Publications by authors named "Shibukawa S"

Background: Diffusion Tensor Image Analysis Along the Perivascular Space (DTI-ALPS) evaluates the glymphatic system in patients with idiopathic normal-pressure hydrocephalus (iNPH). However, white matter compression due to ventricular enlargement may affect the ALPS index. This study aimed to investigate the relationship among the ALPS index, white matter changes, and clinical symptoms in patients with iNPH.

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Understanding muscle response to exercise is critical for optimizing training strategies. This study investigated the effects of dorsiflexion and plantar flexion exercises on T2* values in the tibialis anterior (TA) and soleus (SOL) muscles and explored their relationship with muscle cross-sectional area (MCA), strength, and perceived exertion. Forty participants were divided into two exercise protocols: 30 performed dorsiflexion, 16 performed plantar flexion, and 6 completed both.

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Ex vivo studies of the brain are often employed as experimental systems in neuroscience. In general, brains for ex vivo MRI studies are usually fixed with paraformaldehyde to preserve molecular structure and prevent tissue destruction during long-term storage. As a result, fixing brain tissue causes microstructural changes and a decrease in brain volume.

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The common marmoset is an essential model for understanding social cognition and neurodegenerative diseases. This study explored the structural and functional brain connectivity in a marmoset under isoflurane anesthesia, aiming to statistically overcome the effects of high inter-individual variability and noise-related confounds such as physiological noise, ensuring robust and reliable data. Similarities and differences in individual subject data, including assessments of functional and structural brain connectivities derived from resting-state functional MRI and diffusion tensor imaging were meticulously captured.

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Introduction: This study aimed to evaluate the potential of dual-energy computed tomography (CT) to distinguish postoperative ascites, pancreatic fistula, and abscesses.

Materials And Method: Patients who underwent biliary and pancreatic surgery performed at our institution between June 2021 and February 2022 were included in the study. Postoperative body fluid samples were collected through a drain or percutaneous drainage.

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In normal-pressure hydrocephalus, disturbances in cerebrospinal fluid (CSF) circulation occur; therefore, understanding CSF dynamics is crucial. The two-dimensional phase-contrast (2D-PC) method, a common approach for visualizing CSF flow on MRI, often presents challenges owing to prominent vein signals and excessively high contrast, hindering the interpretation of morphological information. Therefore, we devised a new imaging method that utilizes T-weighted high-signal intensification of the CSF and saturation pulses, without requiring specialized imaging sequences.

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Lipid nanoparticles often contain a phosphatidylcholine with a long chain fatty acid, 1,2-distearoyl--3-phosphocholine (DSPC). However, their preparation often encounters difficulties such as the inability to yield <20 nm nanoparticles due to the aggregation-prone behavior of DSPC. High-density lipoproteins (HDLs) are ∼10 nm protein-bound lipid nanoparticles in our body, and microfluidic preparations of HDL-mimicking nanoparticles (μHDL) have been reported.

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Article Synopsis
  • - The study investigates the effectiveness of a new lower extremity MRA technique (TSE-Acc), which uses enhanced acceleration-selective arterial spin labeling, in diagnosing peripheral arterial disease (PAD) without relying on ECG or contrast agents, thus reducing risks like nephrogenic systemic fibrosis.
  • - Nine healthy volunteers and a patient with PAD underwent MRI scans to assess various metrics like signal intensity ratio (SIR), contrast-to-noise ratio (CNR), arterial visibility, and artifact contamination, using statistical tests for analysis with significance set at p < 0.05.
  • - The results indicated that while SIRs were similar across three MRA methods, TSE-Acc showed significantly higher CNRs in some arteries and
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Using theta burst stimulation (TBS) to induce neural plasticity has played an important role in improving the treatment of neurological disorders. However, the variability of TBS-induced synaptic plasticity in the primary motor cortex prevents its clinical application. Thus, factors associated with this variability should be explored to enable the creation of a predictive model.

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Quantitative susceptibility mapping is a magnetic resonance imaging technique that measures brain tissues' magnetic susceptibility, including iron deposition and myelination. This study examines the relationship between subcortical volume and magnetic susceptibility and determines specific differences in these measures among patients with major depressive disorder (MDD), patients with schizophrenia, and healthy controls (HCs). This was a cross-sectional study.

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The drug loading capacity of an engineered lipoprotein (eLP1) and the colloidal stability of drug-loaded eLP1s were assessed with 12 drugs with different charges/hydrophobicities. The capacity was largely correlated with their log P values, and the binding to the protein moiety was suggested for two drugs. The size of drug-loaded eLP1 formulations after freeze-drying followed by resolubilization hardly changed.

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The internalization of engineered high-density lipoprotein nanoparticles (engineered lipoproteins [eLPs]) with different lipid and protein compositions, zeta potentials, and/or sizes were analyzed in representative plant and mammalian cells. The impact of the addition of a cell-penetrating peptide to eLPs on the internalization was very small in Bright Yellow (BY)-2 protoplasts compared with HeLa cells. When eLPs were prepared with one of the abundant lipids in BY-2 cells, digalactosyldiacylglycerol (DGDG) (eLP4), its internalization was dramatically increased only in HeLa cells.

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Motion artefacts caused by the patient's body movements affect magnetic resonance imaging (MRI) accuracy. This study aimed to compare and evaluate the accuracy of motion artefacts correction using a conditional generative adversarial network (CGAN) with an autoencoder and U-net models. The training dataset consisted of motion artefacts generated through simulations.

