Table 2. Contrast Medium Spread in Cephalad and Caudal Directions, by Group: Lateral Image.

Data are expressed as number of levels and are presented as median (interquartile range). Group A: 1 ml contrast medium injection in thoracic transforaminal epidural block, Group B: total of 2 ml contrast medium injected, Group C: total of 3 ml contrast medium injected. ^*In bidirectional spread, the difference within group (cephalad vs caudal) are significant (P value < 0.05) and direction is caudal < cephalad. ^†In cephalad spread, the difference among groups are significant (P value < 0.001) and the direction is Group A < Group B < Group C. ^‡In caudal spread, the difference among groups are significant (P value < 0.001) and the direction is Group A < Group B < Group C.