Publications by authors named "Higaki T"

Article Synopsis
  • Diffusion-weighted imaging (DW imaging) is a vital magnetic resonance imaging technique used primarily for diagnosing acute cerebral infarctions and for oncologic assessments.
  • Computed DW imaging synthesizes enhanced DW images from existing measurements, resulting in images with a stronger diffusion effect and higher signal-to-noise ratios while also reducing imaging time.
  • The accuracy of computed DW images depends on using the correct mathematical models (mono-, bi-, or triexponential) and ensuring proper alignment of the input data to minimize artifacts.
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Objective:: The purpose of the current study is to create a contrast medium extraction method using raw-data-based electron density (rED) and CT number from dual-energy CT (DECT) for automatic delineation of the contrast region.

Methods:: A CT-ED phantom containing tissue-equivalent inserts and an acrylic phantom with an iodinated contrast medium were scanned by DECT. The contrast medium extraction system was created using Python.

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Objectives: The objective of this study was to investigate the usefulness of model-based iterative reconstruction (IR) for detecting neointimal formations after carotid artery stenting.

Methods: In a cervical phantom harbouring carotid artery stents, we placed simulated neointimal formations measuring 0.40, 0.

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The optical properties of metal nanoparticles have attracted wide interest. Recent progress in controlling nanoparticles with atomic precision (often called nanoclusters) provide new opportunities for investigating many fundamental questions, such as the transition from excitonic to plasmonic state, which is a central question in metal nanoparticle research because it provides insights into the origin of surface plasmon resonance (SPR) as well as the formation of metallic bond. However, this question still remains elusive because of the extreme difficulty in preparing atomically precise nanoparticles larger than 2 nm.

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Background: IL-10 is a major anti-inflammatory cytokine that prevents inflammation-mediated tissue damage. We characterized the production of IL-10 by sinonasal tissue cells following exposure to Staphylococcus aureus enterotoxin B (SEB), which elicits cellular responses and is associated with the pathogenesis of eosinophilic chronic rhinosinusitis (ECRS).

Methods: Dispersed nasal polyp (NP) cells and uncinate tissue (UT) cells were prepared from patients with CRS with and without NP, respectively.

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We previously found that sucrose solution immersion treatment permitted ectopic guard cell differentiation, resulting in clustered stomatal guard cells. Using this system, we examined the effects of sucrose solution-induced stomatal clustering on guard cell cortical microtubules and the stomatal response to fusicoccin. Confocal observation revealed that the radial orientation of cortical microtubules was largely maintained in clustered guard cells.

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Conventional regimens for unresectable intrahepatic cholangiocarcinoma are considered of limited effectiveness. To evaluate the efficacy and toxicity of combination chemotherapy with hepatic arterial infusion of IA-call (a fine-powder formulation of cisplatin) plus oral S-1 in patients with unresectable intrahepatic cholangiocarcinoma. The clinicopathological data and long-term outcome of 12 patients who were received with IA-call plus S-1 were compared with those of 16 patients who were received other treatments, such as radiation therapy, trans-arterial chemoembolization, and systemic chemotherapy.

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To clarify whether high transient elevation of serum transaminase predicts severe complications and is related to the ischemic area on CT. Postoperative laboratory data and ischemia area on CT were analyzed on the basis of the presence of high transaminase elevation (aspartate aminotransferase (AST) > 1,000 IU/L within postoperative day (POD) 2 after liver resection. In the high elevation group, volume of ischemic areas was assessed by CT on POD2.

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Objective: To evaluate the effect of patient characteristics on popliteal aortic contrast enhancement at lower extremity CT angiography (LE-CTA) scanning.

Materials And Methods: Prior informed consent to participate was obtained from all 158 patients. All were examined using a routine protocol; the scanning parameters were tube voltage 100 kVp, tube current 100 mA to 770 mA (noise index 12), 0.

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Background: Resection of hepatocellular carcinoma located in the caudate lobe is challenging because this anatomical location is difficult to approach, especially the caval portion.

Methods: We performed resection of the caval portion of the caudate lobe using a ventral approach combined with the resection of segment IV, VII, or VIII for hepatocellular carcinoma in 41 patients (extended segmentectomy group). As a control group, 138 patients with hepatocellular carcinoma who underwent segmentectomy for IV, VII, or VIII (segmentectomy group) were studied.

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Arterial peak enhancement on contrast-enhanced CT (CECT) images is thought to be higher in patients with low cardiac function. Using computer simulations, we tested the hypothesis that the relationship between the cardiac index and the aortic peak CT number (PCTN) is affected by the contrast material (CM) injection duration. We created computer simulation software for the contrast enhancement of various organs and vessels based on the Bae pharmacokinetics model and implemented models for CM transmission within organs and CM diffusion in blood plasma based on the osmotic pressure.

