MR spectroscopy and diffusion MR imaging in characterization of common sellar and supra-sellar neoplastic lesions

Abstract

Background: MR spectroscopy and diffusion-weighted imaging are useful non invasive imaging modalities used for characterization of different sellar and suprasellar lesions. Patient and methods: We studied 30 cases of suprasellar SOLs (as proved by conventional MRI), MRS and DWI. Our findings were correlated with histopathological analysis after surgical resection. Results: Three false positive cases in which cMRI give diagnosis mismatched with that obtained after adding the MRS findings and ADC values. MR spectrum type IIC is found in macroadenoma, craniopharyngioma, meningioma and germinoma with characteristic broad lipid peak in the second and forth types and elevated alanine peak in meningioma. Glioma had MRS appearance of type IIB. Simple differentiation between tumor types were achieved by the mean ADC values which were statistically significant (p < 0.001) when correlated to the histological diagnosis. When the ADC value of 0.6 × 10−3 mm2/s this strongly points to macroadenoma, ADC value of 1.05 × 10−3 mm2/s in meningiomas, ADC value 1.88 8 × 10−3 mm2/s strongly points to craniopharyngioma, while gliomas and germinoma had ADC values 1.6 × 10−3 mm2/s and 1.0 × 10−3 mm2/s respectively. Conclusion: MR spectroscopy and DWMRI are considered important diagnostic tools complementary to cMRI in pre-surgical evaluation and discrimination between different sellar and suprasellar lesions.

Keywords

• MRS
• DWI
• Supra-sellar