Publications by authors named "N Karakatsanis"
Objective: Our purpose was to describe our initial institutional experience using dedicated brain [18F]-Fluoroestradiol (FES) PET/CT or PET/MRI in the management of patients with estrogen-receptor-positive (ER+) breast cancer brain metastases (BCBM), and compare to [18F]-Fluorodeoxyglucose (FDG) PET and MRI.
Materials & Methods: Patients with biopsy-proven ER+ disease and MRI findings of suspected new, progressive, or recurrent BCBM were included in this retrospective study. Clinical and demographic data were collected.
Purpose: This simulation study investigated the feasibility of generating Patlak K images using a dual time point (DTP-K) scan protocol involving two 3-min/bed routine static PET scans and, subsequently, assessed DTP-K performance for an optimal DTP scan time frame combination, against conventional Patlak K estimated from complete 0-93 min dynamic PET data.
Methods: Six realistic heterogeneous tumors of different characteristic spatiotemporal [F]FDG uptake distributions for three noise levels commonly found in clinical studies and 20 noise realizations (N = 360 samples) were produced by analytic simulations of the XCAT phantom. Subsequently, DTP-K images were generated by performing standard linear indirect Patlak analysis with t* -min (Patlak) using a scaled population-based input function (sPBIF) model on 66 combinations of early and late 3-min/bed static whole-body PET reconstructed images.
Importance: The chronic neuronal burden of traumatic brain injury (TBI) is not fully characterized by routine imaging, limiting understanding of the role of neuronal substrates in adverse outcomes.
Objective: To determine whether tissues that appear healthy on routine imaging can be investigated for selective neuronal loss using [11C]flumazenil (FMZ) positron emission tomography (PET) and to examine whether this neuronal loss is associated with long-term outcomes.
Design, Setting, And Participants: In this cross-sectional study, data were collected prospectively from 2 centers (University of Cambridge in the UK and Weill Cornell Medicine in the US) between September 1, 2004, and May 31, 2021.
Brain fluid clearance by pathways including the recently described paravascular glymphatic system is a critical homeostatic mechanism by which metabolic products, toxins, and other wastes are removed from the brain. Brain fluid clearance may be especially important after traumatic brain injury (TBI), when blood, neuronal debris, inflammatory cells, and other substances can be released and/or deposited. Using a non-invasive dynamic positron emission tomography (PET) method that models the rate at which an intravenously injected radiolabeled molecule (in this case C-flumazenil) is cleared from ventricular cerebrospinal fluid (CSF), we estimated the overall efficiency of brain fluid clearance in humans who had experienced complicated-mild or moderate TBI 3-6 months before neuroimaging ( = 7) as compared to healthy controls ( = 9).
View Article and Find Full Text PDFBackground And Purpose: WHO grade 3 meningiomas are rare and poorly understood and have a higher propensity for recurrence, metastasis, and worsened clinical outcomes compared with lower-grade meningiomas. The purpose of our study was to prospectively evaluate the molecular profile, PET characteristics, and outcomes of patients with World Health Organization grade 3 meningiomas who were imaged with gallium 68 (Ga) DOTATATE PET/MR imaging.
Materials And Methods: Patients with World Health Organization grade 3 meningiomas enrolled in our prospective observational cohort evaluating the utility of (Ga) DOTATATE PET/MR imaging in somatostatin receptor positive brain tumors were included.