Comparative Evaluation of Prognostic Value of Arterial Spin Labelling and Dynamic Susceptibility Contrast-Enhanced MR Imaging in High-Grade Gliomas

Background and Purpose: Several studies have examined the predictive value of dynamic susceptibility contrast-enhanced (DSC) imaging and arterial spin labelling (ASL) in relation to histological grade, but less is known about their significance in terms of disease prognosis. Since ASL is gaining in importance, the purpose of this study was to evaluate the predictive value of both MRI techniques in assessing time to recurrence (TTR) in patients with high-grade gliomas and to examine for any interchangeability between them. Materials and Methods: Sixty-nine cases of WHO Grade 3–4 gliomas underwent both DSC and ASL MRI. Normalized ASL and DSC-based perfusion maps were analysed yielding mean and maximum values for relative cerebral blood volume (rCBV), relative cerebral blood flow (rCBF), leakage and ASL blood flow estimates. Maps were compared regarding the spatial distribution of maximum DSC-rCBV, DSC-rCBF and ASL-rCBF. Wilcoxon test and Bland Altman plot analysis were applied to compare DSC-rCBF and ASL-rCBF. Spearman’s rank correlation coefficient was determined for all perfusion parameters. Receiver operating characteristic curve analysis was applied to define the optimal cut-off of perfusion values for TTR. Survival curves were calculated by using the Kaplan-Meier method with log-rank test. Results: The median values of ASL-rCBF, DSC-rCBF, and DSC-rCBV were 5.3, 6.9, and 8.0, respectively. Spearman’s rank correlation showed significant correlation between the DSC parameters. There was neither significant correlation nor difference between ASL-rCBF and DSC-rCBF. Proportional bias was demonstrated in the Bland-Altman plot analysis of ASL-rCBF and DSC-rCBF values. In ROC analysis, rCBV outperformed other parameters as prognostic factor (area under curve (AUC) = 0.71). DSC-rCBF was slightly superior to ASLrCBF (AUC = 0.59 vs. 0.58). The combination of rCBV and ASL-rCBF (AUC = 0.71) was even to standalone rCBV. The best predictive value was achieved by combination of DSC-rCBV, DSC-rCBF, leakage and ASL-rCBF (AUC = 0.74). Unlikely to DSC-rCBV, DSC- and ASL-based rCBF parameters demonstrated moderate sensitivity and specificity for tumour recurrence with no statistically significant prognostic values in the survival analysis. Conclusions: There was neither correlation nor interchangeability between the DSC-rCBF and ASL-rCBF estimations, which demonstrated comparable, though not significant prognostic value for TTR. On contrary, rCBV measurements provided the best available sensitivity and specificity to predict tumour recurrence and survival time in these patients. Combination of DSC- and ASL-perfusion metrics showed encouraging results for increasing the prognostic value of each ”standalone” technique.Einleitung: Verschiedene Studien haben sich mit dem diagnostischen Wert der dynamischen kontrastmittel-unterstützten Suszeptibilitäts-gewichteten (dynamic susceptibility contrast enhanced, DSC) Bildgebung und der arteriellen Spinmarkierung (Arterial Spin Labelling, ASL) bei Gliomen in Bezug auf ihre histologische Klassifikation befasst. Über den prädiktiven Wert dieser Magnetresonanztomographie-Techniken hinsichtlich der Prognose der Patienten ist bisher jedoch weniger bekannt. Da die kontrastmittelfreie ASLBildgebung immer weiter an Bedeutung zunimmt, ist der Zweck dieser Studie, einerseits den prädiktiven Wert beider bildgebenden Methoden hinsichtlich der Vorhersage der rezidivfreien Überlebenszeit sowie andererseits deren Austauschbarkeit bei Patienten mit höhergradigen Gliomen zu untersuchen. Material und Methoden: Insgesamt lagen von 69 WHO Grad 3-4 Gliomen die Rohdaten der DSC- und der ASL-Bildgebung vor. Die DSC- und ASL-basierten Perfusionskarten wurden ausgewertet und jeweils die mittleren und maximalen Werte des relativen zerebralen Blutvolumens (relative cerebral blood volume, rCBV), des relativen zerebralen Blutflusses (relative cerebral blood flow, rCBF) und des Kontrastmittel-Austritts in den Extravasalraum (leakage) erfasst. Die Perfusionskarten wurden hinsichtlich der räumlichen Verteilung der maximalen Perfusionswerte innerhalb des Tumors miteinander verglichen. Mittels Wilcoxon-Mann-Whitney-Test und Bland-Altman-Diagramm wurden DSC und ASL hinsichtlich rCBF miteinander verglichen. Der Rangkorrelationskoeffizient nach Spearman wurde für alle Perfusionsparameter bestimmt. Um den optimalen Schwellen-Perfusionswert zur Vorhersage des rezidivfreien Intervalls zu bestimmen, wurde eine Receiver Operating Characteristic (ROC)- Kurve erstellt. Die Überlebenskurven wurden nach Kaplan-Meier mit dem Log-Rang-Test erstellt. Ergebnisse Der Median von ASL-rCBF, DSC-rCBF und DSC-rCBV lag bei 5,3; 6,9; bzw. 8,0. Die Rangkorrelation nach Spearman ergab für alle DSCPerfusionsparameter eine signifikante Korrelation. Für ASL-rCBF und DSCrCBF konnte weder eine signifikante Korrelation noch ein signifikanter Unterschied nachgewiesen werden (Wilcoxon-Mann-Whitney-Test p = 0,07). Im Bland-Altman-Diagramm zeigte sich eine leichte asymmetrische Verzerrung, so dass insbesondere bei höheren Durchschnittswerten keine Austauschbarkeit der DSC-rCBF- und ASL-rCBF-Werte vorlag. In der ROC-Analyse erzielte DSCrCBV das beste Ergebnis als einzelstehender Prognosefaktor (Area under the curve, AUC = 0,71). DSC-rCBF war dem ASL-rCBF mit einer AUC von 0,59 gegenüber 0,58 leicht überlegen. Die Kombination von DSC-rCBV und ASLrCBF (AUC = 0,71) war dem alleinigen DSC-rCBV ebenbürtig. Der beste prädikative Wert konnte durch eine Kombination von DSC-rCBV, DSC-rCBF, leakage und ASL-rCBF (AUC = 0,74) erzielt werden. DSC- und ASL-rCBF wiesen eine moderate Sensitivität und Spezifität für die Vorhersage der rezidivfreien Intervalle auf. Im Gegensatz zu DSC-rCBV (p = 0,002) unterschieden sich die Werte für die rezidivfreien Überlebenszeit in den Kaplan-Meier-Kurven jedoch nicht signifikant. Schlussfolgerung: Es konnte weder eine Korrelation noch eine Austauschbarkeit zwischen den DSC-rCBF- und den ASL-rCBF-Werten festgestellt werden. Der prädiktive Wert von ASL-rCBF war zwar mit DSC-rCBF vergleichbar, jedoch nicht signifikant hinsichtlich der Vorhersage der rezidivfreien Überlebenszeit. Die rCBV-Werte wiesen die beste Sensitivität und Spezifität bei der Vorhersage eines Rezidivs sowie der rezidivfreien Überlebenszeit auf. Die Kombination von DSC- und ASL-Perfusionswerten wies vielversprechende Ergebnisse auf, was die Steigerung des prognostischen Werts beider einzelnstehenden Techniken betrifft

