MRI results?

I am a 3 1/2 year survivor of invasive ductal. (Did chemo and rads and am on tamoxifen) I recently had an MRI along with my mammo.  Mammo said all was fine, but MRI found a 0.5 x 0.7 cm. bilobed enhancing lesion in the same breast as the previous lumpectomy (in a different quadrant).  Now I am scheduled for an ultrasound-guided biopsy.  What does the "bilobed" mean?  Can they do the ultrasound-guided biopsy if this lesion  does not show up on the  ultrasound?  I am postmenopausal, if that has any significance.

I wanted a "watch and wait" approach because I realize that MRIs have a high rate of false positives, but my doctor said "no."

Thanks for your help.

[Cleveland Clinic]

Dear Elle53:  Bilobed means that the abnormality appears to have two sections or lobes.  If the lesion is not visualized with ultrasound, it may be difficult to biopsy with this method and a discussion with the surgeon or radiologist may help to determine further steps if this is the case.  MRI’s do have a high incidence of false positive results but given your history, it may be that your doctor would rather pursue any abnormality earlier rather than later.  

[Elle53]

Guess I asked the wrong question.  I understand that bilobed mean 2 sections.  I was wondering if a lesion does have 2 sections, is that an onimous sign?  I know that spiculated is an onimous sign.  My last tumor was palpable and spiculated.  But I don't know if bilobed is a "good" sign or a "bad" sign.

Thanks to anyone who can help me with this!