In this study the investigators would like to describe FDG-PET/CT responses in patients who are receiving CART-19 immunotherapy for Follicular Lymphoma (FL), Diffuse Large B-cell Lymphoma (DLBCL), and Mantle Cell Lymphoma (MCL) as part of UPCC #13413. Subjects will undergo two FDG-PET/CTs. One performed within 6 weeks of CART-19 infusion and a repeat scan at about 1 month after infusion.

In this study the investigators described FDG-PET/CT responses in patients who were receiving CART-19 immunotherapy for Follicular Lymphoma (FL), Diffuse Large B-cell Lymphoma (DLBCL), and Mantle Cell Lymphoma (MCL) as part of UPCC #13413. Subjects underwent two FDG-PET/CTs. One performed within 6 weeks of CART-19 infusion and a repeat scan at about 1 month after infusion.

Inclusion Criteria:

• Subjects enrolled on the study UPCC 13413 Pilot Study Of Redirected Autologous T Cells Engineered To Contain Anti-Cd19 Attached To Tcr And 4-1bb Signaling Domains In Patients With Chemotherapy Resistant Or Refractory Cd19+ Lymphoma CART-19 autologous T-cell trial with relapsed or refractory DLBCL and FL. As this is a pilot study, we plan to enroll 4 subjects from the two disease types of interest.
• Subjects ≥ 18 years of age
• Subjects able to provide informed consent and agree to comply with study procedures

Exclusion Criteria:

• Subjects who are pregnant or lactating.
• Subjects will be co-enrolled in this study and UPCC 13413 and therefore must comply with the UPCC 13413 Pilot Study Of Redirected Autologous T Cells Engineered To Contain Anti-Cd19 Attached To Tcr And 4-1bb Signaling Domains In Patients With Chemotherapy Resistant Or Refractory Cd19+ Lymphoma requirements pertaining to pregnancy, lactation, conception and contraception use throughout their participation in both studies.

Subjects with DLBCL and FL treated on a phase I study with Autologous T cells