Empowering the Configuration-IP - New PTAS Results for Scheduling with Setups Times

Integer linear programs of configurations, or configuration IPs, are a classical tool in the design of algorithms for scheduling and packing problems, where a set of items has to be placed in multiple target locations. Herein a configuration describes a possible placement on one of the target locations, and the IP is used to chose suitable configurations covering the items. We give an augmented IP formulation, which we call the module configuration IP. It can be described within the framework of n-fold integer programming and therefore be solved efficiently. As an application, we consider scheduling problems with setup times, in which a set of jobs has to be scheduled on a set of identical machines, with the objective of minimizing the makespan. For instance, we investigate the case that jobs can be split and scheduled on multiple machines. However, before a part of a job can be processed an uninterrupted setup depending on the job has to be paid. For both of the variants that jobs can be executed in parallel or not, we obtain an efficient polynomial time approximation scheme (EPTAS) of running time f(1/epsilon) x poly(|I|) with a single exponential term in f for the first and a double exponential one for the second case. Previously, only constant factor approximations of 5/3 and 4/3 + epsilon respectively were known. Furthermore, we present an EPTAS for a problem where classes of (non-splittable) jobs are given, and a setup has to be paid for each class of jobs being executed on one machine

Deep Radio Continuum Imaging of the Dwarf Irregular Galaxy IC10: Tracing Star Formation and Magnetic Fields

