A multi-center study: intra-scan and inter-scan variability of diffusion spectrum imaging.

The objective of this study was to investigate whether it is possible to pool together diffusion spectrum imaging data from four different scanners, located at three different sites. Two of the scanners had identical configuration whereas two did not. To measure the variability, we extracted three scalar maps (ADC, FA and GFA) from the DSI and utilized a region and a tract-based analysis. Additionally, a phantom study was performed to rule out some potential factors arising from the scanner performance in case some systematic bias occurred in the subject study. This work was split into three experiments: intra-scanner reproducibility, reproducibility with twin-scanner settings and reproducibility with other configurations. Overall for the intra-scanner and twin-scanner experiments, the region-based analysis coefficient of variation (CV) was in a range of 1%-4.2% and below 3% for almost every bundle for the tract-based analysis. The uncinate fasciculus showed the worst reproducibility, especially for FA and GFA values (CV 3.7-6%). For the GFA and FA maps, an ICC value of 0.7 and above is observed in almost all the regions/tracts. Looking at the last experiment, it was found that there is a very high similarity of the outcomes from the two scanners with identical setting. However, this was not the case for the two other imagers. Given the fact that the overall variation in our study is low for the imagers with identical settings, our findings support the feasibility of cross-site pooling of DSI data from identical scanners.

Complicated intra-abdominal infections in Europe: preliminary data from the first three months of the CIAO Study.

The CIAO Study is a multicenter observational study currently underway in 66 European medical institutions over the course of a six-month study period (January-June 2012).This preliminary report overviews the findings of the first half of the study, which includes all data from the first three months of the six-month study period.Patients with either community-acquired or healthcare-associated complicated intra-abdominal infections (IAIs) were included in the study.912 patients with a mean age of 54.4 years (range 4-98) were enrolled in the study during the first three-month period. 47.7% of the patients were women and 52.3% were men. Among these patients, 83.3% were affected by community-acquired IAIs while the remaining 16.7% presented with healthcare-associated infections. Intraperitoneal specimens were collected from 64.2% of the enrolled patients, and from these samples, 825 microorganisms were collectively identified.The overall mortality rate was 6.4% (58/912). According to univariate statistical analysis of the data, critical clinical condition of the patient upon hospital admission (defined by severe sepsis and septic shock) as well as healthcare-associated infections, non-appendicular origin, generalized peritonitis, and serious comorbidities such as malignancy and severe cardiovascular disease were all significant risk factors for patient mortality.White Blood Cell counts (WBCs) greater than 12,000 or less than 4,000 and core body temperatures exceeding 38°C or less than 36°C by the third post-operative day were statistically significant indicators of patient mortality.

Intravitreal ranibizumab for age-related macular degeneration - optical coherence tomography guided retreatment intervals and their intra- and inter-individual variability

PURPOSE:To determine whether the need for retreatment after an initial loading phase of 3 monthly intravitreal injections of ranibizumab shows an intra-individual regular rhythm and to what degree it varies between different patients.SETTING:Prospective mono-centre cohort study.METHODS:Prospective study with 42 patients with exudative age-related macular degeneration (AMD), treatment na?ve, giving informed consent. Loading dose of 3 monthly doses of ranibizumab (0,5mg), followed by a 12 months pro re nata (PRN) regimen according to early exudative signs on spectral domain optical coherence tomography (HD-OCT Cirrus Zeiss?, cube 512x126). The follow-up visits were intensified (week 4, 5, 6, 7, 8, 10, 12, 14, 16, 20, 24, etc after each injection) in order to detect exudative recurrences early, and injection followed within 3 days in cases of subretinal fluid, or intraretinal cysts, or central thickness increase of >50?m. Intervals were calculated between injections and the following recurrence was calculated for the 12 month follow-up with PRN treatment. Variability was expressed as standard deviation (SD). RESULTS Visual acuity (VA) improved from a mean ETDRS letter score of 61.6 (SD 10.8) at baseline to 68.0 (SD 10.2, +6.4 letters) at month 3 and increased further to 74.7 (SD 9.0, +13.1 letters from baseline) at month 12. The 15 patients who have completed the study by October 2010 showed maintenance of the VA improvement. Retinal thickness of the central foveal subfield improved from a mean value of 366?m(baseline) to 253?m(month 3), well maintained thereafter. Mean number of injections was 8.8 (SD 3.5) per 12 months of follow-up (after 3 loading doses), ranging from 0 to 12, with mean individual treatment-recurrence intervals ranging from 28 to >365 days (mean 58 days). Intraindividual variability of treatment-recurrence intervals, measured as SD of the individual intervals, was 7.1days as a mean value(range 1.7 ? 22.6 days) for the 33 patients with more than 1 injection during follow-up. SD was higher for longer intervals of an individual patient. It ranged within 20% of the mean intra-individual interval for 30 patients(91%) and within 15% for 21 patients(64%). The first interval was within 1 week of the mean intra-individual interval in 64% of patients and within 2 weeks in 89% of patients.CONCLUSIONS:The majority of AMD patients showed a relatively stable rhythm for PRN injections of intravitreal ranibizumab after initial loading phase, associated with excellent functional and anatomical results. The initial interval between last loading dose and first recurrence may have a predictive value for further need of treatment, therefore potentially facilitating follow-up and patient care.

