Objective To compare the principles,methods and applications of provider-to-population ratios method,gravity-based model,two-step floating catchment area(2SFCA)method and improved two-step floating catchment area method for evaluating the spatial accessibility to healthcare services.Methods Taking the spatial accessibility to maternal and child healthcare services in Nanning prefecture for example,we collected data on vector map,transportation network,population size,and the number of health professionals in maternal and child health institutions.Provider-to-population ratios method,gravity-based model,2SFCA method and improved 2SFCA method were applied to evaluate the spatial accessibility to maternal and child healthcare services,on the scales of county level,township level and village level,respectively.Results The four models showed that the spatial heterogeneity of spatial accessibility to maternal and child health services was significant,and the spatial accessibility was gradually decreased from urban areas of Nanning to rural areas.However,regions with high spatial accessibility and regions with low spatial accessibility,decreasing trend in spatial accessibility across regions,the median and inter quartile range of spatial accessibility were different across the four models.Conclusion The practical significance in evaluating spatial accessibility to healthcare services for provider-to-population ratios method,gravity-based model,2SFCA method and improved 2SFCA method was different,yet the spatial accessibility varied somewhat across the four models.Thus,integrating findings of the four models based on multi space scales is strongly recommended to evaluate the spatial accessibility to healthcare services comprehensively and robustly.

Objective:To investigate the etiologies and clinical characteristics of bilateral adrenal lesions.Methods:The clinical data of 143 patients with bilateral adrenal lesions hospitalized in the First Affiliated Hospital of Chongqing Medical University from Jan. 2013 to Mar. 2018 were collected and analyzed.Results:140 patients were retained for final analysis. 79 were men, and 61 were women. The age was (51.53±13.93) years. Regarding the etiologies, there were primary aldosteronism ( n=44, 31.43%) , Cushing’s syndrome ( n=27, 19.29%) , non-functional lesions ( n=23, 16.43%) , adrenal tuberculosis ( n=17, 12.14%) , pheochromocytoma ( n=11, 7.86%) , congenital adrenal hyperplasia ( n=5, 3.57%) , adrenal metastases ( n=5, 3.57%) , and adrenal lymphoma ( n=4, 2.86) . These patients were classified into the following groups according to the mass size: ≤2 cm, 2-4 cm and ≥4 cm. The highest proportion of primary aldosteronism (62.79%) , Cushing’s syndrome (46.15%) and pheochromocytoma (31.25%) was observed in the ≤2 cm, 2-4 cm and ≥4 cm groups, respectively. The mass sizes of primary aldosteronism, Cushing’s syndrome and pheochromocytoma were compared, with pheochromocytoma the largest, followed by Cushing’s syndrome, non-functional lesion, and primary aldosteronism. Conclusions:For patients with bilateral adrenal lesions in our hospital, primary aldosteronism and Cushing’s syndrome are more common than non-functional lesion. Mass size is of great value in the diagnosis of endocrinological etiology, as well as distinguishing malignant tumors from the benign ones. The imaging phenotype is helpful to determine tumor types.