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  • 1.
    Appel, Lieuwe
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Section of Nuclear Medicine and PET. Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Radiology.
    Jonasson, My
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Section of Nuclear Medicine and PET. Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Radiology.
    Danfors, Torsten
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Section of Nuclear Medicine and PET. Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Radiology.
    Nyholm, Dag
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurology.
    Askmark, Håkan
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurology.
    Lubberink, Mark
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Section of Nuclear Medicine and PET. Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Radiology.
    Sörensen, Jens
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Section of Nuclear Medicine and PET. Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Radiology.
    Use of C-11-PE2I PET in Differential Diagnosis of Parkinsonian Disorders2015In: Journal of Nuclear Medicine, ISSN 0161-5505, E-ISSN 1535-5667, Vol. 56, no 2, p. 234-242Article in journal (Refereed)
    Abstract [en]

    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.

  • 2.
    Danfors, Torsten
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurology. Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Section of Nuclear Medicine and PET.
    11C Molecular Imaging in Focal Epilepsy2012Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Epilepsy is a common neurological disease affecting 6 million people in Europe. Early prevention and accurate diagnosis and treatment are of importance to obtain seizure freedom. In this thesis new applications of carbon-11-labelled tracers in PET and autoradiographic studies were explored in focal epilepsy.

    Patients with low-grade gliomas often experience epileptic seizures. A retrospective PET-study assessing seizure activity, metabolic rate measured with 11C-methionine and other known prognostic factors was performed in patients with glioma. No correlation was found between seizure activity and uptake of methionine. The presence and termination of early seizures was a favourable prognostic factor.

    Activation of the neurokinin-1 (NK1) receptor by substance P (SP) induces epileptic activity. PET with the NK1 receptor antagonist GR205171 was performed in patients with temporal lobe epilepsy (TLE) and healthy controls. In TLE patients an increased NK1 receptor availability was found in both hemispheres, most pronounced in anterior cingulate gyrus ipsilateral to seizure onset. A positive correlation between NK1 receptors and seizure frequency was observed in ipsilateral medial structures consistent with an intrinsic network using the NK1-SP receptor system for transmission of seizure activity.

    The uptake of 18F-fluoro-deoxy-glucose (FDG) is related to cerebral blood flow (CBF). Previously, methods to estimate blood flow from dynamic PET data have been described. A retrospective study was conducted in 15 patients undergoing epilepsy surgery investigation, including PET with 11C-FDG and 11C-Flumazenil (FMZ). The dynamic FMZ dataset and pharmacokinetic modeling with a multilinear reference tissue model were used to determine images of relative CBF. Agreement between data of FDG and CBF was analyzed showing a close association between interictal brain metabolism and relative CBF.

    Epilepsy often occurs after traumatic brain injuries. Changes in glia and inhibitory neuronal cells contribute to the chain of events leading to seizures. Autoradiography with 11C-PK11195, 11C-L-deprenyl and 11C-Flumazenil in an animal model of posttraumatic epilepsy studied the temporal and spatial distribution of microglia, astrocytes and GABAergic neurons. Results showed an instant increase in microglial activity that subsequently normalized, a late formation of astrogliosis and an instant and prolonged decease in GABA binding. The model can be used to visualize pathophysiological events during the epileptogenesis.

    List of papers
    1. Epileptic seizures and survival in early disease of grade 2 gliomas
    Open this publication in new window or tab >>Epileptic seizures and survival in early disease of grade 2 gliomas
    2009 (English)In: European Journal of Neurology, ISSN 1351-5101, E-ISSN 1468-1331, Vol. 16, no 7, p. 823-831Article in journal (Refereed) Published
    Abstract [en]

    Background and purpose

    The aims of this study were (i) to determine the correlation between seizure activity and the metabolic rate of the tumour measured by 11Cmethionine PET (MET PET) in patients with grade 2 gliomas, and (ii) to assess the prognostic impact of early seizure manifestations on patient survival.

    Methods

    In this retrospective review, early seizure manifestations were studied in 101 patients with supratentorial grade 2 gliomas subjected to MET PET as part of the pretreatment tumour investigation. Seizure manifestations as a variable was then used in multivariate survival analyses, together with established prognostic factors for this patient group.

    Results

    Of all 101 cases, 88 patients had seizures at tumour presentation. Fortyseven were seizure free at the early stage of the disease, whereas 54 had recurrent seizures. Patients with seizures at tumour presentation had a more favourable outcome before and after (P = 0.006) adjustment for conventional prognostic factors. However, for those who continued to have seizures early in the disease, the outcome was worse (P = 0.003). We found no significant correlation between MET PET and the seizure manifestations of the patients.

    Conclusion

    The presence and termination of early seizure manifestations may be favourable prognostic factors in patients with low-grade gliomas.

     

    Keywords
    11C methionine positron emission tomography, epileptic seizures, low-grade glioma, survival
    National Category
    Neurology
    Research subject
    Neurology
    Identifiers
    urn:nbn:se:uu:diva-105434 (URN)10.1111/j.1468-1331.2009.02599.x (DOI)000266637000012 ()
    Available from: 2009-06-03 Created: 2009-06-03 Last updated: 2017-12-13Bibliographically approved
    2. Increased neurokinin-1 receptor availability in temporal lobe epilepsy: A positron emission tomography study using [(11)C]GR205171
    Open this publication in new window or tab >>Increased neurokinin-1 receptor availability in temporal lobe epilepsy: A positron emission tomography study using [(11)C]GR205171
    Show others...
    2011 (English)In: Epilepsy Research, ISSN 0920-1211, E-ISSN 1872-6844, Vol. 97, no 1-2, p. 183-189Article in journal (Refereed) Published
    Abstract [en]

    PURPOSE: Activation of the neurokinin-1 (NK1) receptor by neuropeptide substance P (SP) induces and maintains epileptic activity in various experimental models of epilepsy. The primary objective of this study was to investigate whether neurobiological changes linked to NK1-SP receptor system are associated with hyperexcitability in patients with temporal lobe epilepsy (TLE). A secondary objective was to investigate the relationship between seizure frequency and NK1 receptor availability.

    METHODS: A positron emission tomography study was conducted with the selective NK1 receptor antagonist [(11)C]GR205171 in nine patients with TLE and 18 healthy control participants. Parametric PET images were generated using the Patlak graphical method, with cerebellum as reference region. Data analyses including group comparisons were performed using statistical parametric mapping.

    RESULTS: Patients with TLE showed increased NK1 receptor availability in both hemispheres with the most pronounced increase in anterior cingulate gyrus ipsilateral to seizure onset. A positive correlation between NK1 receptor availability and seizure frequency was observed in the medial temporal lobe and in the lentiform nucleus ipsilateral to the seizure onset.

