| 1. |
- Appel, Lieuwe, et al.
(author)
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Use of C-11-PE2I PET in Differential Diagnosis of Parkinsonian Disorders
- 2015
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In: Journal of Nuclear Medicine. - : Society of Nuclear Medicine. - 0161-5505 .- 1535-5667 .- 2159-662X. ; 56:2, s. 234-242
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Journal article (peer-reviewed)abstract
- In idiopathic Parkinson disease and atypical parkinsonian disorders, central dopaminergic and overall brain functional activity are altered to different degrees, causing difficulties in achieving an unambiguous clinical diagnosis. A dual examination using I-123-FP-CIT (I-123-N-omega-fluoropropyl- 2 beta-carbomethoxy-3 beta-(4-iodophenyl) nortropane, or I-123-ioflupane) SPECT and F-18-FDG PET provides complementary information on dopamine transporter (DAT) availability and overall brain functional activity, respectively. Parametric images based on a single, dynamic C-11-PE2I (N-(3-iodoprop-2E-enyl)-2 beta-carbomethoxy-3 beta-(4-methyl-phenyl) nortropane) scan potentially supply both DAT availability (nondisplaceable binding potential [BPND]) and relative cerebral blood flow (relative delivery [R-1]) at voxel level. This study aimed to evaluate the validity of C-11-PE2I PET against the dual-modality approach using I-123-FP-CIT SPECT and F-18-FDG PET.Methods: Sixteen patients with parkinsonian disorders had a dual examination with F-18-FDG PET and I-123-FP-CIT SPECT following clinical routines and additionally an experimental C-11-PE2I PET scan. Parametric BPND and R-1 images were generated using receptor parametric mapping with the cerebellum as a reference. T1-weighted MR imaging was used for automated definition of volumes of interest (VOI). The DAT VOIs included the basal ganglia, whereas the overall brain functional activity was examined using VOIs across the brain. BPND and R-1 values were compared with normalized I-123-FP-CIT and F-18-FDG uptake values, respectively, using Pearson correlations and regression analyses. In addition, 2 masked interpreters evaluated the images visually, in both the routine and the experimental datasets, for comparison of patient diagnoses.Results: Parametric C-11-PE2I BPND and R-1 images showed high consistency with I-123-FP-CIT SPECT and F-18-FDG PET images. Correlations between C-11-PE2I BPND and I-123-FP-CIT uptake ratios were 0.97 and 0.76 in the putamen and caudate nucleus, respectively. Regional C-11-PE2I R-1 values were moderately to highly correlated with normalized F-18-FDG values (range, 0.61-0.94). Visual assessment of DAT availability showed a high consistency between C-11-PE2I BPND and I-123-FP-CIT images, whereas the consistency was somewhat lower for appraisal of overall brain functional activity using I-123-FP-CIT and F-18-FDG images. Substantial differences were found between clinical diagnosis and both neuro-imaging diagnoses.Conclusion: A single, dynamic C-11-PE2I PET investigation is a powerful alternative to a dual examination with I-123-FP-CIT SPECT and F-18-FDG PET for differential diagnosis of parkinsonian disorders. A large-scale patient study is, however, needed to further investigate distinct pathologic patterns in overall brain functional activity for various parkinsonian disorders.
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| 2. |
- Jonasson, My, et al.
(author)
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Development of a clinically feasible [11C]PE2I PET method for differential diagnosis of parkinsonism using reduced scan duration and automated reference region extraction.
- 2017
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In: American Journal of Nuclear Medicine and Molecular Imaging. - 2160-8407. ; 7:6, s. 263-274
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Journal article (peer-reviewed)abstract
- [11C]PE2I is a highly selective dopamine transporter PET ligand. Parametric images based on dynamic [11C]PE2I scans, showing dopamine transporter availability (BPND) and relative cerebral blood flow (R1), can be used in differential diagnosis of parkinsonism. This work aimed to investigate a shortened scan duration and automated generation of parametric images which are two prerequisites for routine clinical application. Twelve subjects with parkinsonism and seventeen healthy controls underwent 80 min dynamic [11C]PE2I PET scans. BPND and R1 images were generated using cerebellum reference region defined on a co-registered MRI, as well as a supervised cluster analysis (SVCA)-based reference. Initial 20, 30 and 40 min of the scans were extracted and images of standardized uptake value ratio (SUVR) and R1 were computed using MRI- and SVCA-based reference. Correlation was high between striatal 80 min MRI-based BPND and 40 min SVCA-based SUVR-1 (R2=0.95). High correlation was also found between R1 values in striatal and limbic regions (R2≥0.91) whereas correlation was moderate for cortical regions (R2=0.71). The results indicate that dynamic [11C]PE2I scans can be restricted to 40 min and that SVCA can be used for automatic extraction of a reference region. These outcomes will support routine applications of [11C]PE2I PET in clinical settings.
