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Fallanca F, Giovacchini G, Ponzoni M, Gianolli L, Ciceri F, Fazio F. Cervical thymic hyperplasia after chemotherapy in an adult patient with Hodgkin lymphoma: a potential cause of false-positivity on [18F]FDG PET/CT scanning. Br J Haematol 2008; 140:477. [DOI: 10.1111/j.1365-2141.2007.06901.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Giovacchini G, Picchio M, Coradeschi E, Scattoni V, Bettinardi V, Cozzarini C, Freschi M, Fazio F, Messa C. [(11)C]choline uptake with PET/CT for the initial diagnosis of prostate cancer: relation to PSA levels, tumour stage and anti-androgenic therapy. Eur J Nucl Med Mol Imaging 2008; 35:1065-73. [PMID: 18200444 DOI: 10.1007/s00259-008-0716-2] [Citation(s) in RCA: 149] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2007] [Accepted: 12/26/2007] [Indexed: 11/24/2022]
Abstract
PURPOSE The accuracy of positron emission tomography (PET)/CT with [(11)C]choline for the detection of prostate cancer is not well established. We assessed the dependence of [(11)C]choline maximum standardized uptake values (SUV(max)) in the prostate gland on cell malignancy, prostate-specific antigen (PSA) levels, Gleason score, tumour stage and anti-androgenic hormonal therapy. METHODS In this prospective study, PET/CT with [(11)C]choline was performed in 19 prostate cancer patients who subsequently underwent prostatectomy with histologic sextant analysis (group A) and in six prostate cancer patients before and after anti-androgenic hormonal therapy (bicalutamide 150 mg/day; median treatment of 4 months; group B). RESULTS In group A, based on a sextant analysis with a [(11)C]choline SUV(max) cutoff of 2.5 (as derived from a receiver-operating characteristic analysis), PET/CT showed sensitivity, specificity, positive predictive value, negative predictive value and accuracy of 72, 43, 64, 51 and 60%, respectively. In the patient-by-patient analysis, no significant correlation was detected between SUV(max) and PSA levels, Gleason score or pathological stage. On the contrary, a significant (P < 0.05) negative correlation was detected between SUV(max) and anti-androgenic therapy both in univariate (r (2) = 0.24) and multivariate (r (2) = 0.48) analyses. Prostate [(11)C]choline uptake after bicalutamide therapy significantly (P < 0.05) decreased compared to baseline (6.4 +/- 4.6 and 11.8 +/- 5.3, respectively; group B). CONCLUSION PET/CT with [(11)C]choline is not suitable for the initial diagnosis and local staging of prostate cancer. PET/CT with [(11)C]choline could be used to monitor the response to anti-androgenic therapy.
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Hasler G, Bonwetsch R, Giovacchini G, Toczek MT, Bagic A, Luckenbaugh DA, Drevets WC, Theodore WH. 5-HT1A receptor binding in temporal lobe epilepsy patients with and without major depression. Biol Psychiatry 2007; 62:1258-64. [PMID: 17588547 PMCID: PMC2170875 DOI: 10.1016/j.biopsych.2007.02.015] [Citation(s) in RCA: 102] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/06/2006] [Revised: 02/08/2007] [Accepted: 02/10/2007] [Indexed: 11/17/2022]
Abstract
BACKGROUND Major depressive disorder (MDD) is the most common comorbid psychiatric condition associated with temporal lobe epilepsy (TLE). Preclinical and clinical studies suggest that 5-HT(1A) receptors play a role in the pathophysiology of both TLE and MDD. There is preliminary evidence for an association between decreased 5-HT(1A) receptor binding in limbic brain areas and affective symptoms in TLE patients. The objective of this study was to compare 5-HT(1A) receptor binding between TLE patients with and without MDD. For the first time, 5-HT(1A) receptor binding was measured in a sample large enough to permit sensitive comparisons between TLE patients with and without comorbid MDD diagnosed by clinical and structured psychiatric interviews. METHODS Thirty-seven epilepsy patients with temporal lobe foci confirmed by ictal video-electroencephalogram (EEG) monitoring were recruited from the Clinical Epilepsy Section, National Institute of Neurological Disorders and Stroke. We performed interictal positron emission tomography scanning, with [(18)F]FCWAY, a fluorinated derivative of WAY100635, on a GE Medical Systems (Waukesha, Wisconsin) Advance scanner with continuous EEG monitoring. The 5-HT(1A) receptor binding was estimated by partial volume-corrected [(18)F]FCWAY V/f(1) values. RESULTS In addition to decreased 5-HT(1A) receptor binding in the epileptic focus itself, comorbid MDD was associated with a significantly more pronounced reduction in 5-HT(1A) receptor binding in TLE patients, extending into non-lesional limbic brain areas outside the epileptic focus. Focus side and the presence of mesial temporal sclerosis were not associated with the presence of comorbid depression. CONCLUSIONS Reductions in 5-HT(1A) receptor binding might help elucidate the neurobiological mechanisms underlying the TLE-MDD comorbidity.
