BACKGROUND AND PURPOSE: Glioblastomas, brain metastases, and PCLs may have similar enhancement patterns on MR imaging, making the differential diagnosis difficult or even impossible. The purpose of this study was to determine whether a combination of DTI and DSC can assist in the differentiation of glioblastomas, solitary brain metastases, and PCLs.

To investigate the clinical significance of endothelin (ET), a potent vasoconstrictor peptide, in subarachnoid hemorrhage (SAH) and SAH-related cerebral vasospasm, we measured the ET-like immunoreactivity (ET-LI) in plasma and cerebrospinal fluid (CSF) obtained serially from patients with SAH due to ruptured cerebral aneurysm who underwent aneurysmal surgery. The normal ET-LI levels in plasma and CSF (n = 24) were 12.4 +/- 2.0 (mean +/- s.d.) and 9.1 +/- 1.2 pg.ml-1, respectively. Plasma ET-LI levels in patients with SAH before surgery (16.8 +/- 7.8 pg.ml-1, n = 8) were higher than the normal values (P < 0.05), and became further elevated after surgery (22.5 +/- 9.4 pg.ml-1). ET-LI levels in plasma and CSF one day after surgery were 18.7 +/- 5.5 and 18.4 +/- 6.8 pg.ml-1 (P < 0.01 vs. normal values), respectively, and declined thereafter. The plasma and CSF ET-LI levels in patients who showed symptomatic vasospasm became concomitantly elevated again. These results suggest that ET is involved in SAH-related vasospasm and raise the possibility that surgical stress influences the vasospasm.