Exposure duration and cerebral amyloidosis in the olfactory cortex of World Trade Center responders: A positron emission tomography and magnetic resonance imaging study.

Background: Amyloid-β proteins, a hallmark of Alzheimer's disease, are believed to play an adaptive role in the cerebral immune response.

Objective: Amyloid is believed to play a role in cerebral immune response and could play a similar role in response to air pollution exposures. In the present study, we examined whether WTC exposure duration was associated with cerebral amyloidosis in WTC responders.

The Potential Utility of (2S,4R)-4-[F]fluoroglutamine as a Novel Metabolic Imaging Marker for Inflammation Explored by Rat Models of Arthritis and Paw Edema.

Purpose: (2S,4R)-4-[F]fluoroglutamine ([F]FGln) is a promising metabolic imaging marker in cancer. Based on the fact that major inflammatory cells are heavily dependent on glutamine metabolism like cancer cells, we explored the potential utility of [F]FGln as a metabolic imaging marker for inflammation in two rat models: carrageenan-induced paw edema (CIPE) and collagen-induced arthritis (CIA).

Procedures: The CIPE model (n = 4) was generated by injecting 200 µL of 3% carrageenan solution into the left hind paw three hours before the PET.

The potential utility of (2S,4R)-4-[18F] fluoroglutamine as a novel metabolic imaging marker for inflammation explored by rat models of arthritis and paw edema.

Purpose: ()-4-[F]fluoroglutamine ([F]FGln) is a promising metabolic imaging marker in cancer. Based on the fact that major inflammatory cells are heavily dependent on glutamine metabolism like cancer cells, we explored the potential utility of [F]FGln as a metabolic imaging marker for inflammation in two rat models: carrageenan-induced paw edema (CIPE) and collagen-induced arthritis (CIA).

Procedures: The CIPE model (n = 4) was generated by injecting 200 μL of 3% carrageenan solution into the left hind paw three hours before the PET.

Proceedings of the 17th International Meeting on Fully 3D Image Reconstruction in Radiology and Nuclear Medicine.

Contained within this volume are the scholarly contributions presented in both oral and poster formats at Fully3D 2023: The 17th International Meeting on Fully Three-Dimensional Image Reconstruction in Radiology and Nuclear Medicine. This conference convened from July 16-21, 2023, at Stony Brook University in New York. For ease of reference, all papers are organized alphabetically according to the last names of the primary authors.

Quantitative functional imaging of the pigeon brain: implications for the evolution of avian powered flight.

The evolution of flight is a rare event in vertebrate history, and one that demands functional integration across multiple anatomical/physiological systems. The neuroanatomical basis for such integration and the role that brain evolution assumes in behavioural transformations remain poorly understood. We make progress by (i) generating a positron emission tomography (PET)-based map of brain activity for pigeons during rest and flight, (ii) using these maps in a functional analysis of the brain during flight, and (iii) interpreting these data within a macroevolutionary context shaped by non-avian dinosaurs.

Assessment of Alzheimer's Disease Imaging Biomarkers in World Trade Center Responders with Cognitive Impairment at Midlife.

 Incidence of early onset neurocognitive dysfunction has been reported in World Trade Center (WTC) responders. Ongoing studies are investigating the underlying etiology, as we are concerned that an underlying risk of neurodegenerative dementia may be occurring because of their stressful and neurotoxic exposures to particulate matter when they responded to the search and rescue efforts on September 11, 2001. The purpose of this study is to report preliminary results from two ongoing positron emission tomography (PET)/magnetic resonance imaging (MRI) imaging studies investigating the presence of Alzheimer's disease (AD) biomarkers, such as β-amyloid, tau, and neurodegeneration, and compare our findings to published norms.

PET Imaging of Leg Arteries for Determining the Input Function in PET/MRI Brain Studies Using a Compact, MRI-compatible PET System.

In this study, we used a compact, high-resolution, and MRI-compatible PET camera (VersaPET) to assess the feasibility of measuring the image-derived input function (IDIF) from arteries in the leg with the ultimate goal of enabling fully quantitative PET brain imaging without blood sampling. We used this approach in five F-FDG PET/MRI brain studies in which the input function was also acquired using the gold standard of serial arterial blood sampling. After accounting for partial volume, dispersion, and calibration effects, we compared the metabolic rates of glucose (MRglu) quantified from VersaPET IDIFs in 80 brain regions to those using the gold standard and achieved a bias and variability of <5% which is within the range of reported test-retest values for this type of study.