    CONCLUSION: Our results suggest that there is an intrinsic network using the NK1-SP receptor system for synaptic transmission and epileptiform activity in TLE.

    Keywords
    Epilepsy, PET, NK1, Substance P, TLE
    National Category
    Neurology
    Research subject
    Neurology
    Identifiers
    urn:nbn:se:uu:diva-159946 (URN)10.1016/j.eplepsyres.2011.08.006 (DOI)00297873800021 ()21925840 (PubMedID)
    Available from: 2011-10-12 Created: 2011-10-12 Last updated: 2017-12-08Bibliographically approved
    3. Relative Cerbral Blood Flow Measurement using dynamic Flumazenil-PET may Replace Fluorodeoxyglucose-PET in Epilepsy Surgical Investigations
    Open this publication in new window or tab >>Relative Cerbral Blood Flow Measurement using dynamic Flumazenil-PET may Replace Fluorodeoxyglucose-PET in Epilepsy Surgical Investigations
    2012 (English)Article in journal (Other academic) Submitted
    National Category
    Neurosciences Other Basic Medicine
    Research subject
    Neurology
    Identifiers
    urn:nbn:se:uu:diva-180846 (URN)
    Available from: 2012-09-11 Created: 2012-09-11 Last updated: 2018-01-12Bibliographically approved
    4. 11C-autoradiographic studies of dynamic changes in glial cells and benzodiazepine receptor binding in a model of posttraumatic epilepsy
    Open this publication in new window or tab >>11C-autoradiographic studies of dynamic changes in glial cells and benzodiazepine receptor binding in a model of posttraumatic epilepsy
    Show others...
    (English)Manuscript (preprint) (Other academic)
    National Category
    Neurosciences
    Identifiers
    urn:nbn:se:uu:diva-180847 (URN)
    Available from: 2012-09-11 Created: 2012-09-11 Last updated: 2018-06-18
  • 3.
    Danfors, Torsten
    et al.
    Uppsala University, Medicinska vetenskapsområdet, Faculty of Medicine, Department of Neuroscience. neurologi.
    Fagius, Ja
    Uppsala University, Medicinska vetenskapsområdet, Faculty of Medicine, Department of Neuroscience. neurologi.
    Akutneurologi2006In: Neurologi, Liber AB, Stockholm , 2006, p. 568-Chapter in book (Other scientific)
  • 4.
    Danfors, Torsten
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurology.
    Ribom, Dan
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurology.
    Berntsson, Shala G.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurology.
    Smits, Anja
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurology.
    Epileptic seizures and survival in early disease of grade 2 gliomas2009In: European Journal of Neurology, ISSN 1351-5101, E-ISSN 1468-1331, Vol. 16, no 7, p. 823-831Article in journal (Refereed)
    Abstract [en]

    Background and purpose

    The aims of this study were (i) to determine the correlation between seizure activity and the metabolic rate of the tumour measured by 11Cmethionine PET (MET PET) in patients with grade 2 gliomas, and (ii) to assess the prognostic impact of early seizure manifestations on patient survival.

    Methods

    In this retrospective review, early seizure manifestations were studied in 101 patients with supratentorial grade 2 gliomas subjected to MET PET as part of the pretreatment tumour investigation. Seizure manifestations as a variable was then used in multivariate survival analyses, together with established prognostic factors for this patient group.

    Results

    Of all 101 cases, 88 patients had seizures at tumour presentation. Fortyseven were seizure free at the early stage of the disease, whereas 54 had recurrent seizures. Patients with seizures at tumour presentation had a more favourable outcome before and after (P = 0.006) adjustment for conventional prognostic factors. However, for those who continued to have seizures early in the disease, the outcome was worse (P = 0.003). We found no significant correlation between MET PET and the seizure manifestations of the patients.

    Conclusion

    The presence and termination of early seizure manifestations may be favourable prognostic factors in patients with low-grade gliomas.

     

  • 5.
    Danfors, Torsten
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurology.
    Samuelsson, Carolina
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurosurgery.
    Estrada, Sergio
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry, Preclinical PET Platform.
    Mats, Bergström
    Ronne-Engström, Elisabeth
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurosurgery.
    Kumlien, Eva
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurology.
    11C-autoradiographic studies of dynamic changes in glial cells and benzodiazepine receptor binding in a model of posttraumatic epilepsyManuscript (preprint) (Other academic)
  • 6.
    Danfors, Torsten
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurology.
    Sörensen, Jens
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Section of Nuclear Medicine and PET.
    Lubberink, Mark
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Section of Medical Physics.
    Kumlien, Eva
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurology.
    Relative Cerbral Blood Flow Measurement using dynamic Flumazenil-PET may Replace Fluorodeoxyglucose-PET in Epilepsy Surgical Investigations2012Article in journal (Other academic)
  • 7.
    Danfors, Torsten
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Section of Nuclear Medicine and PET.
    Velickaite, Vilma
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Radiology.
    Canto Moreira, Nuno
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Radiology.
    The role of methionine positron emission tomography in the evaluation of central nervous system tumors in children2016In: Journal of Cerebral Blood Flow and Metabolism, ISSN 0271-678X, E-ISSN 1559-7016, Vol. 36, no Suppl. 1, p. 394-395, article id 538Article in journal (Other academic)
  • 8.
    Danfors, Torsten
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience. neurologi.
    von Knorring, Anne-Liis
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience. BUP.
    Hartvig, Per
    Hospital Pharmacy.
    Långström, Bengt
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Section of Nuclear Medicine and PET.
    Moulder, Robert
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Section of Nuclear Medicine and PET.
    Strömberg, Bo
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Women's and Children's Health.
    Torstenson, Richard
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Section of Nuclear Medicine and PET.
    Wester, Ulrika
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Women's and Children's Health.
    Watanabe, Yasuyoshi
    Department of Physiology, Osaka City University Graduate School of Medicine, Japan.
    Eeg-Olofsson, Orvar
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Women's and Children's Health.
    Tetrahydrobiopterin in the treatment of children with autistic disorder. A double-blind placebo-controlled crossover study2005In: Journal of Clinical Psychopharmacology, ISSN 0271-0749, E-ISSN 1533-712X, Vol. 25, no 5, p. 485-489Article in journal (Refereed)
    Abstract [en]

    Twelve children, all boys, aged 4 to 7 years, with a diagnosis of autistic disorder and low concentrations of spinal 6R-l-erythro-5,6,7,8-tetrahydrobiopterin (tetrahydrobiopterin) were selected to participate in a double-blind, randomized, placebo-controlled, crossover study. The children received a daily dose of 3 mg tetrahydrobiopterin per kilogram during 6 months alternating with placebo. Treatment-induced effects were assessed with the Childhood Autism Rating Scale every third month. The results showed small nonsignificant changes in the total scores of Childhood Autism Rating Scale after 3- and 6-month treatment. Post hoc analysis looking at the 3 core symptoms of autism, that is, social interaction, communication, and stereotyped behaviors, revealed a significant improvement of the social interaction score after 6 months of active treatment. In addition, a high positive correlation was found between response of the social interaction score and IQ. The results indicate a possible effect of tetrahydrobiopterin treatment.

