Fig. 5.

In vivo factor-XIII (FXIII) imaging to localize venous cerebral thrombi in a mouse. A mouse with cerebral venous th rombosis and a cranial window (inset) received a fluorescent imaging agent (A15) that could visualize the activity of the FXIII coagulation enzyme. Intravital microscopy imaging showed that the imaging agent initially remained intravascular, producing a cerebral angiogram (A). The NIRF signal subsequently decreased in all but thrombosed areas (B; image captured at 30 minutes after A15 injection). The representative H&E sections (C and D; acquired by cutting along the yellow and blue lines of B, respectively) of the superficial brain at the location of the frontal tip of the thrombus signal (black arrow in B) show the corresponding thrombus (yellow and blue arrows, respectively). In addition to the main body of the thrombus, a smaller thrombus in the adjacent vessel (asterisk in D) exhibits an FXIII-related NIRF signal (asterisk in B). Modified from Kim et al.⁷⁰ with permission from the Korean Neurological Association. Scale bars: A, 1 mm; B, 150 µm. NIRF: near-infrared fluorescent.