Publications by authors named "Munenobu Nogami"

Background: Previous reports attempted to evaluate bladder cancer using 18 F-fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) by washing out the excreted FDG with a diuretic. The purpose of this study was to evaluate the value of diuretic FDG PET/plain CT (drtPET/CT) and diuretic FDG PET/contrast-enhanced CT (drtPET/ceCT) in the assessment of upper urinary tract cancers.

Materials And Methods: A total of 66 patients underwent drtPET/CT for suspected upper urinary tract cancer (UUTC).

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Purpose: Minimal misregistration of fused PET and MRI images can be achieved with simultaneous positron emission tomography/magnetic resonance imaging (PET/MRI). However, the acquisition of multiple MRI sequences during a single PET emission scan may impair fusion precision of each sequence. This study evaluated the diagnostic utility of time-synchronized PET/MRI using an MR active trigger and a Bayesian penalized likelihood reconstruction algorithm (BPL) to assess the locoregional extension of endometrial cancer.

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The glymphatic system is considered to play a pivotal role in the clearance of disease-causing proteins in neurodegenerative diseases. This study employed MR diffusion tensor imaging (DTI) to evaluate glymphatic system function and its correlation with brain amyloid accumulation levels measured using [C]Pittsburgh compound-B (PiB) PET/MRI. Fifty-six patients with mild cognitive impairment and early Alzheimer's disease (AD: 70 ± 11 y) underwent [C]PiB PET/MRI to assess amyloid deposition and were compared with 27 age-matched cognitively normal volunteers (CN: 69 ± 10y).

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Subcommittee on Survey of Nuclear Medicine Practice in Japan has performed a nationwide survey of nuclear medicine practice every 5 years since 1982 to survey contemporary nuclear medicine practice and its changes over the years. The subcommittee sent questionnaires, including the number and category of examinations as well as the kind of the radiopharmaceuticals during the 30 days of June 2022 to all nuclear medicine institutes in Japan. The total numbers of them for the year 2022 were estimated depends on the 1-month data.

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Article Synopsis
  • - Metastatic rectal cancer is rare and can be challenging to distinguish from primary rectal cancer, as highlighted in the case of a 79-year-old man who had a rectal mass found during gastric cancer follow-up.
  • - An 18 F-FDG PET/MRI was performed, revealing that the mass had lower FDG uptake and was located outside the rectum, indicating it was likely metastasis from the gastric cancer.
  • - The use of PET/MRI was critical in differentiating the characteristics of the mass and the rectal wall due to MRI's high contrast resolution and the effective image fusion from simultaneous scans.
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This study evaluated the diagnostic value of a rapid whole-body fluorodeoxyglucose (FDG) positron emission tomography (PET)/magnetic resonance imaging (MRI) approach, combining Bayesian penalised likelihood (BPL) PET with an optimised β value and abbreviated MRI (abb-MRI). The study compares the diagnostic performance of this approach with the standard PET/MRI that utilises ordered subsets expectation maximisation (OSEM) PET and standard MRI (std-MRI). The optimal β value was determined by evaluating the noise-equivalent count (NEC) phantom, background variability, contrast recovery, recovery coefficient, and visual scores (VS) for OSEM and BPL with β100-1000 at 2.

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Coronavirus disease (COVID-19) vaccination is known to cause a diagnostic dilemma due to false-positive findings on [F]FDG PET in vaccine-associated hypermetabolic lymphadenopathy. We present two case reports of women with estrogen-receptor (ER)-positive cancer of the breast who were vaccinated for COVID-19 in the deltoid muscle. [F]FDG positron emission tomography (PET) demonstrated primary breast cancer and multiple axillary lymph nodes with increased [F]FDG uptake, diagnosed as vaccine-associated [F]FDG-avid lymph nodes.

