Neural correlates of age-related hearing loss: An MRI and FDG-PET study.

Aim: Age-related hearing loss (ARHL) is a common problem among older adults and contributes to adverse health outcomes such as cognitive impairment. However, the neural mechanisms underlying ARHL remain unclear. We aimed to reveal the structural and metabolic (i.

Age-related changes in EEG signal using triple correlation values.

The alpha rhythm in human electroencephalography (EEG) is known to decrease in frequency with age. Previous study has shown that elderly individuals with dementia exhibit higher S values (spatial variability) and SD values (temporal variability) in the triple correlation of the occipital region (P3, P4, Oz) compared to healthy elderly individuals. The objective of this research is to examine changes in S and SD values of the alpha band with aging in healthy individuals using triple correlation values from the frontal region.

Nearly linear orbital molecules on a pyrochlore lattice.

The interplay of spin-orbit coupling with other relevant parameters gives rise to the rich phase competition in complex ruthenates featuring octahedrally coordinated Ru. While locally, spin-orbit coupling stabilizes a nonmagnetic = 0 state, intersite interactions resolve one of two distinct phases at low temperatures: an excitonic magnet stabilized by the magnetic exchange of upper-lying = 1 states or Ru molecular orbital dimers driven by direct orbital overlap. Pyrochlore ruthenates RuO ( = rare earth, Y) are candidate excitonic magnets with geometrical frustration.

Dynamic Jahn-Teller effect in the strong spin-orbit coupling regime.

Exotic quantum phases, arising from a complex interplay of charge, spin, lattice and orbital degrees of freedom, are of immense interest to a wide research community. A well-known example of such an entangled behavior is the Jahn-Teller effect, where the lifting of orbital degeneracy proceeds through lattice distortions. Here we demonstrate that a highly-symmetrical 5d double perovskite BaMgReO, comprising a 3D array of isolated ReO octahedra, represents a rare example of a dynamic Jahn-Teller system in the strong spin-orbit coupling regime.

Interrater agreement and variability in visual reading of [18F] flutemetamol PET images.

Objective: The purpose of this study was to validate the concordance of visual ratings of [18F] flutemetamol amyloid positron emission tomography (PET) images and to investigate the correlation between the agreement of each rater and the Centiloid (CL) scale.

Methods: A total of 192 participants, clinically classified as cognitively normal (CN) (n = 59), mild cognitive impairment (MCI) (n = 65), Alzheimer's disease (AD) (n = 55), or non-AD dementia (n = 13), participated in this study. Three experts conducted visual ratings of the amyloid PET images for all 192 patients, assigning a confidence level to each rating on a three-point scale (certain, probable, or neither).

Phantom test procedures for a new neuro-oncological amino acid PET tracer: [F]fluciclovine.

Objective: Amino acid positron emission tomography (PET) examinations using anti-1-amino-3-[F]-fluorocyclobutane-1-carboxylic acid ([F]FACBC) were allowed for routine clinical use in July 2024. However, phantom test procedures for [F]FACBC reconstruction parameters have not yet been established. The present study aimed to establish new phantom test procedures for [F]FACBC brain PET imaging to determine optimal reconstruction parameters.

Optimization of penalization function in Bayesian penalized likelihood reconstruction algorithm for [F]flutemetamol amyloid PET images.

Point-spread-function (PSF) correction is not recommended for amyloid PET images due to Gibbs artifacts. Q.Clear™, a Bayesian Penalized Likelihood (BPL) reconstruction method without incorporating PSF correction reduces these artifacts but degrades image contrast by our previous findings.

Clinical Application of 18 F-THK5351 PET to Image Ongoing Astrogliosis in MSA-P and MSA-C.

18 F-labeled THK5351 PET can visualize ongoing astrogliosis by estimating monoamine oxidase B levels and can be used as an adjunct for diagnosing neurodegenerative disorders. Little has been reported on multiple system atrophy (MSA) in the differential diagnosis of parkinsonian syndromes. Here, we present 18 F-THK5351 images in typical cases of MSA-P (parkinsonian type) and MSA-C (cerebellar type), showing intense 18 F-THK5351 uptake in the lateral-posterior part of the putamen (MSA-P) and in the pons and middle cerebellar peduncles (MSA-C).

Hyperactivity of the medial thalamus in patients with photophobia-associated migraine.

Objective: To examine cerebral functional alterations associated with sensory processing in patients with migraine and constant photophobia.

Background: Migraine is a common headache disorder that presents with photophobia in many patients during attacks. Furthermore, some patients with migraine experience constant photophobia, even during headache-free intervals, leading to a compromised quality of life.

Development of a novel phantom for tau PET imaging.

Purpose: The cortical uptake of tau positron emission tomography (PET) tracers corresponds to the Braak stage and reflects the distribution and progression of tau neurofibrillary tangles. The present study aimed to develop and validate the basic performance of a novel tau PET phantom, as well as to establish standard test procedures and analytical methods.

Methods: The tau PET phantom consisted of a brain simulation section simulated medial temporal lobe region and resolution and uniformity sections.

Combining plasma Aβ and p-tau217 improves detection of brain amyloid in non-demented elderly.

Background: Maximizing the efficiency to screen amyloid-positive individuals in asymptomatic and non-demented aged population using blood-based biomarkers is essential for future success of clinical trials in the early stage of Alzheimer's disease (AD). In this study, we elucidate the utility of combination of plasma amyloid-β (Aβ)-related biomarkers and tau phosphorylated at threonine 217 (p-tau217) to predict abnormal Aβ-positron emission tomography (PET) in the preclinical and prodromal AD.

