Publications by authors named "Kota Yokoyama"

Introduction Accurate diagnosis of multiple myeloma (MM) and related disorders depends on imaging studies for lesion detection, which is crucial for treatment planning. The 18F-fluorodeoxyglucose (FDG) PET imaging system is well-established, with high sensitivity and specificity in identifying myeloma lesions. Additionally, 11C-acetate serves as an effective radiotracer for detecting MM lesions.

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Although long COVID refers to numerous COVID-19-related symptoms after infection, including depression, fatigue, anosmia, sleep disturbances, and brain fog, the etiology of long COVID remains largely unknown. A 41-year-old woman presented with a 3-week history of complete insomnia without drowsiness throughout the day after contracting COVID-19. SPECT using N -isopropyl-p-[ 123 I] iodoamphetamine showed a significant regional cerebral blood flow reduction in the bilateral thalamus.

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Article Synopsis
  • Thromboembolism is a critical concern in patients undergoing endovascular treatment for ruptured cerebral aneurysms, and administering antiplatelet agents like aspirin before the procedure may lower this risk.
  • The study, called ASTOP, is a multicenter, randomized, double-blind trial involving 484 patients, comparing the effects of 200 mg of aspirin versus a placebo prior to treatment.
  • Primary outcomes will focus on measuring thromboembolic complications and ischemic lesions during the procedure, while secondary outcomes will assess cerebral ischemic events, bleeding incidents, and patient functional status after 90 days.
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People living with human immunodeficiency virus (HIV) are at high risk of mental health problems. However, little is known about this risk in HIV-infected patients with hemophilia (HPH) who contracted the virus through blood products. This cross-sectional, observational study assessed patients' mood states and the factors associated with them among Japanese HPH to evaluate the need for psychosocial support.

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  • Brain perfusion SPECT is a crucial imaging technique that identifies neurodegenerative changes early on, playing an essential role in dementia evaluation and diagnosis.
  • It highlights different patterns of hypoperfusion associated with various types of dementia, such as Alzheimer's disease and dementia with Lewy bodies, which helps differentiate between them and predicts disease progression.
  • The method is shifting towards using biomarkers like brain perfusion SPECT for diagnosing dementia, guiding treatment with disease-modifying drugs based on individual patient profiles.
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  • Sphenoid sinus hemangiomas are rare and can be difficult to diagnose due to their complex symptoms and location in the brain.* -
  • A case study details a woman in her 40s with worsening headaches and vision issues, where imaging initially suggested a serious tumor but later revealed a cavernous hemangioma after further examination.* -
  • This case underscores the necessity of considering hemangiomas in diagnoses of sphenoid sinus masses and the importance of careful imaging and treatment strategies to distinguish them from more aggressive conditions.*
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We present a unique case of a 45-year-old male with cerebral palsy, who experienced walking difficulties and altered consciousness. The initial MRI revealed an intraventricular mass that rapidly enlarged over a month, consisting of two distinct components with different characteristics on CT and MRI, and was associated with agenesis of the corpus callosum. Despite initial treatment, surgical intervention was necessary, where preoperative imaging suggested an exophytically growing glioblastoma.

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This case report details a rare instance of radiation-induced brachial plexopathy (RIBP) occurring below the typical tolerance dose in a 55-year-old woman following chemoradiotherapy for apical non-small cell lung carcinoma. Despite receiving a radiation dose considered safe (47-48 Gray in 25 fractions), she developed sensory abnormalities and motor weakness in the right upper limb. The diagnostic distinction between RIBP and tumor recurrence was achieved using MRI, which showed characteristic features of radiation-induced damage.

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We report a case of cervicofacial actinomycosis mimicking malignant sarcoma in a 78-year-old man with diabetes. High lesion uptake and decreased cerebral uptake on [F]FDG PET/CT provide a potentially important diagnostic clue suggesting infectious disease in a poorly controlled diabetic patient.

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Objective: 18F-PSMA 1007 is a promising PET tracer for prostate cancer. We aimed to examine the safety, biodistribution, radiation dosimetry, and clinical effectiveness in Japanese healthy volunteers and patients with prostate cancer.

Methods: Part A evaluated the pharmacokinetics and exposure doses in three healthy volunteers.

