Objective To explore the value of diffusion weighted imagine(DWI) and magnetic resonance angiography(MRA) for the clinical significance in acute cerebral infarction in the early stage.Method The results of DWI and MRA and traditional CT and routine MRI in 30 patients with acute cerebral infarction were analyzed.Result Ultra-acute and acute cerebral infarction could be shown on DWI,which may not be shown on CT and T 2.WI.The focus that were shown on T 2.WI were more clearly shown on DWI.Focus and degree of intracranial vascular lesion could be detected rapidly.Conclusion DWI and MRA are sensitive for diagnosis in the early stage of acute cerebral infarction.Cerebral constitution and cerebral vessels can be shown by DWI and MRA,thus offering reliable imaging data for thrombolytic therapy.

Objective To assess the value of spectral CT in differentiating benign and malignant serous cavity effusion in vitro.Methods 41 plastic tubes filled with serous cavity effusion underwent spectral CT imaging.The gemstone spectral imaging(GSI)viewer was used to measure the mean CT values of water -iodine concentration, iodine -water concentration,monochromatic images(40 -140KeV,interval of 5KeV),140KVp QC,and EFF -Z. Slope of spectral curve was measured also.Based on clinical and pathological diagnosis,30 cases of benign and 11 cases of malignant serous cavity effusion were compared.The difference of the spectral characteristic parameters was evaluated statistically by independent -samples t test using SPSS 18.0.Results The EFF -Z,water -iodine concentration,iodine -water concentration,and slope of spectral curve[7.26 ±0.25,(1 021.82 ±6.37)mg/mL, (-3.23 ±1.53)mg/mL,0.26 ±0.12]of benign serous cavity effusion showed no statistically significant differences between the malignant group[7.31 ±0.10,(1 016.17 ±5.32)mg/mL,(-3.06 ±1.18)mg/mL,(0.24 ±0.10), t =0.652,2.016,0.332,0.482,all P >0.05 ].There were statistically significant differences on 55 -140 KeV between the two groups[(4.87 ±7.13)and (10.66 ±6.70),(7.17 ±6.48)and (12.71 ±5.94),(9.58 ±6.11) and (14.96 ±5.65),(11.63 ±5.97)and (16.77 ±5.52),(13.31 ±5.93)and (18.36 ±5.52),(14.66 ± 5.98)and (19.52 ±5.52),(16.06 ±6.06)and (20.90 ±5.63),(17.03 ±6.10)and (21.42 ±5.88), (17.58 ±6.12)and (22.29 ±5.59),(18.05 ±6.14)and (22.74 ±5.49),(18.52 ±6.17)and (23.19 ± 5.51),(18.74 ±6.20)and (23.33 ±5.46),(19.16 ±6.20)and (23.80 ±5.47 ),(19.30 ±6.26 )and (23.87 ±5.45),(19.57 ±6.26)and (24.19 ±5.48),(19.66 ±6.28)and (24.21 ±5.43),(19.92 ±6.31) and (24.46 ±5.44),(20.00 ±6.32)and (24.53 ±5.43),t =2.339,2.474,2.544,2.489,2.456,2.356,2.301, 2.060,2.231,2.223,2.206,2.161,2.188,2.138,2.162,2.122,2.114,2.104,all P <0.05].However,there were no statistically significant differences on 40 -50 KeV[(-5.51 ±11.82)and (0.96 ±11.59),(-0.41 ±9.77) and (5.75 ±9.85),(2.47 ±8.21)and (8.19 ±8.11),t =1.559,1.785,1.984,all P >0.05].The difference be-tween benign and malignant effusion was statistically significant on 140KVp QC also [(10.25 ±6.96,16.60 ±6.84) (t =2.601,P =0.013)].Conclusion Some spectral CT characteristic parameters especially 55 -140 KeV mono-chromatic images can differentiate benign and malignant effusion.Spectral CT maybe afford a new method to differenti-ate benign and malignant effusion.

Objective To explore the feasibility of in vitro biological soft tissue imaging by using synchrotron radiation phase contrast CT.Methods Three samples of resected human cardia,two samples of resected human esophageal carcinoma and esophagus,as well as two samples of middle cerebral artery tissue extracted from corpses were fixed and airdried at room temperature for synchrotron radiation phase contrast CT imaging.The images of soft tissue structures were observed and compared with pathological findings.Results The images of synchrotron radiation phase contrast CT showed three-layer structure of cardia and esophagus,mucous,submucosa and muscular layer.The surface of mucous layer was smooth.The images of esophageal carcinoma showed cancerous tissue infiltrating esophageal wall.The wall and lumen of cerebral arteries could be also clearly displayed.Conclusion Synchrotron radiation phase contrast CT imaging can clearly display fine structures of in vitro biological soft tissue.