Methods: We designed the cross-sectional study including two ethnically distinct cohorts, the Japanese trial-ready cohort for preclinica and prodromal AD (J-TRC) and the Swedish BioFINDER study.

Measurement of Cerebral Glucose Metabolism in the Visual Cortex Predicts the Prognosis of Hemianopia.

Background And Objective: Homonymous hemianopia caused by cerebrovascular disease may improve over time. This study investigated whether functional neuroimaging can predict the prognosis of hemianopia due to cerebral infarction.

Methods: We studied 19 patients (10 men and 9 women) with homonymous hemianopia and compared them with 34 healthy subjects (20 men and 14 women).

Phantom and clinical evaluation of the Bayesian penalised likelihood reconstruction algorithm Q.Clear without PSF correction in amyloid PET images.

Purpose: Bayesian penalised likelihood (BPL) reconstruction, which incorporates point-spread-function (PSF) correction, provides higher signal-to-noise ratios and more accurate quantitation than conventional ordered subset expectation maximization (OSEM) reconstruction. However, applying PSF correction to brain PET imaging is controversial due to Gibbs artefacts that manifest as unpredicted cortical uptake enhancement. The present study aimed to validate whether BPL without PSF would be useful for amyloid PET imaging.

Decreased diffusivity along the perivascular space and cerebral hemodynamic disturbance in adult moyamoya disease.

Moyamoya disease (MMD) causes cerebral arterial stenosis and hemodynamic disturbance, the latter of which may disrupt glymphatic system activity, the waste clearance system. We evaluated 46 adult patients with MMD and 33 age- and sex-matched controls using diffusivity along the perivascular space (ALPS) measured with diffusion tensor imaging (ALPS index), which may partly reflect glymphatic system activity, and multishell diffusion MRI to generate freewater maps. Twenty-three patients were also evaluated via O-gas positron emission tomography (PET), and all patients underwent cognitive tests.

Loss of methylthioadenosine phosphorylase immunoreactivity correlates with poor prognosis and elevated uptake of C-methionine in IDH-mutant astrocytoma.

Purpose: The proximate localization of MTAP, which encodes methylthioadenosine phosphorylase, and CDKN2A/B on Chromosome 9q21 has allowed the loss of MTAP expression as a surrogate for homozygous deletion of CDKN2A/B. This study aimed to determine whether MTAP status correlates with clinical outcomes and C-methionine uptake in astrocytomas with IDH mutations.

Methods: We conducted immunohistochemistry for MTAP in 30 patients with astrocytoma, IDH-mutant who underwent C-methionine positron emission tomography scans prior to surgical resection.

Comparison of consistency in centiloid scale among different analytical methods in amyloid PET: the CapAIBL, VIZCalc, and Amyquant methods.

Objective: The Centiloid (CL) scale is a standardized measure for quantifying amyloid deposition in amyloid positron emission tomography (PET) imaging. We aimed to assess the agreement among 3 CL calculation methods: CapAIBL, VIZCalc, and Amyquant.

Methods: This study included 192 participants (mean age: 71.

Impact of [C]methionine PET with Bayesian penalized likelihood reconstruction on glioma grades based on new WHO 2021 classification.

Objective: The uptake of [C]methionine in positron emission tomography (PET) imaging overlapped in earlier images of tumors. Bayesian penalized likelihood (BPL) reconstruction increases the quantitative values of tumors compared with conventional ordered subset-expectation maximization (OSEM). The present study aimed to grade glioma malignancy based on the new WHO 2021 classification using [C]methionine PET images reconstructed using BPL.

Preclinical validation of a novel brain-penetrant PET ligand for visualization of histone deacetylase 6: a potential imaging target for neurodegenerative diseases.

Purpose: Histone deacetylase 6 (HDAC6) has emerged as a therapeutic target for neurodegenerative diseases such as Alzheimer's disease. Noninvasive imaging of HDAC6 in the brain by positron emission tomography (PET) would accelerate research into its roles in these diseases. We recently discovered an F-labeled derivative of the selective HDAC6 inhibitor SW-100 ([F]FSW-100) as a potential candidate for brain HDAC6 radioligand.

Ventral Variant Posterior Cortical Atrophy with Occipito-temporal Accumulation of Tau Proteins/Astrocyte Gliosis.

A 73-year-old woman with posterior cortical atrophy (PCA) presented with progressive apperceptive visual agnosia, alexia, agraphia, ventral simultanagnosia, prosopagnosia, and allocentric (stimulus-centered) left-sided hemispatial neglect. All of these symptoms were attributed to damage to the bilateral occipito-temporal cortices, consistent with ventral variant PCA. While the Pittsburgh compound B uptake was extensively distributed throughout the occipito-parietal (dorsal) and occipito-temporal (ventral) areas, the THK5351 (ligand binding to tau aggregates/astrocyte gliosis) accumulation was limited to the ventral area.

Pitfalls of Amyloid-Beta PET: Comparisons With 18 F-MK-6240 and 18 F-THK5351 PET.

We present 3 patients as pitfalls of amyloid-beta (Aβ) PET, who underwent 11 C-PiB (Aβ), 18 F-MK-6240 (Alzheimer disease [AD]-tau), and 18 F-THK5351 (astrogliosis) PET examinations. Despite negligible or tiny Aβ pathology, patients 1 and 2 were diagnosed with AD as the cause of symptoms. Despite widespread Aβ pathology, patient 3 was not diagnosed with AD as the cause of symptoms.