A Control Study Of PCASL And DSC-The Evaluation Of Cerebral Ischemia On Different Severities And Different Vascular Territories

Objective: To compare the capacity of p CASL(pseudo-continuous arterial spin labeling,p CASL) and DSC-PWI(dynamic susceptibility contrast enhanced perfusion weighted imaging, DSC-PWI) to evaluatethe cerebral ischemia on differentseveritiesand in different vascular territories, explore the use value of p CASL and providereferencesof the clinical diagnosis and treatment for patients with acute ischemic cerebrovascular disease.Subjects and Methods:This study involved 76 patients with acute cerebral infarction or TIA(transient ischemic attack, TIA). We collected their basic information and related clinical history. Subjects with brain trauma or surgery, tumors, severe mental disorders or autoimmune diseaseswhich may affect cerebral blood flow were excluded. All patients underwent MRI on Siemens 3.0T TIM Trio system utilizing a 8-channel head coil, including routine sequences, MRA(magnetic resonance angiography,MRA), DSC and p CASL. The data was processed by the Matlab7.11.0 and SPM 8 software. We selected bilateral brain parenchyma as ROI(region of interest, ROI) supplied by ACA(anterior cerebral artery, ACA), MCA(middle cerebral artery, MCA) and PCA(posterior cerebral artery, PCA). The hemodynamic parameters of DSC and p CASL were measured by PMA and MRIcron, respectively. Statistical analysis was performed with SPSS 17.0 software:(1) We analyzed the susceptibility of two methods tocerebral ischemia on different severities;(2) We compared their correlation of DSC and p CASL in different vascular territories.Results:(1) On different severities of cerebral ischemia, the difference of absolute value between p CASL-ATT and p CASL-CBF were statistically significant(P<0.001). What’s more, the differences of time parameter ATT on each severitywerestatistically significant(P < 0.001), the correlation between ATT and timeparameters of DSC were good.(2) In ACA territories, similar hemodynamic parameters of p CASL and DSC showed moderate correlations, P< 0.001.The Spearmancorrelation coefficients of p CASL-r ATT and DSC-r MTT, DSC-r TTP, DSC-r Tmax were 0.673, 0.603, 0.568, respectively; Spearman correlation coefficients of CBF and CBV were 0.722 and 0.795, respectively.(3) In MCA territories,the correlation of their similar hemodynamic parameters were the hightest, P < 0.001. Time parameters p CASL-r ATT and DSC-r MTT, DSC-r TTP were highly correlated(r=0.839, 0.832); p CASL-r ATT and DSC-r Tmax showed a moderate correlation(r=0.720); there were a high correlation of CBF(r=0.847) and a moderate correlation of CBV(r=0.609).(4) In PCA territories, similar hemodynamic parameters of p CASL and DSC showed moderate correlations, P < 0.001. The Spearman correlation coefficients of p CASL-r ATT and DSC-r MTT, DSC-r TTP, DSC-r Tmax were 0.716, 0.644, 0.622, respectively; Spearman correlation coefficients of CBF were 0.653; the CBV were 0.756.Conclusion:(1) The time parameterofp CASL, ATT can be used to evaluate the severities of cerebral ischemiain patients with acute ischemic cerebrovascular diseases, and help clinicians to identify patients with ischemic penumbra as well as its ranges, which is important to treatmentselection, it confirms the feasibility of p CASL in acute ischemic cerebrovascular diseases in imaging examination.(2) When estimateing the blood perfusionin different vascular territories, similar hemodynamic parameters of p CASL and DSC were moderately or highly related, their correlations were the hightest in MCA territories.