Publications by authors named "Cyrus Ayubcha"

Alzheimer's disease (AD) involves a complex pathophysiology of neurodegeneration that leads to severe cognitive deficiencies. Understanding the molecular alterations that underlie this disease is fundamental to clinical management and therapeutic innovation. Functional imaging with positron emission tomography (PET) enables a visualization of these impaired pathways, such as cerebral hypometabolism, amyloid and tau accumulation, and neurotransmitter dysfunction.

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The process of aging in the brain is reflective of various factors including the environment, lifestyle, genetics, and management of concurrent chronic conditions. Aging in the brain leads to observable structural changes on neuroimaging, such as brain volume reduction, neuronal atrophy, and synaptic loss, which affect higher cognitive functions. Positron emission tomography imaging can help visualize these changes earlier before structural changes even take place and the associated decline in brain function, revealing important insights into how the brain ages and the impact on neural connectivity and cognitive abilities.

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Traumatic brain injury (TBI) is a major health concern in the United States and worldwide. Neuroimaging is a critical element in the clinical evaluation of TBIs, as computed tomography (CT) and MR imaging are commonly used to identify structural changes that may aid in treatment decision-making and long-term patient monitoring. This article reviews the utility of CT and MR imaging while focusing on the emerging applications of PET in TBI.

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MR imaging is currently the main imaging modality used for the diagnosis and post therapeutic assessment of glioblastomas. Recently, several innovative PET radioactive tracers have been investigated for the evaluation of glioblastomas (GBM). These radiotracers target several biochemical and pathophysiological processes seen in tumors.

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Article Synopsis
  • The COVID-19 pandemic has introduced long COVID, a severe and lingering post-illness condition affecting many individuals, leading to various health problems.
  • The review examines the neurological and psychiatric effects of COVID-19, highlighting issues like astrocyte dysfunction and glutamate regulation that may lead to significant brain injury.
  • It emphasizes the importance of advanced imaging techniques in diagnosing and managing long COVID, suggesting improvements in treatment strategies.
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This article explores the role of PET in the diagnosis and treatment of schizophrenia. PET imaging can reveal neurobiologic aspects such as cerebral blood flow, glucose metabolism, receptor function, and neuroinflammation in schizophrenia. It has supported the dopaminergic hypothesis and helped distinguish symptom types and severity.

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Vascular dementia (VaD) is a unique form of cognitive decline caused by impairment of blood flow to the brain. Atherosclerosis is strongly associated with VaD as plaque accumulation can lead to tissue hypoperfusion or stroke. VaD and atherosclerosis are both diagnosed relatively late in their disease courses, prompting the need for novel diagnostic approaches such as PET to visualize subclinical pathophysiologic changes.

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Article Synopsis
  • Fibroblast activation protein (FAP) is found in cancer-associated fibroblasts and is linked to poor cancer outcomes; PET/CT imaging using FAPI (radiolabeled FAP inhibitors) is being explored for diagnosing various cancers.
  • FAPI PET/CT outperforms F-fluorodeoxyglucose ([F]FDG) in many cases due to better tumor-to-background contrast, improved specificity for certain metastases, and enhanced sensitivity for identifying disease spread.
  • Despite its advantages, FAPI has challenges such as non-specific uptake in some situations, variations with age/menopause, limited clinical accessibility, and a lack of extensive clinical data supporting its use.
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Primary progressive aphasia (PPA) is a disease known to affect the frontal and temporal regions of the left hemisphere. PPA is often an indication of future development of dementia, specifically semantic dementia (SD) for frontotemporal dementia (FTD) and logopenic progressive aphasia (LPA) as an atypical presentation of Alzheimer's disease (AD). The purpose of this review is to clarify the value of 2-deoxy-2-[18F]fluoro-D-glucose (FDG)-positron emission tomography (PET) in the detection and diagnosis of PPA.

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This educational review article aims to discuss growing evidence from PET studies in the diagnosis and treatment of depression. PET has been used in depression to explore the neurotransmitters involved, the alterations in neuroreceptors, non-neuroreceptor targets (e.g.

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Hidradenitis suppurativa (HS) is a chronic skin disorder characterized by nodules, comedones, and sinus tracts that often leave prominent scarring. In recent years, non-invasive imaging techniques have been used to assess the inflammatory activity, vascularization, and treatment response of lesions. Specifically, fluorine-18 fluorodeoxyglucose positron emission tomography/computed tomography (FDG-PET/CT) scans may aid in identifying systemic inflammation in patients with HS, improving diagnosis.

