Publications by authors named "Akio Yamazaki"

To evaluate the usefulness of low-keV multiphasic computed tomography (CT) with deep learning image reconstruction (DLIR) in improving the delineation of pancreatic ductal adenocarcinoma (PDAC) compared to conventional hybrid iterative reconstruction (HIR). Thirty-five patients with PDAC who underwent multiphasic CT were retrospectively evaluated. Raw data were reconstructed with two energy levels (40 keV and 70 keV) of virtual monochromatic imaging (VMI) using HIR (ASiR-V50%) and DLIR (TrueFidelity-H).

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The effect of irradiation during computed tomography (CT) imaging on implantable cardioverter-defibrillators (ICDs) has not been fully evaluated in various settings. The purposes of this study were to evaluate the occurrence of electromagnetic interference (EMI) during CT irradiation in various clinically available ICDs with phantom experiments and to determine the potential risks related to irradiation during CT imaging. Five types of clinically available ICDs from five manufacturers were tested.

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Many pneumonia patients do not produce sputum, and it is unknown whether purulent sputum is required for the identification of species. This study aimed to evaluate the identification rate of species based on sputum quality and the factors predictive of infection. This study included pneumonia patients at Kurashiki Central Hospital from November 2000 to December 2022.

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Article Synopsis
  • Altered gut microbiota may be linked to the development or progression of Chronic Obstructive Pulmonary Disease (COPD), and this study explored this association while considering smoking status.
  • The research involved a comparison of gut microbiomes among three groups: never-smokers, non-COPD ever-smokers, and COPD patients, using advanced gene sequencing techniques.
  • Results showed similarities in gut microbiota between COPD patients and non-COPD ever-smokers, but specific bacteria were identified as potential risk factors for COPD, suggesting a possible therapeutic target.
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Article Synopsis
  • The study investigates the long-term predictors of weight and muscle loss in patients with chronic obstructive pulmonary disease (COPD), focusing on functional and structural measures over an average follow-up of 5 years.
  • Utilizing chest CT scans, researchers measured airway and lung damage, muscle mass, and fat changes in 114 patients, finding that while body mass index remained stable, there were noticeable declines in muscle mass and increases in fat over time.
  • Key findings indicate that severe airflow limitation predicted future muscle wasting, suggesting that patients with a peak expiratory flow below 90% of the normal value may need interventions to prevent further muscle loss.
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Purpose: Disease probability measure (DPM) is a useful voxel-wise imaging assessment of gas-trapping and emphysematous lesions in patients with chronic obstructive pulmonary disease (COPD). To elucidate the progression of COPD, we performed a cluster analysis using the following DPM parameters: normal (DPM), gas-trapping (DPM), and emphysematous lesions (DPM). Our findings revealed the characteristics of each cluster and the 3-year disease progression using imaging parameters.

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A 72-year-old man with chronic obstructive pulmonary disease (COPD) was admitted for coronavirus disease 2019 (COVID-19). He was discharged on day 30; however, he was readmitted 6 days later due to a left lung organizing pneumonia secondary to COVID-19. After methylprednisolone treatment, the patient was discharged on day 15.

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The purpose is to evaluate whether deep learning-based denoising (DLD) algorithm provides sufficient image quality for abdominal computed tomography (CT) with a 30% reduction in radiation dose, compared to standard-dose CT reconstructed with conventional hybrid iterative reconstruction (IR). The subjects consisted of 50 patients who underwent abdominal CT with standard dose and reconstructed with hybrid IR (ASiR-V50%) and another 50 patients who underwent abdominal CT with approximately 30% less dose and reconstructed with ASiR-V50% and DLD at low-, medium- and high-strength (DLD-L, DLD-M and DLD-H, respectively). The standard deviation of attenuation in liver parenchyma was measured as image noise.

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This paper investigates how carbon taxes affect emissions by examining British Columbia's revenue-neutral carbon tax in the manufacturing sector. We theoretically demonstrate that carbon taxes can achieve emission reductions while increasing production. Recycling carbon tax revenues to lower corporate income tax rates encourages investments, allowing plants to emit less per unit of output.

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Objectives: To evaluate the usefulness of deep learning image reconstruction (DLIR) to improve the image quality of dual-energy computed tomography (DECT) of the abdomen, compared to hybrid iterative reconstruction (IR).

Methods: This study included 40 patients who underwent contrast-enhanced DECT of the abdomen. Virtual monochromatic 40-, 50-, and 70-keV and iodine density images were reconstructed using three reconstruction algorithms, including hybrid IR (ASiR-V50%) and DLIR (TrueFidelity) at medium- and high-strength level (DLIR-M and DLIR-H, respectively).

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Introduction: Whether inflammatory biomarkers including procalcitonin (PCT) and C-reactive protein (CRP) are useful for predicting prognosis in nursing and healthcare-associated pneumonia (NHCAP) is unknown. The aim of the present study was to investigate the utility of serial PCT and CRP measurements for predicting prognosis and treatment efficacy for hospitalized NHCAP patients.

Methods: This prospective, observational, cohort study enrolled consecutive NHCAP patients hospitalized at Kurashiki Central Hospital from October 2010 to September 2017.

