Quantitative Susceptibility Mapping for Following Intracranial Hemorrhage

Area of Science:

• Neuroimaging
• Radiology
• Medical Physics

Background:

• Intracranial hemorrhage (ICH) evolution is complex and traditionally assessed with CT.
• Conventional MRI sequences may not fully capture the dynamic changes in ICH.
• Quantitative susceptibility mapping (QSM) offers a novel approach to characterize tissue magnetic properties.

Purpose of the Study:

• To evaluate the utility of quantitative susceptibility mapping (QSM) for monitoring the longitudinal evolution of intracranial hemorrhage (ICH).
• To compare QSM-derived measurements with conventional CT and MRI findings.
• To assess the reproducibility of QSM in quantifying ICH over time.

Main Methods:

• Thirty-six patients with CT-confirmed ICH underwent serial MRI scans at 2, 7, and 30 days post-symptom onset.
• QSM was reconstructed from gradient-echo phase images acquired at 1.5 T or 3.0 T.
• ICH regions were segmented, and QSM values were compared with CT attenuation and conventional MRI intensities; reproducibility was assessed.

Main Results:

• Significant reductions in ICH susceptibility were observed between days 2-7 (P < .001) and days 7-30 (P = .003), reflecting disease progression.
• ICH areas measured by CT and QSM showed a strong linear correlation (r² = 0.98).
• QSM demonstrated excellent intra- and interobserver reproducibility (ICC > 0.96).

Conclusions:

• Longitudinal QSM effectively captures susceptibility changes in ICH across different disease stages, unlike conventional MRI.
• QSM provides a quantitative method to assess ICH iron content evolution.
• QSM shows promise as an advanced tool for managing and monitoring patients with intracranial hemorrhage.