Objective To study the values of apparent diffusion coefficient (ADC) changing with time and space in cerebral infarction,and to provide the evidence in defining the infarction stages.Methods 117 work-ups in 98 patients with cerebral infarction (12 hyperacute,43 acute,29 subacute,10 steady,and 23 chronic infarctions) were imaged with both conventional MRI and diffusion weighted imaging.The average ADC values,the relative ADC (rADC) values,and the ADC values or rADC values from the center to the periphery of the lesion were calculated.Results The average ADC values and the rADC values of hyperacute and acute infarction lesion depressed obviously.rADC values in hyperacute and acute stage was minimized,and progressively increased as time passed and appeared as "pseudonormal" values in approximately 8 to 14 days.Thereafter,rADC values became greater than normal in chronic stage.There was positive correlation between rADC values and time[ (174 ±3.47)% vs (58±6.75)%,t =2.03,P ＜0.05 ].The ADC values and the rADC values in hyperacute and acute lesions had gradient signs that these lesions increased from the center to the periphery.The ADC values and the rADC values in subacute lesions had adverse gradient signs that these lesions decreased from the center to the periphery.Conclusion The ADC values of infarction lesions have evolution rules with time and space.The evolution rules with time and those in space can be helpful to provide the evidence in guiding the treatment or judging the prognosis in infarction.

Objective To analyzed the CT features of struma ovarii(SO).Methods The clinical data and CT features of eleven patients with pathologically proved SO were retrospectively analyzed.CT features were compared with pathological results.Results(1)All tumors were unilateral.On non-enhanced CT,the lesions presented as well-defined irregular masses,which were cystic-solid(n=6,54.5%)or cystic(n=5,45,5%).(2)The cystic portions presented as well-defined,multiple,various size,and there were entire cystic walls with smooth inner wall.The tumors(63.6%)showed a high at attenuation lesions in the cyst portion of the mass on precontrast scans and the attenuation ranged from 72.3 to 113.5 Hounsfield units(HU)in 7 cases.The solid portions showed irregular tissue density,and were often distributed in the cysts.After contrast administration,the cystic portions showed no enhancement,the solid portions marked enhancement,and the cystic walls demonstrated no moderate,or marked enhancement.(3)The tumors(72.7%)showed stippled calcification in solid portions and(or)cystic wall in 8 cases.(4)The tumors(27.3%)accompanied with mature cystic teratomas,and showed fat density in 3 cases.(5)The tumors(27.3%)accompanied a great of ascites and pleural liquid.Conclusion CT characteristics of SO might be of great value for the diagnosis.