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Matsumoto Y, Nakae R, Sekine T, Kodani E, Warnock G, Igarashi Y, Tagami T, Murai Y, Suzuki K, Yokobori S. Rapidly progressive cerebral atrophy following a posterior cranial fossa stroke: Assessment with semiautomatic CT volumetry. Acta Neurochir (Wien) 2023; 165:1575-1584. [PMID: 37119319 DOI: 10.1007/s00701-023-05609-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2023] [Accepted: 04/25/2023] [Indexed: 05/01/2023]
Abstract
BACKGROUND The effect of posterior cranial fossa stroke on changes in cerebral volume is not known. We assessed cerebral volume changes in patients with acute posterior fossa stroke using CT scans, and looked for risk factors for cerebral atrophy. METHODS Patients with cerebellar or brainstem hemorrhage/infarction admitted to the ICU, and who underwent at least two subsequent inpatient head CT scans during hospitalization were included (n = 60). The cerebral volume was estimated using an automatic segmentation method. Patients with cerebral volume reduction > 0% from the first to the last scan were defined as the "cerebral atrophy group (n = 47)," and those with ≤ 0% were defined as the "no cerebral atrophy group (n = 13)." RESULTS The cerebral atrophy group showed a significant decrease in cerebral volume (first CT scan: 0.974 ± 0.109 L vs. last CT scan: 0.927 ± 0.104 L, P < 0.001). The mean percentage change in cerebral volume between CT scans in the cerebral atrophy group was -4.7%, equivalent to a cerebral volume of 46.8 cm3, over a median of 17 days. The proportions of cases with a history of hypertension, diabetes mellitus, and median time on mechanical ventilation were significantly higher in the cerebral atrophy group than in the no cerebral atrophy group. CONCLUSIONS Many ICU patients with posterior cranial fossa stroke showed signs of cerebral atrophy. Those with rapidly progressive cerebral atrophy were more likely to have a history of hypertension or diabetes mellitus and required prolonged ventilation.
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Affiliation(s)
- Yoshiyuki Matsumoto
- Department of Emergency and Critical Care Medicine, Nippon Medical School Hospital, 1-1-5, Sendagi, Bunkyo-Ku, Tokyo, 113-8603, Japan
| | - Ryuta Nakae
- Department of Emergency and Critical Care Medicine, Nippon Medical School Hospital, 1-1-5, Sendagi, Bunkyo-Ku, Tokyo, 113-8603, Japan.
| | - Tetsuro Sekine
- Department of Radiology, Nippon Medical School Musashi Kosugi Hospital, Kanagawa, Japan
| | - Eigo Kodani
- Department of Radiology, Nippon Medical School Musashi Kosugi Hospital, Kanagawa, Japan
| | | | - Yutaka Igarashi
- Department of Emergency and Critical Care Medicine, Nippon Medical School Hospital, 1-1-5, Sendagi, Bunkyo-Ku, Tokyo, 113-8603, Japan
| | - Takashi Tagami
- Department of Emergency and Critical Care Medicine, Nippon Medical School Musashi Kosugi Hospital, Kanagawa, Japan
| | - Yasuo Murai
- Department of Neurological Surgery, Nippon Medical School Hospital, Tokyo, Japan
| | - Kensuke Suzuki
- Department of Neurosurgery, Dokkyo Medical University Saitama Medical Center, Saitama, Japan
| | - Shoji Yokobori
- Department of Emergency and Critical Care Medicine, Nippon Medical School Hospital, 1-1-5, Sendagi, Bunkyo-Ku, Tokyo, 113-8603, Japan
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Eleftheriou A, Ravotto L, Wyss MT, Warnock G, Siebert A, Zaiss M, Weber B. Simultaneous dynamic glucose-enhanced (DGE) MRI and fiber photometry measurements of glucose in the healthy mouse brain. Neuroimage 2023; 265:119762. [PMID: 36427752 DOI: 10.1016/j.neuroimage.2022.119762] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2022] [Revised: 10/27/2022] [Accepted: 11/21/2022] [Indexed: 11/25/2022] Open
Abstract
Glucose is the main energy source in the brain and its regulated uptake and utilization are important biomarkers of pathological brain function. Glucose Chemical Exchange Saturation Transfer (GlucoCEST) and its time-resolved version Dynamic Glucose-Enhanced MRI (DGE) are promising approaches to monitor glucose and detect tumors, since they are radioactivity-free, do not require 13C labeling and are is easily translatable to the clinics. The main principle of DGE is clear. However, what remains to be established is to which extent the signal reflects vascular, extracellular or intracellular glucose. To elucidate the compartmental contributions to the DGE signal, we coupled it with FRET-based fiber photometry of genetically encoded sensors, a technique that combines quantitative glucose readout with cellular specificity. The glucose sensor FLIIP was used with fiber photometry to measure astrocytic and neuronal glucose changes upon injection of D-glucose, 3OMG and L-glucose, in the anaesthetized murine brain. By correlating the kinetic profiles of the techniques, we demonstrate the presence of a vascular contribution to the signal, especially at early time points after injection. Furthermore, we show that, in the case of the commonly used contrast agent 3OMG, the DGE signal actually anticorrelates with the glucose concentration in neurons and astrocytes.
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Affiliation(s)
- Afroditi Eleftheriou
- University of Zurich, Institute of Pharmacology and Toxicology, Zurich, Switzerland; Neuroscience Center Zurich, University and ETH Zurich, Zurich, Switzerland
| | - Luca Ravotto
- University of Zurich, Institute of Pharmacology and Toxicology, Zurich, Switzerland
| | - Matthias T Wyss
- University of Zurich, Institute of Pharmacology and Toxicology, Zurich, Switzerland; Neuroscience Center Zurich, University and ETH Zurich, Zurich, Switzerland
| | - Geoffrey Warnock
- University of Zurich, Institute of Pharmacology and Toxicology, Zurich, Switzerland
| | - Anita Siebert
- University of Zurich, Institute of Pharmacology and Toxicology, Zurich, Switzerland
| | - Moritz Zaiss
- Institute of Neuroradiology, University Hospital Erlangen, Friedrich-Alexander University Erlangen Nürnberg, Erlangen, Germany; High-field Magnetic Resonance Center, Max Planck Institute for Biological Cybernetics, Tübingen, Germany
| | - Bruno Weber
- University of Zurich, Institute of Pharmacology and Toxicology, Zurich, Switzerland; Neuroscience Center Zurich, University and ETH Zurich, Zurich, Switzerland.
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Tanaka A, Sekine T, Ter Voert EEGW, Zeimpekis KG, Delso G, de Galiza Barbosa F, Warnock G, Kumita SI, Veit Haibach P, Huellner M. Reproducibility of Standardized Uptake Values Including Volume Metrics Between TOF-PET-MR and TOF-PET-CT. Front Med (Lausanne) 2022; 9:796085. [PMID: 35308500 PMCID: PMC8924656 DOI: 10.3389/fmed.2022.796085] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2021] [Accepted: 02/07/2022] [Indexed: 11/30/2022] Open
Abstract
Purpose To investigate the reproducibility of tracer uptake measurements, including volume metrics, such as metabolic tumor volume (MTV) and tumor lesion glycolysis (TLG) obtained by TOF-PET-CT and TOF-PET-MR. Materials and Methods Eighty consecutive patients with different oncologic diagnoses underwent TOF-PET-CT (Discovery 690; GE Healthcare) and TOF-PET-MR (SIGNA PET-MR; GE Healthcare) on the same day with single dose−18F-FDG injection. The scan order, PET-CT following or followed by PET-MR, was randomly assigned. A spherical volume of interest (VOI) of 30 mm was placed on the liver in accordance with the PERCIST criteria. For liver, the maximum and mean standard uptake value for body weight (SUV) and lean body mass (SUL) were obtained. For tumor delineation, VOI with a threshold of 40 and 50% of SUVmax was used (VOI40 and VOI50). The SUVmax, SUVmean, SUVpeak, MTV and TLG were calculated. The measurements were compared between the two scanners. Results In total, 80 tumor lesions from 35 patients were evaluated. There was no statistical difference observed in liver regions, whereas in tumor lesions, SUVmax, SUV mean, and SUVpeak of PET-MR were significantly underestimated (p < 0.001) in both VOI40 and VOI50. Among volume metrics, there was no statistical difference observed except TLG on VOI50 (p = 0.03). Correlation between PET-CT and PET-MR of each metrics were calculated. There was a moderate correlation of the liver SUV and SUL metrics (r = 0.63–0.78). In tumor lesions, SUVmax and SUVmean had a stronger correlation with underestimation in PET-MR on VOI 40 (SUVmax and SUVmean; r = 0.92 and 0.91 with slope = 0.71 and 0.72, respectively). In the evaluation of MTV and TLG, the stronger correlations were observed both on VOI40 (MTV and TLG; r = 0.75 and 0.92) and VOI50 (MTV and TLG; r = 0.88 and 0.95) between PET-CT and PET-MR. Conclusion PET metrics on TOF-PET-MR showed a good correlation with that of TOF-PET-CT. SUVmax and SUVpeak of tumor lesions were underestimated by 16% on PET-MRI. MTV with % threshold can be regarded as identical volumetric markers for both TOF-PET-CT and TOF-PET-MR.
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Affiliation(s)
- Aruki Tanaka
- Department of Radiology, Nippon Medical School Hospital, Tokyo, Japan
| | - Tetsuro Sekine
- Department of Radiology, Nippon Medical School Hospital, Tokyo, Japan.,Department of Radiology, Nippon Medical School Musashi Kosugi Hospital, Kanagawa, Japan.,Departments of Nuclear Medicine, University Hospital Zurich, Zurich, Switzerland.,University of Zurich, Zurich, Switzerland
| | - Edwin E G W Ter Voert
- Departments of Nuclear Medicine, University Hospital Zurich, Zurich, Switzerland.,University of Zurich, Zurich, Switzerland
| | - Konstantinos G Zeimpekis
- Departments of Nuclear Medicine, University Hospital Zurich, Zurich, Switzerland.,University of Zurich, Zurich, Switzerland.,Department of Nuclear Medicine, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland
| | | | - Felipe de Galiza Barbosa
- Departments of Nuclear Medicine, University Hospital Zurich, Zurich, Switzerland.,University of Zurich, Zurich, Switzerland
| | - Geoffrey Warnock
- Departments of Nuclear Medicine, University Hospital Zurich, Zurich, Switzerland.,University of Zurich, Zurich, Switzerland.,PMOD Technologies Ltd., Zurich, Switzerland
| | | | - Patrick Veit Haibach
- Departments of Nuclear Medicine, University Hospital Zurich, Zurich, Switzerland.,University of Zurich, Zurich, Switzerland.,Toronto Joint Department Medical Imaging, University Health Network, Sinai Health System, Women's College Hospital, Toronto, ON, Canada.,Department of Medical Imaging, University of Toronto, Toronto, ON, Canada
| | - Martin Huellner
- Departments of Nuclear Medicine, University Hospital Zurich, Zurich, Switzerland.,University of Zurich, Zurich, Switzerland
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Nakae R, Sekine T, Tagami T, Murai Y, Kodani E, Warnock G, Sato H, Morita A, Yokota H, Yokobori S. Rapidly progressive brain atrophy in septic ICU patients: a retrospective descriptive study using semiautomatic CT volumetry. Crit Care 2021; 25:411. [PMID: 34844648 PMCID: PMC8628398 DOI: 10.1186/s13054-021-03828-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2021] [Accepted: 11/17/2021] [Indexed: 12/02/2022] Open
Abstract
Background Sepsis is often associated with multiple organ failure; however, changes in brain volume with sepsis are not well understood. We assessed brain atrophy in the acute phase of sepsis using brain computed tomography (CT) scans, and their findings’ relationship to risk factors and outcomes. Methods Patients with sepsis admitted to an intensive care unit (ICU) and who underwent at least two head CT scans during hospitalization were included (n = 48). The first brain CT scan was routinely performed on admission, and the second and further brain CT scans were obtained whenever prolonged disturbance of consciousness or abnormal neurological findings were observed. Brain volume was estimated using an automatic segmentation method and any changes in brain volume between the two scans were recorded. Patients with a brain volume change < 0% from the first CT scan to the second CT scan were defined as the “brain atrophy group (n = 42)”, and those with ≥ 0% were defined as the “no brain atrophy group (n = 6).” Use and duration of mechanical ventilation, length of ICU stay, length of hospital stay, and mortality were compared between the groups. Results Analysis of all 42 cases in the brain atrophy group showed a significant decrease in brain volume (first CT scan: 1.041 ± 0.123 L vs. second CT scan: 1.002 ± 0.121 L, t (41) = 9.436, p < 0.001). The mean percentage change in brain volume between CT scans in the brain atrophy group was –3.7% over a median of 31 days, which is equivalent to a brain volume of 38.5 cm3. The proportion of cases on mechanical ventilation (95.2% vs. 66.7%; p = 0.02) and median time on mechanical ventilation (28 [IQR 15–57] days vs. 15 [IQR 0–25] days, p = 0.04) were significantly higher in the brain atrophy group than in the no brain atrophy group. Conclusions Many ICU patients with severe sepsis who developed prolonged mental status changes and neurological sequelae showed signs of brain atrophy. Patients with rapidly progressive brain atrophy were more likely to have required mechanical ventilation. Supplementary Information The online version contains supplementary material available at 10.1186/s13054-021-03828-7.
