Having just obtained my copy of Tom Hale's excellent book this week I
enjoy having a project to use it for!...

As to the question of omnipaque (strength 240) for the myelogram - it is
listed in Tom's book under Radiopaque agents, and although it contains
iodine, there is very little free iodine (less than 0.005%) that can get
into mother's milk - most is excreted via mothers' kidneys within 24hrs.
The contrast agent (vs the free iodine) is passed unchanged into
mothers' milk but fortunately is not orally absorbed by the infant
(<0.1%), and some of these agents (not sure about omnipaque
specifically) are cleared for pedriatric use anyway!...  although
apparently the recommendations from the producers are for 24hr break
from BF no adverse affects have been reported...
The references quoted by Tom are:
1. Pharmaceutical Manufacturers Package insert, 1993, 1994
2. Nielsen ST et al.  Excretion of Iohexol and metrizoate in human
breast milk.  Acta. Radiol. 28:523-26, 1987
3. Fritz-John TP et al Intravenous urography during lactation.  Br J
Radiol 55:603-5, 1982

Hope this helps! - and all credit to Tom of course!

Joy MMBS DRACOG  Albany, australia