bluuebunny/crossref_metadata_2025 huggingface dataset:
Energy Analysis of Contention Tree-Based Access Protocols in Dense Machine-to-Machine Area Networks
Authors: Vázquez-Gallego Francisco , Alonso Luis , Alonso-Zarate Jesus
Published: April 2015

Machine-to-Machine (M2M) area networks aim at connecting an M2M gateway with a large number of energy-constrained devices that must operate autonomously for years. Therefore, attaining high energy efficiency is essential in the deployment of M2M networks. In this paper, we consider a dense M2M area network composed of hundreds or thousands of devices that periodically transmit data upon request from a gateway or coordinator. We theoretically analyse the devices’ energy consumption using two Medium Access Control (MAC) protocols which are based on a tree-splitting algorithm to resolve collisions among devices: the Contention Tree Algorithm (CTA) and the Distributed Queuing (DQ) access. We have carried out computer-based simulations to validate the accuracy of the theoretical models and to compare the energy performance using DQ, CTA, and Frame Slotted-ALOHA (FSA) in M2M area networks with devices in compliance with the IEEE 802.15.4 physical layer. Results show that the performance of DQ is totally independent of the number of contending devices, and it can reduce the energy consumed per device in more than 35% with respect to CTA and in more than 80% with respect to FSA.
Expression ofHelicobacter pylori hspAGene inLactococcus lactisNICE System and Experimental Study on Its Immunoreactivity
Authors: Zhang Xiao-Juan , Feng Shu-Ying , Li Zhi-Tao , Feng Yan-Ming
Published: April 2015

Aim. The aim of this study was to develop an oralLactococcus lactis(L. lactis) vaccine againstHelicobacter pylori(H. pylori).Methods. AfterL. lactisNZ3900/pNZ8110-hspAwas constructed, growth curves were plotted to study whether the growth of recombinantL. lactiswas affected afterhspAwas cloned intoL. lactisand whether the growth of empty bacteria, empty plasmid bacteria, and recombinantL. lactiswas affected by different concentrations of Nisin; SDS-PAGE and Western blot were adopted, respectively, to detect the HspA expressed by recombinantL. lactisand its immunoreactivity.Results. There was no effect observed from the growth curve after exogenous genehspAwas cloned intoL. lactisNZ3900; different concentrations of Nisin did not affect the growth of NZ3900 and NZ3900/pNZ8110, while different concentrations of Nisin inhibited the growth of NZ3900/pNZ8110-hspAexcept 10 ng/mL Nisin. No HspA strip was observed from SDS-PAGE. Western blot analysis showed that HspA expressed by recombinant bacteria had favorable immunoreactivity.Conclusion. The growth of recombinantL. lactiswas suppressed even though a small amount of HspA had been induced to express. Therefore recombinantL. lactisonly express HspA which was not suitable to be oral vaccine againstHelicobacter pylori.
An Improved Method for Generating Cutter Points Based on Required Form Accuracy of the Machining Surface
Authors: Ji Shijun , Yu Huijuan , Zhao Ji
Published: April 2015

Recently, freeform surfaces are widely used in optical field. Fabrication of freeform surface optics needs high machining accuracy and high efficiency simultaneously. Using the present ultraprecision manufacturing technologies, the form accuracy of freeform surfaces can reach submicrometric or even nanometer range but at the cost of low efficiency; moreover, the form accuracy cannot be predicted; the number and the position of cutter points cannot be accurately controlled before practical machining. A novel strategy of cutter points distribution is proposed in the paper, which is based on the required accuracy of the freeform surface and the machining efficiency can be improved by eliminating redundant cutter points on the processing trajectory. The new idea is detailed, simulations are conducted, and experiments are done to verify the feasibility of the proposed method in fabricating two sinusoidal ring surfaces.
Use of Placental Growth Factor and Uterine Artery Doppler Pulsatility Index in Pregnancies Involving Intrauterine Fetal Growth Restriction or Preeclampsia to Predict Perinatal Outcomes
Authors: Gomez-Roig M. Dolores , Mazarico Edurne , Sabria Joan , Parra Johanna , Oton Laia , Vela Antonio
Published: April 2015

Aim: The potential of uterine artery (UA) Doppler pulsatility index (PI) and maternal serum placental growth factor (PlGF) level to predict perinatal outcome was explored in pregnancies complicated by intrauterine fetal growth restriction (IUGR) or preeclampsia (PE). Methods: This longitudinal, prospective, and case-controlled study was conducted over a period of 24 months. At-risk pregnancies involving small-for-gestational-age (SGA) fetuses, IUGR, gestational hypertension (GH), or PE were investigated, analyzing UA Doppler PI findings and maternal PlGF levels determined at the time of diagnosis (third trimester). Results: UA Doppler PI and maternal serum PlGF values differed significantly in pregnancies complicated by IUGR and/or PE (vs. SGA or GH, p < 0.01). In the context of IUGR or PE, both parameters also differed significantly by perinatal outcome (adverse vs. normal, p < 0.01), although no predictive advantage over UA Doppler PI alone was conferred by adding a PlGF assay. Conclusion: UA Doppler PI and maternal serum PlGF determinations in the third trimester help identify pregnancies at the highest risk of adverse perinatal outcomes due to IUGR and/or PE. Although joint testing confers no predictive benefit over UA Doppler PI alone, the two diagnostics are interchangeable for this purpose.
Microhabitat Use Affects Brain Size and Structure in Intertidal Gobies
Authors: White Gemma E. , Brown Culum
Published: April 2015