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Giovacchini G, Bonwetsch R, Herscovitch P, Carson RE, Theodore WH. Cerebral blood flow in temporal lobe epilepsy: a partial volume correction study. Eur J Nucl Med Mol Imaging 2007; 34:2066-72. [PMID: 17768621 DOI: 10.1007/s00259-007-0499-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2007] [Accepted: 05/25/2007] [Indexed: 11/27/2022]
Abstract
PURPOSE Previous studies in temporal lobe epilepsy (TLE) have shown that, owing to brain atrophy, positron emission tomography (PET) can overestimate deficits in measures of cerebral function such as glucose metabolism (CMR(glu)) and neuroreceptor binding. The magnitude of this effect on cerebral blood flow (CBF) is unexplored. The aim of this study was to assess CBF deficits in TLE before and after magnetic resonance imaging-based partial volume correction (PVC). METHODS Absolute values of CBF for 21 TLE patients and nine controls were computed before and after PVC. In TLE patients, quantitative CMR(glu) measurements also were obtained. RESULTS Before PVC, regional values of CBF were significantly (p<0.05) lower in TLE patients than in controls in all regions, except the fusiform gyrus contralateral to the epileptic focus. After PVC, statistical significance was maintained in only four regions: ipsilateral inferior temporal cortex, bilateral insula and contralateral amygdala. There was no significant difference between patients and controls in CBF asymmetry indices (AIs) in any region before or after PVC. In TLE patients, AIs for CBF were significantly smaller than for CMR(glu) in middle and inferior temporal cortex, fusiform gyrus and hippocampus both before and after PVC. A significant positive relationship between disease duration and AIs for CMR(glu), but not CBF, was detected in hippocampus and amygdala, before but not after PVC. CONCLUSION PVC should be used for PET CBF measurements in patients with TLE. Reduced blood flow, in contrast to glucose metabolism, is mainly due to structural changes.
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Bettinardi V, Mancosu P, Danna M, Giovacchini G, Landoni C, Picchio M, Gilardi MC, Savi A, Castiglioni I, Lecchi M, Fazio F. Two-dimensional vs three-dimensional imaging in whole body oncologic PET/CT: a Discovery-STE phantom and patient study. THE QUARTERLY JOURNAL OF NUCLEAR MEDICINE AND MOLECULAR IMAGING : OFFICIAL PUBLICATION OF THE ITALIAN ASSOCIATION OF NUCLEAR MEDICINE (AIMN) [AND] THE INTERNATIONAL ASSOCIATION OF RADIOPHARMACOLOGY (IAR), [AND] SECTION OF THE SOCIETY OF... 2007; 51:214-23. [PMID: 17464266] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
AIM To evaluate the performance of the positron emission tomography (PET)/computed tomography (CT) Discovery-STE (D-STE) scanner for lesion detectability in two-dimensional (2D) and three-dimensional (3D) acquisition. METHODS A NEMA 2001 Image-Quality phantom with 11 lesions (7-37 mm in diameter) filled with a solution of 18F (lesion/background concentration ratio: 4.4) was studied. 2D and 3D PET scans were sequentially acquired (10 min each) in list mode (LM). Each scan was unlisted into 4, 3 and 2-min scans. Ten [18F]FDG PET oncological patient studies were also evaluated. Each patient underwent a 3D PET/CT whole body scan, followed by a 2D PET scan (4 min LM) and a 3D PET scan (4 min LM) over a single field of view. Both 2D and 3D scans were unlisted in 3 and 2-min scans. Data were evaluated quantitatively by calculating quality measurements and qualitatively by two physicians who judged lesion detectability compared to statistical variations in background activity. RESULTS Quantitative and qualitative evaluations showed the superiority of 3D over 2D across all measures of quality. In particular, lesion detectability was better in 3D than in 2D at equal scan times and 3D acquisition provided images comparable in quality to 2D in approximately half the time. Interobserver variability was lower in evaluation of 3D scans and lesion shape and volume were better depicted. CONCLUSION In oncological applications, the D-STE system demonstrated good performance in 2D and 3D acquisition, while 3D exhibited better image quality, data accuracy and consistency of lesion detectability, resulting in shorter scan times and higher patient throughput.
