Individual-level metabolic connectivity from dynamic [F]FDG PET reveals glioma-induced impairments in brain architecture and offers novel insights beyond the SUVR clinical standard.

Purpose: This study evaluates the potential of within-individual Metabolic Connectivity (wi-MC), from dynamic [F]FDG PET data, based on the Euclidean Similarity method. This approach leverages the biological information of the tracer's full temporal dynamics, enabling the direct extraction of individual metabolic connectomes. Specifically, the proposed framework, applied to glioma pathology, seeks to assess sensitivity to metabolic dysfunctions in the whole brain, while simultaneously providing further insights into the pathophysiological mechanisms regulating glioma progression.

The brain's "dark energy" puzzle : [F]FDG uptake, delivery and phosphorylation, and their coupling with resting-state brain activity.

The brain's resting-state energy consumption is expected to be mainly driven by spontaneous activity. In our previous work, we extracted a wide range of features from resting-state fMRI (rs-fMRI), and used them to predict [F]FDG PET SUVR as a proxy of glucose metabolism. Here, we expanded upon our previous effort by estimating [F]FDG kinetic parameters according to Sokoloff's model, i.

Performance Characteristics of the NeuroEXPLORER, a Next-Generation Human Brain PET/CT Imager.

The collaboration of Yale, the University of California, Davis, and United Imaging Healthcare has successfully developed the NeuroEXPLORER, a dedicated human brain PET imager with high spatial resolution, high sensitivity, and a built-in 3-dimensional camera for markerless continuous motion tracking. It has high depth-of-interaction and time-of-flight resolutions, along with a 52.4-cm transverse field of view (FOV) and an extended axial FOV (49.

Relationship between neuroimaging and cognition in frontotemporal dementia: An FDG-PET and structural MRI study.

Background And Purpose: Frontotemporal dementia (FTD) is a clinically and pathologically heterogeneous neurodegenerative condition with a prevalence comparable to Alzheimer's disease for patients under 65 years of age. Limited studies have examined the association between cognition and neuroimaging in FTD using different imaging modalities.

Methods: We examined the association of cognition using Montreal Cognitive Assessment (MoCA) with both gray matter (GM) volume and glucose metabolism using magnetic resonance imaging and fluorodeoxyglucose (FDG)-PET in 21 patients diagnosed with FTD.

The brain's "dark energy" puzzle: How strongly is glucose metabolism linked to resting-state brain activity?

Brain glucose metabolism, which can be investigated at the macroscale level with [F]FDG PET, displays significant regional variability for reasons that remain unclear. Some of the functional drivers behind this heterogeneity may be captured by resting-state functional magnetic resonance imaging (rs-fMRI). However, the full extent to which an fMRI-based description of the brain's spontaneous activity can describe local metabolism is unknown.

Relationship between Neuroimaging and Cognition in Frontotemporal Dementia: A [18 F]FDG PET and Structural MRI Study.

Background: Frontotemporal dementia (FTD) is a clinically and pathologically heterogeneous condition with a prevalence comparable to Alzheimer's Disease for patients under sixty-five years of age. Gray matter (GM) atrophy and glucose hypometabolism are important biomarkers for the diagnosis and evaluation of disease progression in FTD. However, limited studies have systematically examined the association between cognition and neuroimaging in FTD using different imaging modalities in the same patient group.

An update on the use of image-derived input functions for human PET studies: new hopes or old illusions?

Background: The need for arterial blood data in quantitative PET research limits the wider usability of this imaging method in clinical research settings. Image-derived input function (IDIF) approaches have been proposed as a cost-effective and non-invasive alternative to gold-standard arterial sampling. However, this approach comes with its own limitations-partial volume effects and radiometabolite correction among the most important-and varying rates of success, and the use of IDIF for brain PET has been particularly troublesome.

A new framework for metabolic connectivity mapping using bolus [F]FDG PET and kinetic modeling.

Metabolic connectivity (MC) has been previously proposed as the covariation of static [F]FDG PET images across participants, i.e., MC (ai-MC).

Linking resting-state network fluctuations with systems of coherent synaptic density: A multimodal fMRI and C-UCB-J PET study.

Resting-state network (RSN) connectivity is a widely used measure of the brain's functional organization in health and disease; however, little is known regarding the underlying neurophysiology of RSNs. The aim of the current study was to investigate associations between RSN connectivity and synaptic density assessed using the synaptic vesicle glycoprotein 2A radioligand C-UCB-J PET. Independent component analyses (ICA) were performed on resting-state fMRI and PET data from 34 healthy adult participants (16F, mean age: 46 ± 15 years) to identify RSNs of interest (default-mode, right frontoparietal executive-control, salience, and sensorimotor networks) and select sources of C-UCB-J variability (medial prefrontal, striatal, and medial parietal).

Modeling venous plasma samples in [F] FDG PET studies: a nonlinear mixed-effects approach.