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Affiliation(s)
- Ryuta Nakae
- Department of Emergency and Critical Care Medicine, Nippon Medical School Hospital, 1-1-5, Sendagi, Bunkyo-ku, Tokyo, 113-8603, Japan.
| | - Tetsuro Sekine
- Department of Radiology, Nippon Medical School Musashi Kosugi Hospital, 1-396, Kosugi-cho, Nakahara-ku, Kawasaki, Kanagawa, 211-8533, Japan
| | - Takashi Tagami
- Department of Emergency and Critical Care Medicine, Nippon Medical School Musashi Kosugi Hospital, 1-396, Kosugi-cho, Nakahara-ku, Kawasaki, Kanagawa, 211-8533, Japan
| | - Yasuo Murai
- Department of Neurosurgery, Nippon Medical School Hospital, 1-1-5, Sendagi, Bunkyo-ku, Tokyo, 113-8603, Japan
| | - Eigo Kodani
- Department of Radiology, Nippon Medical School Musashi Kosugi Hospital, 1-396, Kosugi-cho, Nakahara-ku, Kawasaki, Kanagawa, 211-8533, Japan
| | - Geoffrey Warnock
- PMOD Technologies Ltd., Sumatrastrasse 25, 8006, Zürich, Switzerland
| | - Hidetaka Sato
- Department of Emergency and Critical Care Medicine, Nippon Medical School Hospital, 1-1-5, Sendagi, Bunkyo-ku, Tokyo, 113-8603, Japan
| | - Akio Morita
- Department of Neurosurgery, Nippon Medical School Hospital, 1-1-5, Sendagi, Bunkyo-ku, Tokyo, 113-8603, Japan
| | - Hiroyuki Yokota
- Graduate School of Medical and Health Science, Nippon Sport Science University, 1221-1, Kamoshida-cho, Aoba-ku, Yokohama, Kanagawa, 227-0033, Japan
| | - Shoji Yokobori
- Department of Emergency and Critical Care Medicine, Nippon Medical School Hospital, 1-1-5, Sendagi, Bunkyo-ku, Tokyo, 113-8603, Japan
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Bebié P, Becker R, Commichau V, Debus J, Dissertori G, Djambazov L, Eleftheriou A, Fischer J, Fischer P, Ito M, Khateri P, Lustermann W, Ritzer C, Ritzert M, Röser U, Tsoumpas C, Warnock G, Weber B, Wyss MT, Zagozdzinska-Bochenek A. SAFIR-I: Design and Performance of a High-Rate Preclinical PET Insert for MRI. Sensors (Basel) 2021; 21:7037. [PMID: 34770344 PMCID: PMC8588038 DOI: 10.3390/s21217037] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/30/2021] [Revised: 10/15/2021] [Accepted: 10/19/2021] [Indexed: 11/16/2022]
Abstract
(1) Background: Small Animal Fast Insert for MRI detector I (SAFIR-I) is a preclinical Positron Emission Tomography (PET) insert for the Bruker BioSpec 70/30 Ultra Shield Refrigerated (USR) preclinical 7T Magnetic Resonance Imaging (MRI) system. It is designed explicitly for high-rate kinetic studies in mice and rats with injected activities reaching 500MBq, enabling truly simultaneous quantitative PET and Magnetic Resonance (MR) imaging with time frames of a few seconds in length. (2) Methods: SAFIR-I has an axial field of view of 54.2mm and an inner diameter of 114mm. It employs Lutetium Yttrium OxyorthoSilicate (LYSO) crystals and Multi Pixel Photon Counter (MPPC) arrays. The Position-Energy-Timing Application Specific Integrated Circuit, version 6, Single Ended (PETA6SE) digitizes the MPPC signals and provides time stamps and energy information. (3) Results: SAFIR-I is MR-compatible. The system's Coincidence Resolving Time (CRT) and energy resolution are between separate-uncertainty 209.0(3)ps and separate-uncertainty 12.41(02) Full Width at Half Maximum (FWHM) at low activity and separate-uncertainty 326.89(12)ps and separate-uncertainty 20.630(011) FWHM at 550MBq, respectively. The peak sensitivity is ∼1.6. The excellent performance facilitated the successful execution of first in vivo rat studies beyond 300MBq. Based on features visible in the acquired images, we estimate the spatial resolution to be ∼2mm in the center of the Field Of View (FOV). (4) Conclusion: The SAFIR-I PET insert provides excellent performance, permitting simultaneous in vivo small animal PET/MR image acquisitions with time frames of a few seconds in length at activities of up to 500MBq.
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Affiliation(s)
- Pascal Bebié
- Institute for Particle Physics and Astrophysics, ETH Zürich, 8093 Zürich, Switzerland; (R.B.); (V.C.); (J.D.); (G.D.); (L.D.); (J.F.); (M.I.); (P.K.); (W.L.); (C.R.); (U.R.); (A.Z.-B.)
| | - Robert Becker
- Institute for Particle Physics and Astrophysics, ETH Zürich, 8093 Zürich, Switzerland; (R.B.); (V.C.); (J.D.); (G.D.); (L.D.); (J.F.); (M.I.); (P.K.); (W.L.); (C.R.); (U.R.); (A.Z.-B.)
| | - Volker Commichau
- Institute for Particle Physics and Astrophysics, ETH Zürich, 8093 Zürich, Switzerland; (R.B.); (V.C.); (J.D.); (G.D.); (L.D.); (J.F.); (M.I.); (P.K.); (W.L.); (C.R.); (U.R.); (A.Z.-B.)
| | - Jan Debus
- Institute for Particle Physics and Astrophysics, ETH Zürich, 8093 Zürich, Switzerland; (R.B.); (V.C.); (J.D.); (G.D.); (L.D.); (J.F.); (M.I.); (P.K.); (W.L.); (C.R.); (U.R.); (A.Z.-B.)
| | - Günther Dissertori
- Institute for Particle Physics and Astrophysics, ETH Zürich, 8093 Zürich, Switzerland; (R.B.); (V.C.); (J.D.); (G.D.); (L.D.); (J.F.); (M.I.); (P.K.); (W.L.); (C.R.); (U.R.); (A.Z.-B.)
| | - Lubomir Djambazov
- Institute for Particle Physics and Astrophysics, ETH Zürich, 8093 Zürich, Switzerland; (R.B.); (V.C.); (J.D.); (G.D.); (L.D.); (J.F.); (M.I.); (P.K.); (W.L.); (C.R.); (U.R.); (A.Z.-B.)
| | - Afroditi Eleftheriou
- Institute of Pharmacology and Toxicology, University of Zürich, 8057 Zürich, Switzerland; (A.E.); (G.W.); (B.W.); (M.T.W.)
| | - Jannis Fischer
- Institute for Particle Physics and Astrophysics, ETH Zürich, 8093 Zürich, Switzerland; (R.B.); (V.C.); (J.D.); (G.D.); (L.D.); (J.F.); (M.I.); (P.K.); (W.L.); (C.R.); (U.R.); (A.Z.-B.)
| | - Peter Fischer
- Institute of Computer Engineering, Heidelberg University, 69120 Heidelberg, Germany; (P.F.); (M.R.)
| | - Mikiko Ito
- Institute for Particle Physics and Astrophysics, ETH Zürich, 8093 Zürich, Switzerland; (R.B.); (V.C.); (J.D.); (G.D.); (L.D.); (J.F.); (M.I.); (P.K.); (W.L.); (C.R.); (U.R.); (A.Z.-B.)
| | - Parisa Khateri
- Institute for Particle Physics and Astrophysics, ETH Zürich, 8093 Zürich, Switzerland; (R.B.); (V.C.); (J.D.); (G.D.); (L.D.); (J.F.); (M.I.); (P.K.); (W.L.); (C.R.); (U.R.); (A.Z.-B.)
| | - Werner Lustermann
- Institute for Particle Physics and Astrophysics, ETH Zürich, 8093 Zürich, Switzerland; (R.B.); (V.C.); (J.D.); (G.D.); (L.D.); (J.F.); (M.I.); (P.K.); (W.L.); (C.R.); (U.R.); (A.Z.-B.)
| | - Christian Ritzer
- Institute for Particle Physics and Astrophysics, ETH Zürich, 8093 Zürich, Switzerland; (R.B.); (V.C.); (J.D.); (G.D.); (L.D.); (J.F.); (M.I.); (P.K.); (W.L.); (C.R.); (U.R.); (A.Z.-B.)
| | - Michael Ritzert
- Institute of Computer Engineering, Heidelberg University, 69120 Heidelberg, Germany; (P.F.); (M.R.)
| | - Ulf Röser
- Institute for Particle Physics and Astrophysics, ETH Zürich, 8093 Zürich, Switzerland; (R.B.); (V.C.); (J.D.); (G.D.); (L.D.); (J.F.); (M.I.); (P.K.); (W.L.); (C.R.); (U.R.); (A.Z.-B.)
| | - Charalampos Tsoumpas
- Leeds Institute of Cardiovascular and Metabolic Medicine, University of Leeds, Leeds LS2 9JT, UK;
| | - Geoffrey Warnock
- Institute of Pharmacology and Toxicology, University of Zürich, 8057 Zürich, Switzerland; (A.E.); (G.W.); (B.W.); (M.T.W.)
| | - Bruno Weber
- Institute of Pharmacology and Toxicology, University of Zürich, 8057 Zürich, Switzerland; (A.E.); (G.W.); (B.W.); (M.T.W.)
| | - Matthias T. Wyss
- Institute of Pharmacology and Toxicology, University of Zürich, 8057 Zürich, Switzerland; (A.E.); (G.W.); (B.W.); (M.T.W.)
| | - Agnieszka Zagozdzinska-Bochenek
- Institute for Particle Physics and Astrophysics, ETH Zürich, 8093 Zürich, Switzerland; (R.B.); (V.C.); (J.D.); (G.D.); (L.D.); (J.F.); (M.I.); (P.K.); (W.L.); (C.R.); (U.R.); (A.Z.-B.)
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Ando T, Kemp B, Warnock G, Sekine T, Kaushik S, Wiesinger F, Delso G. Zero Echo Time MRAC on FDG-PET/MR Maintains Diagnostic Accuracy for Alzheimer's Disease; A Simulation Study Combining ADNI-Data. Front Neurosci 2020; 14:569706. [PMID: 33324141 PMCID: PMC7725704 DOI: 10.3389/fnins.2020.569706] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2020] [Accepted: 11/03/2020] [Indexed: 11/13/2022] Open
Abstract
Aim Attenuation correction using zero-echo time (ZTE) - magnetic resonance imaging (MRI) (ZTE-MRAC) has become one of the standard methods for brain-positron emission tomography (PET) on commercial PET/MR scanners. Although the accuracy of the net tracer-uptake quantification based on ZTE-MRAC has been validated, that of the diagnosis for dementia has not yet been clarified, especially in terms of automated statistical analysis. The aim of this study was to clarify the impact of ZTE-MRAC on the diagnosis of Alzheimer's disease (AD) by performing simulation study. Methods We recruited 27 subjects, who underwent both PET/computed tomography (CT) and PET/MR (GE SIGNA) examinations. Additionally, we extracted 107 subjects from the Alzheimer Disease Neuroimaging Initiative (ADNI) dataset. From the PET raw data acquired on PET/MR, three FDG-PET series were generated, using two vendor-provided MRAC methods (ZTE and Atlas) and CT-based AC. Following spatial normalization to Montreal Neurological Institute (MNI) space, we calculated each patient's specific error maps, which correspond to the difference between the PET image corrected using the CTAC method and the PET images corrected using the MRAC methods. To simulate PET maps as if ADNI data had been corrected using MRAC methods, we multiplied each of these 27 error maps with each of the 107 ADNI cases in MNI space. To evaluate the probability of AD in each resulting image, we calculated a cumulative t-value using a fully automated method which had been validated not only in the original ADNI dataset but several multi-center studies. In the method, PET score = 1 is the 95% prediction limit of AD. PET score and diagnostic accuracy for the discrimination of AD were evaluated in simulated images using the original ADNI dataset as reference. Results Positron emission tomography score was slightly underestimated both in ZTE and Atlas group compared with reference CTAC (-0.0796 ± 0.0938 vs. -0.0784 ± 0.1724). The absolute error of PET score was lower in ZTE than Atlas group (0.098 ± 0.075 vs. 0.145 ± 0.122, p < 0.001). A higher correlation to the original PET score was observed in ZTE vs. Atlas group (R 2: 0.982 vs. 0.961). The accuracy for the discrimination of AD patients from normal control was maintained in ZTE and Atlas compared to CTAC (ZTE vs. Atlas. vs. original; 82.5% vs. 82.1% vs. 83.2% (CI 81.8-84.5%), respectively). Conclusion For FDG-PET images on PET/MR, attenuation correction using ZTE-MRI had superior accuracy to an atlas-based method in classification for dementia. ZTE maintains the diagnostic accuracy for AD.
