Fig. 6
Changes in vasculature of 4T1 tumors after ICI treatment. a Exemplary Ktrans and T1 maps post-gadofosveset injection of ICI-treated 4T1 tumors compared to untreated controls. b Area under the curve (AUC), maximum slope (slopemax), Ktrans and ∆T1 analyses indicating increasing tumor perfusion and permeability parameters on day six and day nine. Each dot represents one animal, with horizontal lines indicating the mean. c H&E stainings of 4T1 tumor sections showing strongly increasing intratumoral hemorrhage after treatment. CD31 expression is reduced. Scale bars represent 50 µm. d Transmission electron micrographs (TEM) of 4T1 tumors. Untreated 4T1 tumors show a thin endothelial layer with short interruptions (dashed circles). After ICI treatment, endothelial layers are thin, showing very large interruptions (dashed ovals). Electron dense contrast agent is visible intravasal (white circle) and extravasal (black circles). Scale bars represent 1 µm. e erythrocyte, el endothelial layer, bl basal lamina, cf collagen fibrils. ***p < 0.001, ****p < 0.0001