In vivo localized proton magnetic resonance spectroscopy of intracranial tuberculomas.

In vivo proton magnetic resonance spectroscopy (MRS) was performed in ten patients with intracranial tuberculomas with the aim of finding biochemical finger prints which may help in the noninvasive diagnosis of the disease. Diagnosis of tuberculoma was confirmed in all these cases retrospectively. Ex vivo spectroscopy of formalin fixed samples of four granulomas and a normal brain (cerebellar) tissue, was performed to confirm the in vivo resonances. The in vivo study showed resonance at 1.3 ppm and 0.9 ppm assigned to methylene group (CH2)n and terminal methyl groups (-CH3) of fatty acids respectively which was subsequently confirmed by the ex vivo study. Large resonances of fatty acids in in vivo study appeared to be due to high lipid content of caseous material. It is concluded that in vivo proton spectroscopy may be helpful in differentiating tuberculomas from other intracranial mass lesions which have diagnostic difficulties on MR imaging.