The added value of the CSF cleft on ADC in distinguishing extra-axial from intra-axial tumors

We investigated whether the CSF cleft sign on ADC maps is beneficial for differentiating extra-axial tumors from intra-axial tumors. Seventy-seven intracranial tumor patients were reviewed. Visual grades of CSF cleft sign on T2WI and ADC were compared. The diagnostic performance of CSF cleft sign using ADC plus T2WI was compared with that using T2WI alone. A CSF cleft was more easily visualized on ADC (P < 0.01). The diagnostic performance of CSF cleft sign significantly increased in accuracy of 85.7 to 96.1% (P < 0.01) when ADC and T2WI were used together.