Vivification it's not the official name of the skill you're talking about, it's Acceleration. I am aware that some languages (such as Portuguese) translated it to Vivify, which is a similar concept but with a broader background. Anyway, here's how the mechanic works:
Instead of nutritious the spell, and taking a penalty of -2 (or -1 with the correct quality) in all the controls, you can decide Speed up the spell spending north karma points, 1 per Force point you want to use the spell (and a minimum of 1 karma point), then send it normally to decide the effects if necessary (write down the net impacts). Then you do not need to hold the spell, the metamagic ability is doing that using the karma you spent on it. Also, if someone tries to counterpose and eliminate the target's spell, you get an additional set of dice equal to the karma spent on it.
For example, you want to levitate with force 4, spend 4 karma, throw levitate and now you do not have to hold it anymore. Anyone who tries to eliminate the spell will have to pass a check using their Counter Spell Monkey + Magic[Astral] against the power of your spell (4) + magic + 4 (the karma spent), so 8 + your magic attribute, since you used a force spell 4.