Chuantao Zuo

Misdiagnoses of 11C-choline combined with 18F-FDG PET imaging in brain tumours.

Background and objectiveThe widely applied 18F-FDG is known for its disadvantage in brain tumour PET imaging because of its high background uptake. 11C-choline can achieve high contrast of brain tumour imaging and was expected to have higher sensitivity and specificity. We analysed the misdiagnoses in 11C-choline PET imaging in brain tumours with the aim of improving the accuracy of diagnosis with 11C-choline PET imaging. Patients and methodsWe selected 10 patients proven to have been misdiagnosed on the basis of histopathological correlation and clinical follow-up among 94 patients (110 studies) who underwent 11C-choline PET/CT for diagnosed or suspected brain tumour between 23 March 2005 and 8 February 2007. 11C-choline PET imaging were performed on a Biograph Sensation 16 PET/CT scanner (Siemens Medical Systems), 18F-FDG imaging was also performed as reference. ResultsOf all 10 misdiagnosed patients, five were false positive (one abscess, one tuberculosis, one benign gliocyte proliferation, one inflammatory granuloma and one demyelination), four were false negative (two metastases from lung cancer, one lymphoma, one grade II glioma) and one was misdiagnosed by wrong interpretation due to lack of experience. The rate of false positives was (5/110) 4.55%; the rate of false negatives was (4/110) 3.64%; the accuracy of 11C-choline alone was (93/110) 84.5%; by comparison, the accuracy of 18F-FDG alone was (78/110) 70.9%. Conclusions11C-choline imaging has a certain rate of false positivity and false negativity. With proper application, 11C-choline might have greater potential than 18F-FDG for brain tumour PET imaging.

Reversible changes in brain glucose metabolism following thyroid function normalization in hyperthyroidism.

BACKGROUND AND PURPOSE: Patients with hyperthyroidism frequently present with regional cerebral metabolic changes, but the consequences of endocrine-induced brain changes after thyroid function normalization are unclear. We hypothesized that the changes of regional cerebral glucose metabolism are related to thyroid hormone levels in patients with hyperthyroid, and some of these changes can be reversed with antithyroid therapy. MATERIALS AND METHODS: Relative regional cerebral glucose metabolism was compared between 10 new-onset untreated patients with hyperthyroidism and 20 healthy control participants by using brain FDG-PET scans. Levels of emotional distress were evaluated by using the SAS and SDS. Patients were treated with methimazole. A follow-up PET scan was performed to assess metabolic changes of the brain when thyroid functions normalized. RESULTS: Compared with controls, patients exhibited lower activity in the limbic system, frontal lobes, and temporal lobes before antithyroid treatment. There were positive correlations between scores of depression and regional metabolism in the cingulate and paracentral lobule. The severity of depression and anxiety covaried negatively with pretreatment activity in the inferior temporal and inferior parietal gyri respectively. Compared with the hyperthyroid status, patients with normalized thyroid functions showed an increased metabolism in the left parahippocampal, fusiform, and right superior frontal gyri. The decrease in both FT3 and FT4 was associated with increased activity in the left parahippocampal and right superior frontal gyri. CONCLUSIONS: The changes of regional cerebral glucose metabolism are related to thyroid hormone levels in patients with hyperthyroidism, and some cerebral hypometabolism can be improved after antithyroid therapy.

The effects of thyroid hormones on brown adipose tissue in humans: a PET-CT study

Brown adipose tissue (BAT) is important for energy expenditure through thermogenesis, although its regulatory factors are not well known in humans. There is evidence suggesting that thyroid hormones affect BAT functions in some mammals, but the effects of thyroid hormones on BAT activity in humans are still unclear. The aim of this study was to investigate the effects of thyroid hormones on glucose metabolism of BAT and other organs in humans.

