Statistical methods
Statistical analysis was performed with MATLAB 2015b program (MathWorks
Inc., Natick, MA, U.S.A.). Patients with MSFB were divided into two
groups based on whether they presented IH on CT images; clinical
characteristics and CT findings were compared between groups. Univariate
analysis of categorical variables was performed using the χ2 test or
Fisher’s exact test, where appropriate. Univariate analysis of
continuous variables was performed using the Mann–Whitney U test.
Logistic regression analysis was performed to evaluate the associations
of multiple different variables with MSFB without IH. For each
significant independent variable, the odds ratio (OR) and 95%
confidence interval were calculated. A P-value of <.05 was
considered to be statistically significant.