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Mansueto M, Grimaldi A, Torbica A, Pepe G, Giovacchini G, Messa C, Fazio F. Cost-effectiveness analysis in the clinical management of patients with known or suspected lung cancer: [18F]fluorodeoxyglucose PET and CT comparison. THE QUARTERLY JOURNAL OF NUCLEAR MEDICINE AND MOLECULAR IMAGING : OFFICIAL PUBLICATION OF THE ITALIAN ASSOCIATION OF NUCLEAR MEDICINE (AIMN) [AND] THE INTERNATIONAL ASSOCIATION OF RADIOPHARMACOLOGY (IAR), [AND] SECTION OF THE SOCIETY OF... 2007; 51:224-34. [PMID: 17538525] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
AIM The aim of this study was to evaluate the economic impact of the introduction of positron emission tomography (PET) in the clinical management of patients with known or suspected lung cancer through a cost-effectiveness analysis of different diagnostic strategies. METHODS In Italy, 75 patients with known or suspected lung cancer were included in the study. Three different diagnostic strategies were compared: 1) baseline or traditional strategy, i.e. computed tomography (CT) alone; 2) strategy A, i.e. PET for indefinite CT; 3) strategy B, i.e. PET for all. For each strategy expected costs and life expectancy, as measured by life year saved (LYS), were evaluated. Incremental cost-effectiveness ratio (ICER) was calculated to identify the most effective strategy. RESULTS Compared to the baseline strategy, the introduction of PET changed the clinical management in 40% of cases in strategy A and in 51% of cases in strategy B, with an optimization of the clinical management. Costs of strategy A (2735.42 Euro) and strategy B (2984.52 Euro) were, respectively, 8% and 18% higher than the baseline strategy (2534.81 Euro). LYS was 2.04 and 2.64 for strategy A and B, which were, respectively, 4% and 35% higher than the baseline strategy (1.96 LYS). The ICERs were 2507.63 Euro/LYS and 415.17 Euro/LYS for strategy A and B, respectively. Strategy A is dominated by strategy B, which is more expensive, but also more effective. CONCLUSION In Italy, the introduction of PET in the clinical management of all patients with known or suspected lung cancer previously evaluated with CT is cost-effective and allows to gain 2.64 life years at an annual cost of about 415 Euro.
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Theodore WH, Hasler G, Giovacchini G, Kelley K, Reeves-Tyer P, Herscovitch P, Drevets W. Reduced Hippocampal 5HT1A PET Receptor Binding and Depression in Temporal Lobe Epilepsy. Epilepsia 2007; 48:1526-30. [PMID: 17442003 DOI: 10.1111/j.1528-1167.2007.01089.x] [Citation(s) in RCA: 74] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
PURPOSE To study the relation of hippocampal 5HT1A receptor binding to symptoms of depression in patients with temporal lobe epilepsy. Depression is common in people with epilepsy, and reduced 5HT1A binding has been reported in patients with primary depressive disorders. METHODS We studied 45 patients with temporal lobe epilepsy confirmed by ictal video-EEG recording. Mood was assessed with the Beck Depression Inventory (BDI). Positron emission tomographic measurement of 5HT1A receptors was performed with 18F-FCWAY, a highly specific silent antagonist. 3D-T1-weighted MRI was used to correct for structural atrophy. Receptor distribution volume (V) was corrected for plasma tracer free fraction (f1). RESULTS There was a significant inverse relation between ipsilateral hippocampal v/f1 and the BDI. For contralateral hippocampus, there was a nonsignificant trend. Patients with BDI > 20 had significantly lower ipsilateral hippocampal V/f1 than patients in the low and medium groups. There was no significant effect of the presence of mesial temporal sclerosis, focus laterality, or gender on the BDI. CONCLUSIONS Our study shows a relationship between hippocampal 5HT1A binding and depressive symptoms measured by the BDI in patients with epilepsy. The findings parallel results in patients with MDD.