  • 9.
    Danfors, Torsten
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurology.
    Åhs, Fredrik
    Uppsala University, Disciplinary Domain of Humanities and Social Sciences, Faculty of Social Sciences, Department of Psychology.
    Appel, Lieuwe
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Section of Nuclear Medicine and PET.
    Linnman, Clas
    Uppsala University, Disciplinary Domain of Humanities and Social Sciences, Faculty of Social Sciences, Department of Psychology.
    Fredrikson, Mats
    Uppsala University, Disciplinary Domain of Humanities and Social Sciences, Faculty of Social Sciences, Department of Psychology.
    Furmark, Tomas
    Uppsala University, Disciplinary Domain of Humanities and Social Sciences, Faculty of Social Sciences, Department of Psychology.
    Kumlien, Eva
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurology.
    Increased neurokinin-1 receptor availability in temporal lobe epilepsy: A positron emission tomography study using [(11)C]GR2051712011In: Epilepsy Research, ISSN 0920-1211, E-ISSN 1872-6844, Vol. 97, no 1-2, p. 183-189Article in journal (Refereed)
    Abstract [en]

    PURPOSE: Activation of the neurokinin-1 (NK1) receptor by neuropeptide substance P (SP) induces and maintains epileptic activity in various experimental models of epilepsy. The primary objective of this study was to investigate whether neurobiological changes linked to NK1-SP receptor system are associated with hyperexcitability in patients with temporal lobe epilepsy (TLE). A secondary objective was to investigate the relationship between seizure frequency and NK1 receptor availability.

    METHODS: A positron emission tomography study was conducted with the selective NK1 receptor antagonist [(11)C]GR205171 in nine patients with TLE and 18 healthy control participants. Parametric PET images were generated using the Patlak graphical method, with cerebellum as reference region. Data analyses including group comparisons were performed using statistical parametric mapping.

    RESULTS: Patients with TLE showed increased NK1 receptor availability in both hemispheres with the most pronounced increase in anterior cingulate gyrus ipsilateral to seizure onset. A positive correlation between NK1 receptor availability and seizure frequency was observed in the medial temporal lobe and in the lentiform nucleus ipsilateral to the seizure onset.

    CONCLUSION: Our results suggest that there is an intrinsic network using the NK1-SP receptor system for synaptic transmission and epileptiform activity in TLE.

  • 10.
    Fällmar, David
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Radiology.
    Haller, Sven
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Radiology. Univ Med Ctr Freiburg, Dept Neuroradiol, Freiburg, Germany.; Univ Geneva, Fac Med, Geneva, Switzerland.; Affidea CDRC Ctr Diagnost Radiol Carouge, Carouge, Switzerland..
    Lilja, Johan
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences. Hermes Med Solut, Stockholm, Sweden.
    Danfors, Torsten
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences.
    Kilander, Lena
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Public Health and Caring Sciences, Geriatrics.
    Tolboom, Nelleke
    Vrije Univ Amsterdam, Dept Radiol & Nucl Med, Med Ctr, Neurosci Campus, Amsterdam, Netherlands.
    Egger, Karl
    Univ Med Ctr Freiburg, Dept Neuroradiol, Freiburg, Germany.
    Kellner, Elias
    Univ Freiburg, Dept Radiol, Med Ctr, Fac Med,Med Phys, Freiburg, Germany.
    Croon, Philip M
    Vrije Univ Amsterdam, Dept Radiol & Nucl Med, Med Ctr, Neurosci Campus, Amsterdam, Netherlands.
    Verfaillie, Sander C J
    Vrije Univ Amsterdam, Alzheimer Ctr Amsterdam, Dept Neurol, Med Ctr, Amsterdam, Netherlands.
    van Berckel, Bart N M
    Vrije Univ Amsterdam, Dept Radiol & Nucl Med, Med Ctr, Neurosci Campus, Amsterdam, Netherlands.
    Ossenkoppele, Rik
    Vrije Univ Amsterdam, Alzheimer Ctr Amsterdam, Dept Neurol, Med Ctr, Amsterdam, Netherlands.
    Barkhof, Frederik
    Vrije Univ Amsterdam, Dept Radiol & Nucl Med, Med Ctr, Neurosci Campus, Amsterdam, Netherlands.; UCL, Inst Neurol & Healthcare Engn, London, England..
    Larsson, Elna-Marie
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Radiology.
    Arterial spin labeling-based Z-maps have high specificity and positive predictive value for neurodegenerative dementia compared to FDG-PET.2017In: European Radiology, ISSN 0938-7994, E-ISSN 1432-1084, Vol. 27, no 10, p. 4237-4246Article in journal (Refereed)
    Abstract [en]

    OBJECTIVE: Cerebral perfusion analysis based on arterial spin labeling (ASL) MRI has been proposed as an alternative to FDG-PET in patients with neurodegenerative disease. Z-maps show normal distribution values relating an image to a database of controls. They are routinely used for FDG-PET to demonstrate disease-specific patterns of hypometabolism at the individual level. This study aimed to compare the performance of Z-maps based on ASL to FDG-PET.

    METHODS: Data were combined from two separate sites, each cohort consisting of patients with Alzheimer's disease (n = 18 + 7), frontotemporal dementia (n = 12 + 8) and controls (n = 9 + 29). Subjects underwent pseudocontinuous ASL and FDG-PET. Z-maps were created for each subject and modality. Four experienced physicians visually assessed the 166 Z-maps in random order, blinded to modality and diagnosis.

    RESULTS: Discrimination of patients versus controls using ASL-based Z-maps yielded high specificity (84%) and positive predictive value (80%), but significantly lower sensitivity compared to FDG-PET-based Z-maps (53% vs. 96%, p < 0.001). Among true-positive cases, correct diagnoses were made in 76% (ASL) and 84% (FDG-PET) (p = 0.168).

    CONCLUSION: ASL-based Z-maps can be used for visual assessment of neurodegenerative dementia with high specificity and positive predictive value, but with inferior sensitivity compared to FDG-PET.

    KEY POINTS: • ASL-based Z-maps yielded high specificity and positive predictive value in neurodegenerative dementia. • ASL-based Z-maps had significantly lower sensitivity compared to FDG-PET-based Z-maps. • FDG-PET might be reserved for ASL-negative cases where clinical suspicion persists. • Findings were similar at two study sites.

