Mn-labelled Beta-cyclodextrin for Melanoma Imaging: A Proof-of-concept Preclinical Study.

Background/aim: As prostaglandin E2 (PGE2) and its receptors (EP2) are over-expressed on tumor cells and microenvironment, radiolabeled cyclodextrins targeting such biomolecules are valuable vector candidates in molecular cancer diagnostics. Using experimental melanoma models, we evaluated the in vivo imaging behavior of novel Manganese-52-labeled (Mn) randomly methylated beta-cyclodextrin ([Mn]Mn-DOTAGA-RAMEB) and compared it with the following well-established tumor-specific probes: melanocortin-1 receptor (MC1-R)-affine [Ga]Ga-DOTA-NAPamide and PGE2 selective [Ga]Ga-DOTAGA-RAMEB cyclodextrin.

Materials And Methods: Post-injection of [Ga]Ga-DOTA-NAPamide, [Ga]Ga-DOTAGA-RAMEB, and [Mn]Mn-DOTAGA-RAMEB into MC1-R positive B16F10 melanoma-bearing mice, tumor radio-pharmaceutical uptake was quantified in vivo and ex vivo using preclinical positron emission tomography (PET) and high-performance gamma counter.

Acute Myelomonoblastic Leukemia (My1/De): A Preclinical Rat Model.

Background/aim: Since acute myeloid leukemias still represent the most aggressive type of adult acute leukemias, the profound understanding of disease pathology is of paramount importance for diagnostic and therapeutic purposes. Hence, this study aimed to explore the real-time disease fate with the establishment of an experimental myelomonoblastic leukemia (My1/De) rat model using preclinical positron emission tomography (PET) and whole-body autoradiography.

Materials And Methods: In vitro [F]F-FDG uptake studies were performed to compare the tracer accumulation in the newly cultured My1/De tumor cell line (blasts) with that in healthy control and My1/De bone marrow suspensions.

Concomitant [F]F-FAZA and [F]F-FDG Imaging of Gynecological Cancer Xenografts: Insight into Tumor Hypoxia.

Background/aim: Herein we assessed the feasibility of imaging protocols using both hypoxia-specific [F]F-FAZA and [F]F-FDG in bypassing the limitations derived from the non-specific findings of [F]F-FDG PET imaging of tumor-related hypoxia.

Materials And Methods: CoCl-generated hypoxia was induced in multidrug resistant (Pgp+) or sensitive (Pgp-) human ovarian (Pgp- A2780, Pgp+ A2780AD), and cervix carcinoma (Pgp- KB-3-1, Pgp+ KB-V-1) cell lines to establish corresponding tumor-bearing mouse models. Prior to [F]F-FDG/[F]F-FAZA-based MiniPET imaging, in vitro [F]F-FDG uptake measurements and western blotting were used to verify the presence of hypoxia.

[Coding of laboratory parameters using the LOINC system at the Clinical Center of the University of Debrecen].

Introduction: The research utility of the bulk of the medical data generated at the Clinical Center of the University of Debrecen, which is constituted mainly by the clinical diagnostic laboratory results and medical images, is quite constrained in its present unstandardized form. The primary aim of the Big Data Research and Development project at the University of Debrecen is to facilitate data transformation and standardization to propagate its research utility for the potential end-users. Data generated in the in vitro diagnostic laboratory setting are an ideal candidate for the aforementioned goals.

In vivo assessment of tumor targeting potential of Ga-labelled randomly methylated beta-cyclodextrin (RAMEB) and 2-hydroxypropyl-β-cyclodextrin (HPβCD) using positron emission tomography.

Cyclodextrin derivates (CyDs) can form complexes with cyclooxygenase-2 induced tumor promoting prostaglandin E2 (PGE2). Based on our previous observations, Ga-labelled CyDs may represent promising radiopharmaceuticals in the positron emission tomography (PET) diagnostics of PGE2 positive tumors. We aimed at evaluating the tumor-targeting potential of Ga-NODAGA conjugated randomly methylated beta-cyclodextrin (Ga-NODAGA-RAMEB) and 2-hydroxypropyl-β-cyclodextrin (Ga-NODAGA-HPβCD) using in vivo PET imaging with experimental tumor models.

PET Probes for Preclinical Imaging of GRPR-Positive Prostate Cancer: Comparative Preclinical Study of [Ga]Ga-NODAGA-AMBA and [Sc]Sc-NODAGA-AMBA.

Gastrin-releasing peptide receptors (GRPR) are overexpressed in prostate cancer (PCa). Since bombesin analogue aminobenzoic-acid (AMBA) binds to GRPR with high affinity, scandium-44 conjugated AMBA is a promising radiotracer in the PET diagnostics of GRPR positive tumors. Herein, the GRPR specificity of the newly synthetized [Sc]Sc-NODAGA-AMBA was investigated in vitro and in vivo applying PCa PC-3 xenograft.