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Affiliation(s)
- Takahiro Ando
- Department of Radiology, Nippon Medical School, Tokyo, Japan
| | - Bradley Kemp
- Department of Radiology, Mayo Clinic, Rochester, MN, United States
| | - Geoffrey Warnock
- Institute of Pharmacology and Toxicology, University of Zurich, Zurich, Switzerland.,PMOD Technologies Ltd., Zurich, Switzerland
| | - Tetsuro Sekine
- Department of Radiology, Nippon Medical School, Tokyo, Japan.,Department of Radiology, Nippon Medical School Musashi-Kosugi Hospital, Kawasaki, Japan.,Department of Nuclear Medicine, University Hospital Zurich, Zurich, Switzerland
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7
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Haider A, Bengs S, Warnock G, Akhmedov A, Kozerke S, Kwiatkowski G, Mueller Herde A, Kraemer S, Weber B, Schibli R, Mu L, Kaufmann P, Regitz-Zagrosek V, Ametamey S, Gebhard C. Age-dependent cardiac remodelling – role of sex hormones. Eur Heart J 2020. [DOI: 10.1093/ehjci/ehaa946.3194] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Abstract
Background
While cardiovascular mortality in women has exceeded those in men, women continue to be underrepresented in cardiovascular clinical trials. Further, preclinical experiments are predominantly conducted in male animals, rendering sex-specific variables contributing to cardiovascular disease largely unknown. As age and menopause remain to be key risk factors for cardiovascular disease in women, the aim of this study was to identify key variables of cardiac remodelling in the aging female and male heart, as well as to assess effects of sex hormone deprivation on left ventricular (LV) morphology, LV function and cardiac sympathetic activity.
Materials and methods
Gonadectomized and sham-operated FVB/N mice of both sexes were subjected to positron emission tomography (PET) and cardiac magnetic resonance (CMR) imaging at the age of 4 (young cohort) and 20 (aged cohort) months (total n=123, 55% females). Following tail-vein injection of [11C]meta-hydroxynorephedrine ([11C]mHED), a widely used PET probe in preclinical and clinical assessment of cardiac sympathetic integrity, animals were scanned and cardiac sympathetic outflow was derived from myocardial [11C]mHED uptake. Cardiac parameters including LV volumes and left ventricular ejection fraction (LVEF) were obtained from electrocardiogram (ECG)-gated CMR imaging.
Results and discussion
A significant increase of LVEF was observed in aging females (p=0.012, Figure 1), but not in males. The latter was not associated with a higher cardiac output, and was a consequence of reduced LV end-systolic volumes (p=0.008), unveiling a substantial reduction of size in the aging female heart. As this age-dependent observation was not present in gonadectomized animals (p=0.414), the lack of growth-stimulating estrogen might account for reduction of cardiac size in aging females. Thus, despite a significantly heightened body weight, female heart size is reduced with age. Accordingly, sufficient cardiac output was maintained via increased heart rate (p=0.005) and cardiac sympathetic activity (p=0.040, Figure 1). Gonadectomy accelerated age-dependent changes in LV morphology and function in female mice. While sex hormone deprivation blunted cardiac sympathetic activity and norepinephrine levels in male mice, an opposite trend was observed in females.
Conclusion
Despite increasing body weight with age, aged female and male hearts maintain a stable circulatory blood supply, however, by distinct mechanisms. While the “shrinking” female heart requires an increased heart rate and cardiac sympathetic activity to compensate for smaller ventricular volumes, aging males maintain cardiac size. Importantly, sex hormone deprivation at a young age accelerates age-dependent changes in LV morphology and function in female mice, but not in male mice. The increased sympathetic activity reflects a higher stress level in aged females that might expose them to a higher cardiac vulnerability at postmenopausal age.
Funding Acknowledgement
Type of funding source: Public grant(s) – National budget only. Main funding source(s): Swiss National Science Foundation; Swissheart Foundation
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Affiliation(s)
- A Haider
- University Hospital Zurich, Department of Nuclear Medicine, Zurich, Switzerland
| | - S Bengs
- University Hospital Zurich, Department of Nuclear Medicine, Zurich, Switzerland
| | - G Warnock
- University Hospital Zurich, Department of Nuclear Medicine, Zurich, Switzerland
| | - A Akhmedov
- University Hospital Zurich, Department of Nuclear Medicine, Zurich, Switzerland
| | - S Kozerke
- Swiss Federal Institute of Technology Zurich (ETH Zurich), Institute for Biomedical Engineering, Zurich, Switzerland
| | - G Kwiatkowski
- Swiss Federal Institute of Technology Zurich (ETH Zurich), Institute for Biomedical Engineering, Zurich, Switzerland
| | - A Mueller Herde
- Swiss Federal Institute of Technology Zurich (ETH Zurich), Institute of Pharmaceutical Sciences, Zurich, Switzerland
| | - S.D Kraemer
- Swiss Federal Institute of Technology Zurich (ETH Zurich), Institute of Pharmaceutical Sciences, Zurich, Switzerland
| | - B Weber
- Swiss Federal Institute of Technology Zurich (ETH Zurich), Institute of Pharmacology and Toxicology, Zurich, Switzerland
| | - R Schibli
- Swiss Federal Institute of Technology Zurich (ETH Zurich), Institute of Pharmaceutical Sciences, Zurich, Switzerland
| | - L Mu
- Swiss Federal Institute of Technology Zurich (ETH Zurich), Institute of Pharmaceutical Sciences, Zurich, Switzerland
| | - P.A Kaufmann
- University Hospital Zurich, Department of Nuclear Medicine, Zurich, Switzerland
| | - V Regitz-Zagrosek
- Charite Universitatsmedizin Berlin, Institute for Gender in Medicine, Berlin, Germany
| | - S.M Ametamey
- Swiss Federal Institute of Technology Zurich (ETH Zurich), Institute of Pharmaceutical Sciences, Zurich, Switzerland
| | - C Gebhard
- University Hospital Zurich, Department of Nuclear Medicine, Zurich, Switzerland
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8
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Ritzer C, Becker R, Buck A, Commichau V, Debus J, Djambazov L, Eleftheriou A, Fischer J, Fischer P, Ito M, Khateri P, Lustermann W, Ritzert M, Roser U, Rudin M, Sacco I, Tsoumpas C, Warnock G, Wyss M, Zagozdzinska-Bochenek A, Weber B, Dissertori G. Initial Characterization of the SAFIR Prototype PET-MR Scanner. IEEE Trans Radiat Plasma Med Sci 2020. [DOI: 10.1109/trpms.2020.2980072] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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9
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Sah BR, Sommerauer M, Mu L, Gonzalez GP, Geistlich S, Treyer V, Schibli R, Buck A, Warnock G, Ametamey SM. Radiation dosimetry of [ 18F]-PSS232-a PET radioligand for imaging mGlu5 receptors in humans. EJNMMI Res 2019; 9:56. [PMID: 31240594 PMCID: PMC6593000 DOI: 10.1186/s13550-019-0522-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2018] [Accepted: 05/28/2019] [Indexed: 11/25/2022] Open
Abstract
Purpose (E)-3-(pyridin-2-ylethynyl)cyclohex-2-enone O-(3-(2-[18F]-fluoroethoxy)propyl) oxime ([18F]-PSS232) is a new PET tracer for imaging of metabotropic glutamate receptor subtype 5 (mGlu5), and has shown promising results in rodents and humans. The aim of this study was to estimate the radiation dosimetry and biodistribution in humans, to assess dose-limiting organs, and to demonstrate safety and tolerability of [18F]-PSS232 in healthy volunteers. Methods PET/CT scans of six healthy male volunteers (mean age 23.5 ± 1.7; 21–26 years) were obtained after intravenous administration of 243 ± 3 MBq of [18F]-PSS232. Serial whole-body (vertex to mid-thigh) PET scans were assessed at ten time points, up to 90 min after tracer injection. Calculation of tracer kinetics and cumulated organ activities were performed using PMOD 3.7 software. Dosimetry estimates were calculated using the OLINDA/EXM software. Results Injection of [18F]-PSS232 was safe and well tolerated. Organs with highest absorbed doses were the gallbladder wall (0.2295 mGy/MBq), liver (0.0547 mGy/MBq), and the small intestine (0.0643 mGy/MBq). Mean effective dose was 3.72 ± 0.12 mSv/volunteer (range 3.61–3.96 mSv; 0.0153 mSv/MBq). Conclusion [18F]-PSS232, a novel [18F]-labeled mGlu5 tracer, showed favorable dosimetry values. Additionally, the tracer was safe and well tolerated.
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Affiliation(s)
- Bert-Ram Sah
- Department of Nuclear Medicine, University Hospital Zurich and University of Zurich, Zurich, Switzerland.,Department of Diagnostic, Interventional, and Pediatric Radiology, Inselspital, University of Bern, Bern, Switzerland
| | - Michael Sommerauer
- Department of Nuclear Medicine, University Hospital Zurich and University of Zurich, Zurich, Switzerland.,Department of Neurology, University Hospital Zurich and University of Zurich, Zurich, Switzerland
| | - Linjing Mu
- Department of Nuclear Medicine, University Hospital Zurich and University of Zurich, Zurich, Switzerland
| | - Gloria Pla Gonzalez
- Radiopharmaceutical Science, Department of Chemistry and Applied Biosciences, Institute of Pharmaceutical Sciences, ETH Zurich, Zurich, Switzerland
| | - Susanne Geistlich
- Radiopharmaceutical Science, Department of Chemistry and Applied Biosciences, Institute of Pharmaceutical Sciences, ETH Zurich, Zurich, Switzerland
| | - Valerie Treyer
- Department of Nuclear Medicine, University Hospital Zurich and University of Zurich, Zurich, Switzerland
| | - Roger Schibli
- Radiopharmaceutical Science, Department of Chemistry and Applied Biosciences, Institute of Pharmaceutical Sciences, ETH Zurich, Zurich, Switzerland
| | - Alfred Buck
- Department of Nuclear Medicine, University Hospital Zurich and University of Zurich, Zurich, Switzerland
| | - Geoffrey Warnock
- Department of Nuclear Medicine, University Hospital Zurich and University of Zurich, Zurich, Switzerland. .,PMOD Technologies LLC, Zurich, Switzerland.
| | - Simon M Ametamey
- Radiopharmaceutical Science, Department of Chemistry and Applied Biosciences, Institute of Pharmaceutical Sciences, ETH Zurich, Zurich, Switzerland
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10
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Stieb S, Eleftheriou A, Warnock G, Guckenberger M, Riesterer O. Longitudinal PET imaging of tumor hypoxia during the course of radiotherapy. Eur J Nucl Med Mol Imaging 2018; 45:2201-2217. [PMID: 30128659 DOI: 10.1007/s00259-018-4116-y] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2018] [Accepted: 07/30/2018] [Indexed: 12/11/2022]
Abstract
Hypoxia results from an imbalance between oxygen supply and consumption. It is a common phenomenon in solid malignant tumors such as head and neck cancer. As hypoxic cells are more resistant to therapy, tumor hypoxia is an indicator for poor prognosis. Several techniques have been developed to measure tissue oxygenation. These are the Eppendorf O2 polarographic needle electrode, immunohistochemical analysis of endogenous (e.g., hypoxia-inducible factor-1α (HIF-1a)) and exogenous markers (e.g., pimonidazole) as well as imaging methods such as functional magnetic resonance imaging (e.g., blood oxygen level dependent (BOLD) imaging, T1-weighted imaging) and hypoxia positron emission tomography (PET). Among the imaging modalities, only PET is sufficiently validated to detect hypoxia for clinical use. Hypoxia PET tracers include 18F-fluoromisonidazole (FMISO), the most commonly used hypoxic marker, 18F-flouroazomycin arabinoside (FAZA), 18Ffluoroerythronitroimidazole (FETNIM), 18F-2-nitroimidazolpentafluoropropylacetamide (EF5) and 18F-flortanidazole (HX4). As technical development provides the opportunity to increase the radiation dose to subregions of the tumor, such as hypoxic areas, it has to be ensured that these regions are stable not only from imaging to treatment but also through the course of radiotherapy. The aim of this review is therefore to characterize the behavior of tumor hypoxia during radiotherapy for the whole tumor and for subregions by using hypoxia PET tracers, with focus on head and neck cancer patients.
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Affiliation(s)
- Sonja Stieb
- Department of Radiation Oncology, University Hospital and University of Zurich, Rämistrasse 100, 8091, Zurich, Switzerland. .,Institute of Diagnostic and Interventional Radiology, University Hospital and University of Zurich, Rämistrasse 100, 8091, Zurich, Switzerland.
| | - Afroditi Eleftheriou
- Department of Pharmacology and Toxicology, University of Zurich, Winterthurerstrasse 190, 8057, Zurich, Switzerland
| | - Geoffrey Warnock
- Department of Pharmacology and Toxicology, University of Zurich, Winterthurerstrasse 190, 8057, Zurich, Switzerland.,Department of Nuclear Medicine, University Hospital and University of Zurich, Rämistrasse 100, 8091, Zurich, Switzerland
| | - Matthias Guckenberger
- Department of Radiation Oncology, University Hospital and University of Zurich, Rämistrasse 100, 8091, Zurich, Switzerland
| | - Oliver Riesterer
- Department of Radiation Oncology, University Hospital and University of Zurich, Rämistrasse 100, 8091, Zurich, Switzerland
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11
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Warnock G, Özbay PS, Kuhn FP, Nanz D, Buck A, Boss A, Rossi C. Reduction of BOLD interference in pseudo-continuous arterial spin labeling: towards quantitative fMRI. J Cereb Blood Flow Metab 2018; 38:847-856. [PMID: 28421854 PMCID: PMC5987937 DOI: 10.1177/0271678x17704785] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Fluctuations in blood-oxygenation level dependent (BOLD) signal and perfusion affect the quantification of changes in cerebral blood flow (CBF), coupled to neuronal activity, in arterial spin labeling (ASL). Subtraction methods for control and labeled MR images (i.e. pair-wise, surround subtraction, and subtraction of sinc-interpolated images), postulated to mitigate this interference in pseudo-continuous ASL (pCASL), were evaluated by comparison with quantitative 15O-water PET. At rest, a good agreement in the CBF values was found between PET and MRI for each of the subtraction methods. Stimulation of the visual system resulted in a regional CBF increase in the occipital lobe, which was detectable in both modalities. Bland-Altman analysis showed a systematic underestimation of the CBF values during activation in MRI. Evaluation of the relative CBF change induced by neuronal stimulation showed good inter-modality agreement for the three subtraction methods. Perfusion data obtained with each subtraction method followed the stimulation paradigm without significant differences in the correlation patterns or in the time lag between stimulation and perfusion response. Comparison to the gold standard confirmed the detectability of a neuronal stimulation pattern by pCASL. The results indicate that the combined use of background suppression and short TE reduces the BOLD-weighting in the pCASL signal.