Differences in the metabolic status of healthy adults with and without active brown adipose tissue

SummaryBackgroundPrevious studies have proven the existence of active brown adipose tissue (BAT) in adults; however, its effect on systematic metabolism remains unclear.AimThe current study was designed to investigate the differences in the metabolic profiles of healthy adults with and without active BAT using positron emission tomography–computed tomography (PET-CT) scans in the un-stimulated state.MethodsA cross-sectional analysis was performed to assess the health of adults using PET-CT whole-body scans at Huashan Hospital Medical Centre between November 2009 and May 2010. A total of 62 healthy adults with active BAT were enrolled in the BAT-positive group. For each positive subject, a same-gender individual who underwent PET-CT the same day and who had no detectable BAT was chosen as the negative control. Body composition was measured, and blood samples were collected for assays of metabolic profiles and other biomarkers.ResultsIn both the male and female groups, BAT-positive individuals were younger and had lower body mass indexes, fasting insulin, insulin resistance, and leptin, but a greater level of high-density lipoprotein cholesterol compared with the negative controls. In the male group, body fat content and levels of tumor necrosis factor-α were significantly lower in the BAT-positive than in the negative control group.ConclusionsThe healthy adults with active BAT in an un-stimulated state had favorable metabolic profiles suggesting that active BAT may be a potential target for preventing and treating obesity and other metabolic disorders.ZusammenfassungGrundlagenFrühere Studien haben die Existenz von aktivem braunem Fettgewebe (BAT) bei Erwachsenen nachgewiesen. Die Wirkung dieses Gewebes auf den systemischen Stoffwechsel bleibt allerdings unklar.ZielDie vorliegende Studie plante zu erforschen, ob ein Unterschied in den Stoffwechselprofilen gesunder Erwachsener mit beziehungsweise ohne BAT besteht, wobei PET-CT Scans im nicht stimulierten Zustand verwendet wurden.MethodikAm Huashan Hospital Medical Center wurde zwischen November 2009 und Mai 2010 eine horizontale Analyse durchgeführt, um die Gesundheit von Erwachsenen zu erfassen, wobei PET-CT Ganzkörper Scans zur Verwendung gelangten. Insgesamt wurden 62 gesunde Erwachsene mit aktivem BAT in die BAT positive Gruppe aufgenommen. Für jede positiv getestete Person wurde als negative Kontrolle eine Person gleichen Geschlechts ausgewählt, die am selben Tag eine PET-CT Untersuchung hatte und bei der kein aktives BAT nachgewiesen werden konnte. Die Körperzusammensetzung wurde gemessen und Blutproben zur Bestimmung von Stoffwechselprofilen und anderer Bio-Marker wurden abgenommen.ErgebnisseSowohl die männlichen als auch die weiblichen BAT positiven Individuen waren jünger und hatten einen geringeren BMI, ein niedrigeres Nüchtern-Insulin, niedrigere Insulinresistenz und Leptin. Nur das HDL-Cholesterin war im Vergleich zur BAT negativen Gruppe erhöht. Bei den BAT positiven Männern war der Körperfettgehalt und die Konzentration von Tumornekrosefaktor-alpha (TNF alpha) signifikant niedriger als bei den BAT negativen Kontrollen.SchlussfolgerungenDie gesunden Erwachsenen mit aktivem BAT hatten im nicht-stimulierten Zustand ein günstigeres Stoffwechselprofil. Dies legt nahe, dass das aktive BAT ein mögliches Zielorgan bei der Vorbeugung und Behandlung der Adipositas und anderer Stoffwechselerkrankungen sein könnte.

