Prognostic value of collateral perfusion estimation by arterial spin labeling for acute anterior circulation ischemic stroke.

Purpose: This study aimed to verify the value of arterial spin labeling (ASL) collateral perfusion estimation for predicting functional outcomes in acute anterior circulation ischemic stroke.

Methods: This secondary analysis of an ongoing prospective observational study included data from participants with acute ischemic stroke due to steno-occlusion of the internal carotid artery and/or the middle cerebral artery within 8 h of symptom onset. We compared the collateral map, which is a 5-phase collateral imaging derived from dynamic contrast-enhanced magnetic resonance angiography, and ASL to validate the ASL collateral perfusion estimation.

Subtle Cognitive Deficits Are Associated with Amyloid-β Positivity, but Not Severity of Self-Reported Decline: Results from the CoSCo Study.

Introduction: Subjective cognitive decline (SCD) can be considered as the preclinical manifestation of Alzheimer's disease (AD). The National Institute on Aging and the Alzheimer's Association criteria for preclinical AD proposed that subtle cognitive changes appear along with AD biomarkers in the late stage of preclinical AD. The objective of this study was to explore whether subtle cognitive impairment (SCI) in individuals with SCD is associated with brain amyloid-β (Aβ) status and SCD severity.

Collateral and permeability imaging derived from dynamic contrast material-enhanced MR angiography in prediction of PH 2 hemorrhagic transformation after acute ischemic stroke: a pilot study.

Purpose: To evaluate the role of collateral and permeability imaging derived from dynamic contrast material-enhanced magnetic resonance angiography to predict PH 2 hemorrhagic transformation in acute ischemic stroke.

Methods: The secondary analysis of a published data from participants with acute ischemic stroke. The multiphase collateral map and permeability imaging were generated by using dynamic signals from dynamic contrast material-enhanced magnetic resonance angiography obtained at admission.

Multiphase MR Angiography Collateral Map: Functional Outcome after Acute Anterior Circulation Ischemic Stroke.

Background Collateral circulation determines tissue fate and affects treatment result in acute ischemic stroke. A precise method for collateral estimation in an optimal imaging protocol is necessary to make an appropriate treatment decision for acute ischemic stroke. Purpose To verify the value of multiphase collateral imaging data sets (MR angiography collateral map) derived from dynamic contrast material-enhanced MR angiography for predicting functional outcomes after acute ischemic stroke.

Coexistence of Cerebral Microbleeds and Amyloid Pathology in Patients with Cognitive Complaints.

Background And Purpose: We investigated the prevalence of amyloid positivity and cerebral microbleeds (CMBs) in subjects with cognitive complaints with the aim of identifying differences in clinical parameters and cognitive function according to the pattern of coexistence.

Methods: We retrospectively enrolled 200 subjects with memory impairment and applied both standardized ¹⁸F-florbetaben PET and brain MRI, including susceptibility-weighted imaging. The amyloid burden was visually classified as positive or negative, and the number and location of CMBs were also analyzed visually.

Different Cortical Thinning Patterns Depending on Their Prognosis in Individuals with Subjective Cognitive Decline.

Background And Purpose: Subjective cognitive decline (SCD) may be the first stage corresponding to subtle cognitive changes in patients with Alzheimer's disease (AD) spectrum disorders. We evaluated the differences in cortical thinning patterns among patients with SCD who progressed to mild cognitive impairment or dementia (pSCD), those who remained stable (sSCD), and healthy normal controls (NCs).

Methods: We retrospectively recruited SCD subjects (14 pSCD and 21 sSCD cases) and 29 NCs.

Self- and informant-reported cognitive functioning and awareness in subjective cognitive decline, mild cognitive impairment, and very mild Alzheimer disease.

Objectives: The present study examined self-reports and informant reports of cognitive function and discrepancies between the two reporting methods in healthy controls (HC), subjective cognitive decline (SCD), mild cognitive impairment (MCI), and very mild Alzheimer disease (AD) using three questionnaires.

Methods: The study included a total of 300 individuals (mean age: 74.4 ± 5.

See-Through Type 3D Head-Mounted Display-Based Surgical Microscope System for Microsurgery: A Feasibility Study.