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Affiliation(s)
- Geoffrey Warnock
- 1 Department of Nuclear Medicine, University Hospital Zurich, University of Zurich, Switzerland
| | - Pinar S Özbay
- 2 Institute of Diagnostic and Interventional Radiology University Hospital Zurich, University of Zurich, Switzerland.,3 Institute for Biomedical Engineering, University of Zurich and ETH Zurich, Switzerland.,4 Advanced MRI Section, Laboratory of Functional and Molecular Imaging, National Institutes of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, USA
| | - Felix P Kuhn
- 2 Institute of Diagnostic and Interventional Radiology University Hospital Zurich, University of Zurich, Switzerland
| | - Daniel Nanz
- 2 Institute of Diagnostic and Interventional Radiology University Hospital Zurich, University of Zurich, Switzerland
| | - Alfred Buck
- 1 Department of Nuclear Medicine, University Hospital Zurich, University of Zurich, Switzerland
| | - Andreas Boss
- 2 Institute of Diagnostic and Interventional Radiology University Hospital Zurich, University of Zurich, Switzerland
| | - Cristina Rossi
- 2 Institute of Diagnostic and Interventional Radiology University Hospital Zurich, University of Zurich, Switzerland
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12
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Ledermann K, Jenewein J, Sprott H, Hasler G, Schnyder U, Warnock G, Johayem A, Kollias S, Buck A, Martin-Soelch C. Altered Dopamine Responses to Monetary Rewards in Female Fibromyalgia Patients with and without Depression: A [11C]Raclopride Bolus-plus-Infusion PET Study. Psychother Psychosom 2018; 86:181-182. [PMID: 28490029 DOI: 10.1159/000455927] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/10/2016] [Accepted: 01/08/2017] [Indexed: 11/19/2022]
Affiliation(s)
- Katharina Ledermann
- Unit of Clinical and Health Psychology, Department of Psychology, University of Fribourg, Fribourg, Switzerland
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13
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Ahnen M, Becker R, Buck A, Casella C, Commichau V, Calafiori DD, Dissertori G, Eleftheriou A, Fischer J, Howard AS, Ito M, Khateri P, Kim J, Lustermann W, Ritzer C, Roser U, Rudin M, Solevi P, Tsoumpas C, Warnock G, Weber B, Wyss M, Zagozdzinska-Bochenek A. Performance Measurements of the SAFIR Prototype Detector With the STiC ASIC Readout. IEEE Trans Radiat Plasma Med Sci 2018. [DOI: 10.1109/trpms.2018.2797484] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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14
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Fierstra J, van Niftrik C, Warnock G, Wegener S, Piccirelli M, Pangalu A, Esposito G, Valavanis A, Buck A, Luft A, Bozinov O, Regli L. Staging Hemodynamic Failure With Blood Oxygen-Level–Dependent Functional Magnetic Resonance Imaging Cerebrovascular Reactivity. Stroke 2018; 49:621-629. [DOI: 10.1161/strokeaha.117.020010] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2017] [Revised: 11/03/2017] [Accepted: 11/29/2017] [Indexed: 12/20/2022]
Abstract
Background and Purpose—
Increased stroke risk correlates with hemodynamic failure, which can be assessed with (
15
O-)H
2
O positron emission tomography (PET) cerebral blood flow (CBF) measurements. This gold standard technique, however, is not established for routine clinical imaging. Standardized blood oxygen-level–dependent (BOLD) functional magnetic resonance imaging+CO
2
is a noninvasive and potentially widely applicable tool to assess whole-brain quantitative cerebrovascular reactivity (CVR). We examined the agreement between the 2 imaging modalities and hypothesized that quantitative CVR can be a surrogate imaging marker to assess hemodynamic failure.
Methods—
Nineteen data sets of subjects with chronic cerebrovascular steno-occlusive disease (age, 60±11 years; 4 women) and unilaterally impaired perfusion reserve on Diamox-challenged (
15
O-)H
2
O PET were studied and compared with a standardized BOLD functional magnetic resonance imaging+CO
2
examination within 6 weeks (8±19 days). Agreement between quantitative CBF- and CVR-based perfusion reserve was assessed. Hemodynamic failure was staged according to PET findings: stage 0: normal CBF, normal perfusion reserve; stage I: normal CBF, decreased perfusion reserve; and stage II: decreased CBF, decreased perfusion reserve. The BOLD CVR data set of the same subjects was then matched to the corresponding stage of hemodynamic failure.
Results—
PET-based stage I versus stage II could also be clearly separated with BOLD CVR measurements (CVR for stage I 0.11 versus CVR for stage II −0.03;
P
<0.01). Hemispheric and middle cerebral artery territory difference analyses (ie, affected versus unaffected side) showed a significant correlation for CVR impairment in the affected hemisphere and middle cerebral artery territory (
P
<0.01,
R
2
=0.47 and
P
=0.02,
R
2
= 0.25, respectively).
Conclusions—
BOLD CVR corresponded well to CBF perfusion reserve measurements obtained with (
15
O-)H
2
O-PET, especially for detecting hemodynamic failure in the affected hemisphere and middle cerebral artery territory and for identifying hemodynamic failure stage II. BOLD CVR may, therefore, be considered for prospective studies assessing stroke risk in patients with chronic cerebrovascular steno-occlusive disease, in particular because it can potentially be implemented in routine clinical imaging.
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Affiliation(s)
- Jorn Fierstra
- From the Departments of Neurosurgery (J.F., C.v.N., G.E., O.B., L.R.), Neuroradiology (M.P., A.V.), Neurology (S.W., A.L.), Pharmacology and Toxicology (G.W.), and Nuclear Medicine (A.B.), Clinical Neuroscience Center, University Hospital Zurich, University of Zurich, Switzerland
| | - Christiaan van Niftrik
- From the Departments of Neurosurgery (J.F., C.v.N., G.E., O.B., L.R.), Neuroradiology (M.P., A.V.), Neurology (S.W., A.L.), Pharmacology and Toxicology (G.W.), and Nuclear Medicine (A.B.), Clinical Neuroscience Center, University Hospital Zurich, University of Zurich, Switzerland
| | - Geoffrey Warnock
- From the Departments of Neurosurgery (J.F., C.v.N., G.E., O.B., L.R.), Neuroradiology (M.P., A.V.), Neurology (S.W., A.L.), Pharmacology and Toxicology (G.W.), and Nuclear Medicine (A.B.), Clinical Neuroscience Center, University Hospital Zurich, University of Zurich, Switzerland
| | - Susanne Wegener
- From the Departments of Neurosurgery (J.F., C.v.N., G.E., O.B., L.R.), Neuroradiology (M.P., A.V.), Neurology (S.W., A.L.), Pharmacology and Toxicology (G.W.), and Nuclear Medicine (A.B.), Clinical Neuroscience Center, University Hospital Zurich, University of Zurich, Switzerland
| | - Marco Piccirelli
- From the Departments of Neurosurgery (J.F., C.v.N., G.E., O.B., L.R.), Neuroradiology (M.P., A.V.), Neurology (S.W., A.L.), Pharmacology and Toxicology (G.W.), and Nuclear Medicine (A.B.), Clinical Neuroscience Center, University Hospital Zurich, University of Zurich, Switzerland
| | - Athina Pangalu
- From the Departments of Neurosurgery (J.F., C.v.N., G.E., O.B., L.R.), Neuroradiology (M.P., A.V.), Neurology (S.W., A.L.), Pharmacology and Toxicology (G.W.), and Nuclear Medicine (A.B.), Clinical Neuroscience Center, University Hospital Zurich, University of Zurich, Switzerland
| | - Giuseppe Esposito
- From the Departments of Neurosurgery (J.F., C.v.N., G.E., O.B., L.R.), Neuroradiology (M.P., A.V.), Neurology (S.W., A.L.), Pharmacology and Toxicology (G.W.), and Nuclear Medicine (A.B.), Clinical Neuroscience Center, University Hospital Zurich, University of Zurich, Switzerland
| | - Antonios Valavanis
- From the Departments of Neurosurgery (J.F., C.v.N., G.E., O.B., L.R.), Neuroradiology (M.P., A.V.), Neurology (S.W., A.L.), Pharmacology and Toxicology (G.W.), and Nuclear Medicine (A.B.), Clinical Neuroscience Center, University Hospital Zurich, University of Zurich, Switzerland
| | - Alfred Buck
- From the Departments of Neurosurgery (J.F., C.v.N., G.E., O.B., L.R.), Neuroradiology (M.P., A.V.), Neurology (S.W., A.L.), Pharmacology and Toxicology (G.W.), and Nuclear Medicine (A.B.), Clinical Neuroscience Center, University Hospital Zurich, University of Zurich, Switzerland
| | - Andreas Luft
- From the Departments of Neurosurgery (J.F., C.v.N., G.E., O.B., L.R.), Neuroradiology (M.P., A.V.), Neurology (S.W., A.L.), Pharmacology and Toxicology (G.W.), and Nuclear Medicine (A.B.), Clinical Neuroscience Center, University Hospital Zurich, University of Zurich, Switzerland
| | - Oliver Bozinov
- From the Departments of Neurosurgery (J.F., C.v.N., G.E., O.B., L.R.), Neuroradiology (M.P., A.V.), Neurology (S.W., A.L.), Pharmacology and Toxicology (G.W.), and Nuclear Medicine (A.B.), Clinical Neuroscience Center, University Hospital Zurich, University of Zurich, Switzerland
| | - Luca Regli
- From the Departments of Neurosurgery (J.F., C.v.N., G.E., O.B., L.R.), Neuroradiology (M.P., A.V.), Neurology (S.W., A.L.), Pharmacology and Toxicology (G.W.), and Nuclear Medicine (A.B.), Clinical Neuroscience Center, University Hospital Zurich, University of Zurich, Switzerland
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Knešaurek K, Warnock G, Kostakoglu L, Burger C. Comparison of Standardized Uptake Value Ratio Calculations in Amyloid Positron Emission Tomography Brain Imaging. World J Nucl Med 2018; 17:21-26. [PMID: 29398961 PMCID: PMC5778709 DOI: 10.4103/wjnm.wjnm_5_17] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
Abstract
Amyloid positron emission tomography (PET) imaging with florbetapir 18F (18F-AV-45) allows in vivo assessment of cerebral amyloid load and can be used in the evaluation of progression of Alzheimer's disease (AD) and other dementias associated with b-amyloid. However, cortical amyloid deposition can occur in healthy cases, as well as in patients with AD and quantification of cortical amyloid burden can improve the 18F-AV-45 PET imaging evaluations. The quantification is mostly performed by cortical-to-cerebellum standardized uptake value ratio (SUVr). The aim of our study was to compare two methods for SUVr calculations in amyloid florbetapir 18F PET brain imaging. In amyloid florbetapir 18F PET brain imaging study, we imaged 42 cases with the mean age of 72.6 ± 9.9 (mean ± standard deviation). They were imaged on different PET/computed tomography systems with 369.0 ± 34.2 kBq of 18F florbetapir. Data were reconstructed using the vendor's reconstruction software. Corresponding magnetic resonance imaging (MRI) data were retrieved, and matched PET and MRI data were transferred to a common platform. Two methods were used for the calculation of the ratio of cortical-to-cerebellar signal (SUVr). One method was based on the MIM Software Inc., Version 6.4 software and only uses PET data. The second approach used the PMOD Neuro tool (version 3.5). This approach utilizes PET and corresponding MRI data (preferably T1-weighted) for better brain segmentation. For all the 42 cases, the average SUVr values for MIM and PMOD applications were 1.24 ± 0.26 and 1.22 ± 0.25, respectively, with a mean difference of 0.02 ± 0.15. The repeatability coefficient was 0.15 (12.3% of the mean). The Spearman's rank correlation coefficient was very high, r = 0.96. For amyloid-negative cases, the average SUVr values were lower than all group SUVr average values, 0.96 ± 0.07 and 1.00 ± 0.09, for MIM and PMOD applications, respectively. A mean difference was 0.04 ± 0.12, the repeatability coefficient was 0.12 (12.9% of the mean) and the Spearman's rank correlation coefficient was modest, r = 0.55. For amyloid-positive patients, the average SUVr values were higher than the same all group values, 1.34 ± 0.16 and 1.35 ± 0.20, respectively, with a mean difference of 0.01 ± 0.16. The repeatability coefficient was 0.16 (11.9% of the mean). The Spearman's rank correlation coefficient was high, r = 0.93. Our results indicated that the SUVr values derived using MIM and PMOD Neuro are effectively interchangeable and well correlated. However, PET template-based quantification (MIM approach) is clinically friendlier and easier to use. MRI template-based quantification (PMOD Neuro) better delineates different regions of the brain, can be used with any tracer, and therefore is more suitable for research.
