A rotating double-headed positron camera

Based on a double-headed rotating uncollimated scintillation camera system, a positron imaging device was developed. After a rotating data acquisition in coincidence mode, 16 transverse section images are reconstructed by back projection. To obtain a uniform response, a limited angle reconstruction option is incorporated in this process. After correction for the system response by a three-dimensional deconvolution technique, the 16 transverse section images are stored on disk as a standard patient study for further analysis. The system can also be operated in a stationary mode. In this mode longitudinal tomographic images are obtained. Return to single photon scintigraphy is possible by remounting the collimators and by switching off the coincidence electronics

Increased Amounts of D-Enantiomer Dependent on Alkaline Concentration in the Synthesis of L-[methyl-11C] Methionine

開始ページ、終了ページ: 冊子体のページ付

On the quantification of [F-18]MPPF binding to 5-HT1A receptors in the human brain

Previous studies have shown that 4-(2 ' -methoxyphenyl)-1 [2 '-(N-2 "- pyridinyl)-p- [F-18]fluorobenzamido]ethylpiperazine ([F-18]MPPF) binds with high selectivity to serotonin (5-HT1A) receptors in man. However, in these studies, the calculation of the binding potential (BP, which equals receptor density divided by equilibrium dissociation constant) used a metabolite-corrected arterial input. The aim of this study was to determine whether metabolite correction and arterial sampling are essential for the assessment of BP. Methods: Five analytic methods using full datasets obtained from 6 healthy volunteers were compared. In addition, the clinical applicability of these methods was appraised. Three methods were based on Logan analysis of the dynamic PET data using metabolite-corrected and uncorrected arterial plasma input and cerebellar input. The other 2 methods consisted of a simplified reference tissue model and standard compartmental modeling. Results: A high correlation was found between BP calculated with Logan analysis using the metabolite-corrected plasma input (used as the reference method for this study) and Logan analysis using either the uncorrected arterial plasma input (r(2) = 0.95, slope = 0.85) or cerebellar input (r(2) = 0.98, slope = 0.91), A high correlation was also found between our reference method and the simplified reference tissue model (r(2) = 0.94, slope = 0.92). In contrast, a poor correlation was observed between our reference method and the standard compartmental model (r(2) = 0.45, slope = 1.59). Conclusion: These results indicate that neither metabolite analysis nor arterial sampling is necessary for clinical evaluation of BP in the human brain with [18F]MPPF. Both the Logan analysis method with cerebellar input and the simplified reference tissue method can be applied clinically

On the quantification of [F-18]MPPF binding to 5-HT1A receptors in the human brain

Previous studies have shown that 4-(2 ' -methoxyphenyl)-1 [2 '-(N-2 "- pyridinyl)-p- [F-18]fluorobenzamido]ethylpiperazine ([F-18]MPPF) binds with high selectivity to serotonin (5-HT1A) receptors in man. However, in these studies, the calculation of the binding potential (BP, which equals receptor density divided by equilibrium dissociation constant) used a metabolite-corrected arterial input. The aim of this study was to determine whether metabolite correction and arterial sampling are essential for the assessment of BP. Methods: Five analytic methods using full datasets obtained from 6 healthy volunteers were compared. In addition, the clinical applicability of these methods was appraised. Three methods were based on Logan analysis of the dynamic PET data using metabolite-corrected and uncorrected arterial plasma input and cerebellar input. The other 2 methods consisted of a simplified reference tissue model and standard compartmental modeling. Results: A high correlation was found between BP calculated with Logan analysis using the metabolite-corrected plasma input (used as the reference method for this study) and Logan analysis using either the uncorrected arterial plasma input (r(2) = 0.95, slope = 0.85) or cerebellar input (r(2) = 0.98, slope = 0.91), A high correlation was also found between our reference method and the simplified reference tissue model (r(2) = 0.94, slope = 0.92). In contrast, a poor correlation was observed between our reference method and the standard compartmental model (r(2) = 0.45, slope = 1.59). Conclusion: These results indicate that neither metabolite analysis nor arterial sampling is necessary for clinical evaluation of BP in the human brain with [18F]MPPF. Both the Logan analysis method with cerebellar input and the simplified reference tissue method can be applied clinically

Positron emission tomography for staging of oesophageal and gastroesophageal malignancy.

Positron emission tomography (PET) with [18F]-fluoro-2-deoxy-D-glucose (FDG) was prospectively investigated as a means of detecting metastatic disease in patients with oesophageal tumours and compared with computerized tomography (CT), with the surgical findings as a gold standard. Twenty-six patients with a malignant tumour of the oesophagus or gastroesophageal junction underwent CT and PET of the chest and the abdomen. Seven patients underwent laparoscopy to establish resectability. Fifteen patients underwent laparotomy without prior laparoscopy. Four patients did not undergo surgery. The primary tumour was visualized in 81% of patients with CT and in 96% with PET. Neither CT nor PET were suited to assess the extent of wall invasion. Surgically assessed nodal status corresponded in 62% with CT and in 90% with PET. Distant metastases were found in five patients with CT and in eight with PET. The diagnostic accuracy of CT in determining resectability was 65% and for PET 88%. For CT and PET together this was 92%. The present study indicates that FDG-PET can be of importance for staging patients with oesophageal tumours. PET has a higher sensitivity for nodal and distant metastases and a higher accuracy for determining respectability than CT. PET and CT together would have decreased ill-advised surgery by 90%