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We retrospectively investigated the success rate of pulmonary arteriovenous separation in a single-phase computed tomography (CT) protocol using the estimated time of arrival (ETA) method. A total of 223 patients who underwent a single-phase CT protocol using the ETA method for pulmonary arteriovenous separation were included in the analysis. Dual source CT (SOMATOM Force, SIEMENS) was used for imaging.

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Introduction: Whether the sensitivity of the BinaxNOW Streptococcus pneumoniae urinary antigen test kit (BinaxNOW), adjusted by some variables including vital signs, laboratory examinations and pneumonia severity, has been decreasing is unknown. The aim of the present study was to investigate whether BinaxNOW sensitivity has decreased recently and to identify the predictors of the BinaxNOW result, including the time trend.

Methods: This prospective cohort study enrolled consecutive patients with pneumococcal community-acquired pneumonia who were hospitalised at Kurashiki Central Hospital from January 2001 to December 2015.

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The aim of the present study was to investigate the predictors of targeted therapy (TT) for pneumococcal community-acquired pneumonia (PCAP) with a positive urinary antigen test (UAT) and compare the outcomes with those of nontargeted therapy. This prospective cohort study enrolled consecutive PCAP patients with a positive UAT who were hospitalized at Kurashiki Central Hospital from October 2010 to November 2019. A total of 286 patients were included.

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Introduction: Whether β-lactam and macrolide combination therapy reduces mortality in severe community-acquired pneumonia (SCAP) patients hospitalized in the intensive care unit (ICU) is controversial. The aim of the present study was to evaluate the usefulness of β-lactam and macrolide combination therapy for SCAP patients hospitalized in the ICU.

Methods: A prospective, observational, cohort study of hospitalized pneumonia patients was performed.

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Introduction: Japan experienced a heavy rainfall event from June 28 to July 8, 2018, and many casualties were caused by both heavy rainfall and flooding. Few studies have investigated patients' characteristics and the causative pathogens of community-acquired pneumonia before and after heavy rainfall events. The aim of the present study was to evaluate the causative pathogens and clinical characteristics of hospitalized patients with community-acquired pneumonia before and after the heavy rainfall event using prospective cohort data.

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Purpose: To evaluate the usefulness of the deep learning image reconstruction (DLIR) to enhance the image quality of abdominal CT, compared to iterative reconstruction technique.

Method: Pre and post-contrast abdominal CT images in 50 patients were reconstructed with 2 different algorithms: hybrid iterative reconstruction (hybrid IR: ASiR-V 50%) and DLIR (TrueFidelity). Standard deviation of attenuation in normal liver parenchyma was measured as the image noise on pre and post-contrast CT.

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Objectives: Nursing and healthcare-associated pneumonia (NHCAP) was proposed by the Japanese Respiratory Society to refer to healthcare-associated pneumonia. This study aimed to investigate whether antipseudomonal antibiotic therapy improved the prognosis of NHCAP patients at high risk for antimicrobial-resistant pathogens.

Methods: Consecutive hospitalised NHCAP patients in Kurashiki Central Hospital between October 2010 and December 2016 were prospectively enrolled.

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Disorders of the fractality of an airway tree and a vessel tree have been studied in pulmonary diseases. Here we successfully applied Mishima's D to the bronchial minimal inner cross-sectional area (iCSA) measured in multidetector computed tomography (MDCT) images of chronic obstructive pulmonary disease (COPD) and non-COPD smokers ( = 162), by defining D in the following formula: log(≥) = -D × log + c, where is a certain iCSA value, (≥) is the number of airway branches having iCSA greater than or equal to , and c is a constant. Mathematically, this D of iCSA was associated with the expected reduction ratio of iCSA at bifurcations, which can be estimated by 2.

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Article Synopsis
  • The research involved comparing 30-day mortality rates between patients receiving combination therapy and those on β-lactam monotherapy, using different severity classification systems.
  • Results showed that while combination therapy didn't significantly impact mortality for mild to moderate cases, it significantly reduced mortality in severe cases according to the IDSA/ATS criteria.
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The usefulness of existing pneumonia severity indices for predicting mortality in nursing and healthcare-associated pneumonia (NHCAP) is unclear. This study compared the usefulness of existing pneumonia severity indices for predicting mortality in NHCAP and community-acquired pneumonia (CAP). Consecutive hospitalized pneumonia patients including NHCAP and CAP patients were prospectively enrolled between October 2010 and November 2017.

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Background: Empyema is an important and serious disease with high morbidity and mortality worldwide. However, the bacteriology and prognostic factors of empyema remain poorly understood, and data on the relationships among these parameters are scant.

Methods: We retrospectively analyzed a prospectively collected database of patients with empyema admitted to Kurashiki Central Hospital, Japan, between May 2007 and September 2015.

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Background This study aimed to investigate the usefulness of inflammatory biomarkers such as white blood cell (WBC) count, C-reactive protein (CRP) and procalcitonin (PCT) for differentiating cryptogenic organising pneumonia (COP) from community-acquired pneumonia (CAP). Methods COP patients hospitalised in Kurashiki Central Hospital between January 2010 and December 2017 whose WBC counts and CRP and PCT levels were measured were investigated retrospectively, and their results were compared with those of hospitalised CAP patients who were prospectively enrolled between October 2010 and November 2017. Definite COP was defined by specific histopathological findings, and possible COP was defined as a consolidation shadow on chest computed tomography and lymphocyte dominance in bronchoalveolar lavage fluid in the absence of specific histopathological findings or lung specimens.

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