Analysis of magnetic susceptibility in acute cerebral ischemia using quantitative susceptibility mapping / 中国医学影像技术

ABSTRACT

Objective To analyze the changes of susceptibility in acute cerebral ischemia (ACI) using quantitative susceptibility mapping (QSM).Methods Twenty-three patients with ACI who met the criteria underwent conventional brain MR and QSM scan,and the susceptibility maps were obtained with QSM post-processing software in image processing workstation.According to DWI images,ROIs were manually drawn on lesions of ACI to obtain magnetic susceptibility on susceptibility map,including cortical gray matter (CGM),subcortical white matter (SWM),caudate (CA),globus pallidus (GP),putamen (PU),thalamus (TH),substantia nigra (SN),dentate nucleus (DN) and pons (PO).Then magnetic susceptibility of contralateral position was obtained.According to whether cerebral microbleeds (CMBs) were observed,the ACI patients were divided into CMBs group and non-CMBs group.The magnetic susceptibility of groups and different ROIs of ACI and the contralateral area were compared statistically.Results There was significant difference in magnetic susceptibility between CMBs group [(79.04 ± 52.25) × 10-9 ppd] and non-CMBs group ([-4.01 ± 44.57] × 10 9 ppd;Z=-3.297,P =0.001).The difference of magnetic susceptibility between the lesion side and the contralateral side ([-12.10±16.75]× 10-9 ppd) was statistically significant in CMBs group (Z=-3.296,P=0.001),but not in non-CMBs group (contralateral side [1.61 ±32.77] × 10-9 ppd;Z=-0.157,P=0.875).According to the location of ROIs,magnetic susceptibility had statistical differences only in PO,CGM and contralateral side (Z=-2.023,--3.130,P=0.043,0.002).Conclusion QSM can be used to quantitatively analyze magnetic susceptibility of ACI lesions and find CMBs,therefore is helpful to guiding treatment.