Evaluation of different cerebral mass lesions by perfusion-weighted MR imaging

Abstract

Purpose: To investigate the contribution of perfusion-weighted MR imaging (PWI) by using the relative cerebral blood volume (rCBV) ratio in the differential diagnosis of various intracranial space-occupying lesions. Materials and Methods: This study involved 105 patients with lesions (high-grade glioma (N = 26), low-grade glioma (N= 11), meningioma (N = 23), metastasis (N 25), hemangioblastoma (N = 6), pyogenic abscess (N 4), schwannoma (N = 5), and lymphoma. (N = 5)). The patients were examined with a T2*-weighted (T2*W) gradient-echo singleshot EPI sequence. The rCBV ratios of the lesions were obtained by dividing the values obtained from the normal white matter. Statistical analysis was performed with the Mann-Whitney U-test. A P-value less than 0.05 was considered statistically significant. Results: The rCBV ratio was 5.76 +/- 3.35 in high-grade gliomas, 1.69 +/- 0.51 in low-grade gliomas, 8.02 +/- 3.89 in meningiomas, 5.27 +/- 3.22 in metastases, 11.36 +/- 4.41 in hemangioblastomas, 0.76 +/- 0.12 in abscesses, 1.10 +/- 0.32 in lymphomas, and 3.23 +/- 0.81 in schwannomas. The rCBV ratios were used to discriminate between 1) high- and low-grade gliomas (P < 0.00 1), 2) hemangioblastomas and metastases (P < 0.05), 3) abscesses from high-grade gliomas and metastases (P < 0.001), 4) schwannomas and meningiomas (P < 0.001), 5) lymphomas from high-grade gliomas and metastases (P < 0.001), and 6) typical meningiomas and atypical meningiomas (P < 0.01). Conclusion: rCBV ratios can help discriminate intracranial space-occupying lesions by demonstrating lesion vascularity. It is possible to discriminate between 1) high- and low-grade gliomas, 2) hemangioblastomas and other intracranial posterior fossa masses, 3) abscesses from highgrade gliomas and metastases, 4) schwannomas and meningiomas, 5) lymphomas and high-grade gliomas and metastases, and 6) typical and atypical meningiomas.