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Article Synopsis
  • The study investigates how different metal implants affect gamma ray attenuation when using radioisotopes to visualize biological activity at nonunion sites in the femur, focusing on the impact of CT-based attenuation correction (CTAC).
  • It was found that gamma ray counts significantly differed with and without CTAC and varied between the presence of intramedullary nails and plates, particularly when placed contralaterally to the lesion. This suggests specific positioning influences detection.
  • The standardized uptake values (SUV) were more accurate with CTAC, indicating its importance for precise measurements, though implant type and position did not significantly alter the detection counts compared to non-implant scenarios.
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The integrated positron emission tomography/magnetic resonance imaging (PET/MRI) scanner simultaneously acquires metabolic information via PET and morphological information using MRI. However, attenuation correction, which is necessary for quantitative PET evaluation, is difficult as it requires the generation of attenuation-correction maps from MRI, which has no direct relationship with the gamma-ray attenuation information. MRI-based bone tissue segmentation is potentially available for attenuation correction in relatively rigid and fixed organs such as the head and pelvis regions.

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A 52-year-old woman with a rapidly growing uterine tumor suspected of uterine sarcoma underwent 18F-FDG PET/MRI, revealing a myometrial mass and an endometrial lesion, suggesting dual primary neoplasms. Based on the PET/MRI findings, we changed the intraoperative procedure to determine the necessity of pelvic lymphadenectomy. PET/MRI was useful in diagnosing and differentiating between 2 malignant neoplasms in the uterus compared with PET/CT, due to MRI's high contrast resolution and precise fusion due to the simultaneous acquisition.

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Suppression of hepatic gluconeogenesis is thought to largely underlie the antidiabetes action of metformin. However, this drug also exerts various effects on the gut, one of which is the enhancement of the uptake of F-labeled fluorodeoxyglucose (FDG), a nonmetabolizable glucose derivative, during [F]FDG positron emission tomography (PET)-computed tomography (CT). Whereas the relevance of this effect to the glucose-lowering action of metformin remains unclear, it is of special interest because it was discovered in humans.

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Radiotherapy (RT) is used to manage cervical cancer, and pelvic insufficiency fracture (PIF) is known as a late complication of RT. The present study identified risk factors for PIF after radiotherapy for cervical cancer, and investigated its incidence rate. It also considered the usefulness of positron emission tomography/magnetic resonance imaging (PET/MRI) in PIF diagnosis.

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Objectives: To evaluate a deep learning model for predicting gestational age from fetal brain MRI acquired after the first trimester in comparison to biparietal diameter (BPD).

Materials And Methods: Our Institutional Review Board approved this retrospective study, and a total of 184 T2-weighted MRI acquisitions from 184 fetuses (mean gestational age: 29.4 weeks) who underwent MRI between January 2014 and June 2019 were included.

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Purpose: To retrospectively assess the repeatability of physiological F-18 labeled fluorodeoxyglucose (FDG) uptake in the skin on positron emission tomography/magnetic resonance imaging (PET/MRI) and explore its regional distribution and relationship with sex and age.

Methods: Out of 562 examinations with normal FDG distribution on whole-body PET/MRI, 74 repeated examinations were evaluated to assess the repeatability and regional distribution of physiological skin uptake. Furthermore, 224 examinations were evaluated to compare differences in the uptake due to sex and age.

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Atrial fibrosis and inflammation play important roles in perpetuating and initiating atrial fibrillation (AF). Although the fibrotic area can be visualized as a delayed enhancement area on late gadolinium enhancement magnetic resonance imaging (LGE-MRI), atrial inflammation has not yet been visualized on any imaging modality. We describe the protocol for a feasibility study to visualize atrial inflammation on positron emission tomography/MRI (PET/MRI).

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Background: Atrial inflammation plays an important role in initiating atrial fibrosis, which could perpetuate atrial fibrillation (AF). However, the method of visualization of atrial inflammation has not been established. We sought to investigate whether the intensive atrial inflammation caused by cryoballoon ablation (CBA) could be detected by positron emission tomography/ magnetic resonance imaging (PET/MRI) and whether the atrial inflammation could be associated with consequent fibrosis.