The ecological cognition hypothesis poses that the brains and behaviours of individuals are largely shaped by the environments in which they live and the associated challenges they must overcome during their lives. Here we examine the effect of environmental complexity on relative brain size in 4 species of intertidal gobies from differing habitats. Two species were rock pool specialists that lived on spatially complex rocky shores, while the remainder lived on dynamic, but structurally simple, sandy shores. We found that rock pool-dwelling species had relatively larger brains and telencephalons in particular, while sand-dwelling species had a larger optic tectum and hypothalamus. In general, it appears that various fish species trade off neural investment in specific brain lobes depending on the environment in which they live. Our previous research suggests that rock pool species have greater spatial learning abilities, enabling them to navigate their spatially complex environment, which may account for their enlarged telencephalon, while sand-dwelling species likely have a reduced need for spatial learning, due to their spatially simple habitat, and a greater need for visual acuity. The dorsal medulla and cerebellum size was unaffected by the habitat in which the fish lived, but there were differences between species indicative of species-specific trade-offs in neural investment.
The Contribution of Osteoprogenitor Cells to Arterial Stiffness and Hypertension
Authors: Pikilidou Maria , Yavropoulou Maria , Antoniou Maria , Yovos John
Published: April 2015

Hypertension, the major cause of cardiovascular disease, is bidirectionally linked to arterial stiffness. Evidence shows that vascular calcification, either medial or intimal, induces arterial stiffening further worsening hypertension parallel to substantially increasing cardiovascular risk. The disturbance in the bone-vascular axis that leads to the increase of calcium deposition in the arterial wall may be the result of a shift in the functionality of bone marrow-derived circulating stem cells with a calcifying potential, namely osteoprogenitor cells. These cells deposit bone matrix proteins in the vascular wall that can subsequently become mineralized. The current notion is that these cells derive from diverse cell lines. The present review summarizes the current knowledge on the role of progenitor cells with a calcifying potential on arterial calcification, stiffness and hypertension.
Aspects of Exercise before or after Bariatric Surgery: A Systematic Review
Authors: Pouwels Sjaak , Wit Marjon , Teijink Joep A.W. , Nienhuijs Simon W.
Published: April 2015

Background: Bariatric surgery has a considerable effect on weight loss. A positive relation of exercise and weight loss has been described before. However, the mode of exercise and its timing pre- or postoperatively or a combination remains unclear. Methods: A multi-database search was conducted. Identified articles were reviewed on description of exercise, timing around a bariatric intervention, and outcome. Methodological quality of the included studies was rated using the Physiotherapy Evidence Database scale. A Cohen's kappa score assessed the level of agreement. Outcome measurements were improvement of anthropometric and physical fitness variables, operation related complications, weight regain, and quality of life. Results: A total of 8 prospective studies were included. Four focused on training before and 4 on training after a bariatric procedure. Details of exercises varied from 45 min treadmill up to full descriptive programs. Supervision was frequently included. Significant improvement was encountered for biometric results physical fitness variables. Conclusion: In the majority of reports on exercising in a (future) bariatric population, positive effects on anthropometrics, cardiovascular risk factors and physical fitness were described. However, the results were not unanimous, with a wide range of exercise programs and perioperative timing, therefore hampering adequate practical guidance.
Different Patterns of Disease Spread between Advanced-Stage Type I and II Epithelial Ovarian Cancer
Authors: Bergamini Alice , Candiani Massimo , Taccagni Gianluca , Rabaiotti Emanuela , Viganò Riccardo , De Marzi Patrizia , Ferrari Davide , Mangili Giorgia
Published: April 2015

Background and Aims: Two types of epithelial ovarian carcinoma (EOC) have been recently distinguished. Type I comprises low-grade serous, endometrioid and clear-cell tumors. High-grade endometrioid and serous tumors belong to type II. The aim of this study was to compare patterns of disease spread in advanced-stage type I and II EOCs at primary surgery. Methods: Surgical and pathological data of 233 patients with advanced-stage EOCs were collected, 42 with type I and 191 with type II. The two groups were compared for tumor localization at primary surgery. Intraoperative mapping of ovarian cancer (IMO) was used to assess tumor dissemination. Results: Tumor involvement was significantly higher in the type II group for the following: peritoneum (68.1 vs. 40.5%, p < 0.001), pouch of Douglas (60.2 vs. 40.5%, p = 0.06), vesicouterine ligament (40.8 vs. 19%, p = 0.027), diaphragm (45.0 vs. 11.9%, p < 0.001), serosa of liver (17.2 vs. 4.8%, p = 0.05), omentum (81.1 vs. 59.5%, p = 0.007), mesentery (42.9 vs. 16.7%, p = 0.005), pleural effusions (19.4 vs. 4.6%, p = 0.01) and ascites (60.7 vs. 21.4%, p < 0.001). IMO levels were different between the two groups (p = 0.001). Conclusions: This study provides clinical evidence in favor of the dualistic model of carcinogenesis, since types I and II are characterized by different findings at primary surgery.
Brain Magnetic Resonance Imaging Findings Fail to Suspect Fabry Disease in Young Patients With an Acute Cerebrovascular Event
Authors: Fazekas Franz , Enzinger Christian , Schmidt Reinhold , Grittner Ulrike , Giese Anne-Katrin , Hennerici Michael G. , Huber Roman , Jungehulsing Gerhard J. , Kaps Manfred , Kessler Christof , Martus Peter , Putaala Jukka , Ropele Stefan , Tanislav Christian , Tatlisumak Turgut , Thijs Vincent , von Sarnowski Bettina , Norrving Bo , Rolfs Arndt
Published: April 2015

Background and Purpose—

Fabry disease (FD) may cause stroke and is reportedly associated with typical brain findings on magnetic resonance imaging (MRI). In a large group of young patients with an acute cerebrovascular event, we wanted to test whether brain MRI findings can serve to suggest the presence of FD.

