[Can preoperative prostate MRI before radical prostatectomy predict extracapsular extension and the side of the index lesion?]. / L'IRM de la prostate préopératoire avant prostatectomie radicale peut-elle prédire l'extension extracapsulaire et le côté de la lésion de référence?

AIM: To evaluate the role of preoperative multi-parametric magnetic resonance imaging (MP-MRI) in patients undergoing radical prostatectomy. Specifically, the accuracy of MP-MRI in detecting extracapsular extension (ECE) and individuating the side of the index lesion have been explored. METHODS: Thirty-five consecutive patients undergoing radical prostatectomy have been retrospectively analyzed. The MRI exam incorporated T2-weighted imaging, diffusion-weighted imaging and dynamic contrast enhancement in all patients. χ(2) test was performed to assess an association between an MP-MRI suggestive of ECE and pathologic ECE; similar tests were performed to study the association between the MRI-detected side of the index lesion and its true localization on final pathology. Univariate logistic regression models were constructed to evaluate possible predictors of ECE, including MP-MRI suspected ECE. RESULTS: Seventeen percent (6/35) of men presented ECE on final pathology. MP-MRI was predictive of pathologic ECE with a negative predictive value and specificity of 93% and 90%, respectively. Global accuracy of MP-MRI in predicting ECE was 86%. MRI-detected ECE was significantly predictive of pathologic ECE on logistic regression (OR: 17.3, 95% CI: 2.2-138.2, P=0.007). Moreover, MRI significantly predicted the side of the index lesion (P=0.012). CONCLUSIONS: In this single center cohort, preoperative MP-MRI was significantly predictive of ECE and side of the index lesion. Further studies are necessary to individuate patients who can benefit from preoperative MP-MRI. LEVEL OF EVIDENCE: 5.

Microbunching instability in relativistic electron bunches: direct observations of the microstructures using ultrafast YBCO detectors.

Relativistic electron bunches circulating in accelerators are subjected to a dynamical instability leading to microstructures at millimeter to centimeter scale. Although this is a well-known fact, direct experimental observations of the structures, or the field that they emit, remained up to now an open problem. Here, we report the direct, shot-by-shot, time-resolved recording of the shapes (including envelope and carrier) of the pulses of coherent synchrotron radiation that are emitted, and that are a "signature" of the electron bunch microstructure. The experiments are performed on the UVSOR-III storage ring, using electrical field sensitive YBa2Cu3O(7-x) thin-film ultrafast detectors. The observed patterns are subjected to permanent drifts, that can be explained from a reasoning in phase space, using macroparticle simulations.

Sixty-four-row multisection CT angiography for detection and evaluation of ruptured intracranial aneurysms: interobserver and intertechnique reproducibility.

BACKGROUND AND PURPOSE: The purpose of this work was to assess intertechnique and interobserver reproducibility of 64-row multisection CT angiography (CTA) used to detect and evaluate intracranial aneurysms. MATERIALS AND METHODS: From October 2005 to November 2006, 54 consecutive patients with nontraumatic subarachnoid hemorrhage (SAH) underwent both CTA and digital substraction angiography (DSA). Four radiologists independently reviewed CT images, and 2 other radiologists reviewed DSA images. Aneurysm diameter (D), neck width (N), and the presence of a branch arising from the sac were assessed. RESULTS: DSA revealed 67 aneurysms in 48 patients and no aneurysm in 6 patients. Mean sensitivity and specificity of CTA for the detection of intracranial aneurysms were, respectively, 94% and 90.2%. For aneurysms less than 3 mm, CTA had a mean sensitivity of 70.4%. Intertechnique and interobserver agreements were good for the detection of aneurysms (mean kappa = 0.673 and 0.732, respectively) and for the measurement of their necks (mean kappa = 0.753 and 0.779, respectively). Intertechnique and interobserver agreements were excellent for the measurement of aneurysm diameters (mean kappa = 0.847 and 0.876, respectively). In addition, CTA was accurate in determining the N/D ratio of aneurysms and adjacent arterial branches. However, the N/D ratio was overestimated by all of the readers at CTA. CONCLUSION: Sixty-four-row multisection CTA is an imaging method with a good interobserver reproducibility and a high sensitivity and specificity for the detection and the morphologic evaluation of ruptured intracranial aneurysms. It may be used as an alternative to DSA as a first-intention imaging technique in patients with SAH.

[Neurocognitive changes and negative symptoms in schizophrenia]. / Neurokognitive Veränderungen und Negativsymptomatik bei schizophrenen Erkrankungen.

It is widely recognized that schizophrenic disorders are often associated with impairments of cognitive performance. More recently, disorders of higher cognitive control processes ("executive control functions") have captured the attention of researchers as they can considerably impair patients' abilities to live an independent life. Apart from that, considering the heterogeneity of schizophrenia, there have been attempts to relate psychopathological syndromes to changes in distinct cognitive domains. The present review selectively focuses on evidence associating negative symptoms in schizophrenia with deficient performance in specific executive domains. Neurobiological evidence points to biochemical, structural and functional abnormalities in the frontal cortex and associated fronto-subcortical circuits as a common basis of both schizophrenic negative symptoms and disorders of executive control. In a multitude of neuropsychological studies, an association between negative symptoms and problems in the domains of response inhibition, multitasking, cognitive flexibility, contextual updating, problem solving and verbal fluency has been reported. In some cases, however, the disorganization syndrome but not the negative syndrome has been linked with impaired behaviour in these domains. The inconsistencies might be partly due to the unsatisfactory differentiation between the two symptom complexes. Future research should furthermore consider a more precise differentiation between primary and secondary negative symptoms. Finally, the assessment of executive control functions should be both specific and ecologically valid.

VUV radiometry below 100 nm: the high-power hydrogen arc as a standard source of continuum radiation between 53 nm and 92 nm.

A stationary hydrogen arc discharge may be used as a standard source of radiation in the VUV below 100 nm. The Lyman resonance continuum is used, the cross sections of which are theoretically well known. The method described is based on optically thin radiation, requiring high plasma temperatures and an effective helium gas separation in the arc. The investigations demonstrate that, in appropriate experimental conditions, the plasma is indeed transparent down to the onset of the He ground-state absorption. Above that, the VUV spectral radiance can be predicted within less than 15% uncertainty from conventional plasma diagnostics. For a first application, the He continuum has been measured between 65 nm and 92 nm. The consistency of these results with theoretical calculations confirms the validity of the concept presented.