Percutaneous vertebroplasty is not a risk factor for new osteoporotic compression fractures: results from VERTOS II

Background and purpose: Pv is increasingly used as treatment for osteoporotic vcfs. However, controversy exists as to whether pv increases the risk for new vcfs during follow-up. The purpose of our research was to assess the incidence of new vcfs in patients with acute vcfs randomized to pv and conservative therapy. Materials and methods: Vertos ii is a prospective multicenter randomized controlled trial comparing pv with conservative therapy in 202 patients. Incidence, distribution, and timing of new vcfs during follow-up were assessed from spine radiographs. In addition, further height loss during follow-up of treated vcfs was measured. Results: After a mean follow-up of 11.4 Months (Median, 12.0; Range, 1-24 months), 18 New vcfs occurred in 15 of 91 patients after pv and 30 new vcfs in 21 of 85 patients after conservative therapy. This difference was not significant (P = .44). There was no higher fracture risk for adjacent-versus-distant vertebrae. Mean time to new vcf was 16.2 Months after pv and 17.8 Months after conservative treatment (Logrank, p = .45). The baseline number of vcfs was the only risk factor for occurrence (Or, 1.43; 95% Ci, 1.05-1.95) And number (P = .01) Of new vcfs. After conservative therapy, further height loss of treated vertebrae occurred more frequently (35 Of 85 versus 11 of 91 patients, p < .001) And was more severe (P < .001) Than after pv. Conclusions: Incidence of new vcfs was not different after pv compared with conservative therapy after a mean of 11.4 Months' follow-up. The only risk factor for new vcfs was the number of vcfs at baseline. Pv contributed to preservation of stature by decreasing both the incidence and severity of further height loss in treated vertebrae

Transport of high fluxes of hydrogen plasma in a linear plasma generator

A study was made to quantify the losses during the convective hydrogen plasma transport in the linear plasma generator Pilot-PSI due to volume recombination. A transport efficiency of 35% was achieved at neutral background pressures below ~7 Pa in a magnetic field of 1.2 T. This efficiency decreased to essentially zero at higher pressures. At 1.6 T, the measured downstream plasma density was up to double the upstream density. Apparently plasma pumping and recycling at the target start to play a role under these increased confinement conditions. Feeding the plasma column at this field strength with a net current did not change the downstream density. This indicates that recycling sets the local plasma conditions

Extreme hydrogen plasma densities achieved in a linear plasma generator

A magnetized hydrogen plasma beam was generated with a cascaded arc, expanding in a vacuum vessel at an axial magnetic field of up to 1.6 T. Its characteristics were measured at a distance of 4 cm from the nozzle: up to a 2 cm beam diameter, 7.5×1020 m-3 electron density, ~2 eV electron and ion temperatures, and 3.5 km/s axial plasma velocity. This gives a 2.6×1024 H+ m-2 s-1 peak ion flux density, which is unprecedented in linear plasma generators. The high efficiency of the source is obtained by the combined action of the magnetic field and an optimized nozzle geometry. This is interpreted as a cross-field return current that leads to power dissipation in the beam just outside the source

Septum resection in women with a septate uterus : a cohort study

© The Author(s) 2020. Published by Oxford University Press on behalf of the European Society of Human Reproduction and Embryology.Peer reviewedPublisher PD

CT angiography and CT perfusion improve prediction of infarct volume in patients with anterior circulation stroke

Introduction: We investigated whether baseline CT angiography (CTA) and CT perfusion (CTP) in acute ischemic stroke could improve prediction of infarct presence and infarct volume on follow-up imaging. Methods: We analyzed 906 patients with suspected anterior circulation stroke from the prospective multicenter Dutch acute stroke study (DUST). All patients underwent baseline non-contrast CT, CTA, and CTP and follow-up non-contrast CT/MRI after 3 days. Multivariable regression models were developed including patient characteristics and non-contrast CT, and subsequently, CTA and CTP measures were added. The increase in area under the curve (AUC) and R2 was assessed to determine the additional value of CTA and CTP. Results: At follow-up, 612 patients (67.5 %) had a detectable infarct on CT/MRI; median infarct volume was 14.8 mL (interquartile range (IQR) 2.8–69.6). Regarding infarct presence, the AUC of 0.82 (95 % confidence interval (CI) 0.79–0.85) for patient characteristics and non-contrast CT was improved with addition of CTA measures (AUC 0.85 (95 % CI 0.82–0.87); p < 0.001) and was even higher after addition of CTP measures (AUC 0.89 (95 % CI 0.87–0.91); p < 0.001) and combined CTA/CTP measures (AUC 0.89 (95 % CI 0.87–0.91); p < 0.001). For infarct volume, adding combined CTA/CTP measures (R2 = 0.58) was superior to patient characteristics and non-contrast CT alone (R2 = 0.44) and to addition of CTA alone (R2 = 0.55) or CTP alone (R2 = 0.54; all p < 0.001). Conclusion: In the acute stage, CTA and CTP have additional value over patient characteristics and non-contrast CT for predicting infarct presence and infarct volume on follow-up imaging. These findings could be applied for patient selection in future trials on ischemic stroke treatment

Prediction of outcome in patients with suspected acute ischaemic stroke with CT perfusion and CT angiography: The Dutch acute stroke trial (DUST) study protocol

Background: Prediction of clinical outcome in the acute stage of ischaemic stroke can be difficult when based on patient characteristics, clinical findings and on non-contrast CT. CT perfusion and CT angiography may provide additional prognostic information and guide treatment in the early stage. We present the study protocol of the Dutch acute Stroke Trial (DUST). The DUST aims to assess the prognostic value of CT perfusion and CT angiography in predicting stroke outcome, in addition to patient characteristics and non-contrast CT. For this purpose, individualised prediction models for clinical outcome after stroke based on the best predictors from patient characteristics and CT imaging will be developed and validated.Methods/design: The DUST is a prospective multi-centre cohort study in 1500 patients with suspected acute ischaemic stroke. All patients undergo non-contrast CT, CT perfusion and CT angiography within 9 hours after onset of the neurological deficits, and, if possible, follow-up imaging after 3 days. The primary outcome is a dichotomised score on the modified Rankin Scale, assessed at 90 days. A score of 0-2 represents good outcome, and a score of 3-6 represents poor outcome. Three logistic regression models will be developed, including patient characteristics and non-contrast CT (model A), with addition of CT angiography (model B), and CT perfusion parameters (model C). Model derivation will be performed in 60% of the study population, and model validation in the remaining 40% of the patients. Additional prognostic value of the models will be determined with the area under the curve (AUC) from the receiver operating characteristic (ROC) curve, calibration plots, assessment of goodness-of-fit, and likelihood ratio tests.Discussion: This study will provide insight in the added prognosti