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Choline kinase (CK) is reportedly overexpressed in various malignancies. Among its isoforms, CKα overexpression is presumably related to oncogenic change. Choline positron emission tomography (PET) is reportedly useful for detecting and evaluating therapy outcomes in malignancies.

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Pulmonary vein stenosis (PVS) is a serious complication of catheter ablation (CA) for atrial fibrillation (AF). PVS generally occurs several months after CA and presents with non-specific symptoms and imaging findings. There have been reports of delayed diagnoses due to a misdiagnosis as infection, interstitial pneumonia, or organizing pneumonia.

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Article Synopsis
  • The study aimed to compare [F]FDG PET/CT findings between untreated sarcoidosis and malignant lymphoma (ML) and create convolutional neural network (CNN) models for differentiation using maximum intensity projection (MIP) images.
  • Researchers collected data from patients diagnosed with sarcoidosis and ML, analyzed by nuclear radiologists, and utilized k-fold cross-validation for the CNN models with visualizations through Grad-CAM for key areas.
  • The results showed significant differences in FDG accumulation patterns between the two diseases, with the CNN model achieving an accuracy of 89%, indicating its effectiveness in distinguishing between sarcoidosis and ML based on PET/CT imaging.
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Ectopic tissue is an anatomic abnormality in which tissue develops in an area outside its normal location. It is primarily caused by abnormalities during the process of embryologic development. Although the majority of individuals with ectopic tissues remain asymptomatic, various symptoms and associated complications can occur.

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Squamous cell carcinoma (SCC) arises from a variety of premalignant conditions, including pyoderma. However, an accurate diagnosis of SCC is sometimes challenging due to indistinguishable inflammatory lesions. Here, we present a case of SCC arising from extensive pyoderma, which was successfully diagnosed by taking advantage of thallium-201 scintigraphy.

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Deep learning (DL) image quality improvement has been studied for application to F-fluorodeoxyglucose positron emission tomography/computed tomography (F-FDG PET/CT). It is unclear, however, whether DL can increase the quality of images obtained with semiconductor-based PET/CT scanners. This study aimed to compare the quality of semiconductor-based PET/CT scanner images obtained by DL-based technology and conventional OSEM image with Gaussian postfilter.

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Branch-like enhancement (BLE) on contrast-enhanced (CE) magnetic resonance imaging (MRI) was found to be effective in differentiating primary central nervous system lymphoma (PCNSL) from high-grade glioma (HGG) in the cerebellum. However, whether it can be applied to assessments of secondary central nervous system lymphoma (SCNSL), or other cerebellar lesions is unknown. Hence, we retrospectively reviewed cerebellar masses to investigate the use of BLE in differentiating cerebellar lymphoma (CL), both primary and secondary, from other lesions.

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Article Synopsis
  • - A 44-year-old woman was initially misdiagnosed with liver invasion after treatment for abdominal DLBCL, showing high [F]FDG uptake in a liver lesion post-therapy.
  • - EOB-MRI revealed specific imaging characteristics of the lesion, and its location corresponded with a radiation dose greater than 40.5 Gy, indicating Radiation Induced Liver Disease (RILD).
  • - Follow-up imaging 7 months later showed the liver abnormality had resolved, highlighting the importance of comparing different imaging modalities to accurately diagnose RILD and prevent unnecessary medical procedures.
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Background: The present prospective phase 1/2 study aimed to elucidate the efficacy and safety of Lu-DOTATATE (four cycles of 7.4 GBq) in Japanese patients with unresectable, progressive neuroendocrine tumors (NETs).

Methods: From April 2018 to October 2020, 15 patients with advanced NETs (five midgut, eight pancreatic, and two lung NETs) were enrolled.

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Purpose: To elucidate the noninferiority of ab interno microhook trabeculotomy (μTLO) using a recently developed reusable stainless spatula-type microhook device to incise the trabecular meshwork to Trabectome (Neomeix, Inc) surgery in terms of the 1-year postoperative outcomes of Japanese patients with glaucoma by means of propensity score analyses.

Design: Multicenter, retrospective cohort study.

Participants: We enrolled 553 and 392 patients who underwent Trabectome surgery and μTLO, respectively, between January 2014 and March 2020 at 10 facilities.

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