Objective:To explore the value of apparent diffusion coefficient （ADC） measurement of diffusion weighted imaging（DWI） in diagnosis of brain abscess.Methods:Ten patients with brain abscess （8 being histologically verified

2 clinically confirmed） were examined using conventional MRI and DWI before operations or medications.ADC values of pus

abscess walls

edema at the periphery of abscess and opposite normal white matters of all 10 cases were measured with b values （0 s/mm

2

and 1000 s/mm

2

） and their ADC mean values were calculated.Results:The ADC mean values in 10 cases of pus cavity

abscess walls

edema at the periphery of abscess and opposite normal white matters were （0.57±0.11）×10

-3

mm

2

/s

（1.14±0.06）×10

-3

mm

2

/s

（1.74±0.21）×10

-3

mm

2

/s and （0.77±0.05）×10

-3

mm

2

/s

respectively.The differences in the ADC mean values were significant between either two parts of pus cavity

abscess walls

edema at the pariphery of abscess and opposite normal white matters（P

<

0.05）.Conclusion:A significant decrease in ADC value of pus cavity can be found in brain abscess

and there are significant differences in ADC value between either two parts of pus cavity

abscess walls

edema at the periphery of abscess and opposite normal white matters.ADC value measurement of DWI is very important in diagnosis and differemial diagnosis of brain abscess.