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Affiliation(s)
- Karin Knešaurek
- Department of Radiology, Division of Nuclear Medicine, Icahn School of Medicine at Mount Sinai, New York, USA
| | - Geoffrey Warnock
- Department of Nuclear Medicine, University Hospital Zurich, Zurich, Switzerland
| | - Lale Kostakoglu
- Department of Radiology, Division of Nuclear Medicine, Icahn School of Medicine at Mount Sinai, New York, USA
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16
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Warnock G, Sommerauer M, Mu L, Pla Gonzalez G, Geistlich S, Treyer V, Schibli R, Buck A, Krämer SD, Ametamey SM. A first-in-man PET study of [ 18F]PSS232, a fluorinated ABP688 derivative for imaging metabotropic glutamate receptor subtype 5. Eur J Nucl Med Mol Imaging 2017; 45:1041-1051. [PMID: 29177707 DOI: 10.1007/s00259-017-3879-x] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2017] [Accepted: 11/06/2017] [Indexed: 12/21/2022]
Abstract
PURPOSE Non-invasive imaging of metabotropic glutamate receptor 5 (mGlu5) in the brain using PET is of interest in e.g., anxiety, depression, and Parkinson's disease. Widespread application of the most widely used mGlu5 tracer, [11C]ABP688, is limited by the short physical half-life of carbon-11. [18F]PSS232 is a fluorinated analog with promising preclinical properties and high selectivity and specificity for mGlu5. In this first-in-man study, we evaluated the brain uptake pattern and kinetics of [18F]PSS232 in healthy volunteers. METHODS [18F]PSS232 PET was performed with ten healthy male volunteers aged 20-40 years. Seven of the subjects received a bolus injection and the remainder a bolus/infusion protocol. Cerebral blood flow was determined in seven subjects using [15O]water PET. Arterial blood activity was measured using an online blood counter. Tracer kinetics were evaluated by compartment modeling and parametric maps were generated for both tracers. RESULTS At 90 min post-injection, 59.2 ± 11.1% of total radioactivity in plasma corresponded to intact tracer. The regional first pass extraction fraction of [18F]PSS232 ranged from 0.41 ± 0.06 to 0.55 ± 0.03 and brain distribution pattern matched that of [11C]ABP688. Uptake kinetics followed a simple two-tissue compartment model. The volume of distribution of total tracer (V T, ml/cm3) ranged from 1.18 ± 0.20 for white matter to 2.91 ± 0.51 for putamen. The respective mean distribution volume ratios (DVR) with cerebellum as the reference tissue were 0.88 ± 0.06 and 2.12 ± 0.10, respectively. The tissue/cerebellum ratios of a bolus/infusion protocol (30/70 dose ratio) were close to the DVR values. CONCLUSIONS Brain uptake of [18F]PSS232 matched the distribution of mGlu5 and followed a two-tissue compartment model. The well-defined kinetics and the possibility to use reference tissue models, obviating the need for arterial blood sampling, make [18F]PSS232 a promising fluorine-18 labeled radioligand for measuring mGlu5 density in humans.
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Affiliation(s)
- Geoffrey Warnock
- Department of Nuclear Medicine, University Hospital Zurich, 8091, Zurich, Switzerland
| | - Michael Sommerauer
- Department of Nuclear Medicine, University Hospital Zurich, 8091, Zurich, Switzerland.,Department of Neurology, University Hospital Zurich and University of Zurich, Zurich, Switzerland
| | - Linjing Mu
- Department of Nuclear Medicine, University Hospital Zurich, 8091, Zurich, Switzerland
| | - Gloria Pla Gonzalez
- Radiopharmaceutical Science, Institute of Pharmaceutical Sciences, Department of Chemistry and Applied Biosciences, ETH Zurich, Vladimir-Prelog Weg 4, 8093, Zurich, Switzerland
| | - Susanne Geistlich
- Radiopharmaceutical Science, Institute of Pharmaceutical Sciences, Department of Chemistry and Applied Biosciences, ETH Zurich, Vladimir-Prelog Weg 4, 8093, Zurich, Switzerland
| | - Valerie Treyer
- Department of Nuclear Medicine, University Hospital Zurich, 8091, Zurich, Switzerland
| | - Roger Schibli
- Radiopharmaceutical Science, Institute of Pharmaceutical Sciences, Department of Chemistry and Applied Biosciences, ETH Zurich, Vladimir-Prelog Weg 4, 8093, Zurich, Switzerland
| | - Alfred Buck
- Department of Nuclear Medicine, University Hospital Zurich, 8091, Zurich, Switzerland
| | - Stefanie D Krämer
- Radiopharmaceutical Science, Institute of Pharmaceutical Sciences, Department of Chemistry and Applied Biosciences, ETH Zurich, Vladimir-Prelog Weg 4, 8093, Zurich, Switzerland
| | - Simon M Ametamey
- Radiopharmaceutical Science, Institute of Pharmaceutical Sciences, Department of Chemistry and Applied Biosciences, ETH Zurich, Vladimir-Prelog Weg 4, 8093, Zurich, Switzerland.
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Wagner F, Hakami YA, Warnock G, Fischer G, Huellner MW, Veit-Haibach P. Comparison of Contrast-Enhanced CT and [18F]FDG PET/CT Analysis Using Kurtosis and Skewness in Patients with Primary Colorectal Cancer. Mol Imaging Biol 2017; 19:795-803. [DOI: 10.1007/s11307-017-1066-x] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
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Wu B, Warnock G, Zaiss M, Lin C, Chen M, Zhou Z, Mu L, Nanz D, Tuura R, Delso G. An overview of CEST MRI for non-MR physicists. EJNMMI Phys 2016; 3:19. [PMID: 27562024 PMCID: PMC4999387 DOI: 10.1186/s40658-016-0155-2] [Citation(s) in RCA: 147] [Impact Index Per Article: 18.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2016] [Accepted: 08/06/2016] [Indexed: 01/16/2023] Open
Abstract
The search for novel image contrasts has been a major driving force in the magnetic resonance (MR) research community, in order to gain further information on the body’s physiological and pathological conditions. Chemical exchange saturation transfer (CEST) is a novel MR technique that enables imaging certain compounds at concentrations that are too low to impact the contrast of standard MR imaging and too low to directly be detected in MRS at typical water imaging resolution. For this to be possible, the target compound must be capable of exchanging protons with the surrounding water molecules. This property can be exploited to cause a continuous buildup of magnetic saturation of water, leading to greatly enhanced sensitivity. The goal of the present review is to introduce the basic principles of CEST imaging to the general molecular imaging community. Special focus has been given to the comparison of state-of-the-art CEST methods reported in the literature with their positron emission tomography (PET) counterparts.
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Affiliation(s)
- B Wu
- GE Healthcare, Waukesha (WI), USA
| | - G Warnock
- PMOD Technologies Ltd., Zurich, Switzerland
| | - M Zaiss
- German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - C Lin
- GE Healthcare, Waukesha (WI), USA
| | - M Chen
- Peking Hospital, Beijing, China
| | - Z Zhou
- GE Healthcare, Waukesha (WI), USA
| | - L Mu
- University of Zurich, Zurich, Switzerland
| | - D Nanz
- University Hospital of Zurich, Zurich, Switzerland
| | - R Tuura
- Children's Hospital Zurich, Zurich, Switzerland
| | - G Delso
- GE Healthcare, Waukesha (WI), USA.
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19
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Sekine T, Ter Voert EEGW, Warnock G, Buck A, Huellner M, Veit-Haibach P, Delso G. Clinical Evaluation of Zero-Echo-Time Attenuation Correction for Brain 18F-FDG PET/MRI: Comparison with Atlas Attenuation Correction. J Nucl Med 2016; 57:1927-1932. [PMID: 27339875 DOI: 10.2967/jnumed.116.175398] [Citation(s) in RCA: 80] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2016] [Accepted: 05/31/2016] [Indexed: 12/19/2022] Open
Abstract
Accurate attenuation correction (AC) on PET/MR is still challenging. The purpose of this study was to evaluate the clinical feasibility of AC based on fast zero-echo-time (ZTE) MRI by comparing it with the default atlas-based AC on a clinical PET/MR scanner. METHODS We recruited 10 patients with malignant diseases not located on the brain. In all patients, a clinically indicated whole-body 18F-FDG PET/CT scan was acquired. In addition, a head PET/MR scan was obtained voluntarily. For each patient, 2 AC maps were generated from the MR images. One was atlas-AC, derived from T1-weighted liver acquisition with volume acceleration flex images (clinical standard). The other was ZTE-AC, derived from proton-density-weighted ZTE images by applying tissue segmentation and assigning continuous attenuation values to the bone. The AC map generated by PET/CT was used as a silver standard. On the basis of each AC map, PET images were reconstructed from identical raw data on the PET/MR scanner. All PET images were normalized to the SPM5 PET template. After that, these images were qualified visually and quantified in 67 volumes of interest (VOIs; automated anatomic labeling, atlas). Relative differences and absolute relative differences between PET images based on each AC were calculated. 18F-FDG uptake in all 670 VOIs and generalized merged VOIs were compared using a paired t test. RESULTS Qualitative analysis shows that ZTE-AC was robust to patient variability. Nevertheless, misclassification of air and bone in mastoid and nasal areas led to the overestimation of PET in the temporal lobe and cerebellum (%diff of ZTE-AC, 2.46% ± 1.19% and 3.31% ± 1.70%, respectively). The |%diff| of all 670 VOIs on ZTE was improved by approximately 25% compared with atlas-AC (ZTE-AC vs. atlas-AC, 1.77% ± 1.41% vs. 2.44% ± 1.63%, P < 0.01). In 2 of 7 generalized VOIs, |%diff| on ZTE-AC was significantly smaller than atlas-AC (ZTE-AC vs. atlas-AC: insula and cingulate, 1.06% ± 0.67% vs. 2.22% ± 1.10%, P < 0.01; central structure, 1.03% ± 0.99% vs. 2.54% ± 1.20%, P < 0.05). CONCLUSION The ZTE-AC could provide more accurate AC than clinical atlas-AC by improving the estimation of head-skull attenuation. The misclassification in mastoid and nasal areas must be addressed to prevent the overestimation of PET in regions near the skull base.
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Affiliation(s)
- Tetsuro Sekine
- Department of Nuclear Medicine, University Hospital Zurich, Zurich, Switzerland .,Department of Radiology, Nippon Medical School, Tokyo, Japan
| | | | - Geoffrey Warnock
- Department of Nuclear Medicine, University Hospital Zurich, Zurich, Switzerland.,Institute of Pharmacology & Toxicology, University of Zurich, Zurich, Switzerland.,PMOD Technologies Ltd., Zurich, Switzerland
| | - Alfred Buck
- Department of Nuclear Medicine, University Hospital Zurich, Zurich, Switzerland
| | - Martin Huellner
- Department of Nuclear Medicine, University Hospital Zurich, Zurich, Switzerland.,Department of Neuroradiology, University Hospital Zurich, Zurich, Switzerland
| | - Patrick Veit-Haibach
- Department of Nuclear Medicine, University Hospital Zurich, Zurich, Switzerland.,Division of Diagnostic and Interventional Radiology, Department of Medical Radiology, University Hospital Zurich, Zurich, Switzerland; and
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20
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Özbay PS, Warnock G, Rossi C, Kuhn F, Akin B, Pruessmann KP, Nanz D. Probing neuronal activation by functional quantitative susceptibility mapping under a visual paradigm: A group level comparison with BOLD fMRI and PET. Neuroimage 2016; 137:52-60. [PMID: 27155125 DOI: 10.1016/j.neuroimage.2016.05.013] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2016] [Revised: 05/02/2016] [Accepted: 05/03/2016] [Indexed: 11/26/2022] Open
Abstract
Dynamic changes of brain-tissue magnetic susceptibility provide the basis for functional MR imaging (fMRI) via T2*-weighted signal-intensity modulations. Promising initial work on a detection of neuronal activity via quantitative susceptibility mapping (fQSM) has been published but consistently reported on ill-understood positive and negative activation patterns (Balla et al., 2014; Chen and Calhoun, 2015a). We set out to (i) demonstrate that fQSM can exploit established fMRI data acquisition and processing methods and to (ii) better describe aspects of the apparent activation patterns using fMRI and PET as standards of reference. Under a standardized visual-stimulation paradigm PET and 3-T gradient-echo EPI-based fQSM, fMRI data from 9 healthy volunteers were acquired and analyzed by means of Independent Component Analysis (ICA) at subject level and, for the first time, at group level. Numbers of activated (z-score>2.0) voxels were counted and their mean z-scores calculated in volumes of interest (occipital lobe (Nocc_lobe), segmented occipital gray-matter (NGM_occ_lobe), large veins (Nveins)), and in occipital-lobe voxels commonly activated in fQSM and fMRI component maps. Common but not entirely congruent regions of apparent activation were found in the occipital lobe in z-score maps from all modalities, fQSM, fMRI and PET, with distinct BOLD-negatively correlated regions in fQSM data. At subject-level, Nocc_lobe, NGM_occ_lobe and their mean z-scores were significantly smaller in fQSM than in fMRI, but their ratio, NGM_occ_lobe/Nocc_lobe, was comparable. Nveins did not statistically differ and the ratio Nveins/NGM_occ_lobe as well as the mean z-scores were higher for fQSM than for fMRI. In veins and immediate vicinity, z-score maps derived from both phase and fQSM-data showed positive and negative lobes resembling dipole shapes in simulated field and phase maps with no correlate in fMRI or PET data. Our results show that standard fMRI tools can directly be used for fQSM processing, and suggest that fQSM may have the potential to detect gray-matter activation distant from large veins, to improve detection of veins with stimulus-induced venous oxygen saturation (SvO2) variations, and to better localize areas of activation. However, our results seem to clearly expose issues that phenomenologically resemble an incomplete dipolar inversion and that need to be subject to further investigation.
