Value of apparent diffusion coefficient of magnetic resonance diffusion-weighted imaging for differential diagnosis of common pediatric posterior fossa tumors / 中华实用儿科临床杂志

ABSTRACT

Objective To investigate the value of apparent diffusion coefficient (ADC) of magnetic resonance diffusion-weighted imaging(DWI) for differential diagnosis of common pediatric posterior fossa tumors.Methods Forty-five children with posterior fossa tumors confirmed by surgery and pathology,who were hospitalized at the First Affiliated Hospital of Henan University of Traditional Chinese Medicine from January 2013 to December 2015 were analyzed by using retrospective case-control study,including 24 cases of medulloblastomas,12 cases of pilocytic astrocytomas,and 9 cases of ependymomas.All the children were examined by preoperative magnetic resonance imaging(MRI) plain scan,enhanced scan and DWI.The minimum ADC (ADCmin) values of different tumors were measured,and the receiver operating characteristic (ROC) curve was delineated.The threshold value of ADCmin,sensitivity,specificity and the accuracy for differential diagnosis of 3 tumors were obtained.Results The ADCmin value of medulloblastoma was the lowest [(0.482±0.290)×10-3 mm2/s],and the ADCmin value of pilocytic astrocytoma was the highest [(1.592±0.320)×10-3 mm2/s],while that of ependymoma was in the middle [(0.826±0.390)×10-3mm2/s].There was a significant difference in ADCmin value among 3 tumors(F=48.415,P=0.000).The threshold value of ADCmin to distinguish medulloblastoma from ependymoma was 0.672×10-3 mm2/s,the sensitivity was 97.0%,the specificity was 100.0%,and the diagnostic accuracy rate was 97.8%.The threshold value ADCmin to distinguish ependymoma from pilocytic astrocytoma was 1.058×10-3 mm2/s,the sensitivity was 95.7%,the specificity was 97.9%,and the diagnostic accuracy rate was 94.7%.Conclusions The minimum ADC value can be used as a supplementary means for conventional MRI,which is helpful for the differential diagnosis of pediatric posterior fossa tumors.