Publications by authors named "Yasuyuki Takahashi"

Objectives: The present study investigated various image reconstruction protocols for amyloid PET using phantom test criteria published by the Japanese Society of Nuclear Medicine (JSNM) and compared them with the composite standardized uptake value ratio (cSUVR) in clinical imaging.

Methods: Hoffman 3D phantoms and cylindrical phantoms were collected for 30 min according to the JSNM guidelines. Images were created under various reconstruction protocols by three physical evaluation items in the guidelines and were assessed: gray matter/white matter contrast (%contrast), uniformity (SDuROImean), and image noise [coefficient of variation (CV)].

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Objectives: This longitudinal text-mining study examines dental hygiene students' perceptions of dental hygienists and dentists at three different points in time during their training course. The null hypothesis of the study was that there would be no change in the dental hygiene students' perceptions of the dental hygienists and dentists over the course of 3 years.

Materials And Methods: First-year dental hygiene students participated in this study beginning with the academic year 2020.

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High-dose chemotherapy followed by autologous hematopoietic stem cell transplantation (HDC/ASCT) has been useful in relapsed or refractory classic Hodgkin lymphoma (RRcHL). Furthermore, a ranimustine, cytarabine, etoposide, and cyclophosphamide (MCVAC) conditioning regimen has been effective in diffuse large B-cell lymphoma. However, limited data are available regarding this conditioning regimen for cHL.

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Objectives: This study aimed to examine the influence of changes in CT values on PET images, specifically focusing on errors in CT-based attenuation correction and scatter coincidence correction (CTAC/SC) caused by gastrointestinal gas. Furthermore, it aimed to demonstrate the effectiveness of time-of-flight (TOF) PET in reducing CTAC/SC errors.

Methods: PET images were reconstructed using multiple CT images with varying CT values.

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infections have been reported to occur in immunocompromised patients. Early diagnosis and therapeutic intervention are especially important for disseminated nocardiosis because of its high mortality rate. A case of disseminated nocardiosis after allogeneic hematopoietic stem cell transplantation, which was promptly treated after identification of the organism by genetic analysis, is presented.

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Background: It is important to understand the career motivations and perceptions of students who intend to become dental health professionals. Both dental and dental hygiene students may have different opinions about the profession and future work prospects. To our knowledge, no study has compared the career motivations and career perceptions of Japanese dental and dental hygiene students after admission to dental or dental hygiene school.

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Respiration gating is used in PET to prevent image quality degradation due to respiratory effects. In this study, we evaluated a type of data-driven respiration gating for continuous bed motion, OncoFreeze AI, which was implemented to improve image quality and the accuracy of semiquantitative uptake values affected by respiratory motion. F-FDG PET/CT was performed on 32 patients with lung lesions.

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A 62-year-old woman was presented at our hospital with visual disturbance. An ocular examination revealed bilateral Roth spots. Laboratory data revealed leukocytosis (236,200 µl) with an excess blast (11%).

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: There is no phantom for image quality test in magnetic resonance imaging combined with positron emission tomography systems (PET/MRI systems). In MRI, radioactive water phantom containing 2-deoxy-2-[F-18] fluoro-D-glucose (F-FDG) cannot be used due to the dielectric effect. Even for phantoms filled with MR-available solutions, the source current of the RF coil is strongly disturbed as the diameter of the phantom increases.

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A 76-year-old woman with leukocytosis and thrombocytopenia was admitted to our hospital. A bone marrow examination showed a composition of 82.0% blasts, i.

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Variable-speed continuous bed motion F-fluorodeoxyglucose positron emission tomography/computed tomography (F-FDG-PET/CT), a reliable imaging technique, allows setting the bed motion speed for arbitrary sections of the body. The purpose of this study was to evaluate the relationship between the PET image quality and the bed speed following shortening of the scanning time for the lower extremities to achieve whole-body acquisition optimization of the examination time. Four sets of images were created by editing four-phase dynamic whole-body PET/CT images acquired at a bed speed of 6 and 14 mm/s in the trunk and lower extremities, respectively.

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Coronavirus disease 2019 (COVID-19) has spread around the world. Its effects go far beyond health care: education has to be conducted so as to prevent infection among students and faculty. Accordingly, changes have occurred in Japan's educational institutions, including methods of preparing students for examinations for nuclear medicine.

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Purpose: The aim of this study was to clarify the artifacts that occurred in the non-activity signal with computed tomography (CT)-based attenuation correction (CTAC) error due to image misregistration.

Methods: We used a cylindrical phantom containing a test tube with a diameter of 15 mm as the non-activity signal part. Positron emission tomography (PET) images were acquired for 30 minutes using the phantom with water in the non-activity signal part and F-fluoro-2-deoxy-d-glucose (F-FDG) (5.

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The number of patients with the extremely rare disease gastroenteropancreatic (GEP) neuroendocrine tumor (NET) has increased rapidly in recent years. In-pentetreotide SPECT in somatostatin receptor scintigraphy has been used for the assessment of GEP NET patients. To diagnose GEP NET, appropriate selection of image correction parameters is critical.