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Esposito G, Giovacchini G, Der M, Liow JS, Bhattacharjee AK, Ma K, Herscovitch P, Channing M, Eckelman WC, Hallett M, Carson RE, Rapoport SI. Imaging signal transduction via arachidonic acid in the human brain during visual stimulation, by means of positron emission tomography. Neuroimage 2006; 34:1342-51. [PMID: 17196833 PMCID: PMC2040045 DOI: 10.1016/j.neuroimage.2006.11.018] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2006] [Revised: 10/20/2006] [Accepted: 11/01/2006] [Indexed: 10/23/2022] Open
Abstract
BACKGROUND Arachidonic acid (AA, 20:4n-6), an important second messenger, is released from membrane phospholipid following receptor mediated activation of phospholipase A(2) (PLA(2)). This signaling process can be imaged in brain as a regional brain AA incorporation coefficient K*. HYPOTHESIS K* will be increased in brain visual areas of subjects submitted to visual stimulation. SUBJECTS AND METHODS Regional values of K* were measured with positron emission tomography (PET), following the intravenous injection of [1-(11)C]AA, in 16 healthy volunteers subjected to visual stimulation at flash frequencies 2.9 Hz (8 subjects) or 7.8 Hz (8 subjects), compared with the dark (0 Hz) condition. Regional cerebral blood flow (rCBF) was measured with intravenous [(15)O]water under comparable conditions. RESULTS During flash stimulation at 2.9 Hz or 7.8 Hz vs. 0 Hz, K* was increased significantly by 2.3-8.9% in Brodmann areas 17, 18 and 19, and in additional frontal, parietal and temporal cortical regions. rCBF was increased significantly by 3.1-22%, often in comparable regions. Increments at 7.8 Hz often exceeded those at 2.9 Hz for both K* and rCBF. Decrements in both parameters also were produced, particularly in frontal brain regions. CONCLUSIONS AA plays a role in signaling processes provoked by visual stimulation, since visual stimulation at flash frequencies of 2.9 and 7.8 Hz compared to 0 Hz modifies both K* for AA and rCBF in visual and related areas of the human brain. The two-stimulus condition paradigm of this study might be used with PET to image effects of other functional activations and of drugs on brain signaling via AA.