We exploit the vastly increased sensitivity of the Expanded Very Large Array (EVLA) to study the radio continuum and polarization properties of the post-starburst, dwarf irregular galaxy IC10 at 6 cm, at a linear resolution of ~50 pc. We find close agreement between radio continuum and Halpha emission, from the brightest HII regions to the weaker emission in the disk. A quantitative analysis shows a strictly linear correlation, where the thermal component contributes 50% to the total radio emission, the remainder being due to a non-thermal component with a surprisingly steep radio spectral index of between -0.7 and -1.0 suggesting substantial radiation losses of the cosmic-ray electrons. We confirm and clearly resolve polarized emission at the 10-20% level associated with a non-thermal superbubble, where the ordered magnetic field is possibly enhanced due to the compression of the expanding bubble. A fraction of the cosmic-ray electrons has likely escaped because the measured radio emission is a factor of 3 lower than what is suggested by the Halpha inferred SFR.Comment: 15 pages, 5 figures, accepted for publication in the EVLA Special Issue of ApJ Letter

The temperature dependent bandstructure of a ferromagnetic semiconductor film

The electronic quasiparticle spectrum of a ferromagnetic film is investigated within the framework of the s-f model. Starting from the exact solvable case of a single electron in an otherwise empty conduction band being exchange coupled to a ferromagnetically saturated localized spin system we extend the theory to finite temperatures. Our approach is a moment-conserving decoupling procedure for suitable defined Green functions. The theory for finite temperatures evolves continuously from the exact limiting case. The restriction to zero conduction band occupation may be regarded as a proper model description for ferromagnetic semiconductors like EuO and EuS. Evaluating the theory for a simple cubic film cut parallel to the (100) crystal plane, we find some marked correlation effects which depend on the spin of the test electron, on the exchange coupling, and on the temperature of the local-moment system.Comment: 11 pages, 9 figure

State Regulation of Policing: POST Commissions and Police Accountability

This Article examines the untapped potential of Peace Officer Standards and Training (POST) commissions to protect communities that experience police misconduct and discrimination. POST commissions, which are created by state laws and exist in all fifty states, have broad authority to regulate police officers and police departments. POST commissions determine eligibility and qualifications for police employment and regulate the content of training officers receive. Most POST commissions can also revoke certification of officers who commit serious misconduct or fail to meet continuing eligibility requirements set by the commissions. In some states, they can also impose statewide, compulsory reforms to policing policy. POST commissions have yet to fulfill their potential to protect the public from harmful police behaviors because (1) they lack clear legislative or organizational mandates to protect the public against unethical or unjust policing and (2) their membership tends to be dominated by law enforcement officials with little or no input from the communities that are most burdened by aggressive and discriminatory policing. If legislatures address these structural problems, POST commissions could regulate policing to protect communities from police abuse and misconduct

Accompanying injuries in tibial shaft fractures: how often is there an additional violation of the posterior malleolus and which factors are predictive? A retrospective cohort study

INTRODUCTION: An undislocated fracture of the posterior malleolus is a common concomitant injury in tibial shaft spiral fractures. Nevertheless, these accompanying injuries cannot always be reliably assessed using conventional X-rays. Thus, the aim of the study is to evaluate how often a fracture of the posterior malleolus occurs with tibial shaft fractures (AO:42A/B/C and AO:43A) and which factors—identifiable in conventional X-rays—are predictive. METHODS: Retrospective evaluation of X-ray and CT images revealed a total of 103 patients with low-energy tibial shaft fractures without direct joint involvement. Proximal fractures and fractures involving the knee were excluded. Basic data on injury, the trauma mechanism, the path of the fracture, bony avulsions of the posterior syndesmosis and the procedures performed were evaluated. RESULTS: Thirty-nine fractures were located in the middle third of the tibia, 64 in the distal third. In 65 cases, a spiral fracture (simple or wedge fracture) was found. In 31/103 fractures, an additional osseous avulsion of the posterior syndesmosis could be detected, 5 (16.1%) of them were not recognized preoperatively due to an absence of CT imaging. In three of these patients, a fracture of the posterior malleolus was only recognized postoperatively, and an additional surgery was necessary. The spiral fractures were classified in the a.p. X-ray according to their path from lateral proximal to medial distal (Type A) or from medial proximal to lateral distal (Type B). A Pearson chi-square test and Fisher’s exact test showed a highly significant accumulation of accompanying posterior malleolus fractures for type A fractures (p = 0.001), regardless of the location of the fracture. In addition, the fractures with involvement of the posterior malleolus had a significantly higher proportion in the fractures of the distal third (p = 0.003). There was no statistically significant relationship between the height of the fracture and the path of the fracture (type A or B). These two factors seem to be independent factors for participation of the posterior malleolus. CONCLUSION: In 40.6% of the tibial shaft fractures in the distal third, in 56.9% of the type A spiral fractures and in 67.6% of the type A fractures in the distal third, the ankle joint is involved with bony avulsion of the posterior syndesmosis, which is not always recognized in conventional X-rays. To avoid complications such as additional operations, instability and post-traumatic arthrosis, we recommend preoperative imaging of the ankle using CT for these fractures. LEVEL OF EVIDENCE: III, retrospective cohort study. TRAIL REGISTRATION NUMBER: DRKS00024536

