[Pneumomyelography with regard to cerebrospinal fluid replacement].

Spinal arachnoidal space was investigated with cerebrospinal fluid drained and replaced with air. Some adequate parameters of the CSF replacement with gases were calculated according to rules derived from 140 pneumomyelographic investigations in patients with lumbar osteochondrosis: baseline CSF pressure, its withdrawal time and total volume. These parameters reflect the volume of arachnoidal space and its conductivity. Due account of these data allowed to determine the beginning of gas insufflation and its total amount.