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Objectives: I-123-ioflupane single photon emission computed tomography (FP-CIT-SPECT) has been used to assess dopamine transporter (DAT) loss in Parkinson's disease. The specific binding ratio (SBR), a quantitative parameter of DAT density in the striatum, may be affected by differences in age, sex, and SPECT system. The purpose of this study was to evaluate the utility of FP-CIT-SPECT using the Japanese normal database (NDB) in the diagnosis of Parkinson's disease.

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Regressive lymphoproliferative disorders (R-LPD) after methotrexate (MTX) withdrawal are one of the specific features of methotrexate - associated lymphoproliferative disorders (MTX-LPD). Although the impact of the absolute lymphocyte count (ALC) on the pathogenesis of R-LPD has been recently emphasized, understanding relapse/regrowth events (RRE) and differences among LPD subtypes is necessary. In this study, we confirmed ALC recovery in the regressive group (R-G; R-LPD without RRE) and relapse/regrowth group (R/R-G; R-LPD with RRE).

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To date, there have been 160 regulatory approvals for environmental safety in Japan for the major genetically modified (GM) crops, including corn, soybean, canola and cotton. Confined field trials (CFTs) have been conducted in Japan for all single events, which contain various traits. The accumulated information from these previously conducted CFTs, as well as the agronomic field study data from other countries, provides a rich source of information to establish "familiarity" with the crops.

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Time-course study of individual dose equivalents of 2-deoxy-2-[F-18]fluoro-D-glucose positron emission tomography (F-FDG PET) was conducted in different hospital workers, and the daily work duties were analyzed. For the measurements, a semiconductor dosimeter was used. The values at intervals of 1 min and 1 h, the monthly cumulative and daily cumulative doses, and trend graphs were acquired with dedicated software and displayed on the reader.

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Although it may not be well known, the Annals of Nuclear Medicine (ANM) Editorial Committee includes one specialty editor of nuclear medicine physics, one of nuclear medicine technology, one of molecular imaging, and two of radiopharmacology. In addition, a statistics editor and a language editor are also on the committee. Manuscripts submitted to ANM can be peer-reviewed by such specialty editors similar to those submitted to highly ranked journals, which is a great pride and joy to us.

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Human parvovirus B19 (HPV-B19) causes hemophagocytic lymphohistiocytosis (HLH). Here we describe a 35-year-old female with hereditary spherocytosis (HS) who developed HLH due to HPV-B19 infection. Upon admission, she had high fever and diarrhea.

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The bone scan index (BSI) is calculated from a whole-body bone scan image; it shows the tumor burden in bone as a percentage of total skeletal mass. It has been used to determine the prognosis and to assess treatment effects; however, little has been reported on whether the BSI calculated using a two-dimensional image can accurately evaluate the three-dimensional spread in tumor volume. We investigated the relationship between tumor volume and BSI using Monte Carlo simulation (MCS).

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Article Synopsis
  • Methotrexate-induced lymphoproliferative disease (MTX-LPD) is gaining attention, particularly in patients with rheumatoid arthritis (RA), and atypical cases are reported.
  • Two RA patients initially diagnosed with non-specific lymphoproliferative disease (LPD-nos) showed complete responses after halting methotrexate or using steroid pulse therapy, but their symptoms recurred 1.5 years later with severe complications.
  • Despite treatments like prednisolone and chemotherapy, one patient was saved by aggressive chemotherapy after diagnosis confirmation, while the other was diagnosed post-mortem; these cases highlight the need for careful monitoring and consideration of aggressive treatment in flare-ups, even without specific LPD subtype confirmation.
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Objectives: The present study was conducted to examine whether the standardized uptake value (SUV) may be affected by the spatial position of a lesion in the radial direction on positron emission tomography (PET) images, obtained via two methods based on time-of-flight (TOF) reconstruction and point spread function (PSF).

Methods: A cylinder phantom with the sphere (30 mm diameter), located in the center was used in this study. Fluorine-18 fluorodeoxyglucose (F-FDG) concentrations of 5.

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Thrombopoietin receptor (TPO-R) agonists have been shown to be effective in refractory chronic immune thrombocytopenia (ITP); however, their efficacy in patients under critical care is not known. We report the case of a female patient with a newly diagnosed ITP who experienced severe bleeding from an external wound. The patient was administered the standard treatments for ITP, which are high-dose intravenous immunoglobulin (IVIg) and corticosteroids.

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The discovery of NM530c with a cadmium-zinc-telluride detector (CdZnTe-SPECT) is superior to the conventional Anger-type SPECT with a sodium-iodide detector (NaI-SPECT) in terms of sensitivity and spatial resolution. However, in the clinical example, even in CdZnTe-SPECT, a count decrease in myocardium due to the attenuation of the gamma ray is an issue. This study was conducted to evaluate the effect of computed tomography attenuation correction (CTAC) in CdZnTe-SPECT with the help of external CT.

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