Friday 7 October 2011

Meningioma MR Spectroscopy

MR Spectroscopy is a noninvasive method for bio chemical evaluation of intra canial mass lesions in vivo. Meningioma has specific spectral pattern which can help in differentiating meningioma a most common non glial tumour from Glioma.

The common pattern found in meningioma is average or slightly high Cho peak is more common than very high levels of Cho. Choline reflects membrane turnover and correlates with malignancy.
Absent or very low NAA implies to non neuronal origin of mass.
Very low or absent Cr.
Variable amounts of lactate.
Most important, double or tipple peaks of Ala centered at 1.47 ppm which inverts on the long TE sequence (Reference AJNR 20:882–885, May 1999)

In this case a well circumscribed extra axial dura based lobulated mass in right parietal region along inter hemisphere fissure on right side of the falx. Punctate T2 flow void of vessels seen at the interphase of mass and adjacent compressed right parietal lobe support extra axial location of mass. Mass is isointense to cortical grey matter. Few t2 hyperintense foci of perilesional odema in adjacent compressed brain parenchyma best depicted on flair.
On sigle voxel MR Spectroscopy performed with 2x2cm voxel placed over the mass in right parietal region with water suppression of 98%. No intra venous contrast given.
Spectral waveform obtained at short TE of 35 ms from right to left;
Triple peaks from 1.2 to 1.6ppm corresponds to alanine.
No peak of NAA at 2.01ppm
No peak of Cr at 3.02ppm
Choline peak at 3.2ppm
Manitol peak at 3.8ppm, manitol is used as part of treatment to reduce cerebral odema.

Imagingwise diagnosis: Falcine Meningioma.

Related post : Multiple intracranial meningiomas


monug said...

Is mannitol peak at 3.8 or 4.8?

Anonymous said...

its 3.8ppm

Dr Balaji Anvekar said...

sorry its typing mistake. i hav corrected it. appreciate u r observation and feedback. thanking u.