Does ILC not show up on PET scans? Anyone tried different contrast?

I was diagnosed with stage 4 ILC about 6 months ago. They found out that the tumors I had from my hysterectomy 3 1/2 years ago were actually ILC so I was essentially misdiagnosed for 3 years. My question is about ILC and PET scans. On my scans basically nothing shows up. The only thing that shows the cancer is MRI’s. They are using ctDNA to determine treatment response. They confirmed that both my previous tumor from the hysterectomy and from bone metastasis in my spine is indeed ILC via genetic testing. I wonder if anyone else has had this happen. I had a regular PET scan and it showed basically zilch but I have MRI’s that show it in my spine pelvis ribs sternum and arms and in the beginning I pushed hard for a PET because I was scared about where else it was that I had not had an MRI. I know there is a PET scan that uses a different type of contrast and is better for ILC. Has anyone had this type of PET and did it show your metastasis.