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| 3. |
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| 4. |
- Jonasson, My, et al.
(author)
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Validation of parametric methods for [(11)C]PE2I positron emission tomography
- 2013
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In: NeuroImage. - : Elsevier BV. - 1053-8119 .- 1095-9572. ; 74, s. 172-178
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Journal article (peer-reviewed)abstract
- OBJECTIVESThe radioligand [(11)C]PE2I is highly selective for dopamine transporter (DAT) and can be used in vivo for investigation of changes in DAT concentration, progression of disease and validation of treatment using positron emission tomography (PET). DAT is an important protein for regulation of central dopamine concentration and DAT deficiency has been associated with several neurodegenerative and neuropsychiatric disorders. Accurate parametric images are a prerequisite for clinical application of [(11)C]PE2I. The purpose of this study was to evaluate different methods for producing [(11)C]PE2I parametric images, showing binding potential (BPND) and relative delivery (R1) at the voxel level, using clinical data as well as simulations.METHODSInvestigations were made in twelve subjects either with social anxiety disorder (n=6) or parkinsonian syndrome (n=6), each receiving an 80min dynamic PET scan. All subjects underwent a T1-weighted MRI scan which was co-registered to the PET images and used for definition of regions of interest using a probabilistic template (PVElab). Two basis function implementations (receptor parametric mapping: RPM, RPM2) of the simplified reference tissue model (SRTM) and three multilinear reference tissue models (MRTMo, MRTM and MRTM2) were used for computation of parametric BPND and R1 images. In addition, reference Logan and standard uptake value ratio (SUVr) were investigated. Evaluations of BPND and R1 images were performed using linear regression to compare the parametric methods to region-based analyses with SRTM and cerebellar gray matter as reference region. Accuracy and precision of each method were assessed by simulations.RESULTSCorrelation and slope of linear regression between parametric and region-based BPND and R1 values in both striatum and extra-striatal regions were optimal for RPM (R(2)=0.99 for both BPND and R1; slopes 0.99 and 0.98 for BPND and R1, respectively, in striatum). In addition, accuracy and precision were best for RPM and RPM2.CONCLUSIONThe basis function methods provided more robust estimations of the parameters compared to the other models and performed best in simulations. RPM, a basis function implementation of SRTM, is the preferred method for voxel level analysis of [(11)C]PE2I PET studies.
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| 6. |
- Sikk, K, et al.
(author)
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Clinical, neuroimaging and neurophysiological features in addicts with manganese-ephedrone exposure
- 2010
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In: Acta Neurologica Scandinavica. - : Hindawi Limited. - 0001-6314 .- 1600-0404. ; 121:4, s. 237-243
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Journal article (peer-reviewed)abstract
- Objective - To identify biomarkers supporting the clinical diagnosis of manganism in patients several years after exposure to manganese (Mn). Methods - Neurophysiological examinations, magnetic resonance imaging (MRI), single-photon emission computed tomography and fluorodeoxyglycose (FDG) positron emission tomography were performed in four former ephedrone addicts with extrapyramidal symptoms. Results - Peripheral nervous system was not affected. No patients had reduced uptake of (123)I Ioflupane in the striatum. MRI signal intensities were slightly changed in the basal ganglia. All patients showed a widespread, but not uniform, pathological pattern of FDG uptake with changes mainly located to the central part of the brain including the basal ganglia and the surrounding white matter. Conclusions - Presynaptic neurons in the nigrostriatal pathway are intact in Mn-induced parkinsonism after prolonged abstinence from ephedrone. The diagnosis is principally based on clinical signs and the history of drug abuse.
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