Île-de-France, France
  • 1996–2014
    • University of Strasbourg
      • Faculty of Medicine
      Strasburg, Alsace, France
  • 2010
    • French Institute of Health and Medical Research
      Lutetia Parisorum, Île-de-France, France
  • 1991–2010
    • CHRU de Strasbourg
      Strasburg, Alsace, France
  • 2007–2009
    • Unité Inserm U1077
      Caen, Lower Normandy, France
  • 1992–1997
    • Hospices Civils de Lyon
      Lyons, Rhône-Alpes, France
  • 1993
    • Centre Hospitalier Universitaire de Dijon
      Dijon, Bourgogne, France
  • 1988
    • Centre Hospitalier Régional d'Orléans
      Orléans, Centre, France