Reduced cerebellar cortical thickness in World Trade Center responders with cognitive impairment.

Prior research has demonstrated high levels of cognitive and physical functional impairments in World Trade Center (WTC) responders. A follow-up neuroimaging study identified changes to white matter connectivity within the cerebellum in responders with cognitive impairment (CI). In the first study to examine cerebellar cortical thickness in WTC responders with CI, we fielded a structural magnetic resonance imaging protocol.

Glymphatic Cerebrospinal Fluid and Solute Transport Quantified by MRI and PET Imaging.

Over the past decade there has been an enormous progress in our understanding of fluid and solute transport in the central nervous system (CNS). This is due to a number of factors, including important developments in whole brain imaging technology and computational fluid dynamics analysis employed for the elucidation of glymphatic transport function in the live animal and human brain. In this paper, we review the technical aspects of dynamic contrast enhanced magnetic resonance imaging (DCE-MRI) in combination with administration of Gd-based tracers into the cerebrospinal fluid (CSF) for tracking glymphatic solute and fluid transport in the CNS as well as lymphatic drainage.

PET/MRI reveals ongoing metabolic activity in ACL grafts one year post-ACL reconstruction.

Purpose: To use serial PET/MRI imaging to radiographically evaluate the metabolic activity of the ACL graft over the first post-operative year.

Methods: Six patients undergoing primary ACL reconstruction were recruited in this prospective study in an inpatient university hospital. All patients underwent femoral and tibial suspensory cortical fixation with quadrupled semitendinosus autograft hamstring ACL reconstruction by an orthopaedic surgeon.

Evaluation of quantitative, efficient image reconstruction for VersaPET, a compact PET system.

Purpose: Previously we developed a high-resolution positron emission tomography (PET) system-VersaPET-characterized by a block geometry with relatively large axial and transaxial interblock gaps and a compact geometry susceptible to parallax blurring effects. In this work, we report the qualitative and quantitative evaluation of a graphic processing unit (GPU)-accelerated maximum-likelihood by expectation-maximization (MLEM) image reconstruction framework for VersaPET which features accurate system geometry and projection space point-spread-function (PSF) modeling.

Methods: We combined the ray-tracing module from software for tomographic image reconstruction (STIR), an open-source PET image reconstruction package, with VersaPET's exact block geometry for the geometric system matrix.

Positron emission tomography-magnetic resonance liver parenchyma attenuation correction artifact in secondary hemochromatosis.

Positron emission tomography-magnetic resonance (PET-MR) hybrid imaging is a relatively new imaging modality combining the superb MR contrast capabilities among different soft-tissue structures with the high sensitivity of PET functional imaging. With the development of any new technology, a variety of limitations will be encountered including the introduction of new types of artifacts. In this case report, we present a restaging PET-MR scan for multiple myeloma that showed severely decreased fluorodeoxyglucose activity in the liver on the PET attenuated corrected images.

Correction: MIF inhibition enhances pulmonary angiogenesis and lung development in congenital diaphragmatic hernia.

In the original version of this article, the name of the author "Kamesh Ayasolla" was incorrectly given as "Kamesh Ayyasola". This has now been corrected to "Kamesh Ayasolla" in both the PDF and HTML versions of the article.

MIF inhibition enhances pulmonary angiogenesis and lung development in congenital diaphragmatic hernia.

Background: Congenital diaphragmatic hernia (CDH) is a complex birth anomaly with significant mortality and morbidity. Lung hypoplasia and persistent pulmonary hypertension (PPHN) limit survival in CDH. Macrophage migration inhibitory factor (MIF), a key regulator of innate immunity, is involved in hypoxia-induced vascular remodeling and PPHN.

Behavioral neuroimaging in birds using PET.

Background: Birds comprise the most diverse group of terrestrial vertebrates. This success likely is related to the evolution of powered flight over 75 mya. Modern approaches for studying brain function, however, have yet to be fully adapted and applied to birds, especially as they relate to specific behaviors including flight.