  • 11.
    Fällmar, David
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Radiology.
    Lilja, Johan
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Radiology.
    Danfors, Torsten
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Radiology.
    Kilander, Lena
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Public Health and Caring Sciences, Geriatrics.
    Iyer, Victor
    Lubberink, Mark
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Radiology.
    Larsson, Elna-Marie
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Radiology.
    Sörensen, Jens
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Radiology.
    Z-score maps from low-dose 18F-FDG PET of the brain in neurodegenerative dementia.2018In: American Journal of Nuclear Medicine and Molecular Imaging, ISSN 2160-8407, Vol. 8, no 4, p. 239-246Article in journal (Refereed)
    Abstract [en]

    Neuroimaging is a central part of diagnostic work-up of patients with suspected neurodegenerative disease. FDG-PET can reveal pathological changes earlier and more reliably than morphological imaging. Diagnostic accuracy can be improved by constructing 3D SSP Z-score maps, showing patterns of significant deficits. During FDG-PET, the subject receives a moderate but not insignificant dose of ionizing radiation, and a dose reduction with retained image quality is desirable. With lower dose, repeated examinations can become a useful tool for monitoring disease progress and potential effects of disease-modifying interventions. The aim of this study was to evaluate Z-maps created from low-dose and normal-dose FDG-PET of the brain, with quantitative and qualitative methods. Nine patients with neurodegenerative disorders were prospectively enrolled and nine age-matched controls were recruited through advertising. All subjects (n=18) underwent two FDG-PET scans on separate occasions; a routine and a low-dose scan. The routine dosage of FDG was 3 MBq/kg, and low dosage was 0.75 MBq/kg. 3D-SSP images showing Z-scores of < -1.96 were created from 10-minute summations. The study was comprised of a quantitative part comparing the Z-scores, and a qualitative part where experienced nuclear medicine specialists visually assessed the images. Regarding the quantitative part, Bland-Altman analysis showed a slight constant bias (0.206). Regarding qualitative discrimination between patients and controls, the performance between normal- and low-dose were equal, both showing 72% sensitivity, 83% specificity and 78% accuracy. In this study, visual assessment of 3D-SSP Z-score maps from low-dose FDG-PET provided diagnostic information highly comparable to normal-dose, with minor quantitative discrepancies.

  • 12.
    Fällmar, David
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurology. Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Radiology.
    Lilja, Johan
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Radiology. Hermes Medical Solutions, Stockholm, Sweden..
    Kilander, Lena
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Public Health and Caring Sciences, Geriatrics.
    Danfors, Torsten
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurology. Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Radiology.
    Lubberink, Mark
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Radiology.
    Larsson, Elna-Marie
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Radiology.
    Sörensen, Jens
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Radiology.
    Validation of true low-dose 18F-FDG PET of the brain2016In: American Journal of Nuclear Medicine and Molecular Imaging, ISSN 2160-8407, Vol. 6, no 5, p. 269-276Article in journal (Refereed)
    Abstract [en]

    The dosage of F-18-FDG must be sufficient to ensure adequate PET image quality. For younger patients and research controls, the lowest possible radiation dose should be used. The purpose of this study was to find a protocol for FDG-PET of the brain with reduced radiation dose and preserved quantitative characteristics. Eight patients with neurodegenerative disorders and nine controls (n= 17) underwent FDG-PET/ CT twice on separate occasions, first with normal-dose (3 MBq/ kg), and second with low-dose (0.75 MBq/ kg, 25% of the original). Five additional controls (total n= 22) underwent FDG-PET twice, using normal-dose and ultra-low-dose (0.3 MBq/ kg, 10% of original). All subjects underwent MRI. Ten-minute summation images were spatially normalized and intensity normalized. Regional standard uptake value ratios (SUV-r) were calculated using an automated atlas. SUV-r values from the normal-and low-dose images were compared pairwise. No clinically significant bias was found in any of the three groups. The mean absolute difference in regional SUV-r values was 0.015 (1.32%) in controls and 0.019 (1.67%) in patients. The ultra-low-dose protocol produced a slightly higher mean difference of 0.023 (2.10%). The main conclusion is that 0.75 MBq/ kg (56 MBq for a 75-kg subject) is a sufficient FDG dose for evaluating regional SUV-ratios in brain PET scans in adults with or without neurodegenerative disease, resulting in a reduction of total PET/ CT effective dose from 4.54 to 1.15 mSv. The ultra-low-dose (0.5 mSv) could be useful in research studies requiring serial PET in healthy controls or children.

  • 13.
    Fällmar, David
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Radiology.
    Lilja, Johan
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Radiology.
    Velickaite, Vilma
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Radiology.
    Danfors, Torsten
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences.
    Lubberink, Mark
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences.
    Ahlgren, André
    Lund Univ, Dept Med Radiat Phys, Lund, Sweden.
    van Osch, Matthias J P
    eiden Univ, Med Ctr, Dept Radiol, CJ Gorter Ctr High Field MRI, Leiden, Netherlands.
    Kilander, Lena
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Public Health and Caring Sciences, Geriatrics.
    Larsson, Elna-Marie
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Radiology.
    Visual Assessment of Brain Perfusion MRI Scans in Dementia: a Pilot Study2016In: Journal of Neuroimaging, ISSN 1051-2284, E-ISSN 1552-6569, Vol. 26, no 3, p. 324-330Article in journal (Refereed)
    Abstract [en]

    PURPOSE: Functional imaging is becoming increasingly important for the detection of neurodegenerative disorders. Perfusion MRI with arterial spin labeling (ASL) has been reported to provide promising diagnostic possibilities but is not yet widely used in routine clinical work. The aim of this study was to compare, in a clinical setting, the visual assessment of subtracted ASL CBF maps with and without additional smoothing, to FDG-PET data.

    METHODS: Ten patients with a clinical diagnosis of dementia and 11 age-matched cognitively healthy controls were examined with pseudo-continuous ASL (pCASL) and 18F-Fluorodeoxyglucose positron emission tomography (FDG-PET). Three diagnostic physicians visually assessed the pCASL maps after subtraction only, and after postprocessing using Gaussian smoothing and GLM-based beta estimate functions. The assessment scores were compared to FDG PET values. Furthermore, the ability to discriminate patients from healthy elderly controls was assessed.

    RESULTS: Smoothing improved the correlation between visually assessed regional ASL perfusion scores and the FDG PET SUV-r values from the corresponding regions. However, subtracted pCASL maps discriminated patients from healthy controls better than smoothed maps. Smoothing increased the number of false-positive patient identifications. Application of beta estimate functions had only a marginal effect.

    CONCLUSION: Spatial smoothing of ASL images increased false positive results in the discrimination of hypoperfusion conditions from healthy elderly. It also decreased interreader agreement. However, regional characterization and subjective perception of image quality was improved.

