An ioversol-enhanced micro-CT workflow for hematoma visualization and preoperative localization in a murine autologous blood model of intracerebral hemorrhage

Abstract

Abstract Autologous blood injection produces a discrete striatal clot in mice, but the hematoma is usually confirmed only after brain removal and sectioning, making craniotomy planning difficult for evacuation studies. To address this limitation, we mixed freshly collected autologous blood with ioversol and tested whether the resulting hematoma could be localized by micro-CT before surgery. Conventional CT and non-contrast micro-CT did not reliably identify the lesion, whereas ioversol-enhanced micro-CT clearly visualized the hematoma, with the strongest signal at an ioversol-to-blood ratio of 1:10. Lower ioversol ratios weakened the contrast signal, while neurological scores, balance beam performance, and section-based hematoma volumes were broadly comparable among the tested groups. No detectable increase in gross Evans blue extravasation or TUNEL-positive staining was observed at 24 h under dose-matched ioversol-only conditions. The 1:10 mixture was then used to guide a separate targeted bone flap for hematoma evacuation 24 h after ICH induction. Postoperative micro-CT and coronal sections documented reduction of the contrast-positive hematoma, although the faint residual signal overlapped with the surgical cavity and background density, precluding reliable residual-volume segmentation or calculation of evacuation efficiency. Thus, postoperative micro-CT was used as qualitative documentation of clot reduction. During 21 days of follow-up, exploratory analyses showed lower behavioral scores in operated mice, while perihematomal TNF-α, IFN-γ, and IL-6 levels were lower on day 7 than in non-operated ICH mice. These findings support a micro-CT-guided mouse ICH workflow for preoperative localization and surgical-window planning, while behavioral and cytokine outcomes should be interpreted as feasibility data rather than definitive evidence of surgical efficacy.