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Carbon dioxide (CO) treatment is reported to have an antitumor effect owing to the improvement in intratumoral hypoxia. Previous studies were based on histological analysis alone. In the present study, the improvement in intratumoral hypoxia by percutaneous CO treatment was determined using F-fluoromisonidazole positron emission tomography-computed tomography (F-FMISO PET-CT) images.

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Background: Recently, a standardized uptake value (SUV) has been used to evaluate bone single-photon emission computed tomography (SPECT). The aim of this study was to investigate quantitative SPECT imaging of uninfected nonunion to compare hypertrophic nonunion and non-hypertrophic nonunion using volume-based parameters.

Methods: We evaluated 23 patients with uninfected nonunion who underwent SPECT acquisition 3 h after an injection of Tc-hydroxymethylene diphosphonate or Tc-methylene diphosphonate from April 2014 to November 2019.

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Aim: To investigate the relationships between various clinical variables and the metformin-induced accumulation of fluorodeoxyglucose (FDG) in the intestine, with distinction between the intestinal wall and lumen, in individuals with type 2 diabetes who were receiving metformin treatment and underwent F-labelled FDG ([ F]FDG) positron emission tomography (PET)-MRI.

Materials And Methods: We evaluated intestinal accumulation of [ F]FDG with both subjective (a five-point visual scale determined by two experienced radiologists) and objective analyses (measurement of the maximum standardized uptake value [SUV ]) in 26 individuals with type 2 diabetes who were receiving metformin and underwent [ F]FDG PET-MRI. [ F]FDG accumulation within the intestinal wall was discriminated from that in the lumen on the basis of SUV .

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Objectives: The Asian Intensive Reader of Pneumoconiosis (AIR Pneumo) is a training program designed to improve diagnostic skills for chest radiographies (CXRs) in accordance with the ILO/ICRP 2000. The purpose was to determine the prevalence of occupational environmental pulmonary disease findings in construction workers on thin-slice computed tomography (thin-slice CT), and to compare the diagnostic performance with CXR evaluated by AIR Pneumo-trained physicians.

Methods: Ninety-seven male construction workers underwent low-dose thin-slice CT and CXR on the same day.

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Purpose: Accurate prediction of post-hepatectomy liver failure (PHLF) is important in advanced hepatocellular carcinoma (HCC). We aimed to retrospectively evaluate the utility of gadoxetic acid-enhanced MRI for predicting PHLF in patients who underwent anatomic hepatectomy for HCC with portal vein invasion.

Methods: Forty-one patients (32 men, 9 women) were included.

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Objective: Positron emission tomography (PET)-computed tomography has revealed that metformin promotes the intestinal accumulation of [F]fluorodeoxyglucose (FDG), a nonmetabolizable glucose derivative. It has remained unknown, however, whether this accumulation occurs in the wall or intraluminal space of the intestine. We here addressed this question with the use of [F]FDG PET-MRI, a recently developed imaging method with increased accuracy of registration and high soft-tissue contrast.

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The optic nerve is morphologically classified as a peripheral nerve, but histologically it shares characteristics with the central nerves. Diseases that affect vision and the optic nerve are many and varied: optic neuritis, demyelination (multiple sclerosis, acute disseminated encephalomyelitis, neuromyelitis optica spectrum disorder, and myelin oligodendrocyte glycoprotein antibody-related disorders), drugs, collagen disease, vasculitis, infection, trauma, vascular abnormalities, tumours, and non-tumoural masses. In this review, we summarise the magnetic resonance imaging findings for various pathological conditions that cause deterioration in visual acuity.

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Objectives: This study aimed to evaluate the diagnostic performance of the lung zero-echo time (ZTE) sequence in FDG PET/MRI for detection and differentiation of lung lesions in oncologic patients in comparison with conventional two-point Dixon-based MR imaging.

Methods: In this single-institution retrospective study approved by the institutional review board, 209 patients with malignancies (97 men and 112 women; age range, 17-89 years; mean age, 66.5 ± 12.

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