Home About us Contact
|
Home About us Contact | ||
|
|
||
Glucose Positron Emission Tomography (glucose + positron_emission_tomography)
Selected AbstractsEffect of drug-induced cytotoxicity on glucose uptake in Hodgkin's lymphoma cellsEUROPEAN JOURNAL OF HAEMATOLOGY, Issue 2 2006Ursula Banning Abstract:,Background:,In Hodgkin's lymphoma, F-18-fluoro-deoxy- d -glucose positron emission tomography (FDG-PET) is used for staging and response evaluation after chemotherapy. However, drug-mediated downregulation of glucose uptake in viable Hodgkin's lymphoma cells might limit the use of FDG-PET. Methods:,We analyzed the effect of etoposide on cell viability and uptake of F-18-fluoro-deoxy- d -glucose or the glucose analog 2-[N -(7-nitrobenz-2-oxa-1,3-diazol-4-yl)amino]-2-deoxyglucose (2-NBDG) in vitro. Results:,Etoposide induced a dose-dependent cytotoxicity in HDLM-2 cells which was significantly correlated with reduced FDG uptake. However, it also significantly increased the portion of viable cells which did not take up 2-NBDG. Interestingly, etoposide-induced cytotoxicity was mainly mediated via caspase-dependent mechanisms, whereas the cell death induced by deprivation of glucose was mediated via caspase-independent mechanisms. Conclusion:,Etoposide-mediated reduction of glucose uptake by Hodgkin's lymphoma cells is mainly caused by cell death. In a small fraction of viable cells, etoposide might downregulate glucose transporters and/or hexokinase activity and by that inhibit glucose uptake. This, however, might not lead to false-negative results of response evaluation in Hodgkin's lymphoma patients after chemotherapy, because inhibition of glucose uptake itself seems to be a strong inducer of cell death. Altogether, this study provides important in vitro evidence to clarify the mechanisms by which FDG-PET monitors the effect of anti-cancer treatment in Hodgkin's lymphoma patients. [source] Early detection of bone infection and differentiation from post-surgical inflammation using 2-deoxy-2-[18F]-fluoro- D -glucose positron emission tomography (FDG-PET) in an animal modelJOURNAL OF ORTHOPAEDIC RESEARCH, Issue 6 2005Laurie Jones-Jackson Abstract Diagnosing bone infection in the context of post-surgical inflammation is problematic since many of the early signs of infection are similar to normal post-surgical changes. We used a rabbit osteomyelitis model to evaluate the use of 2-deoxy-2-[18F]-fluoro- D -glucose positron emission tomography (FDG-PET) as a means of detecting post-operative infection in the context of post-surgical inflammation. Comparisons were made between infected and non-infected rabbits in which infection with Staphylococcus aureus was initiated at the time of surgery. Weekly PET scans were obtained 30 and 60 min after the introduction of FDG and analyzed based on standardized uptake values (SUV) at the surgical site and visual assessment of the presence or absence of infection. Concurrent X-rays were taken immediately prior to scanning. At 4 weeks post-operatively, animals were sacrificed for histologic and bacteriologic confirmation of infection. Uptake of FDG was evident in the bone of all rabbits on day 1 post-surgery, however, SUV comparisons from the surgical site could not be used to distinguish between the infected and uninfected groups until day 15. Visual analysis of FDG-PET scans revealed a significant difference (p < 0.01) between the infected and uninfected groups as early as day 8. This was due in part to the ability to visualize regional lymph nodes by FDG-PET.© 2005 Orthopaedic Research Society. Published by Elsevier Ltd. All rights reserved. [source] Functional imaging: I. Relative predictive value of intracranial electroencephalographyANNALS OF NEUROLOGY, Issue 1 2008MSPH, Robert C. Knowlton MD Objective To gain information on the predictive and prognostic value of magnetic source imaging (MSI), 2-[18F]fluoro-2-deoxy- D -glucose positron emission tomography (18FDG-PET), and ictal single-photon emission computed tomography (SPECT) as compared with intracranial electroencephalography (ICEEG) localization in epilepsy surgery. Methods This work was part of a cohort study of epilepsy surgery candidates not sufficiently localized with noninvasive studies. Of 160 patients enrolled over 4 years, 77 completed ICEEG seizure monitoring. Sensitivity, specificity, and predictive values relative to ICEEG were computed for each modality. Results Seizures were not captured in five patients. Of the 72 diagnostic ICEEG studies, seizure localization results were 74% localized, 10% multifocal, and 17% nonlocalized. Sixty-one percent were localized to neocortical regions. Depending on patient subgroup pairs, sensitivity ranged from 58 to 64% (MSI), 22 to 40% (PET), and 39 to 48% (SPECT); specificity ranges were 79 to 88% (MSI), 53 to 63% (PET), and 44 to 50% (SPECT). Gains in diagnostic yield were seen only with the combination of MSI and PET or MSI and ictal SPECT. Localization concordance with ICEEG was greatest with MSI, but a significant difference was demonstrated only between MSI and PET. Moderate redundancy was seen between PET and ictal SPECT (, = 0.452; p = 0.011). Interpretation Conclusively positive MSI has a high predictive value for seizures localized with ICEEG. Diagnostic gain may be achieved with addition of either PET or ictal SPECT to MSI. Diagnostic values for imaging tests are lower than "true values" because of the limitations of ICEEG as a gold standard. Ann Neurol 2008 [source] Diaschisis after thalamic stroke: a comparison of metabolic and structural changes in a patient with amnesic syndromeACTA NEUROLOGICA SCANDINAVICA, Issue 2007V. Stenset Introduction,, We present a patient with a left anteromedial thalamic lesion with an amnesic syndrome. The patient underwent neuropsychological testing, cerebrospinal fluid (CSF) analyses, magnetic resonance imaging (MRI) [T2, flair, and diffusion tensor imaging (DTI)] and [18F]-2-fluoro-deoxy- d -glucose positron emission tomography (FDG-PET) to assess indirect effects of thalamic lesions on cortical function. Case report,, A 67-year-old right-handed woman was admitted to a university-based memory unit because of memory and concentration problems. Neuropsychological testing revealed dysfunction of episodic memory, semantic memory and working memory. General intellectual function and attention capacity were preserved. MRI revealed an anteromedial thalamic lesion in the left hemisphere. FDG-PET showed decreased uptake in the frontal, parietal and temporal lobes of the left hemisphere. Regions of interest (ROI) in white matter were selected and left and right hemispheres were compared. Fractional anisotropy (FA) in ROI representing thalamo-cortical connections were decreased in the left hemisphere when compared with the right. Conclusion,, The results show the importance of a network that include the anterior and dorsomedian nuclei, which influence the activity in areas of the cortex responsible for memory processes. The imaging findings suggest that areas of cortical diaschisis after thalamic infarction correspond to areas affected by thalamo-cortical fibre loss as measured with FA. [source] | ||||||||||