scholarly journals Fuzzy Statistical Unsupervised Learning Based Total Lesion Metabolic Activity Estimation in Positron Emission Tomography Images

2011 ◽  
pp. 233-240 ◽  
Author(s):  
Jose George ◽  
Kathleen Vunckx ◽  
Sabine Tejpar ◽  
Christophe M. Deroose ◽  
Johan Nuyts ◽  
...  
Keyword(s):  
Positron Emission Tomography ◽  
Unsupervised Learning ◽  
Metabolic Activity ◽  
Emission Tomography ◽  
Positron Emission ◽  
Activity Estimation

scholarly journals The Effect of Diazepam Sedation on Cerebral Glucose Metabolism in Alzheimer's Disease as Measured Using Positron Emission Tomography

1987 ◽  
Vol 7 (4) ◽  
pp. 415-420 ◽  
Author(s):  
Norman L. Foster ◽  
Abraham F. L. VanDerSpek ◽  
Michael S. Aldrich ◽  
Stanley Berent ◽  
Richard H. Hichwa ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Positron Emission Tomography ◽  
Glucose Metabolism ◽  
Metabolic Activity ◽  
Glucose Utilization ◽  
Activity Level ◽  
Emission Tomography ◽  
Positron Emission ◽  
Intravenous Diazepam

The effect of sedation induced by intravenous diazepam on cerebral glucose metabolic activity was examined with [18F]2-fluoro-2-deoxy-D-glucose (FDG) and positron emission tomography (PET) in five patients with probable Alzheimer's disease. Each subject was studied on 2 separate days: on one occasion at rest with eyes patched and ears open, and on the second when sedated with intravenous diazepam titrated to maintain stage II sleep by clinical and EEG criteria. Similar patterns of glucose uptake were observed in both the presence and the absence of sedation, but overall glucose utilization was depressed an average of 20% and was closely correlated with the amount of diazepam administered prior to the injection of FDG. The predominant temporoparietal hypometabolism and relative sparing of frontal metabolism observed in this disease are therefore not explained by differences in anxiety or activity level in this patient group. Utilization of diazepam sedation for PET study appears to be safe and may permit the study of patients otherwise unable to cooperate with FDG-PET procedures.

Breast Imaging With Positron Emission Tomography and Fluorine-18 Fluorodeoxyglucose: Use and Limitations

2000 ◽  
Vol 18 (20) ◽  
pp. 3495-3502 ◽  
Author(s):  
N. Avril ◽  
C.A. Rosé ◽  
M. Schelling ◽  
J. Dose ◽  
W. Kuhn ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Positron Emission Tomography ◽  
Positive Predictive Value ◽  
Metabolic Activity ◽  
Pet Imaging ◽  
Emission Tomography ◽  
Breast Carcinomas ◽  
Positron Emission ◽  
High Positive Predictive Value ◽  
Fluorine 18 Fluorodeoxyglucose

PURPOSE: To evaluate the diagnostic value of positron emission tomography (PET) using fluorine-18 fluorodeoxyglucose (FDG) for the diagnosis of primary breast cancer. PATIENTS AND METHODS: Preoperatively, 144 patients with masses suggestive of breast cancer underwent PET imaging of the breast. To identify breast cancer by increased metabolic activity, parametric FDG-PET images were analyzed for increased tracer uptake applying conventional image reading (CIR) and sensitive image reading (SIR). One hundred eighty-five breast tumors were evaluated by histology, revealing 132 breast carcinomas and 53 benign masses. RESULTS: Breast carcinomas were identified with an overall sensitivity of 64.4% (CIR) and 80.3% (SIR). The increase in sensitivity (SIR) resulted in a noticeable decrease in specificity, from 94.3% (CIR) to 75.5% (SIR). At stage pT1, only 30 (68.2%) of 44 breast carcinomas were detected, compared with 57 (91.9%) of 62 at stage pT2. A higher percentage of invasive lobular carcinomas were false-negative (65.2%) compared with invasive ductal carcinomas (23.7%). Nevertheless, positive PET scans provided a high positive-predictive value (96.6%) for breast cancer. CONCLUSION: Partial volume effects and varying metabolic activity (dependent on tumor type) seem to represent the most significant limitations for the routine diagnostic application of PET. The number of invasive procedures is therefore unlikely to be significantly reduced by PET imaging in patients presenting with abnormal mammography. However, the high positive-predictive value, resulting from the increased metabolic activity of malignant tissue, may be used with carefully selected subsets of patients as well as to determine the extent of disease or to assess therapy response.

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