Objective    To evaluate the diagnostic value of  dynamic susceptibility T

2

*

-weighted contrast-enhanced perfusion MR imaging for pseudotumor demyelinating lesion in the central neuronal system.     Methods    Totally 2 pathologically proved cases and 7 clinically proved cases of pseudotumor demyelinating lesions in the central neuronal system were retrospectively analyzed with dynamic susceptibility T

2

*

-weighted contras

t-enhanced perfusion MR imaging

and there were 12 lesions included which diameters were all more than 2 cm.   The maximum relative regional cerebral blood volume (rCBV)

the maximum relative regional cerebral blood flow （rCBF)

and the maximum relative regional mean transit time（rMTT）were calculated according to perfusion MR data. The perfusion values from 12 patients with intracranial neoplasms served as control

which have very similar features of pseudotumor demyelinating lesions from conventional MR images.     Results    The rCBV

rCBF and rMTT mean values of pseudotumor demyelinating lesions were (1.17±0.32)

(1.09±0.23) and (1.12±0.40) respectively; the rCBV

rCBF and rMTT mean values of intracranial neoplasms were (4.41±2.86)

(2.25±0.64) and (2.06±1.25) respectively; the difference in rCBV

rCBF and rMTT values between the 2 groups was statistically significant respectively (P＜0.05).     Conclusion    Dynamic susceptibility T

2

*-weighted contrast-enhanced perfusion MR imaging is a useful diagnostic tool in differentiating pseudotumor demyelinating lesions from intracranial neoplasms.