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Pritchett Y, McCarberg B, Watkin J, Chappell A, Robinson M, Xu J, Rotz B, Wernicke J, Detke M, Iyengar S, Henck J, Bymaster F, Callaghan J, Knadler M, Thase M, Meratee M, Chung J, Schweitzer J, Byrnes K, Stoica B, Giovanni S, Biase A, Knoblach S, Hoffman E, Faden A, Michaeli S, Sorce D, Öz G, Ugurbil K, Garwood M, Tuite P, Jett D, Deberdt W, Csernansky J, Buckley P, Peiskens J, Lipkovich I, Kollack-Walter S, Houston J, Zhang Y, Liu-Siefert H, Buckley PF, Csernansky JG, Peuskens J, Kollack-Walker S, Houston JP, Rotelli M, Theodore W, Giovacchini G, Bagic A, Herscovitch P, Carson R, Herholz K, Weisenbach S, Hilker R, Heiss W, Nahab F, Hallett M, El-Khodor B, Edgar N, Chen A, Heyes MP, Jiang Q, Ahmed S, Pedersen R, Musgnung J, Entsuah R, Nordberg A, Masdeu J, Gerhard A, Ebmeier K, Pappata S, Perani D, Laere K, Halldin C, Salmon E, Knudsen G, Robins S, Fehlings M, Baptiste D, Skolnick BE, Davis SM, Bran NC, Mathew SE, Mayer SA, Kaminski RM, Marini H, Ortinski PI, Yonekawa W, Vicini S, Rogawski MA, Gasior M, Tang R, White N. Abstracts from the ASENT 2006 Annual Meeting March 8–11, 2006. NeuroRx 2006. [DOI: 10.1016/j.nurx.2006.05.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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Theodore WH, Giovacchini G, Bonwetsch R, Bagic A, Reeves-Tyer P, Herscovitch P, Carson RE. The Effect of Antiepileptic Drugs on 5-HT1A-Receptor Binding Measured by Positron Emission Tomography. Epilepsia 2006; 47:499-503. [PMID: 16529612 DOI: 10.1111/j.1528-1167.2006.00458.x] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
PURPOSE To study the effect of antiepileptic drugs (AEDs) on 5-HT(1A)-receptor binding in patients with temporal lobe epilepsy. 5-HT(1A)-receptor binding, measured by positron emission tomography, is reduced in patients with temporal lobe epilepsy. Antiepileptic drugs may act on the serotonergic system, as shown in animal models, and thus affect receptor-binding measurements. METHODS We analyzed the effect of AEDs on 5-HT(1A)-receptor binding in 31 patients and 10 normal controls. Patients with structural lesions, progressive neurologic disorders, or taking other medications were excluded. None had a seizure for >or=2 days before positron emission tomography (PET). [(18)F]FCWAY PET was performed on a GE Advance scanner with continuous EEG monitoring. Functional images of the distribution volume (V) were generated. Anatomic regions of interest were applied to co-registered PET images, after correction for partial-volume effect. RESULTS Patients had significantly higher [(18)F]FCWAY free fraction (f(1)) than did controls. No AED effects were observed on interictal [(18)F]FCWAY binding after correction for plasma free fraction. [(18)F]FCWAY V/f1 reduction in epileptic foci was not affected by AEDs. CONCLUSIONS 5-HT(1A)-receptor binding is reduced in temporal lobe epileptic foci after partial-volume correction. AED plasma free fractions should be measured when PET receptor studies are performed in patients with epilepsy.
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MESH Headings
- Anticonvulsants/pharmacokinetics
- Anticonvulsants/pharmacology
- Anticonvulsants/therapeutic use
- Brain Mapping
- Cerebral Cortex/diagnostic imaging
- Cerebral Cortex/drug effects
- Cerebral Cortex/metabolism
- Cyclohexanes
- Drug Therapy, Combination
- Electroencephalography/statistics & numerical data
- Epilepsy, Temporal Lobe/diagnostic imaging
- Epilepsy, Temporal Lobe/drug therapy
- Epilepsy, Temporal Lobe/metabolism
- Fluorine Radioisotopes
- Functional Laterality/drug effects
- Functional Laterality/physiology
- Hippocampus/diagnostic imaging
- Hippocampus/drug effects
- Hippocampus/metabolism
- Humans
- Monitoring, Physiologic
- Piperazines
- Positron-Emission Tomography
- Receptor, Serotonin, 5-HT1A/drug effects
- Receptor, Serotonin, 5-HT1A/metabolism
- Receptors, Serotonin/drug effects
- Receptors, Serotonin/metabolism
- Temporal Lobe/diagnostic imaging
- Temporal Lobe/drug effects
- Temporal Lobe/metabolism
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Giovacchini G, Lang L, Ma Y, Herscovitch P, Eckelman WC, Carson RE. Differential effects of paroxetine on raphe and cortical 5-HT1A binding: a PET study in monkeys. Neuroimage 2005; 28:238-48. [PMID: 15993625 DOI: 10.1016/j.neuroimage.2005.05.042] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2005] [Revised: 05/03/2005] [Accepted: 05/19/2005] [Indexed: 10/25/2022] Open