Methods—

The Stroke in Young Fabry Patients (SIFAP 1) study prospectively collected clinical, laboratory, and radiological data of 5023 patients (18–55 years) with an acute cerebrovascular event. Their MRI was interpreted centrally and blinded to all other information. Biochemical findings and genetic testing served to diagnose FD in 45 (0.9%) patients. We compared the imaging findings between FD and non-FD patients in patients with at least a T2-weighted MRI of good quality.

Results—

A total of 3203 (63.8%) patients had the required MRI data set. Among those were 34 patients with a diagnosis of FD (1.1%), which was definite in 21 and probable in 13 cases. The median age of patients with FD was slightly lower (45 versus 46 years) and women prevailed (70.6% versus 40.7%;
P
<0.001). Presence or extent of white matter hyperintensities, infarct localization, vertebrobasilar artery dilatation, T1-signal hyperintensity of the pulvinar thalami, or any other MRI finding did not distinguish patients with FD from non-FD cerebrovascular event patients. Pulvinar hyperintensity was not present in a single patient with FD but seen in 6 non-FD patients.

Conclusions—

Brain MRI findings cannot serve to suspect FD in young patients presenting with an acute cerebrovascular event. This deserves consideration in the search for possible causes of young patients with stroke.

Clinical Trial Registration—

URL:
http://www.clinicaltrials.gov
. Unique identifier: NCT00414583.
Brain Circuit for Cognitive Control Is Shared by Task and Language Switching
Authors: De Baene Wouter , Duyck Wouter , Brass Marcel , Carreiras Manuel
Published: April 2015

Controlling multiple languages during speech production is believed to rely on functional mechanisms that are (at least partly) shared with domain-general cognitive control in early, highly proficient bilinguals. Recent neuroimaging results have indeed suggested a certain degree of neural overlap between language control and nonverbal cognitive control in bilinguals. However, this evidence is only indirect. Direct evidence for neural overlap between language control and nonverbal cognitive control can only be provided if two prerequisites are met: Language control and nonverbal cognitive control should be compared within the same participants, and the task requirements of both conditions should be closely matched. To provide such direct evidence for the first time, we used fMRI to examine the overlap in brain activation between switch-specific activity in a linguistic switching task and a closely matched nonlinguistic switching task, within participants, in early, highly proficient Spanish–Basque bilinguals. The current findings provide direct evidence that, in these bilinguals, highly similar brain circuits are involved in language control and domain-general cognitive control.
First record of Mollisquama sp. (Chondrichthyes: Squaliformes: Dalatiidae) from the Gulf of Mexico, with a morphological comparison to the holotype description of Mollisquama parini Dolganov
Authors: GRACE MARK A. , DOOSEY MICHAEL H. , BART HENRY L. , NAYLOR GAVIN J. P.
Published: April 2015

The description of the pocket shark genus Mollisquama (M. parini Dolganov, 1984) is based on a single known specimen collected from the Nazca Ridge of the southeast Pacific Ocean. A second Mollisquama specimen has been captured in the central Gulf of Mexico establishing a considerable range extension and a parturition locality because the specimen has a healed vitelline scar. Both the holotype of M. parini and the Gulf of Mexico specimen possess the remarkable pocket gland with its large slit-like external opening located just above the pectoral fin. Features found on the Gulf of Mexico specimen that were not noted in the description of M. parini include a series of ventral abdominal photophore agglomerations and a modified dermal denticle surrounded by a radiating arrangement of denticles just posterior to the mouth. Based on a morphometric and meristic comparison of the Gulf of Mexico specimen with information in the description of M. parini, the Gulf of Mexico specimen is identified as Mollisquama sp. due to differences in tooth morphology and vertebral counts. Phylogenetic analysis of NADH2 gene sequences places Mollisquama sister to Dalatias plus Isistius within the family Dalatiidae.
Spatiotemporal Characteristics of Rainstorm-Induced Hazards Modified by Urbanization in Beijing
Authors: Hu HaiBo
Published: April 2015

The rainfall data of 20 rain gauge stations are used for analysis on the spatiotemporal characteristics of rainstorm-induced hazards in Beijing. A local model used to calculate rainstorm hazards index values (RHIVs) has been developed to reflect the degree of rainstorm-induced hazards. The Mann–Kendall test on the RHIVs series recognizes 1984 as the changepoint in the series, which is shortly after the beginning of a rapid urban expansion period in 1981. The RHIV trend analysis reveals that the trends indices of all stations are negative before 1984 but mostly positive after 1984. Although the climate in north China shows drought conditions, and the annual rainfalls have decreased in recent years, no relationship is implied to a reduction in rainstorm-induced hazards. By using the lognormal distribution model, the probability analysis on the RHIVs of 20 stations indicates that very extreme precipitation occurred in increasing frequency after 1984. Moreover, the estimated spatial distributions of 100-, 150-, and 200-mm daily rainfall exceedance probabilities (EPs) indicate that these EPs have increased mainly in the urban areas and northward, which are the downwind of the summer monsoon, whereas the EPs to the south of the urban areas have decreased since 1984. Such spatiotemporal characteristics of the RHIVs can be attributed to modification of precipitation by the changed land use and land cover in urban areas. Moreover, the urban-induced rainfall downwind of the urban areas enhanced the rain intensity and rain rate, which led to an increase in RHIVs and contributed to the frequent occurrences of flash floods in Beijing metropolis.
On the Long-Term Climate Memory in the Surface Air Temperature Records over Antarctica: A Nonnegligible Factor for Trend Evaluation
Authors: Yuan Naiming , Ding Minghu , Huang Yan , Fu Zuntao , Xoplaki Elena , Luterbacher Juerg
Published: April 2015