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Background: Despite curative resection of hepatocellular carcinoma, patients have a high probability of recurrence. We examined indications for liver resection in cases of recurrent hepatocellular carcinoma.

Methods: Patients undergoing a second liver resection (n=210) or treatment by transcatheter arterial chemoembolization (n=184) for recurrent hepatocellular carcinoma of up to 3 lesions were included.

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Congenital long QT syndrome (LQTS) caused by compound mutations is usually associated with more severe clinical phenotypes. We identified a LQTS family harboring three compound mutations in different genes (KCNQ1-R174C, hERG-E1039X and SCN5A-E428K). KCNQ1-R174C, hERG-E1039X and SCN5A-E428K mutations and/or relevant wild-type (WT) cDNAs were respectively expressed in mammalian cells.

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Regulation of cortical microtubule reorganization is essential for plant cell survival under high salinity conditions. In response to salt stress, microtubules undergo rapid depolymerization followed by reassembly to form a new microtubule network that promotes cell survival; however, the upstream regulatory mechanisms for this recovery response are largely unknown. In this study, we demonstrate that ethylene signaling facilitates salt stress-induced reassembly of cortical microtubules in Arabidopsis ().

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Our previous report indicated that vascular injury enhances vascular remodeling in fetal growth restriction (FGR) mice. The angiotensin II type 2 receptor (ATR) is relatively highly expressed in fetal mice. Therefore, we investigated the roles of ATR in FGR-induced cardiovascular disease using ATR knockout (ATKO) mice.

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Objective: To compare the utility of high-precision computed diffusion-weighted imaging (hc-DWI) and conventional computed DWI (cc-DWI) for the diagnosis of hepatocellular carcinoma (HCC) at 3 T.

Methods: We subjected 75 HCC patients to DWI (b-value 150 and 600 s/mm). To generate hc-DWI we applied non-rigid image registration to avoid the mis-registration of images obtained with different b-values.

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Objectives: To investigate whether hepatic perfusion CT yields early imaging biomarkers predictive of the prognosis of hepatocellular carcinoma (HCC) patients treated with sorafenib.

Methods: We evaluated 36 HCC patients who underwent hepatic perfusion CT before- and one week after sorafenib therapy. We measured arterial and portal perfusion in the hepatic tumor and liver parenchyma [(AP)(PP)], [(AP)(PP)].

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The network structure of cellulose fibrils provides mechanical properties to the primary cell wall, thereby determining the shapes and growth patterns of plant cells. Despite intensive studies, the construction process of the network structure remains largely unknown, mainly due to the lack of a robust, straightforward technique to evaluate network configuration. Here, we developed a quantitative confocal imaging method for general use in the study of cell wall dynamics in protoplasts derived from Arabidopsis leaf mesophyll cells.

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Aim: Liver resection for hepatocellular carcinoma (HCC) has been recommended only for patients with a single tumor without portal hypertension. We aimed to validate this treatment strategy that is based on by the Barcelona Clinic Liver Cancer staging system.

Methods: Patients undergoing liver resection were divided into two groups: patients with single HCC without portal hypertension (Group 1) and those with at least one factors of portal hypertension and multiple tumors, up to three lesions each ≤3 cm (Group 2).

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22q11.2 deletion syndrome is one of the most common human microdeletion syndromes. The clinical phenotype of 22q11.

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Background: Congenital long QT syndrome (LQTS) can cause ventricular arrhythmic events with syncope and sudden death resulting from malignant torsades de pointes (TdP) followed by ventricular fibrillations (VFs). However, the syndrome is often overlooked prior to the development of arrhythmic events in patients with congenital heart diseases demonstrating right bundle branch block on electrocardiogram (ECG). We present a case of an adult patient with congenital heart disease who developed VFs postoperatively, potentially due to his mutation in a LQTS related gene, which was not identified on preoperative assessment due to incomplete evaluation of his family history.

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To assess a two-phase contrast injection protocol for contrast enhancement during cardiac computed tomography (CT) in children with congenital heart disease. Forty-three children (20 boys, 23 girls) of median age 13 months (range 3 days-8.3 years) and weighing ≤ 20 kg who underwent cardiac CT using a two-phase contrast injection protocol at our institution were retrospectively identified.

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Objective: To evaluate the accuracy of raw-data-based effective atomic number (Z) values and monochromatic CT numbers for contrast material of varying iodine concentrations, obtained using dual-energy CT.

Methods: We used a tissue characterization phantom and varying concentrations of iodinated contrast medium. A comparison between the theoretical values of Z and that provided by the manufacturer was performed.

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The transition from molecular to plasmonic behaviour in metal nanoparticles with increasing size remains a central question in nanoscience. We report that the giant 246-gold-atom nanocluster (2.2 nm in gold core diameter) protected by 80 thiolate ligands is surprisingly non-metallic based on UV/Vis and femtosecond transient absorption spectroscopy as well as electrochemical measurements.

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