my first reaction is EEK !
my first experience with it was in 1979, i was told a routine test to see if my issue was with a disc or not. After a newbie tech told me i was his first for this procedure, i was not alarmed until i woke up 3days after the test with a headache where it felt i had an elephant sitting on my head, the damage was done, my L4-L5 disc was completely blown out, told i was to have surgery for the disc, but hey, it was on the house as long as i agreed not to sue their pants off..............................
my second in 2002, i was tense as heck, and nervous for a week before, tried everything i knew to get out of it, but did it with my fingers and toes crossed, and it was easy with a capable Doc behind the needle, all the worry was for nothing, but then again it usually is.........