In this study, observed temperature records of 12 stations from Antarctica island, coastline, and continental areas are analyzed by means of detrended fluctuation analysis (DFA). After Monte Carlo significance tests, different long-term climate memory (LTM) behaviors are found: temperatures from coastal and island stations are characterized by significant long-term climate memory whereas temperatures over the Antarctic continent behave more like white noise, except for the Byrd station, which is located in the West Antarctica. It is argued that the emergence of LTM may be dominated by the interactions between local weather system and external slow-varying systems (ocean), and therefore the different LTM behaviors between temperatures over the Byrd station and that over other continental stations can be considered as a reflection of the different climatic environments between West and East Antarctica. By calculating the trend significance with the effect of LTM taken into account, and further comparing the results with those obtained from assumptions of autoregressive (AR) process and white noise, it is found that 1) most of the Antarctic stations do not show any significant trends over the past several decades, and 2) more rigorous trend evaluation can be obtained if the effect of LTM is considered. Therefore, it is emphasized that for air temperatures over Antarctica, especially for the Antarctica coastline, island, and the west continental areas, LTM is nonnegligible for trend evaluation.
A Comparative Analysis of Kuroshio Extension Indices from a Modeling Perspective
Authors: Pierini Stefano
Published: April 2015

Dynamical indices previously introduced to characterize the Kuroshio Extension (KE) decadal variability (DV) from altimeter data are comparatively analyzed to assess their ability to reveal the same phenomenon from model outputs. Based on this analysis, a new combined index identifying each stage of the KE DV in numerical simulations is then proposed. The analysis begins by recognizing that the numerical simulation of the nonlinear frontal KE DV is very sensitive to changes in model implementation, whereas the linear broad-scale baroclinic Rossby wave field known to trigger the KE DV is a robust model feature. This selective model sensitivity poses a subtle problem concerning the diagnosis of the KE DV from model outputs, and requires the use of indices that unequivocally identify the KE frontal structure. The capability of six indices to achieve this task is thus investigated. Two model outputs representing paradigms of a fairly realistic simulation and of an unrealistic simulation in which only the broad-scale variability is present are used. A synthesized index is well captured by both simulations: it is therefore recognized to be unsuitable for model studies. An integrated SSH index does not resolve explicitly the frontal variability. Among the remaining indices, the KE path length (modified through the application of the wavelet transform) and the mean KE latitudinal position are shown to provide, in combination, an unambiguous identification of each stage of the KE DV (recognized to exhibit chaotic hysteresis) and are therefore suggested to be used with model outputs.
Observations of Water Mass Transformation and Eddies in the Lofoten Basin of the Nordic Seas
Authors: Richards Clark G. , Straneo Fiammetta
Published: April 2015

The Lofoten basin of the Nordic Seas is recognized as a crucial component of the meridional overturning circulation in the North Atlantic because of the large horizontal extent of Atlantic Water and winter surface buoyancy loss. In this study, hydrographic and current measurements collected from a mooring deployed in the Lofoten basin from July 2010 to September 2012 are used to describe water mass transformation and the mesoscale eddy field. Winter mixed layer depths (MLDs) are observed to reach approximately 400 m, with larger MLDs and denser properties resulting from the colder 2010 winter. A heat budget of the upper water column requires lateral input, which balances the net annual heat loss of ~80 W m−2. The lateral flux is a result of mesoscale eddies, which dominate the velocity variability. Eddy velocities are enhanced in the upper 1000 m, with a barotropic component that reaches the bottom. Detailed examination of two eddies, from April and August 2012, highlights the variability of the eddy field and eddy properties. Temperature and salinity properties of the April eddy suggest that it originated from the slope current but was ventilated by surface fluxes. The properties within the eddy were similar to those of the mode water, indicating that convection within the eddies may make an important contribution to water mass transformation. A rough estimate of eddy flux per unit boundary current length suggests that fluxes in the Lofoten basin are larger than in the Labrador Sea because of the enhanced boundary current–interior density difference.
Spinal Epidural Hematoma in Hemophilia-A
Authors: Varsha J. , Prashant S. , Manohar S. , Sachin G.
Published: April 2015

A case of a 10-year old boy with an anterior spinal epidural hematoma in the cervical spine is presented. Subsequent to the MR examination clinical and laboratory work-up revealed the child to have a severe form of Hemophilia-A. The intraspinal bleeding was the first manifestation of this disease in the boy; the site of bleeding too was unusual. Subsequent imaging studies after treatment with Factor VIII replacement are also depicted. The pivotal role of MRI in the diagnosis of the hematoma is stressed.