  • 14.
    Jonasson, My
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Radiology.
    Appel, Lieuwe
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Radiology.
    Danfors, Torsten
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Radiology.
    Nyholm, Dag
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurology.
    Askmark, Håkan
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurology.
    Frick, Andreas
    Uppsala University, Disciplinary Domain of Humanities and Social Sciences, Faculty of Social Sciences, Department of Psychology.
    Engman, Jonas
    Uppsala University, Disciplinary Domain of Humanities and Social Sciences, Faculty of Social Sciences, Department of Psychology.
    Furmark, Tomas
    Uppsala University, Disciplinary Domain of Humanities and Social Sciences, Faculty of Social Sciences, Department of Psychology.
    Sörensen, Jens
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Radiology.
    Lubberink, Mark
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Radiology.
    Development of a clinically feasible [11C]PE2I PET method for differential diagnosis of parkinsonism using reduced scan duration and automated reference region extraction.2017In: American Journal of Nuclear Medicine and Molecular Imaging, ISSN 2160-8407, Vol. 7, no 6, p. 263-274Article in journal (Refereed)
    Abstract [en]

    [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.

  • 15.
    Jonasson, My
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Section of Nuclear Medicine and PET.
    Appel, Lieuwe
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Section of Nuclear Medicine and PET.
    Engman, Jonas
    Uppsala University, Disciplinary Domain of Humanities and Social Sciences, Faculty of Social Sciences, Department of Psychology.
    Frick, Andreas
    Uppsala University, Disciplinary Domain of Humanities and Social Sciences, Faculty of Social Sciences, Department of Psychology.
    Nyholm, Dag
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurology.
    Askmark, Håkan
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurology.
    Danfors, Torsten
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurology.
    Sörensen, Jens
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Section of Nuclear Medicine and PET.
    Furmark, Tomas
    Uppsala University, Disciplinary Domain of Humanities and Social Sciences, Faculty of Social Sciences, Department of Psychology.
    Lubberink, Mark
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Section of Nuclear Medicine and PET.
    Parametric methods for [11C]PE2I positron emission tomography2012In: Journal of Cerebral Blood Flow and Metabolism, ISSN 0271-678X, E-ISSN 1559-7016, Vol. 32, no S1, p. S155-S155Article in journal (Other academic)
  • 16.
    Jonasson, My
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Section of Nuclear Medicine and PET.
    Appel, Lieuwe
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Section of Nuclear Medicine and PET.
    Engman, Jonas
    Uppsala University, Disciplinary Domain of Humanities and Social Sciences, Faculty of Social Sciences, Department of Psychology.
    Frick, Andreas
    Uppsala University, Disciplinary Domain of Humanities and Social Sciences, Faculty of Social Sciences, Department of Psychology.
    Nyholm, Dag
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurology.
    Askmark, Håkan
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurology.
    Danfors, Torsten
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurology.
    Sörensen, Jens
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Section of Nuclear Medicine and PET.
    Furmark, Tomas
    Uppsala University, Disciplinary Domain of Humanities and Social Sciences, Faculty of Social Sciences, Department of Psychology.
    Lubberink, Mark
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Section of Nuclear Medicine and PET.
    Validation of parametric methods for [(11)C]PE2I positron emission tomography2013In: NeuroImage, ISSN 1053-8119, E-ISSN 1095-9572, Vol. 74, p. 172-178Article in journal (Refereed)
    Abstract [en]

    OBJECTIVES

    The 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.

    METHODS

    Investigations 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.

    RESULTS

    Correlation 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.

    CONCLUSION

    The 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.

  • 17.
    Jonasson, My
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Radiology.
    Langaas, G.
    Uppsala University.
    Appel, Lieuwe
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Radiology.
    Danfors, Torsten
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Radiology.
    Fazio, P.
    Karolinska Inst, Stockholm, Sweden.
    Lubberink, Mark
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Radiology.
    Varrone, A.
    Karolinska Inst, Stockholm, Sweden.
    Blood Flow Dependence of Early [C-11]PE2I and [F-18]FE-PE2I PET SUVR Measurements Used In the Differential Diagnosis of Parkinsonian Disorders2018In: European Journal of Nuclear Medicine and Molecular Imaging, ISSN 1619-7070, E-ISSN 1619-7089, Vol. 45, p. S303-S304Article in journal (Other academic)
  • 18.
    Lindström, Elin
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Radiology. Uppsala Univ Hosp, Med Phys, Uppsala, Sweden..
    Lindsjö, Lars
    Uppsala Univ Hosp, PET Ctr, Uppsala, Sweden..
    Ilan, Ezgi
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Radiology. Uppsala Univ Hosp, Med Phys, Uppsala, Sweden..
    Sundin, Anders
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Radiology. Uppsala Univ Hosp, PET Ctr, Uppsala, Sweden..
    Sörensen, Jens
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Radiology. Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Sciences, Clinical Physiology. Uppsala Univ Hosp, PET Ctr, Uppsala, Sweden..
    Danfors, Torsten
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Radiology. Uppsala Univ Hosp, PET Ctr, Uppsala, Sweden..
    Antoni, Gunnar
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry, Division of Molecular Imaging. Uppsala Univ Hosp, PET Ctr, Uppsala, Sweden..
    Lubberink, Mark
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Radiology. Uppsala Univ Hosp, Med Phys, Uppsala, Sweden..
    Optimisation of penalized likelihood estimation reconstruction (Q.Clear) on a digital time-of-flight PET-CT scanner for four different PET tracers2017In: Journal of Nuclear Medicine, ISSN 0161-5505, E-ISSN 1535-5667, Vol. 58, no S1, article id 1355Article in journal (Other academic)
    Abstract [en]

    Objectives: The penalized likelihood estimation reconstruction algorithm Q.Clear (GE Healthcare) allows for full convergence and edge preservation through a block sequential regularized expectation maximization technique. In this study the performance of Q.Clear was investigated for different penalization factors (β) with the aim to optimize its clinical use for four different tracers.

    Methods: Q.Clear reconstructions with β values of 200, 400, 600 and 800 were compared to time-of-flight ordered subset expectation maximization (TF-OSEM) (3 iterations, 16 subsets and 5 mm Gaussian filter) with point spread function recovery. Clinical whole-body PET/CT (Discovery MI, GE Healthcare) scans with 68Ga-DOTATOC, 18F-FDG, 11C-acetate or 18F-fluoride were analyzed for level of noise in healthy liver tissue, signal to noise ratio (SNR), signal to background ratio (SBR) and maximum standardized uptake value (SUVmax). In addition, acquisition times per bed position and transaxial field of view (FOV) of the reconstructed images were varied. For each tracer, images from 10 patients were included, with a mean of 30 lesions per tracer. A spherical reference volume of interest (VOI) was placed in the liver and lesions were delineated employing a 41% threshold of the maximum voxel.

