Stereotactic biopsy in gliomas guided by 3-tesla 1H-chemical-shift imaging of choline.

OBJECTIVE

To investigate chemical-shift imaging (CSI) to guide stereotactic biopsy of the choline 'hot spot' in cerebral lesions suggestive of low-grade glioma.

METHODS

Nine patients with hyperintense lesions on T(2)-weighted images of standard magnetic resonance imaging without contrast enhancement underwent advanced magnetic resonance studies. These studies included 3-dimensional T(1)-weighted sequences with contrast enhancement and 2-dimensional (1)H-CSI spectroscopy at 3 T. Signal intensity maps with relative signal intensities for choline were generated. The region with the highest choline signal intensity (the hot spot) was chosen as the target for stereotactic biopsy. The histopathological results were correlated with the increase in choline.

RESULTS

All spectroscopic data were of sufficient quality. In 5 instances the neuropathological diagnosis was grade II glioma, according to the WHO classification, and in 4 instances it was grade III glioma. According to the CSI criteria, all grade III gliomas and 4 of the 5 grade II gliomas were classified correctly. One grade II glioma was overestimated by CSI as a high-grade glioma.

CONCLUSION

(1)H-CSI-guided stereotactic biopsy may offer advantages as compared to conventional stereotactic biopsy. The biopsy of the choline hot spot in suggestive low-grade gliomas may help to identify focal points of higher tumor malignancy independent of contrast enhancement.