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To evaluate the potential value of somatostatin receptor scintigraphy (SRS) using 111In-DTPA (diethylenetriaminepenta acetic acid)-D-Phe1-octreotide (111In-pentetreotide) in patients with recurring or persisting symptoms of myasthenia gravis (MG), 14 consecutive cases with such supplemental receptor imaging during neurological routine follow-up were retrospectively evaluated in this study. All 14 patients underwent SRS in addition to chest computed tomography (CT). Mean follow-up after imaging was 34 months. Eight patients had previous thymectomy, and three patients were referred to surgery after scintigraphy and chest CT. SRS was positive in one of the 14 patients with local recurrence of thymoma and pleural invasion, and negative in the remaining 13 patients. CT was positive for thymoma in three patients, inconclusive in four patients and negative in seven patients. In conclusion, while SRS may be able to detect thymoma lesions including metastases, it seems of limited value in patients with inconspicuous CT findings. Our initial experience fails to point out a benefit of SRS in the management of persisting or recurring MG (with regard to detection of thymic disorders) compared to CT. Whether SRS is useful for differentiating thymoma from non-neoplastic thymic disease may be investigated by larger series. A predominant proportion of patients with unsatisfactory treatment response, however, continue to suffer an unfavourable clinical course despite absent evidence for thymic pathology. [ABSTRACT FROM AUTHOR]

A series of polycrystalline YMn1-xRuxO3 (0≤x≤0.2) samples were prepared by traditional solidstate reaction method. Effects of doping on the microstructures and magnetic properties were investigated. Microstructural results reveal that samples crystallize in a single hexagonal structure with P63cm group for x≤0.1. Lattice parameters a, c, and unit-cell volume of YMn1-xRuxO3 are found to increase with doping content, which are ascribed to the larger radius of Ru3+ than that of Mn3+. Weak ferromagnetism is found and is enhanced with increasing doping concentration x. The bond angles of Mn-O3-Mn and Mn-O4-Mn are changed in the opposite trends, which break the Mn-Mn exchange interaction, thus the antiferromagnetic ordering. The MnO5 bipyramid is found to be relieved and the trimerization of Mn ions is weakened. These structural modifications result in the increase of weak ferromagnetism ordering in samples. [ABSTRACT FROM AUTHOR]

Aim: To assess the clinical value of dual time point 2-[(18)F]-fluoro-2-deoxy-d-glucose positron emission tomography ((18)F-FDG PET) imaging for the differentiation between malignant and benign lesions. Materials and Methods: Ninety-six patients (28 patients with primary lung cancer, 18 patients with digestive system carcinoma, 13 patients with other malignant tumours, and 37 patients with benign lesions) underwent FDG-PET/CT at two time points: examination 1 at 45-55 min and examination 2 at 160+/-24 (150-180) min after the intravenous injection of 233+/-52 (185-370)MBq (18)F-FDG. Reconstructed images were evaluated qualitatively and quantitatively. The maximum standardized uptake values (SUVmax) of the lesions were calculated for both time points. An increase was considered to have occurred if the SUVs at examination 2 had increased by >10% as compared with those at the examination 1. Results: The lesions in 24 of 28 (86%) patients with primary lung cancer had an SUVmax > or = 2.5 at examination 1. Of these, SUVmax values increased in 23 patients, but had not changed in one patient, at examination 2. The lesions in the other four patients with primary lung tumour had SUVmax values between 1.5 and 2.5 at examination 1, which were considered as suspected positive, increased SUVmax values were observed in three of these patients at examination 2. The malignant lesions in 17 of 18 patients with digestive system carcinoma showed SUVmax values > or = 2.5 and only one patient had an SUVmax value < 1.5 at examination 1; all lesions showed an increase in SUVmax values at examination 2. In 13 patients with other malignant tumours, all lesions had SUVmax values > or = 2.5 at examination 1 and the SUVmax values were further increased at examination 2. Therefore, the malignant lesions in 54/59 (92%) of patients had SUVmax values > or = 2.5 at examination 1 and showed a further increase in SUVmax value at examination 2. Only 12 of 37 (32%) patients with benign lesions showed SUVmax values > or = 2.5 at examination 1 and nine patients with benign lesions had SUVmax values > or = 2.5 in examination 2. The sensitivity, specificity, accuracy, positive and negative predictive values for the early and delayed imaging were 91.5, 67.6, 82.3, 81.8, and 83.3%, and 98.3, 75.7, 89.6, 86.6, and 96.6%, respectively. Conclusion: The results of the present study provide further evidence that dual time point (18)F-FDG PET imaging is an important noninvasive method for the differentiation of malignant and nonmalignant lesions. [ABSTRACT FROM AUTHOR]

Aim: To assess the clinical value of dual time point 2-[18F]-fluoro-2-deoxy-d-glucose positron emission tomography (18F-FDG PET) imaging for the differentiation between malignant and benign lesions. Materials and methods: Ninety-six patients (28 patients with primary lung cancer, 18 patients with digestive system carcinoma, 13 patients with other malignant tumours, and 37 patients with benign lesions) underwent FDG-PET/CT at two time points: examination 1 at 45–55min and examination 2 at 160±24 (150–180)min after the intravenous injection of 233±52 (185–370)MBq 18F-FDG. Reconstructed images were evaluated qualitatively and quantitatively. The maximum standardized uptake values (SUVmax) of the lesions were calculated for both time points. An increase was considered to have occurred if the SUVs at examination 2 had increased by >10% as compared with those at the examination 1. Results: The lesions in 24 of 28 (86%) patients with primary lung cancer had an SUVmax ≥2.5 at examination 1. Of these, SUVmax values increased in 23 patients, but had not changed in one patient, at examination 2. The lesions in the other four patients with primary lung tumour had SUVmax values between 1.5 and 2.5 at examination 1, which were considered as suspected positive, increased SUVmax values were observed in three of these patients at examination 2. The malignant lesions in 17 of 18 patients with digestive system carcinoma showed SUVmax values ≥2.5 and only one patient had an SUVmax value <1.5 at examination 1; all lesions showed an increase in SUVmax values at examination 2. In 13 patients with other malignant tumours, all lesions had SUVmax values ≥2.5 at examination 1 and the SUVmax values were further increased at examination 2. Therefore, the malignant lesions in 54/59 (92%) of patients had SUVmax values ≥2.5 at examination 1 and showed a further increase in SUVmax value at examination 2. Only 12 of 37 (32%) patients with benign lesions showed SUVmax values ≥2.5 at examination 1 and nine patients with benign lesions had SUVmax values ≥2.5 in examination 2. The sensitivity, specificity, accuracy, positive and negative predictive values for the early and delayed imaging were 91.5, 67.6, 82.3, 81.8, and 83.3%, and 98.3, 75.7, 89.6, 86.6, and 96.6%, respectively. Conclusion: The results of the present study provide further evidence that dual time point 18F-FDG PET imaging is an important noninvasive method for the differentiation of malignant and nonmalignant lesions. [Copyright &y& Elsevier]