MR-based cerebral blood volume maps as a diagnostic tool for brain tumours

Purpose: Today contrast enhanced MR imaging is a reliable method for detecting mostly distinguishing between different histological types of tumours. In this study we use a MR-based method to measure the regional cerebral blood volume (rCBV). Using this technique we try to judge the grading and vitality of the tumours. Methods: 26 patients with various types of brain tumours were examined. To calculate rCBV-maps of one slice, low-dosed Gd-DTPA was injected as a bolus. Using the relaxation effect the obtained signal intensity-time curves were converted pixel-wise into rCBV images. For the tumours rCBV-ratios were calculated relative to the corresponding area in the contralateral hemisphere. Results. In the investigated group all tumours were detected on the basis of a raised rCBV-ratio. Since only vital parts of the tumour are perfused, the rCBV maps may be used to determine the place of biopsy. Conclusions: The differential diagnosis of all histological tumour types was not possible on the basis of rCBV values. Distinction between low grade and high grade gliomas was also not significant. However, a low grade glioma can be excluded if the morphological images definitely indicate an astrocytoma and if the rCBV-ratio was higher than 2.