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Punctate white matter lesions (PWMLs) in infants may be related to neurodevelopmental outcomes based on the location or number of lesions. This study aimed to assess the automatic detectability of PWMLs in infants on deep learning using composite images created from several cases. To create the initial composite images, magnetic resonance (MR) images of two infants with the most PWMLs were used; their PWMLs were extracted and pasted onto MR images of infants without abnormality, creating many composite PWML images.

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Objective: Brain temperature monitoring using a catheter thermometer has been reported to be a useful technique to predict prognosis in neurosurgery. To investigate the possibility of measuring intracranial cerebrospinal fluid temperature for postoperative monitoring in patients with Moyamoya disease (MMD) after bypass surgery.

Materials And Methods: This study evaluated fifteen patients with MMD who were indicated for bypass surgery.

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Arm positions employed during magnetic resonance imaging (MRI) can affect magnetic field distribution, which may result in variability in proton density fat fraction (PDFF) measurements. This study evaluated the effect of arm position on lumbar PDFF measured using chemical-shift-encoded MRI (CSE-MRI). Fifteen healthy volunteers from a single-center underwent lumbar CSE-MRI at two different arm positions (side and elevated) using a single 3T scanner.

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Background: To evaluate the possible clinical use of the compressed sensing-volumetric-interpolated breath-hold examination (CS-VIBE) in patients with liver tumors by evaluating tumor contrast enhancement effect by radiologists.

Methods: We examined 22 patients with pathologically confirmed neoplastic lesions in the liver and 62 patients with lesions confirmed by imaging and clinical observation. To evaluate image quality, dynamic contrast-enhanced multiphase breath-hold magnetic resonance imaging was performed.

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To reduce the determination errors of CSF pulsation in diffusion-weighted image (DWI) thermometry, we investigated whether applying second-order motion compensation diffusion tensor imaging (2nd-MC DTI) and fractional anisotropy (FA) processing improves the measurement of intracranial cerebrospinal fluid (CSF) temperature. In a phantom study, we investigated the relationship between temperature and FA in artificial CSF (ACSF) to determine the threshold for FA processing. The calculated temperatures of ACSF were compared with those of water.

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Purpose: To evaluate the influence of arm position on B and proton density fat fraction (PDFF) in the liver using chemical shift-encoded magnetic resonance imaging.

Materials And Methods: Participants were 8 healthy volunteers without liver disease and 36 patients with presumed or proven fatty liver. We assessed two preliminary examinations in healthy subjects, i.

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Purpose: Enhanced acceleration selective arterial spin labeling (eAccASL) was introduced as non-enhanced and non-gated magnetic resonance angiography (MRA). This technique has not been applied to hand MRA. The objective of this study was to optimize the eAccASL for MRA of the hands and to investigate the factors for MRA visibility of the hands.

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This study aimed to assess the feasibility for applying enhanced acceleration-selective arterial spin labeling (eAccASL) to non-electrocardiogram-gated and non-enhanced peripheral MRA. We compared eAccASL and background suppressed single shot turbo field echo (TFE)-triggered angiography non-contrast-enhanced sequence (BASS TRANCE) required electrocardiographic-gating in eight volunteers and three patients. In the volunteer study, eAccASL demonstrated a comparable arterial visualization compared with BASS TRANCE.

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Superficial siderosis is a progressively disabling disease caused by recurrent subarachnoid hemorrhage with accumulation of hemosiderin in the surface of the central nervous system. Although a wide variety of conditions may cause superficial siderosis, approximately half of the cases are reported to be associated with a defect in the ventral spinal dura mater, in which case treatment entails surgical repair of the defect. Here, we report a case of superficial siderosis and report on our method to pinpoint the dural defect using a combination of magnetic resonance imaging (MRI) techniques.

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DWI thermometry is affected by CSF pulsation. To achieve more accurate determination of intraventricular temperature, we compared conventional DWI (c-DWI), acceleration motion compensation DWI (aMC-DWI), and motion compensation DWI (MC-DWI) when using two different b values (commonly used b value [1000 s/mm] and theoretically optimized b value according to the diffusion coefficient of the CSF [400 s/mm]). Eight healthy volunteers were scanned using a 3.

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High-density lipoprotein (HDL) is a naturally occurring composite of lipids and lipid-binding proteins. The cholate dialysis method, first reported by Jonas in 1969, is the most widely used approach for reconstituting discoidal HDL (dHDL) in test tubes with phospholipids and the most dominant protein, apolipoprotein A-1 (apoA-I). Here, we show that a dHDL-relevant complex can also be prepared by gently mixing 1,2-dimyristoyl--glycero-3-phosphocholine (DMPC) and apoA-I or its mutants in ethanol/HO solutions containing urea at a concentration of a few molar and then incubating the mixture at the gel-liquid crystalline phase transition temperature in test tubes.

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The feasibility of the 3D dynamic improved motion-sensitized driven-equilibrium steady-state free precession (3D dynamic iMSDE SSFP) was evaluated for visualizing CSF motion and the appropriate parameters were determined. Both flow phantom and volunteer studies revealed that linear ordering and the shortest acquisition duration time were optimal. 3D dynamic iMSDE SSFP provides good quality imaging of CSF motion in the whole brain and enables visualization of flow in arbitrary planes from a single 3D volume scan.

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