In a young male child with these clinical and imaging features, one should investigate the possibility of hemophilia and congenital coagulation defects
Endovascular Treatment of Brain Arteriovenous Malformations
Authors: Bradač GB , Bergui M. , Stura G.
Published: April 2015

In spite of major advances in the endovascular tools and a better understanding of the disease, the treatment of brain arteriovenous malformations remains difficult. Many aspects of the disease are still unpredictable, and the therapeutic approach frequently depends on the experience and skill of the teams involved. Different approaches - neuro/radiosurgical or endovascular, are possible. A consensus on the best treatment has not yet been reached and to date a combined treatment is probably the best possible choice for the majority of the patients, avoiding overestimation of a single technique. We report our experience in the endovascular treatment of 44 consecutive cases of brain arteriovenous malformations.
Malattia di Wilson: Reperti RM in 13 casi
Authors: D'Amico A. , Caranci F. , Briganti F. , Di Salle F. , Tortora F. , Criscuolo C. , Pellecchia M.T. , Cirillo S. , Elefante R.
Published: April 2015

La malattia di Wilson è un disordine del metabolismo del rame a trasmissione auto-somica recessiva. Sono colpiti i tessuti ove si accumula preferenzialmente il rame: fegato, cornea, reni e gangli della base.

La malattia può esordire con sintomatologia epatica o neurologica, quest'ultimo con sintomi extrapiramidali (75% dei casi) o cerebellari (25%, forma pseudosclerotica di Westphal-Strumpell).

Dalla nostra esperienza, basata sullo studio con Risonanza Magnetica (RM) in 13 pazienti, emerge l'importanza della metodica in fase diagnostica.

La malattia di Wilson mostra un quadro RM abbastanza polimorfo, con interessamento sia della sostanza grigia profonda che della bianca e del tronco encefalico.

Frequente il coinvolgimento bilaterale e simmetrico dei nuclei profondi; aree di alterato segnale possono localizzarsi a livello della sostanza bianca, più frequentemente lungo le vie extrapiramidali rispetto al coinvolgimento delle vie piramidali. Ulteriori aree di coinvolgimento della sostanza bianca riscontrate nei nostri pazienti comprendono le regioni retrotrigonali, la lamina midollare interna del talamo, lo splenio del corpo calloso. Non sono state invece riscontrate le più frequenti localizzazioni alla sostanza bianca emisferica cerebellare. In 7 dei nostri pazienti era presente il caratteristico segno “del panda” (iperintensità nelle immagini a TR lungo del mesencefalo con preservata ipointensità dei peduncoli cerebrali e dei nuclei rossi, della porzione laterale della pars reticulata della sostanza nera e dei collicoli superiori); in alcuni casi era presente una alterazione di segnale dei nuclei rossi, in altri un quadro tipo “mielinolisi centrale”, con differenti gradi di gravità.

L'atrofia corticale cerebrale è più frequentemente riportata in sede sopratentoriale rispetto a quella sottotentoriale; l'atrofia del tronco, meno comune, è stata riscontrata più frequentemente nei soggetti con sintomatologia tipo Westphal-Strumpell.

Non meno importante il ruolo della RM nel follow-up post-terapeutico: la metodica può evidenziare regressione totale o parziale delle lesioni, con elevata correlazione con il quadro clinico.
Magnetic Resonance Imaging in Confirmation of Brain Death
Authors: Tali E.T. , Yücel A.S. , Tevfik M. , Gökçora N. , Dalmaz S. , Günaydin B. , Kaya K.
Published: April 2015

Brain death is defined as an irreversible cessation of all cerebral and brain stem functions despite the maintenance of cardiopulmonary functions by artificial means. The importance of early diagnosis of brain death has increased particularly with advances in organ transplantation.

Our purpose was to determine the value of MRI as an ancillary test and to compare it with routine EEG and radionuclide studies.

Eleven patients who met the clinical criteria of brain death were imaged both with radionuclide studies (RCA and SPECT) and MRI. The diagnosis of all the patients was verified by both studies. Eight of the patients underwent EEG and the results of seven were consistent with the previously confirmed diagnosis while there was one false negative result.

MR proved to be as successful as radionuclide studies in the confirmation of brain death while it seemed to be more valuable than EEG in this limited study group. MR imaging also provided detailed structural information, findings and evidence to shed light on the etiology and give clues as to cerebral blood supply. MRI can be the modality of choice especially in cases of unknown etiology.
La chirurgia delle malformazioni artero-venose cerebrali
Authors: Calbucci F. , Fioravanti A. , Consales A. , Simonetti L. , Leonardi M.
Published: April 2015

La scelta del trattamento chirurgico delle MAV cerebrali rappresenta oggi uno degli argomenti più dibattuti ed attuali in ambito neurochirurgico, in considerazione dell'avvento di tecniche alternative o complementari che possono dare un contributo essenziale e spesso risolutivo al trattamento di queste lesioni. Sulla base dell'esperienza di 47 casi operati consecutivamente presso l'Ospedale Bellaria negli ultimi anni, si è cercato di vedere quali fossero i criteri che hanno ispirato la scelta chirurgica e di valutare i risultati della stessa per una revisione critica di queste scelte. Da un'analisi completa dei casi le conclusioni possono essere che, se si escludono le situazioni in cui è necessario intervenire in emergenza, in tutti gli altri casi, il criterio della scelta chirurgica adottato si è rivelato nel complesso utile per avere un risultato definitivo buono (asportazione completa della MAV), con rischi contenuti. In particolare si è potuto desumere che l'indicazione chirurgica può essere ancora oggi la scelta preferibile nelle malformazioni di grado I-II-III (secondo Spetzler e Martin), se si escludono casi particolari in sedi cerebrali critiche. Nelle malformazioni di grado IV invece la chirurgia deve essere riservata a situazioni molto particolari, in cui la MAV risulta non trattabile in via alternativa e vi sia stato un evento emorragico di presentazione. In queste circostanze, l'embolizzazione pre-operatoria può essere un contributo molto importante per la soluzione chirurgica.
Motion Artifact Mimicking the Pulvinar Sign
Authors: Mori H. , Aoki S. , Ohtomo K.
Published: April 2015