    Results: The lowest levels of noise were reached with the highest beta factor resulting in the highest SNR, but this in turn gave the lowest SBR. Noise equivalence to OSEM was found with β 600 for 68Ga-DOTATOC, 18F-FDG and 18F-fluoride, and β 400 for 11C-acetate with a resulting significant increase of SUVmax (19.4%, 9.7%, 22.5% and 19.0% respectively) (P < 0.0001, paired t-test), SNR (22.1%, 22.6%, 9.5% and 33.6%) and SBR (19.5%, 11.7%, 21.3% and 18.5%) compared to OSEM. SNR decreased while SBR increased for all tracers when extending FOV from 500 to 700 mm, but only significantly for 18F-fluoride. Decreasing image acquisition time gave no statistical difference of SUVmax for 68Ga-DOTATOC, 18F-fluoride (2 to 1.5 min) for any reconstruction method nor for 11C-acetate (3 to 2 min) with β 蠅 400. Decreasing time for 18F-FDG (3 to 2 min) resulted in a change of optimal beta to β 800 in order to reach noise equivalence to OSEM along with maintaining a higher SNR than OSEM.

    Conclusion: Images reconstructed by Q.Clear result in a tracer-dependent increase in tumour SUVmax values compared to OSEM at matched levels of noise, and an improved SNR. The optimal penalization factor, both in terms of noise-equivalence to OSEM and in terms of absolute SNR, is tracer dependent.

  • 19.
    Lindström, Elin
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Radiology. Uppsala Univ Hosp, Uppsala, Sweden.
    Oddstig, J.
    Skane Univ Hosp, Malmo, Sweden.
    Danfors, Torsten
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Radiology. Uppsala Univ Hosp, Uppsala, Sweden.
    Lindsjö, L.
    Uppsala Univ Hosp, Uppsala, Sweden.
    Hansson, O.
    Lund Univ, Malmo, Sweden.
    Lubberink, Mark
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Radiology. Uppsala Univ Hosp, Uppsala, Sweden.
    Flutemetamol and FDG Brain-PET Image Reconstruction Methods Affect Software-Aided Diagnosis in Patients with Neurodegenerative Diseases2018In: European Journal of Nuclear Medicine and Molecular Imaging, ISSN 1619-7070, E-ISSN 1619-7089, Vol. 45, p. S305-S305Article in journal (Other academic)
  • 20.
    Lindström, Elin
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Radiology. Department of Medical Physics, Uppsala University Hospital, Uppsala, Sweden.
    Sundin, Anders
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Radiology.
    Trampal, Carlos
    Lindsjö, Lars
    Ilan, Ezgi
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Radiology. Department of Medical Physics, Uppsala University Hospital, Uppsala, Sweden .
    Danfors, Torsten
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Radiology.
    Antoni, Gunnar
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry, Preparative Medicinal Chemistry.
    Sörensen, Jens
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Radiology. PET Centre, Uppsala University Hospital, Uppsala, Sweden.
    Lubberink, Mark
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Radiology. Department of Medical Physics, Uppsala University Hospital, Uppsala, Sweden .
    Evaluation of penalized likelihood estimation reconstruction on a digital time-of-flight PET/CT scanner for 18F-FDG whole-body examinations2018In: Journal of Nuclear Medicine, ISSN 0161-5505, E-ISSN 1535-5667, Vol. 59, no 7, p. 1152-1158Article in journal (Refereed)
    Abstract [en]

    The resolution and quantitative accuracy of PET are highly influenced by the reconstruction method. Penalized-likelihood estimation algorithms allow for fully convergent iterative reconstruction, generating a higher image contrast than ordered-subsets expectation maximization (OSEM) while limiting noise. In this study, a type of penalized reconstruction known as block-sequential regularized expectation maximization (BSREM) was compared with time-of-flight OSEM (TOF OSEM). Various strengths of noise penalization factor β were tested along with various acquisition durations and transaxial fields of view (FOVs) with the aim of evaluating the performance and clinical use of BSREM for 18F-FDG PET/CT, both quantitatively and in a qualitative visual evaluation. Methods: Eleven clinical whole-body 18F-FDG PET/CT examinations acquired on a digital TOF PET/CT scanner were included. The data were reconstructed using BSREM with point-spread function recovery and β-factors of 133, 267, 400, and 533—and using TOF OSEM with point-spread function—for various acquisition times per bed position and various FOVs. Noise level, signal-to-noise ratio (SNR), signal-to-background ratio (SBR), and SUV were analyzed. A masked evaluation of visual image quality, rating several aspects, was performed by 2 nuclear medicine physicians to complement the analysis. Results: The lowest levels of noise were reached with the highest β-factor, resulting in the highest SNR, which in turn resulted in the lowest SBR. A β-factor of 400 gave noise equivalent to TOF OSEM but produced a significant increase in SUVmax (11%), SNR (22%), and SBR (12%). BSREM with a β-factor of 533 at a decreased acquisition duration (2 min/bed position) was comparable to TOF OSEM at a full acquisition duration (3 min/bed position). Reconstructed FOV had an impact on BSREM outcome measures; SNR increased and SBR decreased when FOV was shifted from 70 to 50 cm. The evaluation of visual image quality resulted in similar scores for reconstructions, although a β-factor of 400 obtained the highest mean whereas a β-factor of 267 was ranked best in overall image quality, contrast, sharpness, and tumor detectability. Conclusion: In comparison with TOF OSEM, penalized BSREM reconstruction resulted in an increased tumor SUVmax and an improved SNR and SBR at a matched level of noise. BSREM allowed for a shorter acquisition than TOF OSEM, with equal image quality.

  • 21.
    Lubberink, Mark
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Radiology.
    Appel, Lieuwe
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Radiology.
    Gaging, Johannes
    Uppsala Univ, Uppsala, Sweden..
    Lindskog, Karolina
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Radiology.
    Danfors, Torsten
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Radiology.
    Larsson, Elna-Marie
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Radiology.
    Kumlien, Eva
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurology.
    Antoni, Gunnar
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry, Division of Molecular Imaging.
    Tracer kinetic analysis of the SV2A ligand 11C-UCBA as a PET marker for synaptic density in humans2017In: Journal of Nuclear Medicine, ISSN 0161-5505, E-ISSN 1535-5667, Vol. 58, no S1, article id 631Article in journal (Other academic)
    Abstract [en]

    Objectives: Quantitative imaging of the synaptic vesicle glycoprotein 2A (SV2A) with PET can be used as a measure of synaptic density in the human brain (Finnema et al, Science Tr Med 2016), changes of which occur in many neurodegenerative diseases. 11C-UCBA has previously been validated as an SV2A tracer in pigs (Estrada et al, Nucl Med Biol 2016), showing dose-dependent blocking and reversible binding. The aim of the present work was to evaluate tracer kinetic models and simplified methods for quantification of synaptic density using 11C-UCBA in humans.