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Affiliation(s)
- Pinar Senay Özbay
- Institute of Diagnostic and Interventional Radiology, University Hospital Zurich, University of Zurich, Zurich, Switzerland; Institute for Biomedical Engineering, University of Zurich, ETH Zurich, Switzerland.
| | - Geoffrey Warnock
- PMOD Technologies Ltd., Zurich, Switzerland; Department of Nuclear Medicine, University Hospital Zurich, University of Zurich, Zurich, Switzerland
| | - Cristina Rossi
- Institute of Diagnostic and Interventional Radiology, University Hospital Zurich, University of Zurich, Zurich, Switzerland
| | - Felix Kuhn
- Department of Nuclear Medicine, University Hospital Zurich, University of Zurich, Zurich, Switzerland
| | - Burak Akin
- Department of Radiology, Medical Physics, Medical Center - University of Freiburg, Faculty of Medicine, University of Freiburg, Germany
| | | | - Daniel Nanz
- Institute of Diagnostic and Interventional Radiology, University Hospital Zurich, University of Zurich, Zurich, Switzerland
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21
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Sekine T, Burgos N, Warnock G, Huellner M, Buck A, Ter Voert EEGW, Cardoso MJ, Hutton BF, Ourselin S, Veit-Haibach P, Delso G. Multi-Atlas-Based Attenuation Correction for Brain 18F-FDG PET Imaging Using a Time-of-Flight PET/MR Scanner: Comparison with Clinical Single-Atlas- and CT-Based Attenuation Correction. J Nucl Med 2016; 57:1258-64. [PMID: 27013697 DOI: 10.2967/jnumed.115.169045] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2015] [Accepted: 02/25/2016] [Indexed: 02/07/2023] Open
Abstract
UNLABELLED In this work, we assessed the feasibility of attenuation correction (AC) based on a multi-atlas-based method (m-Atlas) by comparing it with a clinical AC method (single-atlas-based method [s-Atlas]), on a time-of-flight (TOF) PET/MRI scanner. METHODS We enrolled 15 patients. The median patient age was 59 y (age range, 31-80). All patients underwent clinically indicated whole-body (18)F-FDG PET/CT for staging, restaging, or follow-up of malignant disease. All patients volunteered for an additional PET/MRI scan of the head (no additional tracer being injected). For each patient, 3 AC maps were generated. Both s-Atlas and m-Atlas AC maps were generated from the same patient-specific LAVA-Flex T1-weighted images being acquired by default on the PET/MRI scanner during the first 18 s of the PET scan. An s-Atlas AC map was extracted by the PET/MRI scanner, and an m-Atlas AC map was created using a Web service tool that automatically generates m-Atlas pseudo-CT images. For comparison, the AC map generated by PET/CT was registered and used as a gold standard. PET images were reconstructed from raw data on the TOF PET/MRI scanner using each AC map. All PET images were normalized to the SPM5 PET template, and (18)F-FDG accumulation was quantified in 67 volumes of interest (VOIs; automated anatomic labeling atlas). Relative (%diff) and absolute differences (|%diff|) between images based on each atlas AC and CT-AC were calculated. (18)F-FDG uptake in all VOIs and generalized merged VOIs were compared using the paired t test and Bland-Altman test. RESULTS The range of error on m-Atlas in all 1,005 VOIs was -4.99% to 4.09%. The |%diff| on the m-Atlas was improved by about 20% compared with s-Atlas (s-Atlas vs. m-Atlas: 1.49% ± 1.06% vs. 1.21% ± 0.89%, P < 0.01). In generalized VOIs, %diff on m-Atlas in the temporal lobe and cerebellum was significantly smaller (s-Atlas vs. m-Atlas: temporal lobe, 1.49% ± 1.37% vs. -0.37% ± 1.41%, P < 0.01; cerebellum, 1.55% ± 1.97% vs. -1.15% ± 1.72%, P < 0.01). CONCLUSION The errors introduced using either s-Atlas or m-Atlas did not exceed 5% in any brain region investigated. When compared with the clinical s-Atlas, m-Atlas is more accurate, especially in regions close to the skull base.
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Affiliation(s)
- Tetsuro Sekine
- Department of Nuclear Medicine, University Hospital Zurich, Zurich, Switzerland Department of Radiology, Nippon Medical School, Tokyo, Japan
| | - Ninon Burgos
- Translational Imaging Group, Centre for Medical Image Computing, University College London, NW1 2HE, London, United Kingdom
| | - Geoffrey Warnock
- Institute of Pharmacology & Toxicology, University of Zurich, Zurich, Switzerland PMOD Technologies Ltd., Zurich, Switzerland
| | - Martin Huellner
- Department of Nuclear Medicine, University Hospital Zurich, Zurich, Switzerland Department of Neuroradiology, University Hospital Zurich, Zurich, Switzerland
| | - Alfred Buck
- Department of Nuclear Medicine, University Hospital Zurich, Zurich, Switzerland
| | | | - M Jorge Cardoso
- Translational Imaging Group, Centre for Medical Image Computing, University College London, NW1 2HE, London, United Kingdom Dementia Research Centre, Institute of Neurology, University College London, WC1N 3AR London, United Kingdom
| | - Brian F Hutton
- Institute of Nuclear Medicine, University College London, NW1 2BU London, United Kingdom Centre for Medical Radiation Physics, University of Wollongong, NSW 2522 Wollongong, Australia
| | - Sebastien Ourselin
- Translational Imaging Group, Centre for Medical Image Computing, University College London, NW1 2HE, London, United Kingdom Dementia Research Centre, Institute of Neurology, University College London, WC1N 3AR London, United Kingdom
| | - Patrick Veit-Haibach
- Department of Nuclear Medicine, University Hospital Zurich, Zurich, Switzerland Division of Diagnostic and Interventional Radiology, Department of Medical Radiology, University Hospital Zurich, Zurich, Switzerland; and
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22
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Michels L, Warnock G, Buck A, Macauda G, Leh SE, Kaelin AM, Riese F, Meyer R, O'Gorman R, Hock C, Kollias S, Gietl AF. Arterial spin labeling imaging reveals widespread and Aβ-independent reductions in cerebral blood flow in elderly apolipoprotein epsilon-4 carriers. J Cereb Blood Flow Metab 2016; 36:581-95. [PMID: 26661143 PMCID: PMC4794091 DOI: 10.1177/0271678x15605847] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/09/2014] [Accepted: 10/07/2015] [Indexed: 12/11/2022]
Abstract
Changes in cerebral blood flow are an essential feature of Alzheimer's disease and have been linked to apolipoprotein E-genotype and cerebral amyloid-deposition. These factors could be interdependent or influence cerebral blood flow via different mechanisms. We examined apolipoprotein E-genotype, amyloid beta-deposition, and cerebral blood flow in amnestic mild cognitive impairment using pseudo-continuous arterial spin labeling MRI in 27 cognitively normal elderly and 16 amnestic mild cognitive impairment participants. Subjects underwent Pittsburgh Compound B (PiB) positron emission tomography and apolipoprotein E-genotyping. Global cerebral blood flow was lower in apolipoprotein E ɛ4-allele carriers (apolipoprotein E4+) than in apolipoprotein E4- across all subjects (including cognitively normal participants) and within the group of cognitively normal elderly. Global cerebral blood flow was lower in subjects with mild cognitive impairment compared with cognitively normal. Subjects with elevated cerebral amyloid-deposition (PiB+) showed a trend for lower global cerebral blood flow. Apolipoprotein E-status exerted the strongest effect on global cerebral blood flow. Regional analysis indicated that local cerebral blood flow reductions were more widespread for the contrasts apolipoprotein E4+ versus apolipoprotein E4- compared with the contrasts PiB+ versus PiB- or mild cognitive impairment versus cognitively normal. These findings suggest that apolipoprotein E-genotype exerts its impact on cerebral blood flow at least partly independently from amyloid beta-deposition, suggesting that apolipoprotein E also contributes to cerebral blood flow changes outside the context of Alzheimer's disease.
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Affiliation(s)
- Lars Michels
- Institute of Neuroradiology, University Hospital Zurich, Zurich, Switzerland Center of MR-Research, University Children's Hospital Zurich, Zurich, Switzerland
| | - Geoffrey Warnock
- Clinic of Nuclear Medicine, University Hospital Zurich, Zurich, Switzerland
| | - Alfred Buck
- Clinic of Nuclear Medicine, University Hospital Zurich, Zurich, Switzerland
| | - Gianluca Macauda
- Institute of Neuroradiology, University Hospital Zurich, Zurich, Switzerland Neuropsychology Unit, Department of Neurology, University Hospital Zurich, Zurich, Switzerland
| | - Sandra E Leh
- Division of Psychiatry Research and Psychogeriatric Medicine, University of Zurich, Zurich, Switzerland
| | - Andrea M Kaelin
- Division of Psychiatry Research and Psychogeriatric Medicine, University of Zurich, Zurich, Switzerland
| | - Florian Riese
- Division of Psychiatry Research and Psychogeriatric Medicine, University of Zurich, Zurich, Switzerland
| | - Rafael Meyer
- Division of Psychiatry Research and Psychogeriatric Medicine, University of Zurich, Zurich, Switzerland
| | - Ruth O'Gorman
- Center of MR-Research, University Children's Hospital Zurich, Zurich, Switzerland
| | - Christoph Hock
- Division of Psychiatry Research and Psychogeriatric Medicine, University of Zurich, Zurich, Switzerland
| | - Spyros Kollias
- Institute of Neuroradiology, University Hospital Zurich, Zurich, Switzerland
| | - Anton F Gietl
- Division of Psychiatry Research and Psychogeriatric Medicine, University of Zurich, Zurich, Switzerland
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Warnock G, Mackay A, Stenhouse P. The relationship between out of hours discharge and hospital outcome. Intensive Care Med Exp 2015. [PMCID: PMC4796732 DOI: 10.1186/2197-425x-3-s1-a360] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
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24
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Warnock G, Young L. A Review of Self-Poisoning Admissions in a Five-Bed Intensive Care Unit in Scotland. Intensive Care Med Exp 2015. [PMCID: PMC4796972 DOI: 10.1186/2197-425x-3-s1-a497] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
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25
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Warnock G. The relationship between time of admission and icu outcome. Intensive Care Med Exp 2015. [PMCID: PMC4797959 DOI: 10.1186/2197-425x-3-s1-a529] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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26
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Sekine T, Buck A, Delso G, Ter Voert EEGW, Huellner M, Veit-Haibach P, Warnock G. Evaluation of Atlas-Based Attenuation Correction for Integrated PET/MR in Human Brain: Application of a Head Atlas and Comparison to True CT-Based Attenuation Correction. J Nucl Med 2015; 57:215-20. [PMID: 26493207 DOI: 10.2967/jnumed.115.159228] [Citation(s) in RCA: 66] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2015] [Accepted: 10/07/2015] [Indexed: 11/16/2022] Open
Abstract
UNLABELLED Attenuation correction (AC) for integrated PET/MR imaging in the human brain is still an open problem. In this study, we evaluated a simplified atlas-based AC (Atlas-AC) by comparing (18)F-FDG PET data corrected using either Atlas-AC or true CT data (CT-AC). METHODS We enrolled 8 patients (median age, 63 y). All patients underwent clinically indicated whole-body (18)F-FDG PET/CT for staging, restaging, or follow-up of malignant disease. All patients volunteered for an additional PET/MR of the head (additional tracer was not injected). For each patient, 2 AC maps were generated: an Atlas-AC map registered to a patient-specific liver accelerated volume acquisition-Flex MR sequence and using a vendor-provided head atlas generated from multiple CT head images and a CT-based AC map. For comparative AC, the CT-AC map generated from PET/CT was superimposed on the Atlas-AC map. PET images were reconstructed from the list-mode raw data from the PET/MR imaging scanner using each AC map. All PET images were normalized to the SPM5 PET template, and (18)F-FDG accumulation was quantified in 67 volumes of interest (VOIs; automated anatomic labeling atlas). Relative difference (%diff) between images based on Atlas-AC and CT-AC was calculated, and averaged difference images were generated. (18)F-FDG uptake in all VOIs was compared using Bland-Altman analysis. RESULTS The range of error in all 536 VOIs was -3.0%-7.3%. Whole-brain (18)F-FDG uptake based on Atlas-AC was slightly underestimated (%diff = 2.19% ± 1.40%). The underestimation was most pronounced in the regions below the anterior/posterior commissure line, such as the cerebellum, temporal lobe, and central structures (%diff = 3.69% ± 1.43%, 3.25% ± 1.42%, and 3.05% ± 1.18%), suggesting that Atlas-AC tends to underestimate the attenuation values of the skull base bone. CONCLUSION When compared with the gold-standard CT-AC, errors introduced using Atlas-AC did not exceed 8% in any brain region investigated. Underestimation of (18)F-FDG uptake was minor (<4%) but significant in regions near the skull base.