T2-weighted MR imaging (T2WI) in patients presenting with variant Creutzfeldt-Jakob disease (vCJD) can demonstrate high signal intensity lesions in both pulvinars and/or medial side of thalami (the pulvinar sign) at a high rate. Nevertheless, since patients with dementia are frequently uncooperative and restless, the T2WI sequence may often fail. This article presents a clinically effective case involving application of PROPELLER MRI with correction of reduced motion artifacts to exclude the pulvinar sign.
Unusual MRI Appearance of Paraganglioma of the Cauda Equina
Authors: Parthiban J.K.B.C. , Murugan K.S.
Published: April 2015

A unique Magnetic Resonance Imaging feature of a histopathologically confirmed case of paraganglioma of the cauda equina is described.
Aneurysmal Bone Cyst of Skull
Authors: Purkayastha S. , Gupta A.K. , Kapilamoorthy T.R. , Bodhey N.K. , Thomas B.
Published: April 2015

An aneurysmal bone cyst is a benign lesion usually involving the long bones, vertebrae including odontoid, hypoid and mandible. Skull is a rare site for aneurysmal bone cyst. Only 3% occur in the cranium and sites of involvement include temporal, occipital, orbital, frontal, parietal, ethmoids and sphenoid bones in order of frequency. We report two cases of aneurysmal bone cysts in occipital bone and maxilla. We discuss the radiological features, surgical findings and emphasize the role of endovascular management in these lesions.
Cerebellar Lesions in Children with Tuberous Sclerosis Complex
Authors: Jurkiewicz E. , Jóźwiak S. , Bekiesińska-Figatowska M. , Pakieła-Domańska D. , Pakuła-Kościesza I. , Walecki J.
Published: April 2015

Cerebellar lesions in tuberous sclerosis complex are less frequent than cerebral findings. We present the magnetic resonance (MR) features of uncommon cerebellar changes found in a large series of children with tuberous sclerosis complex (TSC). MR examinations of 73 children (38 males and 35 females) with TSC were reviewed. Twelve patients with cerebellar lesions were selected. Patients' ages ranged from 2.5 years to 21.25 (median: 10.6). The number, anatomic location, signal intensity and contrast enhancement of these lesions were evaluated. MR studies were performed with a 1.5 T scanner obtaining T1, T2-weighted images and FLAIR sequences. Gadolinium was administrated in all cases. Cerebellar tubers were found in 12 patients (16.4%). The total number of cerebellar tubers was 21. Most cerebellar tubers were hyperintense on T2-weighted and FLAIR images and slightly hypointense on T1-weighted images. Eleven of these lesions (52.38%) revealed contrast enhancement. None of cortical cerebral tubers showed contrast enhancement. Atrophy of seven cerebellar tubers was noticed. The mutation in TSC2 gene was confirmed in eight patients. Cerebellar tubers are uncommon. They were not found in the absence of cerebral tubers and may associated with parenchymal volume loss.
Angiographic Exclusion of Intracranial Arteriovenous Malformations Using Onyx®
Authors: Mathews M.S. , Owen C.M. , Nguyen B.V. , Kostanian V. , Nwagwu C.I.
Published: April 2015

Historically, endovascular treatment for cerebral arteriovenous malformations (AVMs) has been reserved as an adjunct to other modalities, namely radiosurgery and microsurgery, as the cure rate for cerebral AVMs treated solely with endovascular technique and older embolic agents is low. We report a series of five consecutive patients treated successfully with Onyx®, the newest available embolic agent, with resultant angiographic cure. Five patients aged three, nine, 33, 49, and 63 years were treated endovascularly for cerebral AVMs with a total of 19 embolizations with Onyx®. All procedures were performed under general anesthesia with biplanar fluoroscopy. Complete angiographic obliteration of the AVM nidus was obtained in all cases with no residual filling. No immediate hemorrhagic or thromboembolic complications were observed. This early experience suggests that Onyx® has excellent embolization potential, and endovascular cure of AVMs may now be achieved with single modality therapy. Long terms data needs to be collected to further validate this observation.
Endovascular Management for Bilateral Ophthalmic Segment “Kissing” Aneurysms Presenting with Nasal Bleeding
Authors: Lv Xianli , Li Youxiang , Wu Zhongxue
Published: April 2015

A rare case of bilateral ophthalmic segment “kissing” aneurysms is reported. A 32-year-old man presented with nasal bleeding and headaches. Cerebral angiography demonstrated bilateral internal carotid-ophthalmic aneurysms. Both aneurysms were treated in the same procedure because of uncertainty over which aneurysm had bled. The left aneurysm was coiled intrasaccularly, the right one was treated by parent artery occlusion. Surgery for kissing aneurysms has been recognized as hazardous and challenging. We emphasize that the endovascular technique described is reasonable.
Recurrent Intraventricular Hemorrhages Caused by an AVM Detected by Angiography with Initially Normal Angiogram
Authors: De Marco A. , La Tessa G. , De Bellis L. , Zenna L. , Fasano F. , Santangelo R. , Napolitano M. , De Falco F.A. , Sirabella G.
Published: April 2015