    Methods: Eight subjects (6 epilepsy patients, 2 controls) underwent 90 min PET scans starting with injection of 5 MBq/kg 11C-UCBA on a time-of-flight integrated PET-MR scanner (Signa PET-MR, GE Healthcare). Arterial blood was withdrawn for measurements of whole blood and plasma concentrations and metabolite analysis. Images were reconstructed using zero-echo-time MR-based attenuation correction, accounting for bone attenuation. A probabilistic VOI template was defined on a T1-MRI image, acquired during the PET scan, and transferred to the dynamic PET images. A centrum semiovale VOI was drawn as potential reference tissue. Data were analysed using single-tissue (1T2k), two-tissue irreversible (2T3k) and reversible (2T4k) models, as well as the simplified reference tissue model (SRTM) and plasma- and reference-Logan methods, resulting in total distribution volume (VT) and binding potential (BPND) values, with binding potential both estimated directly and as distribution volume ratio to centrum semiovale (DVR). The optimal compartment model was determined using the Akaike information criterion (AIC). Standardized uptake value ratios (SUVR) at various time points were compared to modelling outcomes using regression analysis.

    Results: Plasma and brain kinetics of 11C-UCBA were slow, with peak activity in brain at 70-80 min. Parent fraction was approximately 50% at 90 min. Plasma-input data were best described using the 2T4k model, but this could often not provide robust VT or BPND values. Mean plasma-Logan VT was 24±17. Plasma-Logan DVR using centrum semiovale as reference tissue correlated well with 2T4k DVR (R2 0.94) for those regions where robust DVR values could be determined. Reference-Logan DVR showed good correlation with plasma-Logan DVR (R2 0.72). Plasma-Logan DVR-1 and SUVR-1 images are shown in Figure 1. SUVR for the 40-60 and 70-90 min intervals correlated well with reference-Logan DVR (R2 0.92 and 0.98).

    Conclusion: Slow kinetics of 11C-UCBA resulted in poor robustness of outcome parameters of reversible compartment models. However, reference-Logan DVR correlated well with plasma-Logan DVR. SUVR at 70-90 min p.i. correlated well with DVR and may be used as a simplified measure of synaptic density using 11C-UCBA. Research Support: Uppsala County Council

  • 22.
    Lubberink, Mark
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Radiology. Uppsala Univ Hosp, Med Phys..
    Appel, Lieuwe
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Radiology. Uppsala Univ Hosp, Med Imaging Ctr..
    Lindskog, K.
    Uppsala Univ Hosp, Med Phys..
    Danfors, Torsten
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Radiology. Uppsala Univ Hosp, Med Imaging Ctr..
    Sprycha, M.
    Uppsala Univ Hosp, Med Imaging Ctr..
    Daging, J.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience. Uppsala Univ Hosp, Neurol..
    Eriksson, Jonas
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry, Organic Pharmaceutical Chemistry. Uppsala Univ Hosp, Med Imaging Ctr..
    Larsson, Elna-Marie
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Radiology. Uppsala Univ Hosp, Med Imaging Ctr..
    Kumlien, Eva
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurology. Uppsala Univ Hosp, Neurol..
    Antoni, Gunnar
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry, Division of Molecular Imaging. Uppsala Univ Hosp, Med Imaging Ctr..
    Quantitative assessment of synaptic density using the SV2A ligand C-11-UCBA in humans2017In: Journal of Cerebral Blood Flow and Metabolism, ISSN 0271-678X, E-ISSN 1559-7016, Vol. 37, p. 74-74Article in journal (Other academic)
  • 23.
    Lubberink, Mark
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Radiology.
    Widström, Charles
    Uppsala Univ Hosp, Uppsala, Sweden.
    Jonasson, My
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Radiology. Uppsala Univ Hosp, Uppsala, Sweden.
    Appel, Lieuwe
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Radiology.
    Fällmar, David
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Radiology. Uppsala Univ Hosp, Uppsala, Sweden.
    Nyholm, Dag
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurology. Uppsala Univ Hosp, Uppsala, Sweden.
    Sörensen, Jens
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Radiology. Uppsala Univ Hosp, Uppsala, Sweden.
    Danfors, Torsten
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Radiology. Uppsala Univ Hosp, Uppsala, Sweden.
    Differential diagnosis of patients with parkinsonian syndrome using multilinear regression to disease-specific C-11-PE2I-PET templates and classification tree learning2018In: European Journal of Nuclear Medicine and Molecular Imaging, ISSN 1619-7070, E-ISSN 1619-7089, Vol. 45, p. S409-S409Article in journal (Other academic)
  • 24.
    Romanos Zapata, Romina
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Radiology.
    Danfors, Torsten
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Radiology.
    Wikström, Johan
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Radiology.
    Raininko, Raili
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Radiology.
    Differential diagnosis of therapy-related changes and recurrent intracranial tumours using perfusion MRI and methionine PET2014In: Insight into Imaging, ISSN 1869-4101, E-ISSN 1869-4101, Vol. 5, no Suppl 1, p. S239-, article id B-0485Article in journal (Refereed)
  • 25.
    Roodakker, Kenney Roy
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurology.
    Alhuseinalkhudhur, Ali
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurology. Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Radiology.
    Al-Jaff, Mohammed
    Uppsala University, Disciplinary Domain of Science and Technology, Mathematics and Computer Science, Department of Information Technology, Division of Visual Information and Interaction. Uppsala University, Disciplinary Domain of Science and Technology, Mathematics and Computer Science, Department of Information Technology, Computerized Image Analysis and Human-Computer Interaction.
    Georganaki, Maria
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Immunology, Genetics and Pathology, Vascular Biology.
    Zetterling, Maria
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurosurgery.
    Berntsson, Shala G.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurology.
    Danfors, Torsten
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Radiology.
    Strand, Robin
    Uppsala University, Disciplinary Domain of Science and Technology, Mathematics and Computer Science, Department of Information Technology, Division of Visual Information and Interaction. Uppsala University, Disciplinary Domain of Science and Technology, Mathematics and Computer Science, Department of Information Technology, Computerized Image Analysis and Human-Computer Interaction.
    Edqvist, Per-Henrik
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Immunology, Genetics and Pathology, Experimental and Clinical Oncology. Uppsala University, Science for Life Laboratory, SciLifeLab.
    Dimberg, Anna
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Immunology, Genetics and Pathology, Vascular Biology.
    Larsson, Elna-Marie
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Radiology.
    Smits, Anja
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurology.
    Region-by-region analysis of PET, MRI, and histology in en bloc-resected oligodendrogliomas reveals intra-tumoral heterogeneity2019In: European Journal of Nuclear Medicine and Molecular Imaging, ISSN 1619-7070, E-ISSN 1619-7089, Vol. 46, no 3, p. 569-579Article in journal (Refereed)
  • 26.
    Ryttlefors, Mats
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurosurgery.
    Danfors, Torsten
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Radiology.
    Latini, Francesco
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurosurgery.
    Montelius, Anders
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Immunology, Genetics and Pathology, Medical Radiation Science.
    Blomquist, Erik
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Immunology, Genetics and Pathology, Experimental and Clinical Oncology.
    Gudjonsson, Olafur
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurosurgery.
    Long-term evaluation of the effect of hypofractionated high-energy proton treatment of benign meningiomas by means of (11)C-L-methionine positron emission tomography2016In: European Journal of Nuclear Medicine and Molecular Imaging, ISSN 1619-7070, E-ISSN 1619-7089, Vol. 43, no 8, p. 1432-1443Article in journal (Refereed)
    Abstract [en]