Role of intra-operative duplex ultrasound in living renal donor transplantation

Objective: The treatment of choice in end-stage renal disease is¦transplantation.¦Hemodynamic disturbances can evoke graft loss, while early ultrasound¦identification of vascular problems improves outcome. The primary endpoint¦of this study was to identify differences in post-op complications with and¦without systematic, intraoperative Doppler ultrasound use. A secondary aim¦was to find a predictive resistance index limit which would show where surgical¦reintervention was necessary.¦Methods: Between Jan 2000 and Dec 2010, 108 renal transplants were¦performed from living donors at our institution. In group 1 (n = 67),¦intra-operative duplex ultrasound and intra-parenchymatous resistance index¦measurements assessed patients, while in group 2 (n = 41), no ultrasound was¦performed.¦Results. There were no inter-group differences in the overall post-op¦complication rate or in benefit to graft or patient survival with Doppler use,¦however, significantly more vascular complications (10% vs. 0%, p = 0·02) and¦more acute rejections (37% vs. 10%) occurred in group 2 than in group 1,¦respectively. When the resistance index was <0·5 intra-operatively, immediate¦surgical revision was undertaken to raise the index >0·6.¦Results: There were no inter-group differences in the overall post-op¦complication rate or in benefit to graft or patient survival with Doppler use,¦however, significantly more vascular complications (10% vs. 0%, p = 0·02) and¦more acute rejections (37% vs. 10%) occurred in group 2 than in group 1,¦respectively. When the resistance index was <0·5 intra-operatively, immediate¦surgical revision was undertaken to raise the index >0·6.¦Conclusion: This is the first report demonstrating benefits of systematic¦intraoperative Doppler ultrasound on post-operative complications in renal¦transplantation from living donors. Our results support surgical revision with a¦resistance index <0·5.

Extreme prematurity and intra uterine growth restriction effects in brain network topology at school age

Higher risk for long-term behavioral and emotional sequelae, with attentional problems (with or without hyperactivity) is now becoming one of the hallmarks of extreme premature (EP) birth and birth after pregancy conditions leading to poor intra uterine growth restriction (IUGR) [1,2]. However, little is know so far about the neurostructural basis of these complexe brain functional abnormalities that seem to have their origins in early critical periods of brain development. The development of cortical axonal pathways happens in a series of sequential events. The preterm phase (24-36 post conecptional weeks PCW) is known for being crucial for growth of the thalamocortical fiber bundles as well as for the development of long projectional, commisural and projectional fibers [3]. Is it logical to expect, thus, that being exposed to altered intrauterine environment (altered nutrition) or to extrauterine environment earlier that expected, lead to alterations in the structural organization and, consequently, alter the underlying white matter (WM) structure. Understanding rate and variability of normal brain development, and detect differences from typical development may offer insight into the neurodevelopmental anomalies that can be imaged at later stages. Due to its unique ability to non-invasively visualize and quantify in vivo white matter tracts in the brain, in this study we used diffusion MRI (dMRI) tractography to derive brain graphs [4,5,6]. This relatively simple way of modeling the brain enable us to use graph theory to study topological properties of brain graphs in order to study the effects of EP and IUGR on childrens brain connectivity at age 6 years old.

Is intracerebral hemorrhage a time-dependent phenomenon after successful combined intravenous and intra-arterial therapy?

BACKGROUND AND PURPOSE: Onset-to-reperfusion time (ORT) has recently emerged as an essential prognostic factor in acute ischemic stroke therapy. Although favorable outcome is associated with reduced ORT, it remains unclear whether intracranial bleeding depends on ORT. We therefore sought to determine whether ORT influenced the risk and volume of intracerebral hemorrhage (ICH) after combined intravenous and intra-arterial therapy. METHODS: Based on our prospective registry, we included 157 consecutive acute ischemic stroke patients successfully recanalized with combined intravenous and intra-arterial therapy between April 2007 and October 2011. Primary outcome was any ICH within 24 hours posttreatment. Secondary outcomes included occurrence of symptomatic ICH (sICH) and ICH volume measured with the ABC/2. RESULTS: Any ICH occurred in 26% of the study sample (n=33). sICH occurred in 5.5% (n=7). Median ICH volume was 0.8 mL. ORT was increased in patients with ICH (median=260 minutes; interquartile range=230-306) compared with patients without ICH (median=226 minutes; interquartile range=200-281; P=0.008). In the setting of sICH, ORT reached a median of 300 minutes (interquartile range=276-401; P=0.004). The difference remained significant after adjustment for potential confounding factors (adjusted P=0.045 for ICH; adjusted P=0.002 for sICH). There was no correlation between ICH volume and ORT (r=0.16; P=0.33). CONCLUSIONS: ORT influences the rate but not the volume of ICH and appears to be a critical predictor of symptomatic hemorrhage after successful combined intravenous and intra-arterial therapy. To minimize the risk of bleeding, revascularization should be achieved within 4.5 hours of stroke onset.

