Hell J Nucl Med
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Solid pseudopapillary tumors (SPT) are rare, unique pancreatic tumors with benign entity and low malignant potential. Limited information is available in the literature reporting their accumulation of fluorine-18 fluoro deoxyglucose ((18)F-FDG) using positron emission tomography/computed tomography (PET/CT). The aim of this retrospective study was to define t he uptake-accumulation of (18)F-FDG PET/CT in a comparatively large cohort of SPT, and to compare their uptake with the uptake of (18)F-FDG in pancreatic ductal adenocarcinomas (PAC) and neuroendocrine tumors (PNET). ⋯ Images of CT were of low dose and thus were not evaluated. In conclusion, our results suggest that SPT benign or malignant are consistently hyperaccumulating (18)F-FDG above SUVmax 3. Differentiation from PAC and PNET if only based on the higher SUVmax values was not possible but if based on lower SUVmax, of ≤2.6 (in 14%) and ≤2.5 (in 21,4%) of PAC and PNET, respectively, these pancreatic tumors could be differentiated from SPT.
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Our aim was to quantify the degree of pulmonary inflammation associated with centrilobular emphysema using fluoro-18-2-fluoro-2-deoxy-D-glucose positron emission tomography ((18)F-FDG-PET) and diagnostic unenhanced computed tomography (CT) based image segmentation and partial volume correction. Forty-nine subjects, with variable amounts of centrilobular emphysema, who had prior diagnostic unenhanced chest CT and either (18)F-FDG-PET or (18)F-FDG-PET/CT were selected. Lung parenchymal volume (L) (in cm³) excluding large and small pulmonary vessels, emphysema volume (E) (in cm³) based on a -910HU threshold, fraction of lung emphysema (F=E/L), and mean attenuation (HU) of non-emphysematous lung parenchyma (A) were calculated from CT images using the image analysis software 3DVIEWNIX. ⋯ In conclusion, the degree of pulmonary inflammation increases with emphysema severity based on (18)F-FDG-PET or (18)F-FDG-PET/CT assessment, but is only detectable when (18)F-FDG uptake is corrected for the partial volume effect based on data provided from diagnostic chest CT images. These results support the notion that pulmonary inflammation plays an important role in the pathophysiology of emphysema. This novel image analysis approach has great potential for practical, accurate, and precise combined structural-functional PET quantification of pulmonary inflammation in patients with emphysema or other pulmonary conditions, although further validation and refinement will be required.
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Accurate and reliable staging of disease extent in patients with malignant MM is essential to ensure appropriate treatment planning. The detection of recurrent or residual malignancy after primary treatment is important to allow for early intervention and to optimise patient survival. 2-deoxy-2-[(18)F]fluoro-D-glucose ((18)F-FDG) PET or PET computed tomography (PET/CT) is indicated for surveillance of malignant MM due to its high sensitivity and specificity for soft-tissue or nodal recurrences and metastases. It has been claimed that including lower extremities and skull in addition to 'eyes to thigh' images in PET/CT evaluation of metastatic MM routinely is warranted. We have studied retrospectively the reports of whole-body PET/CT scans in all patients with MM scanned in our Department from April 2005 to December 2010. ⋯ In conclusion, whole body PET/CT scan showed about 1% unexpected primary or metastatic MM lesions involving the head or lower extremities, which seldom offered significant additional clinical benefit and were unlikely to change clinical management. No clinically significant change in staging would have occurred. Routine 'eyes to thighs' images were adequate for this subset of patients.
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As fluorine-18-fluorodesoxyglucose positron emission tomography/computed tomography ( (18)F-FDG PET/CT) is gaining wider availability, more and more patients with malignancies undergo whole body PET/CT, mostly to assess tumor spread in the rest of the body, but not in the brain. Brain is a common site of metastatic spread in patients with solid extracranial tumors. Gold standard in the diagnosis of brain metastases remains magnetic resonance imaging (MRI). ⋯ The detection rate of brain metastases was relatively low, but information was obtained with a minimum increase of radiation burden. In conclusion, whole body (18)F-FDG PET/CT detected brain metastases in 1% of the patients if brain was included in the scanned field. Brain scanning as a part of whole body scan cannot replace routine imaging techniques, but in case of positive findings provides early and crucial information for further patient management, especially in asymptomatic patients.
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Letter Case Reports
Acute respiratory distress syndrome suggested by ¹⁸F-FDG PET/CT.