Figure 1
Molecular imaging results in advanced stage lymphoma-bearing mice. (a) PET/MR image in advanced stage: FDG-avid enlarged mesenteric lymph nodes are visible (horizontal plane, representative image). (b) Colour overlay of Cerenkov light emission (CLI) on the white light photograph of the intestinal preparation, with the spleen at the top of the image. FDG-avid lymphomatous regions and foci in the peritoneum and omentum are coloured orange. The H&E staining (upper right) depicts the diffuse infiltration of the omentum (scale bar = 200 µm), in the area marked by an ellipse on the CLI picture (scale bar = 200 µm). Lower-right image with high-power magnification shows lymphoblastic dominance corresponding to the area marked with rectangle (scale bar = 50 µm). Representative images from a cohort of mice with n = 3. (c) Ex-vivo CLI in late stage lymphoma: FDG-avid Bc-DLFL.1 lymphoma foci with H&E staining in mesenteric lymph node (top) and mesenterium (bottom) CLI (left) and, Stereomicroscopic picture of the intestinal preparation (middle), Histology (right): the red arrow shows that the upper encircled area in the stereomicroscopic picture emits Cerenkov light and corresponds to the mesenteric lymph node complex, containing a massive lymphoma infiltrate demonstrated on the top right image (connected by dashed red arrow). The bottom green arrow connects one branch of the mesentery with lesser Cerenkov signal intensity (marked with ellipse), with an extensive lymphoma infiltrate surrounding the mesenteric artery (arrowhead). Scale bar = 200 µm. Representative images from a cohort of mice with n = 3. (d) Flow cytometric analysis of enlarged mesenteric lymph nodes (mLN) reveals residual small-sized (in R1 gate) CD3-positive T cells and B220-positive B cells (left, middle), latter cells mostly co-expressing IgM (left, bottom), and large number of blast-sized cells (in R2 gate) displaying B220 B-cell marker and absence of CD3-positive cells (right, middle), but lacking surface IgM and CD3 (right, bottom). Lymphocytes from peripheral lymph nodes (pLN) do not contain a distinguishable blast population within the R2 gate (right, top). Representative images from a cohort of mice with n = 3.