The gold-standard approach to quantifying dynamic PET images relies on using invasive measures of the arterial plasma tracer concentration. An attractive alternative is to employ an image-derived input function (IDIF), corrected for spillover effects and rescaled with venous plasma samples. However, venous samples are not always available for every participant.

Image-derived Input Function in brain [F]FDG PET data: which alternatives to the carotid siphons?

Quantification of brain [F] fluorodeoxyglucose ([F]FDG) positron emission tomography (PET) data requires an input function. A noninvasive alternative to gold-standard arterial sampling is the image-derived input function (IDIF), typically extracted from the internal carotid arteries (ICAs), which are however difficult to segment and subjected to spillover effects. In this work, we evaluated the feasibility of extracting the IDIF from two different vascular sites, i.

Variability of regional glucose metabolism and the topology of functional networks in the human brain.

The brain consumes the most energy per relative mass amongst the organs in the human body. Theoretical and empirical studies have shown that behavioral processes are relatively inexpensive metabolically, and that most energy goes to maintaining the status quo, i.e.

Assessing different approaches to estimate single-subject metabolic connectivity from dynamic [F]fluorodeoxyglucose Positron Emission Tomography data.

Metabolic connectivity is conventionally calculated in terms of correlation of static positron emission tomography (PET) measurements across subjects. There is increasing interest in deriving metabolic connectivity at the single-subject level from dynamic PET data, in a similar way to functional magnetic resonance imaging. However, the strong multicollinearity among region-wise PET time-activity curves (TACs), their non-Gaussian distribution, and the choice of the best strategy for TAC standardization before metabolic connectivity estimation, are non-trivial methodological issues to be tackled.

Randomized control study of the outback LTD reentry catheter versus manual reentry for the treatment of chronic total occlusions in the superficial femoral artery.

Purpose: To assess the efficacy and safety of the Outback device in patients with a chronic total occlusion (CTO) of the superficial femoral artery and evaluate its impact on fluoroscopy and procedural times.

Materials And Methods: From October 2006 to March 2007, 52 patients affected by TASC II-D superficial femoral artery CTO were treated with subintimal recanalization. Clinical indications for endovascular recanalization were: claudication, tissue loss, and at rest leg pain with critical limb ischemia.

Alternative techniques for treatment of complex below-the knee arterial occlusions in diabetic patients with critical limb ischemia.

Purpose: The purpose of this study was to describe alternative endovascular (EV) techniques and assess their feasibility and efficacy in minimizing failure rates in limb salvage for the treatment of complex below-the knee (BTK) occlusions that could not be crossed with a conventional antegrade access.

Materials And Methods: Between December 2007 and November 2010, 1,035 patients (557 male) underwent EV treatment for critical limb ischemia in our institution. In 124 (12% [83 male], mean age 68.

Percutaneous decompression of lumbar spinal stenosis with a new interspinous device.

Objective: This study was designed to evaluate the feasibility of the implantation of a new interspinous device (Falena) in patients with lumbar spinal stenosis. The clinical outcomes and imaging results were assessed by orthostatic MR during an up to 6-month follow-up period.

Methods: Between October 2008 and February 2010, the Falena was implanted at a single level in 26 patients (17 men; mean age, 69 (range, 54-82) years) who were affected by degenerative lumbar spinal stenosis.

Percutaneus osteoplasty in the treatment of extraspinal painful multiple myeloma lesions.

Purpose: The aim of our study was to assess the efficacy and safety of percutaneous osteoplasty (PO), a technical extension of percutaneous vertebroplasty, in the treatment of extraspinal bone lesions from multiple myeloma causing pain resistant to NSAID therapy or treated with opioids.

Methods: Between March 2006 and January 2009, 39 patients (22 female), median age 64 years (range 48-88 years) with diagnosis of multiple myeloma, were treated with percutaneous osteoplasty for painful extraspinal bone lesions resistant to NSAID therapy or treated with opioids.

Results: Technical success was achieved in all cases.

Intraluminal recanalization of long infrainguinal chronic total occlusions using the Crosser system.

Purpose: To assess the safety and efficacy of a device for vibrational angioplasty in the percutaneous intraluminal recanalization of long infrainguinal chronic total occlusions (CTO).

Technique: The Crosser CTO Recanalization System is a mechanical recanalization device that uses high-frequency vibrational energy to disrupt and channel through fibrocalcific plaque without harming the vessel wall, thus assisting in the recanalization of an occluded artery. In 12 diabetic patients (7 men; median age 71 years, range 58-80) with critical limb ischemia owing to long (median length 26 cm, range 21-32) infrainguinal CTOs resistant to conventional guidewire techniques, the Crosser CTO Recanalization System was successful in intraluminally crossing the occlusion in 9 (75%) patients in <5 minutes (mean 4:03 minutes).