    PURPOSE: To determine if (11)C-L-methionine PET is a useful tool in the evaluation of the long-term effect of proton beam treatment in patients with meningioma remnant.

    METHODS: Included in the study were 19 patients (4 men, 15 women) with intracranial meningioma remnants who received hypofractionated high-energy proton beam treatment. Patients were examined with (11)C-L-methionine PET and MRI prior to treatment and after 6 months, and 1, 2, 3, 5, 7 and 10 years. Temporal changes in methionine uptake ratio, meningioma volume, meningioma regrowth and clinical symptoms throughout the follow-up period were evaluated.

    RESULTS: In 17 patients the tumour volume was unchanged throughout the follow-up. The methionine uptake ratio on PET decreased over the years in most patients. In two patients the tumour remnant showed progression on MRI. In these patients, prior to the volume increase on MRI, the methionine uptake ratio increased. One patient experienced transient clinical symptoms and showed radiological evidence of a radiation-induced reaction close to the irradiated field.

    CONCLUSION: Proton beam treatment is a safe and effective treatment for achieving long-term growth arrest in meningioma remnants. Follow-up with (11)C-L-methionine PET may be a valuable adjunct to, but not a replacement for, standard radiological follow-up.

  • 27.
    Sousa, Joao M.
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Radiology.
    Appel, Lieuwe
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Radiology.
    Papadimitriou, S.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience.
    Nyholm, Dag
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurology.
    Sörensen, Jens
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Radiology.
    Danfors, Torsten
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurology.
    Larsson, Eva
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Ophthalmology.
    Delso, G.
    GE Healthcare, Zurich, Switzerland..
    Wiesinger, F.
    GE Healthcare, Zurich, Switzerland..
    Ahlström, Håkan
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Radiology.
    Lubberink, Mark
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Radiology.
    Validation of Zero-Echo Time PET-MR against stand-alone PET using dynamic dopamine transporter imaging2016In: European Journal of Nuclear Medicine and Molecular Imaging, ISSN 1619-7070, E-ISSN 1619-7089, Vol. 43, p. S79-S79Article in journal (Refereed)
  • 28.
    Stanisic, Milo
    et al.
    Oslo Univ Hosp, Rikshosp, Dept Neurosurg, N-0027 Oslo, Norway..
    Coello, Christopher
    Oslo Univ Hosp, PET Core Facil, PET Ctr, N-0027 Oslo, Norway..
    Ivanovic, Jugoslav
    Oslo Univ Hosp, Rikshosp, Dept Neurosurg, N-0027 Oslo, Norway..
    Egge, Arild
    Oslo Univ Hosp, Rikshosp, Dept Neurosurg, N-0027 Oslo, Norway..
    Danfors, Torsten
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Radiology.
    Hald, John
    Oslo Univ Hosp, Dept Radiol, N-0027 Oslo, Norway..
    Heminghyt, Einar
    Oslo Univ Hosp, Dept Clin Psychol & Neuropsychol, Natl Ctr Epilepsy, N-0027 Oslo, Norway..
    Mikkelsen, Marjan Makki
    Oslo Univ Hosp, Dept Adult Epilepsy, Natl Ctr Epilepsy, N-0027 Oslo, Norway..
    Krossnes, Bard Kronen
    Oslo Univ Hosp, Dept Pathol, N-0027 Oslo, Norway..
    Pripp, Are Hugo
    Oslo Univ Hosp, Oslo Ctr Biostat & Epidemiol, Res Support Serv, N-0027 Oslo, Norway..
    Larsson, Pal Gunnar
    Oslo Univ Hosp, Dept Neurosurg, Clin Neurophysiol Labs, N-0027 Oslo, Norway..
    Seizure outcomes in relation to the extent of resection of the perifocal fluorodeoxyglucose and flumazenil PET abnormalities in anteromedial temporal lobectomy2015In: Acta Neurochirurgica, ISSN 0001-6268, E-ISSN 0942-0940, Vol. 157, no 11, p. 1905-1916Article in journal (Refereed)
    Abstract [en]

    The area of predominant perifocal [F-18]fluorodeoxyglucose (F-18-FDG) hypometabolism and reduced [C-11]flumazenil (C-11-FMZ) -binding on PET scans is currently considered to contain the epileptogenic zone and corresponds anatomically to the area localizing epileptogenicity in patients with temporal lobe epilepsy (TLE). The question is whether the volume of the perifocal pre-operative PET abnormalities, the extent of their resection, and the volume of the non-resected abnormalities affects the post-operative seizure outcome. The sample group consisted of 32 patients with mesial temporal sclerosis who underwent anteromedial temporal lobe resection for refractory TLE. All patients had pathologic perifocal findings on both of the PET modalities as well as on the whole-brain MRI. The volumetric data of the PET and MRI abnormalities within the resected temporal lobe were estimated by automated quantitative voxel-based analysis. The obtained volumetric data were investigated in relation to the outcome subgroups of patients (Engel classification) determined at the 2-year post-operative follow-up. The mean volume of the pre-operative perifocal F-18-FDG- and C-11-FMZ PET abnormalities in the volumes of interest (VOI) of the epileptogenic temporal lobe, the mean resected volume of these PET abnormalities, the mean volume of the non-resected PET abnormalities, and the mean MRI-derived resected volume were not significantly related to the outcome subgroups and had a low prediction for individual freedom from seizures. The extent of pre-surgical perifocal PET abnormalities, the extent of their resection, and the extent of non-resected abnormalities were not useful predictors of individual freedom from seizures in patients with TLE.

1 - 28 of 28
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