We present two types of Si photonics-wireless interface (PWI) integrated circuits (ICs) realized in standard Si technology. Our PWI ICs convert optical signals into radio-frequency (RF) signals for downlink remote antenna units in fiber-wireless networks. Characterization and modeling of Si avalanche photodetectors (APDs) fabricated in two different Si technologies are carried out and used for ...

This article presents a cognitive model that reconciles a surprising observation in the picture-word interference (PWI) paradigm with the general notion that PWI is a form of Stroop interference. Dell'Acqua, Job, Peressotti, and Pascali (2007) assessed PWI using a psychological refractory period (PRP) paradigm, and concluded that the locus of interference in PWI is during the perceptual encodin...

BACKGROUND AND PURPOSE For MR perfusion-diffusion (PWI-DWI) mismatch to become routine in thrombolysis patient selection, rapid and reliable assessment tools are required. We examined interrater variability in PWI/DWI volume measurements and developed a rapid assessment tool based on the Alberta Stroke Program Early CT Scores (ASPECTS) system. METHODS DWI and PWI were performed in 35 patients...

Introduction: One of the goals of MR imaging in acute ischemic stroke (AIS) is to identify tissue, which can be salvaged with reperfusion therapies. The salvageable tissue with MRI is approximated as regions of perfusion change without a corresponding diffusion abnormality and termed as the diffusion–perfusion mismatch [1]. Though the ease of its measurement has made mismatch (MM) an attractive...

BACKGROUND AND PURPOSE The perfusion-weighted imaging (PWI)-diffusion-weighted imaging (DWI) mismatch paradigm is widely used in stroke imaging studies. Arterial spin labeling (ASL) is an alternative perfusion method that does not require contrast. This study compares the agreement of ASL-DWI and PWI-DWI mismatch classification in patients with stroke. METHODS This was a retrospective study d...

BACKGROUND AND PURPOSE We generated regional cerebral blood volume (rCBV) and regional cerebral blood flow (rCBF) studies from dynamic susceptibility contrast-enhanced MR images after an intravenous bolus injection of contrast agent (perfusion-weighted imaging [PWI]) by applying indicator dilution theory. We used a multishot echo-planar imaging (EPI) sequence to obtain adequate arterial input f...

BACKGROUND Postoperative wound infection (PWI) after intracranial neurosurgery remains a significant worldwide problem, resulting in substantial morbidity/mortality if not combatted quickly and energetically. Although the danger of PWI is universally recognized, the reported incidence of PWI after intracranial neurosurgery remains variable, ranging from 1% to 8% in published series. The impact ...

BACKGROUND AND PURPOSE The absence of acute ischemic lesions in diffusion-weighted imaging (DWI) in transient ischemic attack (TIA) patients makes it difficult to diagnose the true vascular etiologies. Among patients with DWI-negative TIA, we investigated whether the presence of a perfusion-weighted imaging (PWI) abnormality implied a true vascular event by identifying new acute ischemic lesion...

BACKGROUND AND PURPOSE It has been reported that National Institutes of Health Stroke Scale (NIHSS) scores correlate poorly with hypoperfused tissue measured by perfusion-weighted imaging (PWI) in nondominant hemisphere stroke. We conducted 2 studies to determine whether tests of hemispatial neglect provide a better measure of hypoperfusion and reperfusion than NIHSS in nondominant hemisphere s...

BACKGROUND AND PURPOSE The classical representation of acute ischemic lesions on MRI is a central diffusion-weighted imaging (DWI) lesion embedded in a perfusion-weighted imaging (PWI) lesion. We investigated spatial relationships between final infarcts and early DWI/PWI lesions before and after intravenous thrombolysis in the Diffusion and perfusion imaging Evaluation For Understanding Stroke ...