The prevalence and predictors of active brown adipose tissue in Chinese adults

OBJECTIVEnPrevious studies have shown that active brown adipose tissue (BAT) is present in adults and may play important roles in the regulation of energy homeostasis. However, nearly every study has been carried out in patients undergoing scanning for cancer surveillance (CS), whose metabolism and BAT activity may not reflect those of healthy individuals. The objective of this study was to investigate the prevalence and predictors of active BAT in Chinese adults, particularly in healthy individuals.nnnDESIGNnA total of 31,088 consecutive subjects aged ≥18 years who had undergone positron emission tomography/computed tomography (PET/CT) scanning of BAT were evaluated in this study.nnnMETHODSnWe measured BAT activity via (18)F-fluorodeoxyglucose PET/CT in subjects who had undergone scanning for either a routine medical checkup (MC) or CS in Shanghai. Then, we investigated the predictors of active BAT, particularly in healthy individuals.nnnRESULTSnIn both groups, the prevalence of BAT was higher in women than in men. Using a multivariate logistic analysis, we found age, sex, BMI, and high thyroid glucose uptake to be significant predictors of BAT activity in the MC group. Similarly, we found age, sex, and BMI to be significant predictors of BAT activity, but not thyroid high glucose uptake, in the CS group.nnnCONCLUSIONSnIn Chinese adults, BAT activity inversely correlates with BMI and thyroid high glucose uptake, which reinforces the central role of brown fat in adult metabolism and provides clues to a potential means for treating the metabolic syndrome.

Metabolic imaging of deep brain stimulation in anorexia nervosa: a 18F-FDG PET/CT study.

Objectives Anorexia nervosa (AN), a disorder of unknown etiology, has the highest mortality rate of any psychiatric disorder. Drawing the brain metabolic pattern of AN may help to target the core biological and psychological features of the disorder and to perfect the diagnosis and recovery criteria. In this study, we used 18F-FDG PET to show brain metabolic network for AN. Methods Glucose metabolism in 6 AN patients and 12 age-matched healthy controls was studied using 18F-FDG PET. SPM2 was used to compare brain metabolism in AN patients with that in healthy controls. Four of 6 AN patients took deep brain stimulation (DBS) targeted in nucleus accumbens (NAcc). About 3 to 6 months after the surgery, the 4 AN patients took another 18F-FDG PET scan to assess the change in brain glucose metabolism. Results The SPM (statistical parametric mapping ) analysis showed hypermetabolism in the frontal lobe (bilateral, BA10, BA11, BA47), the limbic lobe (bilateral, hippocampus, and amygdala), lentiform nucleus (bilateral), left insula (BA13), and left subcallosal gyrus (BA25). It also showed hypometabolism in the parietal lobe (bilateral, BA7, BA40). The hypermetabolism in frontal lobe, hippocampus, and lentiform nucleus decreased after NAcc-DBS. Conclusions The changes in brain glucose metabolism illustrated the brain metabolic pattern in AN patients. Furthermore, the pattern can be modulated by NAcc-DBS, which confirmed specificity of the pattern. The regions with altered metabolism could interconnect to form a network and integrate information related to appetite. Our study may provide information for targeting the potential candidate brain regions for understanding the pathophysiology of AN and assessing the effects of existing and future treatment approaches.

Stability in Brain Glucose Metabolism Following Brown Adipose Tissue Inactivation in Chinese Adults

BACKGROUND AND PURPOSE: The thermogenesis of BAT is believed to be controlled through some pathways initiated in the brain, though the changes in brain activity among different states of BAT-positive subjects are still unclear. We hypothesized that some significant differences of regional cerebral metabolism between various groups were related to the BAT activities regardless of temperature changes. MATERIALS AND METHODS: Relative regional cerebral glucose metabolism was compared between 15 healthy subjects with activated BAT and 30 healthy controls without activated BAT by using a brain FDG-PET scan. A follow-up PET scan was performed to assess metabolic changes of the brain when BAT activity was eliminated by heat exposure. RESULTS: Compared with controls, BAT-positive subjects exhibited lower activity in the inferior parietal lobule, limbic system, and frontal lobe and higher activity in the precuneus before heat exposure. Compared with the BAT elimination status, subjects with activated BAT showed a decreased metabolism in the parietal lobe, frontal lobe, culmen, cingulate gyrus, and sublobar region. Compared with controls, BAT-positive subjects after BAT inactivation had significant hypometabolic areas in the temporal lobe and limbic lobe and hypermetabolic areas in the parietal lobe. CONCLUSIONS: Our findings illustrate that changes of regional cerebral metabolism are related to BAT activities regardless of temperature changes. This before-after controlled study supports the finding that the brain responses appear to be active in modulating the metabolic function of BAT activity.

