Correlation and agreement between flexed and relaxed opening CSF pressure measurement in patients in the lateral recumbent position: 1A. Scatter plot showing the positive correlation between the opening pressure in the flexed position and the opening pressure in the relaxed position; however, the pressure values in flexed position tend to exceed those in the relaxed position as shown in the area between straight line (agreement line) and dot line (showed the F-OP value of 400 mmH2O). 1B. Bland-Altman plot showing the relation between the difference between F-OP and R-OP and the mean of F-OP and R-OP. There is a significant disagreement between the pressure values in different positions. The average of the difference (bias) is 18.02 (straight line) compared to the agreement line at zero (dotted) line. In addition, the 95% confidence of the bias is shown as the two dashed lines, which is between -30.12 and 66.16.