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For more than two years, lingering sequalae of COVID-19 have been extensively investigated. Approximately 10% of individuals infected by COVID-19 have been found to experience long-term symptoms termed "long COVID-19". The neurological and psychiatric manifestations of long COVID-19 are of particular concern.

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The utilization of machine learning techniques in medicine has exponentially increased over the last decades due to innovations in computer processing, algorithm development, and access to big data. Applications of machine learning techniques to neuroimaging specifically have unveiled various hidden interactions, structures, and mechanisms related to various neurological disorders. One application of interest is the imaging of Alzheimer's disease, the most common cause of progressive dementia.

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Stroke is the leading cause of disability worldwide, the second most common cause of dementia and the third leading cause of death. Though the etiology of stroke has been explored extensively, there remains open questions in the scientific and clinical study of stroke. Traditional imaging techniques, such as magnetic resonance imaging and computed tomography, have been applied extensively and remain mainstays in clinical practice.

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Objectives: HIV affects 36 million people globally with prevalence decreasing due to antiretroviral therapy (ART) and social awareness; transmission occurs during substance use. Cocaine usage independently affects brain activity and may result in reduced ART adherence. This study evaluates brain glucose metabolism measured by 18 F-fluorodeoxyglucose positron emission tomography/computed tomography ( 18 F-FDG PET/CT) in cocaine users with HIV infection.

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Gliomas are the most common primary brain tumors. Hybrid PET/MR imaging has revolutionized brain tumor imaging, allowing for noninvasive, simultaneous assessment of morphologic, functional, metabolic, and molecular parameters within the brain. Molecular information obtained from PET imaging may aid in the detection, classification, prognostication, and therapeutic decision making for gliomas.

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The quantification of positron emission tomography/computed tomography (PET/CT) in multiple myeloma (MM) is challenging. Different methods of PET/CT quantification for assessment of fluorodeoxyglucose (FDG) uptake in myeloma patients have been suggested. This is the first review article that focuses on the advantages and disadvantages of each approach.

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To investigate the association of state-level Medicaid expansion and non-elderly mortality rates from 1999 to 2018 in Northeastern urban settings. This quasi-experimental study utilized a synthetic control method to assess the association of Medicaid expansion on non-elderly urban mortality rates [1999-2018]. Counties encompassing the largest cities in the Northeastern Megalopolis (Washington D.

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Alzheimer's disease (AD) is the most prevalent neurodegenerative condition. The definitive diagnosis of AD remains a post-mortem neuropathological study of the brain. Unfortunately, there are no established diagnostic criteria to achieve an accurate diagnosis of AD in a similarly objective fashion among living patients.

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Evolving scientific evidence has begun to point towards hyperphosphorylated tau as a major neurotoxic component in the pathophysiological development of many major neurodegenerative conditions. In response to a need for accurate and reliable diagnosis and disease monitoring in clinical and trial settings, there has been great effort put into the development of tau radiotracers. While first-generation and second-generation radiotracers have provided a basis for assessing tau, concerns of inadequate specificity and selectivity have continued to motivate further study of these radiotracers and the development of novel radiopharmaceuticals.

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Tau proteins play a significant role in a variety of degenerative neurologic conditions. Postmortem neuropathology studies of victims of repeat and severe head trauma have defined a unique spatial expression of neurologic tauopathies in these individuals, known as chronic traumatic encephalopathy. Established and newly developed radiotracers are now being applied to head injury populations with the intent of diagnosis and disease monitoring.

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The brain is a common site for metastases as well as primary tumors. Although evaluation of these malignancies with contrast-enhanced MR imaging defines current clinical practice, F-fluorodeoxyglucose (FDG)-PET has shown considerable utility in this area. In addition, many other tracers targeting various aspects of tumor biology have been developed and tested.

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Background: To compare the NaF uptake in the thoracic aorta and whole heart, as an early indicator of atherosclerosis, in multiple myeloma (MM) and smoldering multiple myeloma (SMM) patients with a healthy control (HC) group.

Methods: Forty-four untreated myeloma patients (35 MM and nine SMM) and twenty-six age and gender-matched HC subjects were collected. Each individual's NaF uptake in three parts of the aorta (AA: ascending aorta, AR: aortic arch, DA: descending aorta) and the whole heart was segmented.

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Objectives: 18F-sodium fluoride (NaF) is a radiotracer used in PET that reflects calcium metabolism and osteoblastic activity. In this study, we assessed the construct validity of a novel application of global assessment to measure NaF uptake in the femoral neck as a method of evaluating physiologic changes in osteoblastic metabolism with age.

Methods: Whole-body NaF-PET/computed tomography (CT) images and MRI of 24 male patients with a history of nonmetastatic prostate cancer between the ages of 36 and 82 years (67.

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