Objective: To investigate the clinical and pathological characteristics of thyroid nodules, as well as to evaluate the significance of ultrasonographically detected thyroid calcification in the diagnosis of thyroid carcinomas. Methods: Retrospective data were studied from 1,051 consecutive patients who underwent a thyroidectomy in the Provincial Hospital of Fujian Medical University in South China between January 2003 and July 2006 for nodular thyroid disease. Complete sonographical information before surgery was only collected from 758 of the 1,051 patients. Results: Among the 1,051 patients, benign lesions were found in 857 (81.54%) patients, of whom 612 (71.41%) were nodular goiter; malignant lesions were found in 194 (18.46%) patients, in whom benign thyroid lesions were also found in 85 (43.81%) patients. A total of 48 patients suffered from microcarcinomas, of whom 37 patients had benign lesions; these 37 accounted for 43.53 and 77.08%, respectively, of the 85 malignant cases with benign lesions and the 48 cases with microcarcinomas. In the 758 patients who underwent thyroid ultrasonography before surgery, intrathyroidal calcifications were apparent in 243 patients (32.06%). The incidence of calcification was significantly higher in patients with thyroid carcinoma (54.17%) than in those with benign lesions (26.87%; p < 0.005). Detection of calcification in thyroid lesions by ultrasound had a sensitivity of 32.38% and a specificity of 87.35%, with an OR of 3.31 (95% CI, 2.24–4.63), positive likelihood ratio of 2.56, negative likelihood ratio of 0.77 and a κ value of 0.23. Conclusion: Thyroid carcinoma, especially microcarcinoma, often coexists with benign thyroid disease. Calcification detected by thyroid ultrasound represents a risk factor for malignancy, but is of limited use as a sole marker of malignancy.

Abstract:With support of GIS tools and Theil index, the spatial variance of urban energy consumption in China was discussed in this paper through the parallel comparison and quantitative analysis of the 30 provincial capital cities of mainland China in 2005, in terms of scale, efficiency and structure. The indicators associated with urban energy consumption show large spatial variance across regions, possibly due to diversities of geographic features, economic development levels and local energy source availability in China. In absolute terms, cities with the highest total energy consumption are mostly distributed in economic-developed regions as Beijing-Tianjin-Tangshan Area, Yangtze River Delta and Pearl River Delta of China, however, the per capita urban energy use is significantly higher in the Mid-and-Western regions. With regard to the energy mix, coal still plays the dominant role and cities in Mid-and-Western regions rely more on coal. In contrast, high quality energy carrier as electricity and oils are more used in southeast coastal zone and northern developed areas. The energy intensive cities are mainly located in the northwest, while the cities with higher efficiency are in southeast areas. The large spatial variance of urban energy consumption was also verified by the Theil indices. Considering the Chinese economy-zones of East, Middle and West, the within-group inequalities are the main factor OPEN ACCESSEnergies 2011, 4 27 contributing to overall difference, e.g., the Theil index for per capita energy consumption of within-group is 0.18, much higher than that of between group (0.07), and the same applies to other indicators. In light of the spatial variance of urban energy consumptions in China, therefore, regionalized and type-based management of urban energy systems is badly needed to effectively address the ongoing energy strategies and targets.

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