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Affiliation(s)
- Tetsuro Sekine
- Department of Nuclear Medicine, University Hospital Zurich, Zurich, Switzerland University of Zurich, Zurich, Switzerland Department of Radiology, Nippon Medical School, Tokyo, Japan
| | - Alfred Buck
- Department of Nuclear Medicine, University Hospital Zurich, Zurich, Switzerland University of Zurich, Zurich, Switzerland
| | - Gaspar Delso
- Department of Nuclear Medicine, University Hospital Zurich, Zurich, Switzerland University of Zurich, Zurich, Switzerland GE Healthcare, Waukesha, Wisconsin
| | - Edwin E G W Ter Voert
- Department of Nuclear Medicine, University Hospital Zurich, Zurich, Switzerland University of Zurich, Zurich, Switzerland
| | - Martin Huellner
- Department of Nuclear Medicine, University Hospital Zurich, Zurich, Switzerland University of Zurich, Zurich, Switzerland Department of Neuroradiology, University Hospital Zurich, Zurich, Switzerland; and
| | - Patrick Veit-Haibach
- Department of Nuclear Medicine, University Hospital Zurich, Zurich, Switzerland University of Zurich, Zurich, Switzerland Division of Diagnostic and Interventional Radiology, Department of Medical Radiology, University Hospital Zurich, Zurich, Switzerland
| | - Geoffrey Warnock
- Department of Nuclear Medicine, University Hospital Zurich, Zurich, Switzerland University of Zurich, Zurich, Switzerland
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27
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Bretin F, Mauxion T, Warnock G, Bahri MA, Libert L, Lemaire C, Luxen A, Bardiès M, Seret A, Plenevaux A. Hybrid microPET imaging for dosimetric applications in mice: improvement of activity quantification in dynamic microPET imaging for accelerated dosimetry applied to 6-[18 F]fluoro-L-DOPA and 2-[18 F]fluoro-L-tyrosine. Mol Imaging Biol 2015; 16:383-94. [PMID: 24249641 DOI: 10.1007/s11307-013-0706-z] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
PURPOSE Dynamic microPET imaging has advantages over traditional organ harvesting, but is prone to quantification errors in small volumes. Hybrid imaging, where microPET activities are cross-calibrated using post scan harvested organs, can improve quantification. Organ harvesting, dynamic imaging and hybrid imaging were applied to determine the human and mouse radiation dosimetry of 6-[18 F]fluoro-L-DOPA and 2-[18 F]fluoro-L-tyrosine and compared. PROCEDURES Two-hour dynamic microPET imaging was performed with both tracers in four separate mice for 18 F-FDOPA and three mice for 18 F-FTYR. Organ harvesting was performed at 2, 5, 10, 30, 60 and 120 min post tracer injection with n = 5 at each time point for 18 F-FDOPA and n = 3 at each time point for 18 F-FTYR. Human radiation dosimetry projected from animal data was calculated for the three different approaches for each tracer using OLINDA/EXM. S-factors for the MOBY phantom were used to calculate the animal dosimetry. RESULTS Correlations between dose estimates based on organ harvesting and imaging was improved from r = 0.997 to r = 0.999 for 18 F-FDOPA and from r = 0.985 to r = 0.996 (p < 0.0001 for all) for 18 F-FTYR by using hybrid imaging. CONCLUSION Hybrid imaging yields comparable results to traditional organ harvesting while partially overcoming the limitations of pure imaging. It is an advantageous technique in terms of number of animals needed and labour involved.
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Affiliation(s)
- F Bretin
- Cyclotron Research Centre, University of Liege, Allée du 6 Août, Building B30, Sart Tilman, 4000, Liege, Belgium
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Riese F, Gietl A, Zölch N, Henning A, O'Gorman R, Kälin AM, Leh SE, Buck A, Warnock G, Edden RAE, Luechinger R, Hock C, Kollias S, Michels L. Posterior cingulate γ-aminobutyric acid and glutamate/glutamine are reduced in amnestic mild cognitive impairment and are unrelated to amyloid deposition and apolipoprotein E genotype. Neurobiol Aging 2014; 36:53-9. [PMID: 25169676 DOI: 10.1016/j.neurobiolaging.2014.07.030] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2014] [Revised: 07/18/2014] [Accepted: 07/23/2014] [Indexed: 02/08/2023]
Abstract
The biomarker potential of the inhibitory neurotransmitter γ-aminobutyric acid (GABA) for the in vivo characterization of preclinical stages in Alzheimer's disease has not yet been explored. We measured GABA, glutamate + glutamine (Glx), and N-acetyl-aspartate (NAA) levels by single-voxel MEGA-PRESS magnetic resonance spectroscopy in the posterior cingulate cortex of 21 elderly subjects and 15 patients with amnestic mild cognitive impairment. Participants underwent Pittsburgh Compound B positron emission tomography, apolipoprotein E (APOE) genotyping, and neuropsychological examination. GABA, Glx, and NAA levels were significantly lower in patients. NAA was lower in Pittsburgh Compound B-positive subjects and APOE ε4 allele carriers. GABA, Glx, and NAA levels were positively correlated to CERAD word learning scores. Reductions in GABA, Glx, and NAA levels may serve as metabolic biomarkers for cognitive impairment in amnestic mild cognitive impairment. Because GABA and Glx do not seem to reflect amyloid β deposition or APOE genotype, they are less likely biomarker candidates for preclinical Alzheimer's disease.
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Affiliation(s)
- Florian Riese
- Division of Psychiatry Research and Psychogeriatric Medicine, University of Zurich, Zurich, Switzerland
| | - Anton Gietl
- Division of Psychiatry Research and Psychogeriatric Medicine, University of Zurich, Zurich, Switzerland
| | - Niklaus Zölch
- Institute of Biomedical Engineering, University and ETH Zurich, Zurich, Switzerland
| | - Anke Henning
- Institute of Biomedical Engineering, University and ETH Zurich, Zurich, Switzerland; Max-Planck Institute for Biological Cybernetics, Tübingen, Germany
| | - Ruth O'Gorman
- Center of MR-Research, University Children's Hospital Zurich, Zurich, Switzerland
| | - Andrea M Kälin
- Division of Psychiatry Research and Psychogeriatric Medicine, University of Zurich, Zurich, Switzerland
| | - Sandra E Leh
- Division of Psychiatry Research and Psychogeriatric Medicine, University of Zurich, Zurich, Switzerland
| | - Alfred Buck
- Institute of Nuclear Medicine, University Hospital Zurich, Zurich, Switzerland
| | - Geoffrey Warnock
- Institute of Nuclear Medicine, University Hospital Zurich, Zurich, Switzerland
| | - Richard A E Edden
- Russell H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins University School of Medicine, Baltimore, MD, USA; F.M. Kirby Center for Functional Brain Imaging, Kenneddy Krieger Institute, Baltimore, MD, USA
| | - Roger Luechinger
- Institute of Biomedical Engineering, University and ETH Zurich, Zurich, Switzerland
| | - Christoph Hock
- Division of Psychiatry Research and Psychogeriatric Medicine, University of Zurich, Zurich, Switzerland
| | - Spyros Kollias
- Clinic of Neuroradiology, University Hospital Zurich, Zurich, Switzerland
| | - Lars Michels
- Clinic of Neuroradiology, University Hospital Zurich, Zurich, Switzerland.
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Riese F, Gietl A, Zölch N, Henning A, O'Gorman R, Kälin AM, Leh SE, Buck A, Warnock G, Luechinger R, Hock C, Kollias S, Michels L. P3‐225: POSTERIOR CINGULATE GABA AND GLX ARE REDUCED IN AMNESTIC MILD COGNITIVE IMPAIRMENT. Alzheimers Dement 2014. [DOI: 10.1016/j.jalz.2014.05.1316] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Affiliation(s)
| | | | | | | | - Ruth O'Gorman
- University Children's Hospital ZurichZurichSwitzerland
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Goetti R, Warnock G, Kuhn FP, Guggenberger R, O'Gorman R, Buck A, Khan N, Scheer I. Quantitative cerebral perfusion imaging in children and young adults with Moyamoya disease: comparison of arterial spin-labeling-MRI and H(2)[(15)O]-PET. AJNR Am J Neuroradiol 2013; 35:1022-8. [PMID: 24335546 DOI: 10.3174/ajnr.a3799] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
BACKGROUND AND PURPOSE Cerebral perfusion assessment is important in the preoperative evaluation and postoperative follow-up of patients with Moyamoya disease. The objective of this study was to evaluate the correlation of quantitative CBF measurements performed with arterial spin-labeling-MR imaging and H2[(15)O]-PET in children and young adults with Moyamoya disease. MATERIALS AND METHODS Thirteen children and young adults (8 female patients; age, 9.7 ± 7.1 years; range, 1-23 years) with Moyamoya disease underwent cerebral perfusion imaging with H2[(15)O]-PET (Discovery STE PET/CT, 3D Fourier rebinning filtered back-projection, 128 × 128 × 47 matrix, 2.34 × 2.34 × 3.27 mm(3) voxel spacing) and arterial spin-labeling (3T scanner, 3D pulsed continuous arterial spin-labeling sequence, 32 axial sections, TR = 5.5 seconds, TE = 25 ms, FOV = 24 cm, 128 × 128 matrix, 1.875 × 1.875 × 5 mm(3) voxel spacing) within less than 2 weeks of each other. Perfusion of left and right anterior cerebral artery, MCA, and posterior cerebral artery territories was qualitatively assessed for arterial spin-labeling-MR imaging and H2[(15)O]-PET by 2 independent readers by use of a 3-point-Likert scale. Quantitative correlation of relative CBF with cerebellar normalization between arterial spin-labeling-MR imaging and H2[(15)O]-PET was evaluated in a volume-based approach for each vascular territory after 3D image coregistration. RESULTS Interreader agreement was good (κ = 0.67-0.69), and strong and significant correlations were found between arterial spin-labeling-MR imaging and H2[(15)O]-PET for both qualitative perfusion scoring (ρ = 0.77; P < .001) and quantitative perfusion assessment of relative CBF with cerebellar normalization (r = 0.67, P < .001). CONCLUSIONS In children and young adults with Moyamoya disease, quantitative evaluation of CBF is possible with the use of arterial spin-labeling-MR imaging without ionizing radiation or contrast injection with a good correlation to H2[(15)O]-PET after cerebellar normalization.
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Affiliation(s)
- R Goetti
- From the Departments of Diagnostic Imaging (R. Goetti, R. Guggenberger, I.S.)Diagnostic and Interventional Radiology (R. Goetti, F.P.K., R. Guggenberger)
| | - G Warnock
- Nuclear Medicine (G.W., F.P.K., A.B.)
| | - F P Kuhn
- Diagnostic and Interventional Radiology (R. Goetti, F.P.K., R. Guggenberger)Nuclear Medicine (G.W., F.P.K., A.B.)
| | - R Guggenberger
- From the Departments of Diagnostic Imaging (R. Goetti, R. Guggenberger, I.S.)Diagnostic and Interventional Radiology (R. Goetti, F.P.K., R. Guggenberger)
| | | | - A Buck
- Nuclear Medicine (G.W., F.P.K., A.B.)
| | - N Khan
- the Moyamoya Center, Division of Neurosurgery, Department of Surgery (N.K.), University Children's Hospital Zurich, Zurich, Switzerland
| | - I Scheer
- From the Departments of Diagnostic Imaging (R. Goetti, R. Guggenberger, I.S.)
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Salmon E, Bahri MA, Aerts J, Warnock G, Buchanan T, Bretin F, Giacomelli F, Mestdagh N, Mella C, Mievis F, Valade A, Luxen A, Plenevaux A. P2–174: Development of a new PET biomarker for synaptic function. Alzheimers Dement 2013. [DOI: 10.1016/j.jalz.2013.05.819] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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Bretin F, Warnock G, Bahri MA, Aerts J, Mestdagh N, Buchanan T, Valade A, Mievis F, Giacomelli F, Lemaire C, Luxen A, Salmon E, Seret A, Plenevaux A. Preclinical radiation dosimetry for the novel SV2A radiotracer [18F]UCB-H. EJNMMI Res 2013; 3:35. [PMID: 23647774 PMCID: PMC3655042 DOI: 10.1186/2191-219x-3-35] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2013] [Accepted: 04/20/2013] [Indexed: 11/10/2022] Open
Abstract
Background [18F]UCB-H was developed as a novel radiotracer with a high affinity for synaptic vesicle protein 2A, the binding site for the antiepileptic levetiracetam. The objectives of this study were to evaluate the radiation dosimetry of [18F]UCB-H in a preclinical trial and to determine the maximum injectable dose according to guidelines for human biomedical research. The radiation dosimetry was derived by organ harvesting and dynamic micro positron emission tomography (PET) imaging in mice, and the results of both methods were compared. Methods Twenty-four male C57BL-6 mice were injected with 6.96 ± 0.81 MBq of [18F]UCB-H, and the biodistribution was determined by organ harvesting at 2, 5, 10, 30, 60, and 120 min (n = 4 for each time point). Dynamic microPET imaging was performed on five male C57BL-6 mice after the injection of 9.19 ± 3.40 MBq of [18F]UCB-H. A theoretical dynamic bladder model was applied to simulate urinary excretion. Human radiation dose estimates were derived from animal data using the International Commission on Radiological Protection 103 tissue weighting factors. Results Based on organ harvesting, the urinary bladder wall, liver and brain received the highest radiation dose with a resulting effective dose of 1.88E-02 mSv/MBq. Based on dynamic imaging an effective dose of 1.86E-02 mSv/MBq was calculated, with the urinary bladder wall and liver (brain was not in the imaging field of view) receiving the highest radiation. Conclusions This first preclinical dosimetry study of [18F]UCB-H showed that the tracer meets the standard criteria for radiation exposure in clinical studies. The dose-limiting organ based on US Food and Drug Administration (FDA) and European guidelines was the urinary bladder wall for FDA and the effective dose for Europe with a maximum injectable single dose of approximately 325 MBq was calculated. Although microPET imaging showed significant deviations from organ harvesting, the Pearson’s correlation coefficient between radiation dosimetry derived by either method was 0.9666.