Background: The surgical microscope is used primarily for microsurgeries, which are more complicated than other surgical procedures and require delicate tasks for a long time. Therefore, during these surgical procedures, surgeons experience back and neck pain. To solve this problem, new technology, such as wearable displays, is required to help surgeons maintain comfortable postures and enjoy advanced functionality during microsurgery.

Developing a Computational Model of Renal Nerves and Surgical System for Laparoscopic Renal Denervation.

The sympathetic nervous system was known to play an important role in resistant hypertension. Surgical sympathectomy for renal sympathetic nerve removal were performed since the 1930s. Although effective, it had many serious side effects and complications due to non-selective property.

Design and simulation of novel laparoscopic renal denervation system: a feasibility study.

Purpose: In this study, we propose a novel laparoscopy-based renal denervation (RDN) system for treating patients with resistant hypertension. In this feasibility study, we investigated whether our proposed surgical instrument can ablate renal nerves from outside of the renal artery safely and effectively and can overcome the depth-related limitations of the previous catheter-based system with less damage to the arterial walls.

Method: We designed a looped bipolar electrosurgical instrument to be used with laparoscopy-based RDN system.

Smartphone-Based Endoscope System for Advanced Point-of-Care Diagnostics: Feasibility Study.

Background: Endoscopic technique is often applied for the diagnosis of diseases affecting internal organs and image-guidance of surgical procedures. Although the endoscope has become an indispensable tool in the clinic, its utility has been limited to medical offices or operating rooms because of the large size of its ancillary devices. In addition, the basic design and imaging capability of the system have remained relatively unchanged for decades.

Hippocampal and entorhinal structures in subjective memory impairment: a combined MRI volumetric and DTI study.

Background: Subjective memory impairment (SMI) is common among older adults. Increasing evidence suggests that SMI is a risk factor for future cognitive decline, as well as for mild cognitive impairment and dementia. Medial temporal lobe structures, including the hippocampus and entorhinal cortex, are affected in the early stages of Alzheimer's disease.

The Influence of Flush Methods on Transfemoral Catheter Cerebral Angiography: Continuous Flush versus Intermittent Flush.

Purpose: To evaluate the influence of different flush methods on transfemoral cerebral angiography (TFCA).

Materials And Methods: This single-blind randomized controlled trial included 50 patients who had undergone TFCA. Balanced block randomization was used to allocate participants into intermittent-flush (n = 25) and continuous-flush (n = 25) groups.

Memory complaints in subjective cognitive impairment, amnestic mild cognitive impairment and mild Alzheimer's disease.

Memory complaints are a frequent phenomenon in elderly individuals and can lead to opportunistic help-seeking behavior. The aim of this study was to compare different aspects of memory complaints (i.e.

Subjective memory complaints, depressive symptoms and instrumental activities of daily living in mild cognitive impairment.

Background: The diagnostic relevance of subjective memory complaints (SMCs) in mild cognitive impairment (MCI) remains to be unresolved. The aim of this study is to determine clinical correlates of SMCs in MCI. Furthermore, we examined whether there are the differences due to different aspects of complaints (i.

Effects of insulin resistance on white matter microstructure in middle-aged and older adults.

Objective: To investigate the potential relationship between insulin resistance (IR) and white matter (WM) microstructure using diffusion tensor imaging in cognitively healthy middle-aged and older adults.

Methods: Diffusion tensor imaging was acquired from 127 individuals (age range 41-86 years). IR was evaluated by the homeostasis model assessment of IR (HOMA-IR).

Fast mapping of absorbing defects in optical materials by full-field photothermal reflectance microscopy.

We report a technique for rapidly mapping absorbing defects in optical materials, which act as laser-induced damage precursors, based on full-field photothermal reflectance microscopy. An intensity-modulated pump beam heats absorbing defects in the optical sample, creating localized, modulated refractive-index variations around the defects. A probe beam then illuminates the defect sites, and the measured amplitude of the reflectance variation is used to map the distribution of defects in the medium.

High-speed thermoreflectance microscopy using charge-coupled device-based Fourier-domain filtering.

We present a Fourier-domain filtering method for charge-coupled device (CCD)-based thermoreflectance microscopy to improve the thermal imaging speed while maintaining high thermal sensitivity. The time-varying reflected light distribution from the surface of bias-modulated microresistor was recorded by a CCD camera in free-run mode and converted to the frequency domain using the fast Fourier transform (FFT) for all pixels of the CCD. After frequency peak filtering followed by inverse FFT, a thermoreflectance image was obtained.