Topological dissimilarities of hierarchical resting networks in type 2 diabetes mellitus and obesity.

Type 2 diabetes mellitus (T2DM) is reported to cause widespread changes in brain function, leading to cognitive impairments. Research using resting-state functional magnetic resonance imaging data already aims to understand functional changes in complex brain connectivity systems. However, no previous studies with dynamic causal modelling (DCM) tried to investigate large-scale effective connectivity in diabetes.

In vivo investigation of Gallium-68 and Bismuth-205/206 labeled beta cyclodextrin for targeted alpha therapy of prostaglandin E2 receptor-expressing tumors in mice.

Prostaglandin E2 (PGE2) molecule and its receptors play an important role in the development of malignancies and metastases therefore PGE2 may play a crucial role in the diagnosis and a new therapeutic target in the field of radionuclide therapy of PGE2-positive tumors. PGE2 form complexes with RAMEB (randomly-methylated-beta-cyclodextrin) with high affinity therefore the aim of this present study was to synthesize a PGE2-specific DOTAGA-RAMEB, which can be labeled with diagnostic and therapeutic isotopes also and binds to PGE2-positive tumors. DOTAGA-RAMEB was labeled with Ga and Bi radionuclides and their radiochemical purity (RCP%), partition coefficient (logP values), and in vitro and in vivo stability were determined.

Imaging of Neo-angiogenesis of Transplanted Metastases in Subrenal Capsule Assay Induced Rat Model.

Background/aim: Changes in the expression of neo-angiogenic molecules in the primary tumor and its metastases may significantly affect the efficacy of therapies. The aim of this study was to evaluate the alterations in aminopeptidase N (APN/CD13) and αβ integrin receptor expression in serially transplanted mesoblastic nephroma tumor (Ne/De) metastases using Gallium (Ga)-labeled NOTA-cNGR and NODAGA-RGD radiotracers and preclinical positron emission tomography (PET) imaging.

Materials And Methods: Primary and metastatic mesoblastic nephroma (Ne/De) tumors were induced by subrenal capsule assay (SRCA) in Fischer-344 rats.

Imaging of Ischemia/Reperfusion-mediated Aminopeptidase N Expression in Surgical Rat Model Using Ga-NOTA-c(NGR).

Background/aim: Previous studies have already shown that Gallium(Ga)-labeled NGR-based radiopharmaceuticals specifically bind to the neoangiogenic molecule Aminopeptidase N (APN/CD13). The aim of this study was to evaluate the applicability of Ga-NOTA-c(NGR) in the in vivo detection of the temporal changes of APN/CD13 expression in the diabetic retinopathy rat model using positron emission tomography (PET).

Materials And Methods: Ischemia/reperfusion injury was initiated by surgical ligation of the left bulbus oculi of rats.

Automated procedure assessing the accuracy of HRCT-PET registration applied in functional virtual bronchoscopy.

Background: Bronchoscopy serves as direct visualisation of the airway. Virtual bronchoscopy provides similar visual information using a non-invasive imaging procedure(s). Early and accurate image-guided diagnosis requires the possible highest performance, which might be approximated by combining anatomical and functional imaging.

Characterizing Network Search Algorithms Developed for Dynamic Causal Modeling.

Dynamic causal modeling (DCM) is a widely used tool to estimate the effective connectivity of specified models of a brain network. Finding the model explaining measured data is one of the most important outstanding problems in Bayesian modeling. Using heuristic model search algorithms enables us to find an optimal model without having to define a model set a priori.

Effective connectivity differences in motor network during passive movement of paretic and non-paretic ankles in subacute stroke patients.

Background: A better understanding of the neural changes associated with paresis in stroke patients could have important implications for therapeutic approaches. Dynamic Causal Modeling (DCM) for functional magnetic resonance imaging (fMRI) is commonly used for analyzing effective connectivity patterns of brain networks due to its significant property of modeling neural states behind fMRI signals. We applied this technique to analyze the differences between motor networks (MNW) activated by continuous passive movement (CPM) of paretic and non-paretic ankles in subacute stroke patients.

OAR sparing 3D radiotherapy planning supported by fMRI brain mapping investigations.

The human brain as an organ has numerous functions; some of them can be visualized by functional imaging techniques (e.g., functional MRI [fMRI] or positron emission tomography).

Population-Level Correction of Systematic Motion Artifacts in fMRI in Patients with Ischemic Stroke.

Background: The aim of this study was to reveal potential sources of systematic motion artifacts in stroke functional magnetic resonance imaging (fMRI) focusing on those causing stimulus-correlated motion on the individual-level and separate the motion effect on the fMRI signal changing from the activation-induced alteration at population level.