Whole-Blood Taurine Concentrations in Cats With Intestinal Disease

BackgroundIncreased delivery of taurine-conjugated bile acids to the distal bowel can lead to dysbiosis resulting in colitis in mouse models of inflammatory bowel disease. A similar situation also could occur in cats with intestinal disease and might therefore result in decreased whole-body taurine concentration.Hypothesis/objectivesTo determine whether whole-blood taurine concentrations are decreased at the time of diagnosis in cats with intestinal disease and to correlate concentrations with clinical and laboratory variables.AnimalsTwenty-one cats with chronic inflammatory enteropathy and 7 cats with intestinal neoplasia from the University of Bristol.MethodsCats that had undergone a thorough investigation consisting of a CBC, serum biochemistry, serum cobalamin and folate concentrations, transabdominal ultrasound examination and histopathology of intestinal biopsy specimens, as well as additional testing if indicated, were included. Whole-blood from these cats collected at the time of histologic diagnosis and stored in ethylenediaminetetraacetic acid was retrospectively analyzed for taurine with an automated high-performance liquid chromatography amino acid analyzer.ResultsAlthough whole-blood taurine concentrations remained within the reference range, those cats with predominantly large intestinal clinical signs had significantly lower concentrations than did cats with small intestinal and mixed bowel clinical signs (P = 0.033) and this difference also was significant when assessed only in cats with chronic inflammatory enteropathy (P = 0.019).Conclusions and clinical importanceAdditional studies are needed to determine whether large intestinal signs in cats with chronic inflammatory enteropathy are caused by alterations in the microbiota arising as a consequence of increased delivery of taurine-conjugated bile acids

Beyond hip fractures: other fragility fractures' associated mortality, functional and economic importance: a 2-year-Follow-up

BACKGROUND: Hip fractures are well researched in orthogeriatric literature. Equivalent investigations for fragility-associated periprosthetic and periosteosynthetic femoral, ankle joint, pelvic ring, and rib fractures are still rare. The purpose of this study was to evaluate mortality, functional outcome, and socioeconomic parameters associated to the upper-mentioned fragility fractures prospectively in a 2-year follow-up. METHODS: Over the course of a year, all periprosthetic and periosteosynthetic femoral fractures (PPFF), ankle joint fractures (AJ), pelvic ring fractures (PR), and rib fractures (RF), that were treated on a co-managed orthogeriatric ward, were assessed. Parker Mobility Score (PMS), Barthel Index (BI), place of residence, and care level were recorded. After 2 years, patients and/or relatives were contacted by mailed questionnaires or phone calls in order to calculate mortality and reevaluate the mentioned parameters. RESULTS: Follow-up rate was 77.7%, assessing 87 patients overall. The relative mortality risk was significantly increased for PR (2.9 (95% CI: 1.5–5.4)) and PPFF (3.5 (95% CI: 1.2–5.8)) but not for RF (1.5 (95% CI: 0.4–2.6)) and AJ (2.0 (95% CI: 0.0–4.0)). Every fracture group except AJ showed significantly higher BI on average at follow-up. PMS was, respectively, reduced on average for PR and RF insignificantly, but significantly for PPFF and AJ in comparison to pre-hospital values. 10.0–27.3% (each group) of patients had to leave their homes permanently; care levels were raised in 30.0–61.5% of cases. DISCUSSION: This investigation provides a perspective for further larger examinations. PR and PPFF correlate with significant increased mortality risk. Patients suffering from PPFF, PR, and RF were able to significantly recover in their activities of daily living. AJ and PPFF conclude in significant reduction of PMS after 2 years. CONCLUSION: Any fragility fracture has its impact on mortality, function, and socioeconomic aspects and shall not be underestimated. Despite some fractures not being the most common, they are still present in daily practice