Intracranial Hemorrhage Patient CSF Susceptibility Variation: Implications for Quantitative Susceptibility Mapping Reference Selection.

QSM is an emerging MR technique with many clinical applications, especially in the brain. CSF has been used by many researchers as the reference region to obtain quantitative QSM values for inter-subject comparison. Here, we demonstrate the QSM values at hemorrhagic CSF sites are significantly different from that at non-hemorrhagic CSF sites in the same patient with various types of intracranial hemorrhage. This finding has significant clinical implication as selection of CSF as the reference region should be made with caution in patients with intracranial hemorrhage.