Hypertension and intra-operative incidents : a multicentre study of 125000 surgical procedures in Swiss hospitals

Rapport de synthèse : Bien que les complications sévères de l'anesthésie soient actuellement rares, des informations contradictoires existent à propos du rôle et de l'importance de l'hypertension artérielle chronique sur la survenue de complications en cours d'anesthésie. En raison de la prévalence élevée de l'hypertension artérielle dans la population et du grand nombre d'anesthésies effectuées, il est important de clarifier cette relation. Le but de l'étude était d'évaluer si les personnes hypertendues étaient à risque accru de présenter des complications lors d'anesthésies à partir de données collectées de routine lors d'anesthésies usuelles réalisées en Suisse. Nous avons utilisé les données figurant dans le registre ADS (Anesthésie Données Suisse) correspondant à des anesthésies, générales ou locorégionales, réalisées pour chirurgie élective chez des adultes, entre 2000 et 2004 dans 24 hôpitaux suisses. L'attention était portée principalement sur les incidents cardio-vasculaires, mais les autres incidents relevés de routine ont aussi été évalués. La présence d'une hypertension artérielle chronique était définie par la présence d'un traitement antihypertenseur ou par l'anamnèse d'une hypertension artérielle, combinée à la mesure d'une pression artérielle élevée (systolique >160 mm Hg ou diastolique >100 mm Hg) lors de l'examen préopératoire de l'anesthésiste. Les incidents relevés en cours d'anesthésie ont été définis a priori et sont enregistrés de routine sur la feuille d'anesthésie et reportés dans une base de données centralisée. En raison de la structure des données, des analyses hiérarchiques ont été effectuées incluant des variables individuelles (niveau 1), liées aux groupes d'interventions chirurgicales (niveau 2) et à l'hôpital (niveau 3). Parmi les 124 939 interventions, 27 881 (22%) concernaient des patients connus pour une hypertension artérielle chronique. Au moins un incident est survenu dans 16,8% des interventions (95% Cl 16,6 -17,0%). Chez 7 549 patients, au moins un incident cardio- vasculaire est survenu, soit dans 6% des anesthésies (95% Cl 5.9-6.2%). Le rapport des cotes (odds ratio) moyen ajusté pour les incidents cardio-vasculaires chez les patients hypertendus était de 1.38 (95% Cl 1.27-1.49), indiquant une augmentation du risque chez les patients hypertendus. Cependant, l'hypertension n'était pas liée à un risque augmenté de survenue d'un autre incident. Les rapports de cotes ajustés de la survenue d'une complication cardiovasculaire en présence d'une hypertension artérielle variaient selon les hôpitaux entre 0.41 et 2.25. Ainsi, cette étude confirme la présence d'un risque accru de survenue d'une complication cardiovasculaire chez un patient hypertendu lors d'une anesthésie pour chirurgie élective. Il s'agissait le plus souvent d'une arythmie ou d'une perturbation hémodynamique. Cette augmentation du risque proche de 40% a aussi été trouvée dans une revue systématique avec méta-analyse. L'hétérogénéité des institutions -qui persiste même en tenant compte des ajustements pour le type d'intervention chirurgicale et des variables individuelles (case-mix) - suggère des différences de pratique de l'anesthésie selon l'hôpital.

Experimental evidence that intra-specific competition in seagrass meadows reduces reproductive potential in the sea urchin Paracentrotus lividus (Lamarck)

To better understand the biological controls that regulate sea urchin dynamics, we studied the effects of potential inter- and intra-specific competition for food on several biological variables of the main sea urchin in the Mediterranean (Paracentrotus lividus). We carried out a caging experiment in which we manipulated sea urchin density (natural vs. high density) and herbivorous fish (Sarpa salpa) accessibility (free access vs. exclusion) in a Posidonia oceanica meadow. No evidence of competition between fish and urchins was detected. Neither density-dependent mortality nor changes in the somatic variables were found; however, we detected that intra-specific competition affected the reproductive potential of P. lividus. The gonad index of urchins at high population densities was ca. 30% lower than that of urchins at natural densities. As a spawning event had just occurred when urchins were collected, these differences probably reflect differences in reserve content, which may compromise the following reproductive period and decrease survival in the long term, as the gonads are also used as storage organs. For the time period studied, mortality rates appeared to be independent of local densities. The results indicate that a long-term negative feedback mechanism appears to take place in P. lividus in response to increased population density.

Traitement des tumeurs maligne du foie par radiologie interventionnelle: techniques intra-artérielles [Interventional radiology procedures for malignancies of the liver treatment: Intraarterial procedures].

Intraarterial procedures such as chemoembolization and radioembolization aim for the palliative treatment of advanced hepatocellular carcinoma (stage BCLC B and C with tumoral portal thrombosis). The combination of hepatic intraarterial chemotherapy and systemic chemotherapy can increase the probability of curing colorectal cancer with hepatic metastases not immediately accessible to surgical treatment or percutaneous ablation.