TivoDad--(and tyboyz)
Hopefully I can quell your fears just a little...sorry if htis is long--don't mean to bore you!!

I've just been where you are it when it comes from left field-and you hear "spot" it scares the hell out of you. I know abt the liver--not so much abt the lungs. Barb (prior post) gave you great info on that.
The radiologist usually can tell if spots are suspicious or not. They read this stuff day in & day out-that's their job. If you feel the need, by all means ask for a 2nd opin.(The hopsital at which I have my CT's done have two radiologists read all scans.) The radiologist reads scan, then recommends the rescan time based on that facility's standard--some use 3 mos, some use 6 for rescan/check for any change in size. This "spot" could be a couple of things-2 very(most)common usually have no treatment except to recheck 3-6 mos: 1) hemangioma--a cluster of blood vessels grouped together anywhere in or on the liver-can be referred to as a mass, spot or nodule on the report...In rare cases if it gets large(tennis ball size)they may remove it w/no complications and the prognosis is great. 2)fatty tumor,cyst or nodule...very common also-again no treatment but the rescan...(or rarely- removal if it gets really large) Diet and exercise can reverse this w/in a matter of months. ("fatty liver" is when your liver has fat around it due to poor diet and/or you're a little overweight)These are non-life threatening and not cancer--they just sound like it. Most ppl that have them don't know it until they are checked for something else-usually abdominal pain--they show up on the U/S or CT scan of the abdomen. I have only had CT's w/contrast-I think they pick up everything better-so it's very possible the spots were there during your first ct. Did you have your CT and U/S done at the same facility? If so, the radiologists take all that into account and should have your prior test results.
Now the waiting begins-if it were suspect of cancer-they'd probably want to rescan sooner(usually w/MRI) and be talking biopsy. Did either one of you guys have Liver Function Test (blood work) done? Did they give you any AST or ALT info?
Hopefully this helps you guys a little. I know what it's like-you get this info-then THEY want to wait-and you're thinking, "Wait 3 mos?? It's not YOUR liver!!" They're not the ones losing sleep over it. Stress will make things worse in matters of the liver--try to relax... I have both on my liver-fatty tumor and hemangioma...am in the middle of getting rescanned for two new "lesions" on the other lobe (That's another *nice and patient friendly* word they use-haha) so I'm w/you. My fatty tumor was found by U/S then confirmed by CT--hemangioma was found w/CT scan but I was told it had probably been there for a while--just not picked up. So-it does happen.
Tyboys--that's good there was no change when you had your 3 mos rescan...they'll do it again and then maybe space it out to 6 mos or a year.
Hang in there--let me know abt your ALT and AST if you had them done.
Gina