Primary intraventricular haemorrhage (PIVH) is an uncommon type of non-traumatic cerebral haemorrhage limited to the ventricular system arising in adults and children, with diverse aetiology and variable course. Vascular malformations account for 34% of PIVH, whereas no cause is found in 21–47%. When a primary intraventricular haemorrhage is detected in a young patient an underlying lesion such as an arteriovenous malformation (AVM) must be ruled out. The diagnosis may be suspected when there is sudden onset of headache, nausea and vomiting with or without a reduced level of consciousness. Nevertheless, even if clinical features suggest the diagnosis of PIVH, cerebral computed tomography (CT) scan is required for confirmation, and magnetic resonance imaging (MRI) and catheter angiography are necessary to establish the aetiology. We describe a case of isolated recurrent intraventricular haemorrhages caused by AVM detected by diagnostic intracranial angiography with no abnormality demonstrated on angiography four years earlier.
Giant Cystic Intraventricular Cerebral Cavernous Malformation: MRI with Pathologic Correlation
Authors: Muccio C.F. , Catapano G. , Di Blasi A. , Esposito G. , Cerase A.
Published: April 2015

The purpose of this case report is to increase awareness of the spectrum of cerebral cavernous malformations (CCMs). We report the MRI findings and histological features of an uncommon case of a single giant (maximum diameter: >6 cm) cystic CCM of the left lateral ventricle occurring in a 26-year-old man who had undergone 30 Gy cranial irradiation for acute leukemia at the age of six years. Large cystic CCMs must be included in the neuroradiological differential diagnosis of intraventricular hemorrhagic cystic lesions.
Facial Nerve Schwannoma Presenting as a Mass in the Middle Cranial Fossa: Typical Neuroradiological Patterns for a Preoperative Diagnosis
Authors: De Simone M. , Bartolini A. , Esposito G. , Algieri G.M. , Catapano G. , Muccio C.F.
Published: April 2015

Facial nerve schwannoma is a rare primary neurogenic tumour that may originate anywhere along the VIIth nerve course. The clinical presentation is highly dependent on the location of the lesion along the nerve course and this makes the pre-operative diagnosis difficult without radiologic examination. The most common presentation is facial palsy and even though tumours are responsible for only 5% of facial palsies, if a patient does not recover within six months a complete work-up for neoplasm is recommended. On the basis of clinical presentation and imaging characteristics radiologists should try to make a preoperative diagnosis, to help in the patient's management and possibly to plan the surgical approach. We describe the case of a successful preoperative diagnosis of facial nerve schwannoma. The aim is to describe the main CT and MRI findings which may help the radiologist to establish a correct differential diagnosis.
Enhancement of Virchow-Robin Spaces
Authors: Tsitouridis I. , Papaioannou S. , Arvaniti M. , Tsitouridis K. , Rodokalakis G. , Papastergiou C.
Published: April 2015

Virchow-Robin spaces are enclosed spaces filled with interstitial fluid and covered with pia that accompany arteries, arterioles, veins and venules as they perforate the brain. They are round, linear or punctuate areas depending on the image that parallel cerebrospinal fluid attenuation or signal intensity. They are classically described as isointense to cerebrospinal fluid on images obtained with all pulse sequences. They appear hypointense relative to brain on T1-weighted MR scans and present a high signal intensity on T2-weighted MR scans. They also show complete signal suppression on fluid-attenuated inversion recovery (FLAIR) scans and no enhancement after intravenous contrast administration. However, many pathologic states result in abnormal dilation with an increased number of Virchow-Robin spaces visible on MRI imaging and many pathological conditions cause the spaces to enhance. The purpose of this study is to present the major causes of Virchow-Robin enhancement.
Low Grade Gliomas. Can We Predict Tumour Behaviour from Imaging Features?
Authors: Romanowski C.A.J. , Hoggard N. , Jellinek D.A. , Levy David , Wharton S.B. , Kotsarini C. , Batty R. , Wilkinson I.D.
Published: April 2015

Low grade gliomas (WHO grade II) are diffuse, infiltrative glial tumours of the brain. The low grade glioma group includes a number of entities, namely diffuse astrocytoma, oligodendroglioma and oligoastrocytoma. This group of the low-grade gliomas share certain common issues of behaviour, clinical assessment and management. Even though these tumours are termed low grade they are not to be considered “benign”: untreated they are invariably fatal. They may remain “stable” for many years and hence a “watch and wait” treatment policy is often adopted. Unfortunately some tumours progress more rapidly than others with dedifferentiation into high grade tumours which become rapidly fatal. Based on standard imaging criteria it has been difficult to predict which of these low grade gliomas will progress more rapidly. Treatment decisions would benefit from some prediction as to which tumours are likely to progress more rapidly than others. This review will discuss some of the imaging features that may help to predict which low grade gliomas will progress more rapidly than others. Such imaging features include the rate of growth on serial imaging; the morphological features that parallel genetic markers; the assessment and change of tumour vascular status as assessed by MR perfusion imaging and tumour characteristics on PET and MR spectroscopy.
Endovascular Treatment of Large Intracranial Aneurysms by Neuroform Stent-Assisted Coil Placement
Authors: Mu Shiqing , Yang Xingjian , Li Youxiang , Lv Ming , Wu Zhongxue
Published: April 2015