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Affiliation(s)
- Florian Bretin
- Cyclotron Research Centre, University of Liège, Allée du 6 Août, Building B30, Sart Tilman, Liège 4000, Belgium.
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Kim SJ, Widenmaier SB, Choi WS, Nian C, Ao Z, Warnock G, McIntosh CHS. Pancreatic β-cell prosurvival effects of the incretin hormones involve post-translational modification of Kv2.1 delayed rectifier channels. Cell Death Differ 2011; 19:333-44. [PMID: 21818121 DOI: 10.1038/cdd.2011.102] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
Glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide-1 (GLP-1) are the major incretin hormones that exert insulinotropic and anti-apoptotic actions on pancreatic β-cells. Insulinotropic actions of the incretins involve modulation of voltage-gated potassium (Kv) channels. In multiple cell types, Kv channel activity has been implicated in cell volume changes accompanying initiation of the apoptotic program. Focusing on Kv2.1, we examined whether regulation of Kv channels in β-cells contributes to the prosurvival effects of incretins. Overexpression of Kv2.1 in INS-1 β-cells potentiated apoptosis in response to mitochondrial and ER stress and, conversely, co-stimulation with GIP/GLP-1 uncoupled this potentiation, suppressing apoptosis. In parallel, incretins promoted phosphorylation and acetylation of Kv2.1 via pathways involving protein kinase A (PKA)/mitogen- and stress-activated kinase-1 (MSK-1) and histone acetyltransferase (HAT)/histone deacetylase (HDAC). Further studies demonstrated that acetylation of Kv2.1 was mediated by incretin actions on nuclear/cytoplasmic shuttling of CREB binding protein (CBP) and its interaction with Kv2.1. Regulation of β-cell survival by GIP and GLP-1 therefore involves post-translational modifications (PTMs) of Kv channels by PKA/MSK-1 and HAT/HDAC. This appears to be the first demonstration of modulation of delayed rectifier Kv channels contributing to the β-cell prosurvival effects of incretins and of 7-transmembrane G protein-coupled receptor (GPCR)-stimulated export of a nuclear lysine acetyltransferase that regulates cell surface ion channel function.
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Affiliation(s)
- S-J Kim
- Departments of Cellular & Physiological Sciences and the Diabetes Research Group, Life Sciences Institute, University of British Columbia, 2350 Health Sciences Mall, Vancouver, BC, Canada
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Aerts J, Voccia S, Lemaire C, Giacomelli F, Goblet D, Thonon D, Plenevaux A, Warnock G, Luxen A. Fast production of highly concentrated reactive [18F] fluoride for aliphatic and aromatic nucleophilic radiolabelling. Tetrahedron Lett 2010. [DOI: 10.1016/j.tetlet.2009.10.085] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Bahri MA, Plenevaux A, Warnock G, Luxen A, Seret A. NEMA NU4-2008 Image Quality Performance Report for the microPET Focus 120 and for Various Transmission and Reconstruction Methods. J Nucl Med 2009; 50:1730-8. [DOI: 10.2967/jnumed.109.063974] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
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Konstantoulas CJ, Cooper J, Warnock G, Miller GJ, Humphries SE, Ireland H. A combination of two common thrombomodulin gene variants (-1208-1209TTdelTT and A455V) influence risk of coronary heart disease: a prospective study in men. Atherosclerosis 2005; 177:97-104. [PMID: 15488871 DOI: 10.1016/j.atherosclerosis.2004.05.032] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/16/2003] [Revised: 05/26/2004] [Accepted: 05/28/2004] [Indexed: 10/26/2022]
Abstract
In a previous case control study of myocardial infarction (MI), we identified risk associated with the combination of two variants in the thrombomodulin (TM) gene (-1208-1209TTdelTT and A455V) and an interaction with increased body mass index (BMI). The rare alleles at these two common variant sites in the TM gene occur in most individuals on the same allele (V/delTT) and are in strong linkage disequilibrium (Delta=0.67, P <0.0005). We have extended these findings in a prospective study of 2700 UK middle age men; the second Northwick Park Heart Study (NPHSII), in which 227 coronary heart disease (CHD) events have been reported to date. Risk was analysed by tertile of BMI, systolic blood pressure (SBP) and triglyceride. The strongest risk for the V/delTT haplotype was in the mid- and top-tertile of triglyceride; RR 1.95 (CI 1.12-3.40) and 1.77 (CI 1.02-3.09), respectively, compared to non-carriers in the lowest tertile (after adjusting for age, practice, smoking, SBP, BMI; interaction P=0.016). No significant risk was identified for increased triglyceride levels in those with the common TM haplotype. There was a suggestion for greater inflammatory response (C-reactive protein levels, CRP) in those with V/delTT compared to those with the common allele, as triglyceride levels increased. Overall, these findings may suggest that the common TM allele confers protection against the adverse CHD effect of either plasma triglyceride-containing lipoproteins, or the underlying atherosclerotic mechanism of the metabolic syndrome, and that this process is defective in carriers of V/delTT.
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Affiliation(s)
- C J Konstantoulas
- British Heart Foundation Laboratories, Department of Medicine, Center for Cardiovascular Genetics, Royal Free and University College London Medical School, Rayne Building, London WC1E 6JF, UK
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Abstract
Dermoid cysts are rare developmental teratomatous lesions composed of ectodermally derived stratified squamous epithelium and mesodermally derived skin adnexal structures. As part of the teratomatous lesion group, dermoid cysts are related to teratoid cysts, true teratomas, and epignathi. Although several theories have been postulated, the pathogenesis of dermoid cysts, and teratomatous lesions in general, is unclear. Most commonly affecting sites within the head and neck, dermoid cysts may be found in the frontotemporal/lateral brow area, central nasal area, oral cavity, lateral neck, and other sites. We present what is believed to be the first reported case arising within the maxillary sinus and briefly discuss the possible pathogenesis.
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Affiliation(s)
- K R Torske
- Department of Otolaryngic/Endocrine Pathology, Armed Forces Institute of Pathology, Washington, DC 20306-6000, USA
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Abstract
The smaller form of the autoantigen glutamic acid decarboxylase, GAD65 (formerly the 64,000 M(r) autoantigen), is a major target of humoral autoimmunity in type I diabetes. Human autoantisera have been used extensively to characterize the GAD65 antigen in both rat and human islets, but the protein has escaped detection in mouse islets. We have now analyzed the expression of GAD65 and GAD67, the larger glutamic acid decarboxylase protein, in human, rat, and mouse islets of Langerhans and brain, using human monoclonal islet cell autoantibodies, human autoantisera, and experimentally raised antibodies to glutamic acid decarboxylase. Human monoclonal autoantibodies and experimentally raised antibodies reacted with mouse GAD65 produced in a baculovirus expression system by Western blotting and immunoprecipitation and with GAD65 in mouse brain by immunohistochemistry but failed to detect GAD65 in mouse islets by the latter two methods. However, analysis of mouse islets by Western blotting technique, using the most sensitive experimentally raised antibody, showed that mouse islets express both GAD65 and GAD67 but at levels that are severalfold lower than those in mouse brain or in human and rat islets. Furthermore, both human and rat islets predominantly express GAD65, whereas GAD67 is the major glutamic acid decarboxylase protein in mouse islets. Human islets are significantly distinct from mouse and rat islets and from brain because they only express GAD65, which is consistent with the predominant role of this form as a target of autoantibodies associated with beta-cell destruction in humans. Human as well as rat islet GAD65 are found in both membrane-bound and soluble forms. The low level of glutamic acid decarboxylase expression in mouse islets compared with human and rat islets is likely to have implications for both the development of tolerance to glutamic acid decarboxylase as well as the homing of glutamic acid decarboxylase-specific lymphocytes to the mouse beta-cell. In this context, the results suggest 1) that the mouse is ideal for studies of the consequences of an expression of high levels of glutamic acid decarboxylase in the beta-cell from a transgene and 2) that the rat may be better suited than the mouse for development of nontransgenic animal models of glutamic acid decarboxylase autoimmunity by immunization.
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Affiliation(s)
- J Kim
- Department of Medicine, University of California at San Francisco 94143-0534
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Bärmeier H, Ahlmén J, Landin-Olsson M, Rajotte RV, Sundkvist G, Warnock G, Lernmark A. Quantitative analysis of islet glutamic acid decarboxylase p64 autoantibodies in insulin-dependent diabetes mellitus. Autoimmunity 1992; 13:187-96. [PMID: 1472630 DOI: 10.3109/08916939209004823] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Autoantibodies against the beta-cell M(r) 64,000 protein (p64), recently identified as an isoform of glutamic acid decarboxylase (GAD), are prevalent in patients with insulin-dependent diabetes mellitus (IDDM). Dog islets were found to represent an abundant source of native p64 allowing the study of antigen-antibody interactions in IDDM. A quantitative, standardized assay for p64 antibodies based on dog islets was developed and evaluated. Utilizing dog and human islets the p64 antibodies were detected in 17/19 (89%) new onset 15-32-year-old patients, compared to 15/19 (79%) in a rat islet assay. ICA were detected in 15/19 (79%) patients and correlated with the presence of p64 antibodies (rs = 0.59, P < 0.004) but not with age at onset, sex, or C-peptide levels. Sensitivity therefore is improved with the dog islet p64 antibody assay which will allow future studies requiring native p64 antigen in larger quantities are possible based on our findings.
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Affiliation(s)
- H Bärmeier
- Dept. of Medicine, University of Washington, Seattle
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Bärmeier H, McCulloch DK, Neifing JL, Warnock G, Rajotte RV, Palmer JP, Lernmark A. Risk for developing type 1 (insulin-dependent) diabetes mellitus and the presence of islet 64K antibodies. Diabetologia 1991; 34:727-33. [PMID: 1959705 DOI: 10.1007/bf00401518] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
First-degree relatives of Type 1 (insulin-dependent) diabetic patients are at increased risk for developing clinical diabetes. The presence of islet cell or insulin autoantibodies further identifies relatives at greater risk, but not all immunologic-marker-positive relatives progress to disease. Beta-cell dysfunction, however, seems to be more prevalent than clinical Type 1 diabetes, since stable subclinical pancreatic Beta-cell dysfunction may occur. Antibodies against a Mr 64,000 (64K) islet Beta-cell protein, identified as glutamic acid decarboxylase, have been reported both at and several years prior to the clinical onset of Type 1 diabetes. We measured 64K antibodies in first-degree relatives with varying degrees of Beta-cell dysfunction and risk for subsequent Type 1 diabetes to determine whether 64K antibodies improve the predictive power of islet cell antibodies and/or insulin autoantibodies. In the Seattle Family Study first-degree relatives of Type 1 diabetic patients are followed prospectively using detailed Beta-cell function tests, insulin sensitivity, quantitative evaluation of islet cell antibodies and fluid phase assay insulin autoantibodies. 64K antibodies were measured using dog islets. Relatives were selected, based on Beta-cell function to represent individuals at high (n = 6) and low (n = 30) risk for subsequent Type 1 diabetes. The 30 low-risk individuals followed-up for 78 months, had stable Beta-cell function, and six (20%) were negative for all autoantibodies, ten (33%) were positive for insulin autoantibodies, 16 (53%) were islet cell antibody positive while six (20%) were positive for 64K antibodies.(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- H Bärmeier
- Department of Medicine, University of Washington, Seattle
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Baekkeskov S, Warnock G, Christie M, Rajotte RV, Larsen PM, Fey S. Revelation of specificity of 64K autoantibodies in IDDM serums by high-resolution 2-D gel electrophoresis. Unambiguous identification of 64K target antigen. Diabetes 1989; 38:1133-41. [PMID: 2670643 DOI: 10.2337/diab.38.9.1133] [Citation(s) in RCA: 45] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Antibodies in serums from newly diagnosed insulin-dependent (type I) diabetes mellitus (IDDM) patients and individuals experiencing early phases of beta-cell destruction specifically immunoprecipitate a minor pancreatic islet cell membrane protein of 64,000 Mr (64K). In this report, we demonstrate the use of two-dimensional (2-D) gel electrophoresis to unambiguously identify the 64K antigen. By nonequilibrium pH-gradient gel electrophoresis in the first dimension and sodium dodecyl sulphate-polyacrylamide gel electrophoresis in the second dimension, the 64K protein separates into two components, designated alpha and beta, that differ in size but display identical charge heterogeneity. The high resolution of the 2-D method efficiently separates the 64K components from background proteins in immunoprecipitates from crude detergent lysates of islets. The background proteins were identified as major cellular proteins carried nonspecifically through the immunoprecipitation procedure. The high affinity and specificity of the 64K autoantibodies were demonstrated by the exclusive and greater than 1000-fold purification of this minor protein by immunoprecipitation with IDDM serums. The 2-D analyses did not reveal additional proteins specifically immunoprecipitated by IDDM serums, suggesting that the 64K protein is the only protein antigen specifically and consistently recognized by IDDM autoantibodies in the relatively stringent conditions of immunoprecipitation. Moreover, the 2-D analyses demonstrate that purification of membrane protein fractions from both human and rat islets before the immunoprecipitation efficiently removes background proteins and substantially increases the specificity of 64K autoantibody measurements by traditional methods.
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Warnock G, Corio RL. The odontogenic tumors. Ear Nose Throat J 1984; 63:338-46. [PMID: 6468314] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
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