Statistical analysis
The Pearson Chi-squared test (χ2) was used to compare radiological and
pathological stages. The concordance between the radiological and
pathological stages was evaluated by using the к statistic, which is a
measure of agreement between observers that corrects for chance
agreement. The grade of concordance has been defined as ‘fair’, for a of
0–0.2, moderate for 0.21–0.45, substantial for 0.46–0.75 and almost
perfect for 0.76–0.99 [9]. Statistical analysis was performed using
SPSS software package version 22.0 (Statistical Package for Social
ScienceTM, Chicago, IL, USA) and p < 0.05 was considered to
indicate statistical significance.