PURPOSE: The serotonin system is involved in many physiological functions and clinical conditions. Serotonergic neurons originate from the raphe nuclei in the brainstem, and reliable estimates of receptor/transporter availability in the raphe in vivo are thus of interest. Though positron emission tomography (PET) can be used to quantify receptor distribution in the brain, high noise levels prevent reliable estimation of radioligand binding in small regions such as the raphe. For this purpose, parametric imaging in combination with high-resolution PET systems may provide images with reduced noise levels and sufficient contrast for reliable quantification. This study examined the potential to evaluate radioligand binding in brainstem nuclei, and assessed the effect of improved resolution on the outcome measures. METHODS: For comparative purposes, radioligand binding was measured with an ECAT EXACT HR PET system (resolution about 4.5 mm FWHM) and a high-resolution research tomograph (HRRT) system (resolution about 1.5 mm FWHM). Six subjects were examined with both systems on the same day using the serotonin transporter radioligand [(11)C]MADAM. Parametric images of binding potential (BP (ND)) were obtained using a wavelet-aided approach. Regions of interest (ROIs) were delineated using a threshold-based semiautomatic delineation procedure for five brainstem structures. Regional BP (ND) values were estimated by applying the ROIs to the parametric images, and the percentage difference in BP (ND) between the systems was calculated. RESULTS: Signals for [(11)C]MADAM binding were obtained for all five brainstem structures. Overall, the HRRT provided 30-40 % higher BP (ND) values than the HR (p = 0.0017), independent of thresholds used in the ROI delineation procedure. CONCLUSION: The methodology used enabled the estimation of [(11)C]MADAM binding in the small nuclei of the brainstem. Differences in the BP (ND) values calculated using data from the two systems were mainly attributable to their differing resolutions. The estimated BP (ND) values provided lower across-subject variability than those previously obtained using compartment analysis. This procedure may therefore facilitate quantitative studies of receptor/transporter availability in the brainstem.
PURPOSE: The serotonin system is involved in many physiological functions and clinical conditions. Serotonergic neurons originate from the raphe nuclei in the brainstem, and reliable estimates of receptor/transporter availability in the raphe in vivo are thus of interest. Though positron emission tomography (PET) can be used to quantify receptor distribution in the brain, high noise levels prevent reliable estimation of radioligand binding in small regions such as the raphe. For this purpose, parametric imaging in combination with high-resolution PET systems may provide images with reduced noise levels and sufficient contrast for reliable quantification. This study examined the potential to evaluate radioligand binding in brainstem nuclei, and assessed the effect of improved resolution on the outcome measures. METHODS: For comparative purposes, radioligand binding was measured with an ECAT EXACT HR PET system (resolution about 4.5 mm FWHM) and a high-resolution research tomograph (HRRT) system (resolution about 1.5 mm FWHM). Six subjects were examined with both systems on the same day using the serotonin transporter radioligand [(11)C]MADAM. Parametric images of binding potential (BP (ND)) were obtained using a wavelet-aided approach. Regions of interest (ROIs) were delineated using a threshold-based semiautomatic delineation procedure for five brainstem structures. Regional BP (ND) values were estimated by applying the ROIs to the parametric images, and the percentage difference in BP (ND) between the systems was calculated. RESULTS: Signals for [(11)C]MADAM binding were obtained for all five brainstem structures. Overall, the HRRT provided 30-40 % higher BP (ND) values than the HR (p = 0.0017), independent of thresholds used in the ROI delineation procedure. CONCLUSION: The methodology used enabled the estimation of [(11)C]MADAM binding in the small nuclei of the brainstem. Differences in the BP (ND) values calculated using data from the two systems were mainly attributable to their differing resolutions. The estimated BP (ND) values provided lower across-subject variability than those previously obtained using compartment analysis. This procedure may therefore facilitate quantitative studies of receptor/transporter availability in the brainstem.
Authors: M D Underwood; A A Khaibulina; S P Ellis; A Moran; P M Rice; J J Mann; V Arango Journal: Biol Psychiatry Date: 1999-08-15 Impact factor: 13.382
Authors: Floris H P van Velden; Reina W Kloet; Bart N M van Berckel; Fred L Buijs; Gert Luurtsema; Adriaan A Lammertsma; Ronald Boellaard Journal: J Nucl Med Date: 2009-04-16 Impact factor: 10.057
Authors: K Collste; A Forsberg; A Varrone; N Amini; S Aeinehband; I Yakushev; C Halldin; L Farde; S Cervenka Journal: Eur J Nucl Med Mol Imaging Date: 2015-08-22 Impact factor: 9.236
Authors: Vincent Beliveau; Claus Svarer; Vibe G Frokjaer; Gitte M Knudsen; Douglas N Greve; Patrick M Fisher Journal: Neuroimage Date: 2015-05-09 Impact factor: 6.556
Authors: Martin Schain; Simon Benjaminsson; Katarina Varnäs; Anton Forsberg; Christer Halldin; Anders Lansner; Lars Farde; Andrea Varrone Journal: J Cereb Blood Flow Metab Date: 2013-04-10 Impact factor: 6.200
Authors: Emma R Veldman; Andrea Varrone; Katarina Varnäs; Marie M Svedberg; Zsolt Cselényi; Mikael Tiger; Balázs Gulyás; Christer Halldin; Johan Lundberg Journal: J Cereb Blood Flow Metab Date: 2021-10-13 Impact factor: 6.960
Authors: Jonas E Svensson; Mikael Tiger; Pontus Plavén-Sigray; Christer Halldin; Martin Schain; Johan Lundberg Journal: Neuropsychopharmacology Date: 2022-07-11 Impact factor: 8.294