Purpose: To compare the interobserver and intraobserver reliability of mean apparentdiffusion coefficient (ADC) values using contrast-enhanced (CE) T1 weightedimage (WI) and T2WI as structural images between manual and semiautomaticsegmentation methods.
Materials and Methods: Between January 2011 and May 2013, 28 patients whounderwent brain MR with diffusion weighted image (DWI) and were pathologicallyconfirmed as having glioblastoma participated in our study. The ADC values weremeasured twice in manual and semiautomatic segmentation methods using CE-T1WIand T2WI as structural images to obtain interobserver and intraobserver reliability. Moreover, intraobserver reliabilities of the different segmentation methods wereassessed after subgrouping of the patients based on the MR findings.
Results: Interobserver and intraobserver reliabilities were high in both manualand semiautomatic segmentation methods on CE-T1WI-based evaluation, whileinterobserver reliability on T2WI-based evaluation was not high enough to be used ina clinical context. The intraobserver reliability was particularly lower with the T2WI-basedsemiautomatic segmentation method in the subgroups with involved lobes ≤2, with partially demarcated tumor borders, poorly demarcated inner margins of thenecrotic portion, and with perilesional edema.
Conclusion: Both the manual and semiautomatic segmentation methods on CET1WI-based evaluation were clinically acceptable in the measurement of mean ADCvalues with high interobserver and intraobserver reliabilities.