Large intracranial aneurysms represent huge therapeutic challenges for neurosurgeons and endovascular therapists. Since they may involve entire vessels or be irregular in shape, the ratio of complete obliteration of these aneurysms with detachable coils is low and the incidence of recanalisation is very high. So the technique of stent-assisted coil placement was designed for the treatment of large intracranial aneurysms. We report our experience in the treatment of large or complex and wide-necked aneurysms using Neuroform stent-assisted coil placement. Thirty-six patients harboring large intracranial aneurysms were treated by Neuroform stent-assisted coil placement. Thirty-five Neuroform stents were delivered and deployed at the desired location. Of the 35 aneurysms successfully stented, all the aneurysms were occluded with stent-assisted coiling. Twenty-six were totally occluded, four achieved subtotal occlusion, and five incomplete occlusion at the end of the procedure. There were no complications related to the procedure except the migration of stents in two cases. All the patients recovered well. Though Neuroform stent-assisted coil placement may be a favorable technique for treatment of large intracranial aneurysms, further study is necessary to assess the long-term outcome.
Lung Cancer Single Intramedullary Metastasis Vs Delayed Radionecrosis
Authors: Conforti R. , Tagliatatela G. , De Cristoforo M. , Di Costanzo A. , Scuotto A. , Sanpaolo S. , Dericoloso A. , Cirillo S.
Published: April 2015

Intramedullary metastases are rare, accounting for 0.9–5% of spinal metastases. Radiation myelopathy is considered one of the most distressing complications of radiotherapy. In both cases symptoms are aspecific, and there are no characteristic neuroradiologic findings. We describe a case of single intramedullary metastasis from lung microcytoma in a 55-year-old man with a history of malignancy, treated by radiotherapy five years previously. The patient returned to our observation complaining of pain and paraesthesia in the left C7 area. Spinal MRI and rachicentesis findings were aspecific. Ten days later a new MRI showed that the lesion size had increased, and neoplastic cells were found in CSF. Intramedullary metastases are extremely rare, accounting for 0.1–0.4% of all CNS tumors. The risk of developing delayed radionecrosis varies with the total dose administered. In both cases diagnosis is histological, while contrast-enhanced MRI is highly sensitive and specific in identifying and characterizing the lesion. In case of metastatic lesions the prognosis is unfavorable. Differential diagnosis is important because it has a strong effect on patient management.
Multi-Contrast, Isotropic, Single-Slab 3D MR Imaging in Multiple Sclerosis
Authors: Moraal Bastiaan , Roosendaal Stefan D. , Pouwels Petra J. W. , Vrenken Hugo , van Schijndel Ronald A. , Meier Dominik S. , Guttmann Charles R. G. , Geurts Jeroen J. G. , Barkhof Frederik
Published: April 2015

To describe signal and contrast properties of an isotropic, single-slab 3D dataset [double inversion-recovery (DIR), fluid-attenuated inversion recovery (FLAIR), T2, and T1-weighted magnetization prepared rapid acquisition gradient-echo (MPRAGE)] and to evaluate its performance in detecting multiple sclerosis (MS) brain lesions compared to 2D T2-weighted spin-echo (T2SE). All single-slab 3D sequences and 2D-T2SE were acquired in 16 MS patients and 9 age-matched healthy controls. Lesions were scored independently by two raters and characterized anatomically. Two-tailed Bonferroni-corrected Student's t-tests were used to detect differences in lesion detection between the various sequences per anatomical area after log-transformation. In general, signal and contrast properties of the 3D sequences enabled improved detection of MS brain lesions compared to 2D-T2SE. Specifically, 3D-DIR showed the highest detection of intracortical and mixed WM-GM lesions, whereas 3D-FLAIR showed the highest total number of WM lesions. Both 3D-DIR and 3D-FLAIR showed the highest number of infratentorial lesions. 3D-T2 and 3D-MPRAGE did not improve lesion detection compared to 2D-T2SE. Multi-contrast, isotropic, single-slab 3D MRI allowed an improved detection of both GM and WM lesions compared to 2D-T2SE. A selection of single-slab 3D contrasts, for example, 3D-FLAIR and 3D-DIR, could replace 2D sequences in the radiological practice.
Interventional Neuroradiology Marriage
Authors: Prosetti D.
Published: April 2015

Nadia and I wanted a simple intimate wedding that would also be memorable. We also wanted to get married on the island of Elba, a place that means so much to us.
Orbital Cavernous Hemangiomas: Ultrasound and Magnetic Resonance Imaging Evaluation
Authors: Diamantopoulou A. , Damianidis Ch. , Kyriakou V. , Kotziamani N. , Emmanouilidou M. , Goutsaridou F. , Tsitouridis I.
Published: April 2015

Cavernous hemangioma is the most common intraorbital lesion in adults. The aim of our study was to evaluate the magnetic resonance imaging (MRI) and ultrasound (US) characteristics of cavernous hemangioma and their role in the differential diagnosis of orbital tumors. Eight patients with orbital cavernous hemangiomas, five women and three men with a mean age of 48 years were examined in a period of six years. All patients underwent MRI examination and four patients were also evaluated by US. In all cases MRI depicted a well-defined intraconal tumor. The lesions were homogeneous, isointense to muscle on T1-weighted sequence and hyperintense to muscle on T2-weighted sequence in six patients. In one patient the mass was isointense on T1WI with heterogeneous signal intensity on T2WI and in one patient the lesion had heterogeneous signal intensity on both T1- and T2-weighted sequences. After intravenous contrast medium administration, the tumors showed initial inhomogeneous enhancement with progressive accumulation of contrast material on delayed images in seven patients and initial homogeneous enhancement in one patient. On ultrasonography, the orbital masses appeared slightly hyperechoic, heterogeneous with small areas of slow blood flow. The analysis of imaging characteristics of a well-defined intraconal lesion in an adult patient with painless progressive proptosis can be highly suggestive of the diagnosis of cavernous hemangioma.