Table 3:

Causative findings of false results on spot radiographs

Findings	Numbers
False-negative
Inadequate block	10
Insufficient infiltration with injectate leakage		4
Insufficient passage of injectate from a blockade by a huge herniated disk		4
Intraepineural injection		2
Not identified on spot radiographs	10
False-positive
Overflow of injectate into the epidural space or into an adjacent affected level	4
From an injected upper unaffected level		2
From a injected lower unaffected level		2
Not identified on spot radiographs	4