Methods: Eleven ischemic stroke patients were examined by fMRI. The fMRI paradigm was based on passive ankle movement on both the healthy and the paretic leg's side.

A Study on the Basic Criteria for Selecting Heterogeneity Parameters of F18-FDG PET Images.

Textural analysis might give new insights into the quantitative characterization of metabolically active tumors. More than thirty textural parameters have been investigated in former F18-FDG studies already. The purpose of the paper is to declare basic requirements as a selection strategy to identify the most appropriate heterogeneity parameters to measure textural features.

[INDIVIDUAL EVALUATION OF LORETA ABNORMALITIES IN IDIOPATHIC GENERALIZED EPILEPSY].

Background: Contemporary neuroimaging methods disclosed structural and functional cerebral abnormalities in idiopathic generalized epilepsies (IGEs). However, individual electrical (EEG) abnormalities have not been evaluated yet in IGE patients.

Methods: IGE patients were investigated in the drug-free condition and after 3-6 month of antiepileptic treatment.

Increased resting-state EEG functional connectivity in benign childhood epilepsy with centro-temporal spikes.

Purpose: To explore intrahemispheric, cortico-cortical EEG functional connectivity (EEGfC) in benign childhood epilepsy with rolandic spikes (BECTS).

Methods: 21-channel EEG was recorded in 17 non-medicated BECTS children and 19 healthy controls. 180s of spike- and artifact-free activity was selected for EEGfC analysis.

ANXIETY MANAGEMENT AND FUNCTIONAL MAGNETIC RESONANCE IMAGING--SHOULD IT BE A PRIORITY?

Background And Purpose: Studies have shown that a high proportion of patients undergoing MRI examinations experience anxiety and distress which may compromise image quality and successful data acquisition. Research on fMRI related anxiety is limited as to date, therefore, the purpose of this study was to assess the changes in anxiety as well as to examine its interactions with the implementation of a dedicated patient preparation phase prior to the examination.

Methods: An fMRI examination consisting of six paradigms was performed on nine female and nine male healthy volunteers.

A Promising Future: Comparable Imaging Capability of MRI-Compatible Silicon Photomultiplier and Conventional Photosensor Preclinical PET Systems.

Unlabelled: We recently completed construction of a small-animal PET system-the MiniPET-3-that uses state-of-the-art silicon photomultiplier (SiPM) photosensors, making possible dual-modality imaging with MRI. In this article, we compare the MiniPET-3 with the MiniPET-2, a system with the same crystal geometry but conventional photomultiplier tubes (PMTs).

Methods: The standard measurements proposed by the National Electrical Manufacturers Association NU 4 protocols were performed on both systems.

Changes in functional MRI signals after 3D based radiotherapy of glioblastoma multiforme.

The purpose of our study was to examine the potential effects of conventional 3D based radiotherapy on functional MRI activation areas following the treatment of glioblastoma multiforme. Seventeen patients with a histologically proven glioblastoma multiforme were enrolled in this study. A functional MRI examination was performed alongside the planning CT and conventional MRI prior to the delivery of conventional 3D based radiotherapy.

Population based ranking of frameless CT-MRI registration methods.

Background: Clinical practice often requires simultaneous information obtained by two different imaging modalities. Registration algorithms are commonly used for this purpose. Automated procedures are very helpful in cases when the same kind of registration has to be performed on images of a high number of subjects.

[New trends and novel possibilities in functional medical imaging: imaging methods].

The aim of the study is to review the new tomographic imaging technologies which enable to investigate the metabolic activity of the human body. Accordingly, we overview the current promising methodology in the field of PET and SPECT, but we will also mention interesting applications at the area of MRI and CT.

Voxel-wise motion artifacts in population-level whole-brain connectivity analysis of resting-state FMRI.

Functional Magnetic Resonance Imaging (fMRI) based brain connectivity analysis maps the functional networks of the brain by estimating the degree of synchronous neuronal activity between brain regions. Recent studies have demonstrated that "resting-state" fMRI-based brain connectivity conclusions may be erroneous when motion artifacts have a differential effect on fMRI BOLD signals for between group comparisons. A potential explanation could be that in-scanner displacement, due to rotational components, is not spatially constant in the whole brain.

Cold wall effect eliminating method to determine the contrast recovery coefficient for small animal PET scanners using the NEMA NU-4 image quality phantom.

The contrast recovery coefficients (CRC) were evaluated for five different small animal PET scanners: GE Explore Vista, Genisys4, MiniPET-2, nanoScan PC and Siemens Inveon. The NEMA NU-4 2008 performance test with the suggested image quality phantom (NU4IQ) does not allow the determination of the CRC values for the hot regions in the phantom. This drawback of NU4IQ phantom motivated us to develop a new method for this purpose.