Background：To evaluate the utility of rabbit ladderlike model of radiation-induced lung injury （RILI） for the future investigation of computed tomography perfusion.Methods：A total of 72 New Zealand rabbits were randomly divided into two groups：36 rabbits in the test group were administered 25 Gy of single fractionated radiation to the whole lung of unilateral lung;36 rabbits in the control group were sham-radiated.All rabbits were subsequently sacrificed at 1,6,12,24,48,72 h,and 1,2,4,8,1 6,24 weeks after radiation,and then six specimens were extracted from the upper,middle and lower fields of the bilateral lungs.The pathological changes in these specimens were observed with light and electron microscopy;the expression of tumor necrosis factor-α （TNF-a） and transforming growth factor-βl （TGF-β1） in local lung tissue was detected by immunohistochemistry.Results：（1） Radiation-induced lung injury occurred in all rabbits in the test group.（2） Expression of TNF-a and TGF-β1 at 1 h and 48 h after radiation,demonstrated a statistically significant difference between the test and control groups （each P 〈 0.05）.（3） Evaluation by light microscopy demonstrated statistically significant differences between the two groups in the following parameters （each P 〈 0.05）：thickness of alveolar wall,density of pulmonary interstitium area （1 h after radiation）,number offibroblasts and fibrocytes in interstitium （24 h after radiation）.The test group metrics also correlated well with the time ofpostradiation.（4） Evaluation by electron microscopy demonstrated statistically significant differences in the relative amounts of collagen fibers at various time points postradiation in the test group （P 〈 0.005）,with no significant differences in the control group （P 〉 0.05）.At greater than 48 h postradiation the relative amount of collagen fibers in the test groups significantly differ from the control groups （each P 〈 0.05）,correlating well with the time postradiat
Along with the development of digital X-ray imaging technology, a new, economical and practicalpaper-based output system gradually emerged. To reduce cost, more and more radiologic institutions began to change from film copies to lower-priced paper prints for documenting radiologic findings.Therefore, laser paper printers are frequently used as an alternative to duplicating film though the use of printed images is not yet widespread. The aim of this study was to compare the practical value of high-resolution paper printer with dry film copies for detecting small solitary pulmonary nodules （SPNs）.
HU Xiao-yunFANG Xiang-mingCAO YangHU Chun-hongYAO Xuan-junCHEN Hong-weiHU SuSHAO LingHU Gang-feng
