Potential role of CT perfusion parameters in the identification of solitary intra-axial brain tumor grading.

In this study, neoplastic perfusion abnormalities were investigated by computed tomography perfusion (CTP) scanning in 38 patients with solitary intra-axial brain tumors (19 with high grade gliomas, 7 with low grade gliomas and 12 with brain metastasis). Regional cerebral blood flow (rCBF), cerebral blood volume (rCBV), mean transit time (rMTT) and permeability surface flow (rPSF) levels were measured in two different regions of interest: (1) enhancing or non-enhancing tumor tissue and (2) a mirror area of apparently normal brain tissue located in the contralateral hemisphere. rCBF mean levels were greater in tumoral tissue than in the contralateral area for high-grade gliomas (p < 0.02). rCBV and rPSF mean values were higher in tumoral tissue than in the contralateral area for high-grade gliomas (p < 0.01 and p < 0.05, respectively) and metastasis (p < 0.05 and p < 0.001, respectively). rCBV mean values of tumoral tissue were greater in high-grade than in low-grade gliomas (p < 0.05). rPSF mean levels of tumoral tissue were higher in metastasis than in low-grade gliomas (p < 0.02). These findings indicate that multi-parametric CTP mapping may contribute to differential diagnosis of solitary intra-axial brain tumors.

CT perfusion mapping of hemodynamic disturbances associated to acute spontaneous intracerebral hemorrhage.

INTRODUCTION: We sought to quantify perfusion changes associated to acute spontaneous intracerebral hemorrhage (SICH) by means of computed tomography perfusion (CTP) imaging. MATERIALS AND METHODS: We studied 89 patients with supratentorial SICH at admission CT by using CTP scanning obtained within 24 h after symptom onset. Regional cerebral blood flow (rCBF), cerebral blood volume (rCBV) and mean transit time (rMTT) levels were measured in four different regions of interest manually outlined on CT scan: (1) hemorrhagic core; (2) perihematomal low-density area; (3) 1 cm rim of normal-appearing brain tissue surrounding the perilesional area; and (4) a mirrored area, including the clot and the perihematomal region, located in the non-lesioned contralateral hemisphere. RESULTS: rCBF, rCBV, and rMTT mean levels showed a centrifugal distribution with a gradual increase from the core to the periphery (p < 0.0001). Perfusion absolute values were indicative of ischemia in hemorrhagic core, oligemia in perihematomal area, and hyperemia in normal-appearing and contralateral areas. Perihematomal rCBF and rCBV mean levels were higher in small (< or = 20 ml) than in large (>20 ml) hematomas (p < 0.01 and p < 0.02, respectively). CONCLUSION: Multi-parametric CTP mapping of acute SICH indicates that perfusion values show a progressive improvement from the core to the periphery. In the first 24 h, perihemorrhagic region was hypoperfused with CTP values which were not suggestive of ischemic penumbra destined to survive but more likely indicative of edema formation. These findings also argue for a potential influence of early amounts of bleeding on perihematomal hemodynamic abnormalities.