Simultaneous Preclinical Positron Emission Tomography-Magnetic Resonance Imaging Study of Lymphatic Drainage of Chelator-Free Cu-Labeled Nanoparticles.

Background: Hybrid positron emission tomography (PET)-magnetic resonance imaging (MRI) systems have been taken in use as new clinical diagnostic tools including detection and therapy planning of cancer. To reduce the amount of contrast agents injected in patients while fully benefitting both modalities, dual-modality probes are required.

Material And Methods: This study was first aimed at developing a hybrid PET-MRI probe by labeling superparamagnetic iron oxide nanoparticles (SPIONs) with Cu using a fast and chelator-free conjugation method, and second, to demonstrate the ability of the agent to target sentinel lymph nodes (SLNs) in vivo using simultaneous PET-MRI imaging.

Rapid F-FDG Uptake in Brain of Awake, Behaving Rat and Anesthetized Chicken has Implications for Behavioral PET Studies in Species With High Metabolisms.

Brain-behavior studies using F-FDG PET aim to reveal brain regions that become active during behavior. In standard protocols, F-FDG is injected, the behavior is executed during 30-60 min of tracer uptake, and then the animal is anesthetized and scanned. Hence, the uptake of F-FDG is not itself observed and could, in fact, be complete in very little time.

Flying starlings, PET and the evolution of volant dinosaurs.

Birds have evolved behavioral and morphological adaptations for powered flight. Many aspects of this transition are unknown, including the neuroanatomical changes that made flight possible [1]. To understand how the avian brain drives this complex behavior, we utilized positron emission tomography (PET) scanning and the tracer (18)F-fluorodeoxyglucose (FDG) to document regional metabolic activity in the brain associated with a variety of locomotor behaviors.

The state of instrumentation for combined positron emission tomography and magnetic resonance imaging.

Efforts at developing instrumentation for combined positron emission tomography and magnetic resonance imaging have gained considerable momentum in recent years, propelled in particular by new photosensor technologies. Small preclinical prototype systems developed in academia have been scaled up to full-scale small-animal imagers, and commercial whole-body clinical positron emission tomography-magnetic resonance imaging systems are now available. A wide variety of architectures are reviewed, from sequential to simultaneous and preclinical to clinical.

Integrating PET with behavioral neuroscience using RatCAP tomography.

Behavioral studies are an important part of neuroscience. They allow inferences about the functions of the brain and any internal states and processes it controls. Positron emission tomography (PET) is an in vivo imaging technique that provides insights into the mechanisms of neuronal communication.

Small animal simultaneous PET/MRI: initial experiences in a 9.4 T microMRI.

We developed a non-magnetic positron-emission tomography (PET) device based on the rat conscious animal PET that operates in a small-animal magnetic resonance imaging (MRI) scanner, thereby enabling us to carry out simultaneous PET/MRI studies. The PET detector comprises 12 detector blocks, each being a 4 × 8 array of lutetium oxyorthosilicate crystals (2.22 × 2.

Simultaneous assessment of rodent behavior and neurochemistry using a miniature positron emission tomograph.

Positron emission tomography (PET) neuroimaging and behavioral assays in rodents are widely used in neuroscience. PET gives insights into the molecular processes of neuronal communication, and behavioral methods analyze the actions that are associated with such processes. These methods have not been directly integrated, because PET studies in animals have until now required general anesthesia to immobilize the subject, which precludes behavioral studies.

Effects of cell phone radiofrequency signal exposure on brain glucose metabolism.

Context: The dramatic increase in use of cellular telephones has generated concern about possible negative effects of radiofrequency signals delivered to the brain. However, whether acute cell phone exposure affects the human brain is unclear.

Objective: To evaluate if acute cell phone exposure affects brain glucose metabolism, a marker of brain activity.

PET imaging of thin objects: measuring the effects of positron range and partial-volume averaging in the leaf of Nicotiana tabacum.

Introduction: PET imaging in plants is receiving increased interest as a new strategy to measure plant responses to environmental stimuli and as a tool for phenotyping genetically engineered plants. PET imaging in plants, however, poses new challenges. In particular, the leaves of most plants are so thin that a large fraction of positrons emitted from PET isotopes ((18)F, (11)C, (13)N) escape while even state-of-the-art PET cameras have significant partial-volume errors for such thin objects.