1,721,007 research outputs found
Comparison of the prognostic value of SPECT after nitrate administration and metabolic imaging by PET in patients with ischaemic left ventricular dysfunction
No full textPURPOSE: We compared the prognostic value of 99mTc-tetrofosmin single-photon emission computed tomography (SPECT) after nitrate administration and positron emission tomography (PET) with 18F-fluorodeoxyglucose (FDG) in patients with ischaemic left ventricular (LV) dysfunction. METHODS: Eighty-nine patients with previous myocardial infarction and LV dysfunction (LV ejection fraction 33 +/-10%) underwent 99mTc-tetrofosmin SPECT under control conditions (baseline) and
after sublingual administration of 10 mg of isosorbide dinitrate (nitrate). Within 1 week, all patients underwent PET imaging with 18F-FDG. Four patients were excluded because of inadequate FDG uptake caused by severe diabetes. Follow-up data were obtained by phone contact with patients and by review of hospital or physicians' records. Cardiac death, myocardial infarction and late
revascularisation for unstable angina were considered as events. Follow-up data were not available in three patients. Follow-up was 96% complete at a mean period of 29 +/- 19 months. RESULTS: At baseline SPECT, 59 (72%) patients had evidence of viable myocardium, while 23 did not. Of these latter patients, 12 (52%)
demonstrated viable myocardium after nitrate and 13 (56%) had preserved metabolic activity. Cardiac events (cardiac death, myocardial infarction and late revascularisation for unstable angina) occurred in 24 (29%) patients. Event-free survival was similar in patients with and patients without viable myocardium at
baseline SPECT (p = 0.8). In contrast, event-free survival was lower in patients with viable myocardium at nitrate SPECT and PET compared to those without viable myocardium (both p<0.05). CONCLUSION: In patients with ischaemic LV dysfunction, the prognostic value of SPECT imaging after nitrate is comparable to that of PET metabolic imaging
Early 18F-FDG uptake as a reliable imaging biomarker of T790M-mediated resistance but not MET amplification in non-small cell lung cancer treated with EGFR tyrosine kinase inhibitors
Full text linkBackground: The two main mechanisms of resistance to EGFR tyrosine kinase inhibitors (TKIs) in non-small cell lung cancer (NSCLC) are the occurrence of T790M secondary mutation in the kinase domain of EGFR and METamplification. The aim of the present study was to test whether early changes of 18F fluorodeoxyglucose (18F-FDG) uptake in animal models bearing erlotinib-resistant NSCLC may have different imaging patterns of response to erlotinib depending on the molecular mechanisms underlying resistance.
Animal tumor models were developed using NSCLC H1975 cells bearing the T790M mutation and H1993 cells with MET amplification. Nude mice bearing erlotinib-resistant H1975 and H1993 xenografts (four animals for each cell line and for each treatment) were subjected to 18F-FDG PET/CT scan before and immediately after treatment (50 mg/kg p.o. for 3 days) with erlotinib, WZ4002, crizotinib, or vehicle. A three-dimensional region of interest analysis was performed to determine the percent change of 18F-FDG uptake in response to treatment. At the end of the imaging studies, tumors were removed and analyzed for glycolytic and mitochondrial proteins as well as levels of cyclin D1.
Results: Imaging studies with 18F-FDG PET/CT in H1975 tumor-bearing mice showed a reduction of 18F-FDG uptake of 25.87 % ± 8.93 % after treatment with WZ4002 whereas an increase of 18F-FDG uptake up to 23.51 % ± 9.72 % was observed after treatment with erlotinib or vehicle. Conversely, H1993 tumors showed a reduction of 18F-FDG uptake after treatment with both crizotinib (14.70 % ± 1.30 %) and erlotinib (18.40 % ± 9.19 %) and an increase of tracer uptake in vehicle-treated (56.65 % ± 5.65 %) animals. The in vivo reduction of 18F-FDG uptake was always associated with downregulation of HKII and p-PKM2 Tyr105 glycolytic proteins and upregulation of mitochondrial complexes (subunits I–IV) in excised tumors.
Conclusions: 18F-FDG uptake is a reliable imaging biomarker of T790M-mediated resistance and its reversal in NSCLC whereas it may not be accurate in the detection of MET-mediated resistance
Tc-99m tetrofosmin tomography after nitrate administration in patients with ischemic left ventricular dysfunction: relation to metabolic imaging by PET
No full text
Tc-99m tetrofosmin tomography after nitrate administration in patients with ischemic left ventricular dysfunction: relation to metabolic imaging by PET
No full textBone mineral density in a population of children and adolescents with cerebral palsy and mental retardation with or without epilepsy
Full text linkPurpose: The present study aimed to assess bone mineral density (BMD) in a population of children and adolescents with cerebral palsy and mental retardation with or without epilepsy. Methods: One hundred thirteen patients (63 male and 50 female) were recruited for evaluation. Patients were divided in three groups: 40 patients (group 1) were affected by cerebral palsy and mental retardation; 47 (group 2) by cerebral palsy, mental retardation, and epilepsy; and 26 (group 3) by epilepsy. The control group consisted of 63 healthy children and adolescents. Patients underwent a dual-energy x-ray absorptiometry (DEXA) scan of the lumbar spine (L1-L4), and z-score was calculated for each patient; t-score was considered for patients 18 years of age and older. Key Findings: Abnormal BMD by DEXA was found in 17 patients (42.5%) in group 1, in 33 (70.2%) in group 2, and in 3 (11.5%) in group 3. In groups 1 and 2, tetraparesis and severe/profound mental retardation were related to a significantly abnormal BMD (p = 0.003). The multivariate analysis of independent factors on BMD (z-score) revealed a significant correlation between BMD (z-score) and age (p = 0.04), body mass index (BMI; p = 0.002), severe/profound mental retardation (p = 0.03), and epilepsy (p = 0.05). Significance: A significantly lower BMD z-score value was found in patients with cerebral palsy, mental retardation, and epilepsy compared with those without epilepsy. The epileptic disorder appears to be an aggravating factor on bone health when comorbid with cerebral palsy and mental retardation. © 2012 International League Against Epilepsy
Hyperfunctioning parathyroid gland and skeletal involvement on [18F]fluorocholine PET/CT: one look with two views
No full textHyperparathyroidism is an endocrine disorder that may be associated with other metabolic diseases. Non-invasive imaging techniques including [99mTc]Tc-sestamibi singlephoton emission computed tomography (SPECT) and [18 F]fluorocholine positron emission tomography (PET)/computed tomography (CT) play a key role on management of patients with hyperparathyroidism. We report for the first time a case of a patient with evidence of both hyperfunctioning parathyroid tissue and multiple lytic bone lesions on [18 F]fluorocholine PET/CT imaging. The present case report highlights the potential role of whole-body [18 F]fluorocholine PET/CT for the identification of both parathyroid adenoma and multiple bone lesions in a single diagnostic setting
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