Abstract
Positron emission tomography (PET) ligands that are sensitive to transient changes in serotonin (5-HT) concentration are desirable for studies of neuropsychiatric diseases. Few studies, however, have sought to demonstrate that variations in 5-HT concentration can be closely tracked with available serotonergic ligands. Microdialysis studies in rats have shown a maximal increase in 5-HT concentration in raphe nuclei after systemic infusion of selective serotonergic re-uptake inhibitors (SSRIs). We performed PET scans with [(18)F]FPWAY, an intermediate-affinity antagonist of 5-HT(1A) receptors, in 4 anesthetized rhesus monkeys in control studies and after systemic paroxetine administration (5 mg/kg, i.v.). In addition, a paired [(11)C]DASB study revealed that this paroxetine regimen produced an occupancy of 54-83% of the serotonin transporters. According to the conventional receptor competition model, increased 5-HT concentration produces decreased binding of the radioactive ligand. Over a 3-h period following paroxetine infusion, a progressively increasing reduction (ranging from 8 +/- 6% to 27 +/- 10%) of [(18)F]FPWAY-specific binding was found in the raphe nuclei. This result is interpreted as an SSRI-induced increase in 5-HT concentration, potentially combined with reduced binding to internalized 5-HT(1A) receptors. In addition, a transient (1 h) increase in cerebral cortical binding was observed, attributed primarily to a reduction in cortical 5-HT due to the effects of raphe autoreceptor inhibition. This study is the first demonstration of the feasibility of quantifying dynamic changes in 5-HT neurotransmission in the raphe and the cortex with PET. These results lend promise to the use of these serotonergic neuroimaging techniques to study neuropsychiatric disorders.
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Giovacchini G, Toczek MT, Bonwetsch R, Bagic A, Lang L, Fraser C, Reeves-Tyer P, Herscovitch P, Eckelman WC, Carson RE, Theodore WH. 5-HT 1A receptors are reduced in temporal lobe epilepsy after partial-volume correction. J Nucl Med 2005; 46:1128-35. [PMID: 16000281 PMCID: PMC1454475] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/03/2023] Open
Abstract
UNLABELLED Preclinical studies suggest that serotonin 1A receptors (5-HT 1A) play a role in temporal lobe epilepsy (TLE). Previous PET studies reported decreased 5-HT 1A binding ipsilateral to epileptic foci but did not correct for the partial-volume effect (PVE) due to structural atrophy. METHODS We used PET with 18F-trans-4-fluoro-N-2-[4-(2-methoxyphenyl)piperazin-1-yl]ethyl-N-(2-pyridyl)cyclohexanecarboxamide (18F-FCWAY), a 5-HT 1A receptor antagonist, to study 22 patients with TLE and 10 control subjects. In patients, 18F-FDG scans also were performed. An automated MR-based partial-volume correction (PVC) algorithm was applied. Psychiatric symptoms were assessed with the Beck Depression Inventory Scale. RESULTS Before PVC, significant (uncorrected P < 0.05) reductions of 18F-FCWAY binding potential (BP) were detected in both mesial and lateral temporal structures, mainly ipsilateral to the seizure focus, in the insula, and in the raphe. Group differences were maximal in ipsilateral mesial temporal regions (corrected P < 0.05). After PVC, differences in mesial, but not lateral, temporal structures and in the insula remained highly significant (corrected P < 0.05). Significant (uncorrected P < 0.05) BP reductions were also detected in TLE patients with normal MR images (n = 6), in mesial temporal structures. After PVC, asymmetries in BP remained significantly greater than for glucose metabolism in hippocampus and parahippocampus. There was a significant inverse relation between the Beck Depression score and the ipsilateral hippocampal BP, both before and after PVC. CONCLUSION Our study shows that in TLE patients, reductions of 5-HT 1A receptor binding in mesial temporal structures and insula are still significant after PVC. In contrast, partial-volume effects may be an important contributor to 5-HT 1A receptor-binding reductions in lateral temporal lobe. Reduction of 5-HT 1A receptors in the ipsilateral hippocampus may contribute to depressive symptoms in TLE patients.
