Utility of perfusion MRİ sequence ġn hemorrhagic brain tumors and follow-up of cases with brain tumor operation

İntroduction and Purpose: We aimed to investigate the effects of hemorrhagic and postoperative changes on multiphase and single-phase Arterial Spin Labelling (ASL) perfusion MRI and Dynamic Contrast Enhanced (DSC) Perfusion MRI diagnostic sensitivity and accuracy in brain tumor patients. Material and Method: A total of 95 patients with primary or metastatic brain tumors who histopathologicaly diagnosed or clinical and radiological follow-up were included in the study. All examinations were performed in the same session with 1.5 Tesla conventional unenhanced and contrast-enhanced MRI, unenhanced multiphase and single-phase ASL Perfusion MRI and DSC Perfusion MRI. A group (Group 1) was formed from preoperative (native) and nonhemorrhagic cases . Another group (Group 2) was formed from the cases of hemorrhagic tumor or the cases of the postoperative patients with the brain tumor who have hemorrhagic changes or artifacts. Postprocessed on workstation and prepared ASL and DSC perfusion maps. Maps were quantitatively and qualitatively assessed. In order to be able to measure quantitatively, ROI were placed on the lesion and white matter of the contralateral hemisphere on the perfusion maps and relative ASL and DSC rCBF ratios were calculated. These ratios were statistically analyzed separately in all patients and in Group 1 and Group 2 to investigate the diagnostic sensitivity, specificity and accuracy of both techniques. In addition, multiphase and single-phase ASL maps were compared among themselves in terms of recognizing the lesions. Results: The number of cases in Group 1 and Group 2 was 44 and 51, respectively. ROC analysis was used to determine the cut-off value providing the highest diagnostic sensitivity for both methods. When 1.4 was considered for malignancy criteria as the cut-off value for ROI measurements from ASL perfusion MRI, in all patients sensitivity, specificity and accuracy was 84,8% , 85,7% and 85%, respectively, in Group 1 was 90,5% , 82,6% and 86%, in Group 2 was 80%, 88,5% and 84%. When 1.6 was considered as the cut-off value for rCBF in contrast-enhanced DSC perfusion MRI, sensitivity, specificity and accuracy 82,6%, 81,6% and 82%, in Group 1 85,7%, 78,3% and 81%, in Group 2 80%, 84,6% and 82%, respectively. 64 cases had both multiphase and single-phase ASL maps. Ten (15.6%) of these cases could not be distinguished on a single-phase map, although undefined lesions could be selected on a multiphase map. Conclusion: As a result of the study, we found that the sensitivity of rCBF value was higher than that of rCBV in brain tumors. Sensitivity, specificity, positive predictive value, negative predictive value and accuracy of ASL technique found higher than contrast-enhanced DSC perfusion technique in all patients. ASL technique was more efficient in the nonhemorrhagic native group. Sensitivity falls in similar proportions in both ASL and DSC perfusion MRI methods in which cases involving susceptibility artifacts. In addition, multiphase ASL had more diagnostic value than single-phase ASL. Keywords: Brain tumors, perfusion, arterial spin-labeled (ASL) MRI, dynamic susceptibility contrast-enhanced MR imaging (DSCE), hemorrhagic brain tumors, postoperative changes