Possible brain met – need some perspective

Hi all, as much as I am thankful for you all being here, I sure wish I was NOT visiting tonight (and I know you all understand that!)  So here is the short, condensed story:

4/08 Dx Stage III on left foot, mets to left inguinals and surrounding tissue, removed via surgery 5/08.

Clear scans until 4/10 when nodules in lungs caught on PET/CT (6mm left/8mm right lung), monitored with scans for almost a year, then right nodule removed 2/11 (2.1 cm) and left nodule removed 4/11 (.9 cm)  

Hi all, as much as I am thankful for you all being here, I sure wish I was NOT visiting tonight (and I know you all understand that!)  So here is the short, condensed story:

4/08 Dx Stage III on left foot, mets to left inguinals and surrounding tissue, removed via surgery 5/08.

Clear scans until 4/10 when nodules in lungs caught on PET/CT (6mm left/8mm right lung), monitored with scans for almost a year, then right nodule removed 2/11 (2.1 cm) and left nodule removed 4/11 (.9 cm)  

PET/CT of 4/11 (post-op) showed all clear except signs of surgery.  PET scan of June 2011, still clear.  Brain MRI of 4/08 and 1/11 both were clear of any abnormalities.

Today, 9/12/11, I had a PET/CT and for the first time, had no contrast with the CT (long story).  I wasn't home 15 minutes and my oncologist called to tell me there was a 1.6 cm lesion in the right frontal lobe of my brain.  It showed no abnormal fdg uptake.  I don't know if having no contrast on the CT made any difference on the next step but she wanted me to get a brain MRI asap.  So that is in the works for this week hopefully.  Otherwise, everything is clear.

So, my question for those with brain mets is do they ever show up with no abnormal fdg uptake?                                    Can they appear so quickly (in just 3 months) and be to this size already? (My lung nodules were very slow growing) If I had had contrast with CT scan, could it have given any more definitive info (such as it being a vascular issue and lack of contrast would not show the vascular system)?

My husband reminded me that I hit my head pretty hard about 3 weeks ago getting something out of his car.  We are pretty sure it was on the right side and it was bad enough, I felt like I was going to pass out.  From what I read online tonight, head injuries are the most common cause of brain lesions in the frontal lobe.  So I am hopeful.

Any info, suggestions, questions to ask, etc. are welcome.  I just know that there will be people on here that have been down this road.  Thank you for taking the time to read this (and answer if you are able).

Blessings,

Shari (used to be Shari in Cal screen name but changed it because my teen son accidentally came across my posts while doing research on his computer.  So it is still me, just a new screen name to protect my identity a little and my son's concerns).