Search

Supplementary Material 2

In the past three decades, cerebral ultrasound (CUS) has become a trusted technique to study the neonatal brain. It is a relatively cheap, non-invasive, bedside neuroimaging method available in nearly every hospital. Traditionally, CUS was used to detect major abnormalities, such as intraventricular hemorrhage (IVH), periventricular hemorrhagic infarction, post-hemorrhagic ventricular dilatation, and (cystic) periventricular leukomalacia (cPVL). The use of different acoustic windows, such as the mastoid and posterior fontanel, and ongoing technological developments, allows for recognizing other lesion patterns (e.g., cerebellar hemorrhage, perforator stroke, developmental venous anomaly). The CUS technique is still being improved with the use of higher transducer frequencies (7.5–18 MHz), 3D applications, advances in vascular imaging (e.g. ultrafast plane wave imaging), and improved B-mode image processing. Nevertheless, the helpfulness of CUS still highly depends on observer skills, knowledge, and experience. In this special article, we discuss how to perform a dedicated state-of-the-art neonatal CUS, and we provide suggestions for structured reporting and quality assessment.

White matter injury (WMI) is the most frequent form of preterm brain injury. Cranial ultrasound (CUS) remains the preferred modality for initial and sequential neuroimaging in preterm infants, and is reliable for the diagnosis of cystic periventricular leukomalacia. Although magnetic resonance imaging is superior to CUS in detecting the diffuse and more subtle forms of WMI that prevail in very premature infants surviving nowadays, recent improvement in the quality of neonatal CUS imaging has broadened the spectrum of preterm white matter abnormalities that can be detected with this technique. We propose a structured CUS assessment of WMI of prematurity that seeks to account for both cystic and non-cystic changes, as well as signs of white matter loss and impaired brain growth and maturation, at or near term equivalent age. This novel assessment system aims to improve disease description in both routine clinical practice and clinical research. Whether this systematic assessment will improve prediction of outcome in preterm infants with WMI still needs to be evaluated in prospective studies.

Neonatal brain sonography is part of routine clinical practice in neonatal intensive care units, but ultrasound imaging of the posterior fossa has gained increasing attention since the burden of perinatal acquired posterior fossa abnormalities and their impact on motor and cognitive neurodevelopmental outcome have been recognized. Although magnetic resonance imaging (MRI) is often superior, posterior fossa abnormalities can be suspected or detected by optimized cranial ultrasound (CUS) scans, which allow an early and bed-side diagnosis and monitoring through sequential scans over a long period of time. Different ultrasound appearances and injury patterns of posterior fossa abnormalities are described according to gestational age at birth and characteristics of the pathogenetic insult. The aim of this review article is to describe options to improve posterior fossa sequential CUS image quality, including the use of supplemental acoustic windows, to show standard views and normal ultrasound anatomy of the posterior fossa, and to describe the ultrasound characteristics of acquired posterior fossa lesions in preterm and term infants with effect on long-term outcome. The limitations and pitfalls of CUS and the role of MRI are discussed.

Germinal matrix-intraventricular haemorrhage (GMH-IVH), periventricular haemorrhagic infarction (PHI) and its complication, post-haemorrhagic ventricular dilatation (PHVD), are still common neonatal morbidities in preterm infants that are highly associated with adverse neurodevelopmental outcome. Typical cranial ultrasound (CUS) findings of GMH-IVH, PHI and PHVD, their anatomical substrates and underlying mechanisms are discussed in this paper. Furthermore, we propose a detailed descriptive classification of GMH-IVH and PHI that may improve quality of CUS reporting and prediction of outcome in infants suffering from GMH-IVH/PHI.

High Power Microwave (HPM) sources are widely used as signal sources in radar, jammer, and Counter Improvised Explosive Devices (CIED). Such devices usually are heavy and bulky, characteristics that are in conflict with the small weight and power (SWaP) approach so that it is practically impossible to mount such HPMs on several platforms with reduced spaces (e.g., avionic, UAVs). During the last century, several devices have been proposed, all of them heavy due to the components that they need such as the magnetic material of the Magnetron, Klystron, or Gyrotron. Considering the HPM sources for pulsed applications, the VIRtual CAThode oscillatOR (Vircator) represents the best candidate due to the compact dimension and reduced weight due to the absence of a magnetic source. The signal generated by this HPM device is characterized by a pulsed output power of some GW for a narrow frequency below 10 GHz. In this work, the analysis of the three most used types of Vircator, Axial Vircator, Coaxial Vircator, and Reflex Triode, is reported. A novel anode design and characterization procedure is reported, which led to the analysis of the interaction between electrons and a realistic anode grid.

We aim to present clinical features, imaging findings, treatment aspects of the elastofibroma dorsi (ED), which is a benign tumor arising from connective tissue at the scapular region, and long-term outcomes after surgical resection.We evaluated retrospectively 82 patients (55 females, 27 males; mean age, 60 years; age range, 23-78 years) with ED who underwent surgery between January 1994 and May 2014; subsequently all patients were invited for follow-up, which consisted of physical and US examinations.Subscapular location was almost constant (79/82 patients). Right, left and bilateral location was noted in 39, 28 and 15 cases, respectively. 52/82 patients were symptomatic. The diagnosis was made on physical examination and imaging studies: 49 ultrasound, 43 computed tomography and 54 magnetic resonance examinations were performed overall. Surgical treatment consisted in marginal excision; in all cases diagnosis was confirmed by histological examination. The mean hospitalization was 3 days, with minor complications. Out of the 82 patients, only 25 gave their consent to follow-up; mean time passed after surgery was 64.7 months; 1 case of local recurrence was suspected by ultrasound and, then, confirmed by magnetic resonance imaging.In our series, clinical features and imaging findings of ED are consistent with current evidence; however, results of our follow-up group marks a difference from the literature, according to which there is no evidence of local recurrence after complete resection. Diagnosis of ED is based on clinical and imaging features; treatment is surgical, especially in symptomatic cases. Prolonging the clinical and US follow-up period may be useful in identifying local recurrence.

A complete Tx/Rx module for avionic and naval applications was developed and tested. A multifunction PHEMT MMIC chip set was realized. Multi chip integration in hermetic MoCu package was adopted in order to reduce cost, space and assembly time. High performances in the Tx channel was achieved using a 4W wideband amplifier.

InGaAs/InP heterojunction bipolar transistors grown in a multi-wafer metal-organic chemicalvapor deposition system will be demonstrated.Excellent large and small area DC and RF results are obtained for single and double heterojunction structures. The large area DC current gain was increased by a factor of 3 at a given base sheet resistance via growth optimization. DHBT devices exhibit a current gain cut-off frequency of ft ~ 125 GHz and a unilateral gain cut-off frequency of fmax ~ 125 GHz.

ESM wide open receivers have need, next to antenna, to a wide bandwidth preamplifier with a low noise figure, in order to increase the sensitivity. It is also important to have a high output third order interception point to reduce the harmonics and spurious. For this reason a low noise MMIC GaAsFET Pseudomorphic HEMT amplifier has been designed and developed in collaboration with Alenia Ricerche Foundry. Based on a travelling-wave amplifier structure, this component has good performances in term of noise figure, bandwidth, return loss and output power.