AFP-producing hepatoid adenocarcinoma of appendix: a case report of 18F-FDG PET/CT

Hepatoid adenocarcinoma (HAC) is a rare tumor. We described here a rare case of appendix HAC. A 59-year-old man underwent F-18-fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) for gradually elevated alpha-Fetoprotein level. Multiple masses in the abdominal cavity with moderate FDG uptake were revealed, suggesting malignant tumor with peritoneal metastasis. The patient underwent radical resection, and the postoperative pathological result was HAC originated from the appendix. To our knowledge, it is the first report of HAC of the appendix. Our study suggests that FDG PET/CT may help in detecting the primary tumor and the metastases of HAC.

Prognostic value of 2-[18F]fluoro-2-deoxy-D-glucose uptake as measured by PET scan in patients with non-small cell lung cancer

This study aimed to evaluate the prognostic value of 2-[18F]fluoro-2-deoxy-D-glucose (18F-FDG) uptake determined by positron emission tomography (PET) in patients with non-small cell lung cancer (NSCLC) in relation to disease stage and/or tumor histology. A retrospective review of 144 patients with newly diagnosed lung cancer undergoing PET imaging was performed. Differences in survival were compared by univariate and multivariate analyses. Univariate analysis identified three prognostic factors: stage, lesion size and the standardized 18F-FDG uptake value. The latter was a better prognostic predictor in lung cancer patients with early-stage disease than in those at advanced stages. Multivariate analysis revealed that the most important prognostic factors were tumor-node-metastasis (TNM) stage and the standardized 18F-FDG uptake value. Patients with standardized uptake values (SUVs) >8 had a 2.5 times higher mortality rate than those with values ≤8. A one-unit increase in SUV corresponded with a 7% increase in the hazard of death. SUVs provided stronger prognostic stratification in patients with adenocarcinoma than in those with squamous cell carcinoma (SCC). Furthermore, the best choice of prognostic predictor differed between the two types of lung cancer: the SUV was best for SCC, while TNM stage was most significant for adenocarcinoma. In conclusion, 18F-FDG uptake in primary lung lesions is an independent prognostic predictor in patients with NSCLC, especially those with adenocarcinoma or early-stage disease. Further stratification of patients with the same TNM stage based on SUVs may allow for the modification of individual treatment strategies, resulting in improved outcome.

Modified Fluorodeoxyglucose Metabolism in Motor Circuitry by Subthalamic Deep Brain Stimulation

Background: Adjustment of the motor circuitry has been described in the treatment of Parkinson disease (PD). Objectives: To evaluate the modulation of the motor circuitry of PD patients by subthalamic deep brain stimulation (STN DBS) using 18F-fluorodeoxyglucose (FDG) and positron emission tomography (PET). Methods: Resting-state brain 18F-FDG PET imaging was performed for 8 PD patients before surgery and also 1 year after STN DBS treatment; changes in regional glucose metabolism were identified. The PD-related pattern (PDRP) of metabolic covariation was also evaluated. In addition, the correlations between glucose metabolism and clinical alleviation were determined. Results: Pronounced elevations in parietal and occipital glucose metabolism due to STN DBS modification were found; an obvious reduction in caudate, putamen, cerebellum, and frontal cortex glucose metabolism was detected after STN DBS interventions. The alleviation of rigidity correlated with an increment in glucose metabolism in the parietal lobe. STN DBS inhibited the PDRP; the decrease in the PDRP correlated with the inhibition of the glucose metabolism of the caudate and the augmented glucose metabolism of the occipital lobe. Conclusion: STN DBS modulates cortical function through the cortical-striatothalamocortial motor circuitry and cerebellothalamocortical motor circuitry.