Precise temperature mapping of GaN-based LEDs by quantitative infrared micro-thermography.

A method of measuring the precise temperature distribution of GaN-based light-emitting diodes (LEDs) by quantitative infrared micro-thermography is reported. To reduce the calibration error, the same measuring conditions were used for both calibration and thermal imaging; calibration was conducted on a highly emissive black-painted area on a dummy sapphire wafer loaded near the LED wafer on a thermoelectric cooler mount. We used infrared thermal radiation images of the black-painted area on the dummy wafer and an unbiased LED wafer at two different temperatures to determine the factors that degrade the accuracy of temperature measurement, i.

Low bone mineral density is associated with poor clinical outcome in acute ischemic stroke.

Background: Chronic low bone mineral density is associated with an increased risk of stroke. However, little is known about the influence of bone mineral density at the time of stroke on clinical outcome. We investigated the association between bone mineral density and functional disability at three-months in patients with acute ischemic stroke.

Acetazolamide-challenged perfusion magnetic resonance imaging for assessment of cerebrovascular reserve capacity in patients with symptomatic middle cerebral artery stenosis: comparison with technetium-99m-hexamethylpropyleneamine oxime single-photon emission computed tomography.

Objectives: Acetazolamide-challenged perfusion magnetic resonance imaging (MRI) has been shown as a method for assessment of cerebrovascular reserve (CVR) capacity in patients with atherosclerotic steno-occlusive disease of internal carotid artery. We have assessed the feasibility of the acetazolamide-challenged perfusion MRI for evaluating CVR in symptomatic patients with severe middle cerebral artery (MCA) stenosis (≥70%) by comparison with the acetazolamide-challenged technetium-99m-hexamethylpropyleneamine oxime (HMPAO) single-photon emission computed tomography (SPECT).

Methods: Seventeen prospectively enrolled patients with symptomatic unilateral MCA stenosis underwent technetium-99m-hexamethylpropyleneamine oxime SPECT and perfusion MRI without and with acetazolamide challenge, respectively.

Microlensed dual-fiber probe for depth-resolved fluorescence measurements.

We propose and demonstrate a compact microlensed dual-fiber probe that has a good collection efficiency and a high depth-resolution ability for fluorescence measurements. The probe is formed with a conventional fusion splicer creating a common focusing lens on two fibers placed side by side. The collection efficiency of the fabricated probe was evaluated by measuring the fluorescence signal of a fresh ginkgo leaf.

Measurement of precuneal and hippocampal volumes using magnetic resonance volumetry in Alzheimer's disease.

Background And Purpose: Alzheimer's disease (AD) is associated with structural alterations in the medial temporal lobe (MTL) and functional alterations in the posterior cortical region, especially in the early stages. However, it is unclear what mechanisms underlie these regional discrepancies or whether the posterior cortical hypometabolism reflects disconnection from the MTL lesion or is the result of local pathology. The precuneus, an area of the posteromedial cortex that is involved in the early stages of AD, has recently received a great deal of attention in functional neuroimaging studies.

Nonlinear endomicroscopy using a double-clad fiber coupler.

A double-clad fiber coupler is developed to be used in two-photon-excited fluorescence endomicroscopy to replace a dichroic mirror and separate the fluorescence signal from the excitation laser beam. With the double-clad fiber coupler, the endomicroscope becomes more compact, easier to be aligned, and more stable in alignment. The double-clad fiber coupler can transmit 62% of the excitation laser beam through the core.

Ultrawideband photonic crystal fiber coupler for multiband optical imaging system.

We report a photonic crystal fiber (PCF) coupler having an ultrawide spectral bandwidth keeping single mode operation. The use of the PCF coupler in a fiber-based optical coherence tomography (OCT) system enables us to handle the wide spectral bands of various light sources, including superluminescent diodes (SLDs) at 1300 nm and 820 nm, Ti:sapphire lasers, and white-light sources. The multiband imaging performances of the PCF-based OCT system are demonstrated by obtaining dental images at 1300 nm and 820 nm with the same setup.