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Giovacchini G, Lerner A, Toczek MT, Fraser C, Ma K, DeMar JC, Herscovitch P, Eckelman WC, Rapoport SI, Carson RE. Brain incorporation of 11C-arachidonic acid, blood volume, and blood flow in healthy aging: a study with partial-volume correction. J Nucl Med 2004; 45:1471-9. [PMID: 15347713] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/30/2023] Open
Abstract
UNLABELLED PET with 11C-arachidonic acid (AA) can be used to quantify neural signaling related to phospholipase A2 (PLA2). Animal studies suggest reduction in the activity of this signaling system with age. The aim of this study was to evaluate the effect of healthy aging on brain incorporation of 11C-AA, before and after partial-volume correction (PVC). METHODS Absolute measurements of cerebral blood flow (CBF) were obtained in 8 young and 7 old healthy subjects (mean age +/- SD, 27 +/- 5 y and 65 +/- 9 y) with bolus injection of 15O-water. About 15 min later, dynamic 60-min 3-dimensional scans were acquired after the injection of 11C-AA. Radioactivity frames of 11C-AA were corrected for head motion and registered to magnetic resonance (MR) images. A 3-segment (3S) and a 2-segment (2S) PVC was applied pixel-by-pixel to the activity frames. For the 3S method, the white matter value was estimated using a new automatic method by extrapolating the activity values of pixels with white matter membership > 0.99. Parametric images of the brain incorporation rate of 11C-AA (K*) and cerebral blood volume (Vb), as well as CBF, were generated and regional gray matter values were obtained. RESULTS Among cortical areas, there were no significant differences (uncorrected P < 0.05) in K* or Vb absolute values between young and old subjects before or after PVC. A significant reduction of CBF was detected in the frontal cortex of the elderly group. After normalization to the global gray average, K*, Vb, and CBF values revealed significant reductions in the frontal lobe of old subjects; none of these differences were significant after PVC. CONCLUSION These results confirm previous PET findings that brain function at rest is minimally affected by healthy aging. Proper PVC methodology is of critical importance in accurate quantitative assessment of PET physiologic measures.
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Giovacchini G, Chang MCJ, Channing MA, Toczek M, Mason A, Bokde ALW, Connolly C, Vuong BK, Ma Y, Der MG, Doudet DJ, Herscovitch P, Eckelman WC, Rapoport SI, Carson RE. Brain incorporation of [11C]arachidonic acid in young healthy humans measured with positron emission tomography. J Cereb Blood Flow Metab 2002; 22:1453-62. [PMID: 12468890 DOI: 10.1097/01.wcb.0000033209.60867.7a] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Arachidonic acid (AA) is an important second messenger involved in signal transduction mediated by phospholipase A2. The goal of this study was to establish an in vivo quantitative method to examine the role of AA in this signaling process in the human brain. A simple irreversible uptake model was derived from rat studies and modified for positron emission tomography (PET) to quantify the incorporation rate K* of [11C]AA into brain. Dynamic 60-minute three-dimensional scans and arterial input functions were acquired in 8 young healthy adults studied at rest. Brain radioactivity was corrected for uptake of the metabolite [11C]CO2. K* and cerebral blood volume (Vb) were estimated pixel-by-pixel and were calculated in regions of interest. K* equaled 5.6+/-1.2 and 2.6+/-0.5 microL x min(-1) x mL(-1) in gray and white matter, respectively. K* and Vb values were found to be unchanged with data analysis periods from 20 to 60 minutes. Thus, PET can be used to obtain quantitative images of the incorporation rate K* of [11C]AA in the human brain. As brain incorporation of labeled AA has been shown in awake rats to be increased by pharmacological activation associated with phospholipase A2-signaling, PET and [11C]AA may be useful to measure signal transduction in the human brain.
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Marchetti S, Salvadori PA, Giovacchini G, Iudice A, Ferrari E, Pisani P, Sorace O, Farnetani MA, Fois A, Pietrini P, Guazzelli M. Interictal Qualitative Positron Emission Tomography with Fluoro-Desoxyglucose (PET-FDG) May Contribute to the Diagnostic Accuracy of Epileptic Foci in Drug-Resistant Patients. CLINICAL POSITRON IMAGING : OFFICIAL JOURNAL OF THE INSTITUTE FOR CLINICAL P.E.T 1999; 2:344. [PMID: 14516641 DOI: 10.1016/s1095-0397(99)00104-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/27/2023]
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