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Proton magnetic resonance imaging combined with frameless stereotaxy in glioma surgery
International Congress Series 1268 (2004) 1289
Proton magnetic resonance imaging combined with frameless stereotaxy in glioma surgery O. Ganslandt *, Ch. Nimsky, R. Fahlbusch, E. Moser, A. Stadlbauer Department of Neurosurgery, University Erlangen-Nuremberg, Schwabachanlage 6, Erlangen 91054, Germany
1. Purpose We improved the delineation of the infiltration zone in gliomas using proton magnetic resonance imaging (1H MRSI). Our purpose was to correlate tumor cell density from histopathologic specimens obtained by stereotactic guided procedures with the co-registered metabolic maps. 2. Methods All studies were performed on a 1.5 T scanner. MRSI parameters were TR/TE 1600/135 ms, 24 24 circular phase-encoding scheme across a 16 16 cm FOV, slice thickness 10 mm, 50% Hamming-filter and 2 NEX, spectral width 1000 Hz and 1024 complex points acquisition size. The nominal voxel size was 1.0 0.67 0.67 cm3 (approximately 0.45 cm3 resolution). An algorithm was developed that user-independently calculates pathologic voxels and displays them as metabolic maps. These maps were integrated into a 3D MR data set used for frameless stereotaxy. Stereotactic biopsies were taken from three different areas around the tumor involving the maximum pathologic change, the border zone and an area from outside the spectroscopically suspicious area and were then further evaluated histopathologically. We applied this method in 10 patients with gliomas (WHO grade II – III). 3. Results In all cases 1H MRSI correctly predicted areas of high tumor invasion in the center of the glioma and regions of low tumor invasion at the border zone defined by the metabolic map overlaid onto the anatomical T1 and T2 weighted MR studies. When comparing the area of T2 weighted signal and the area of the spectroscopically pathological area, we found that all patients had segmented 1H MRSI tumor areas that exceeded the T2 weighted hyperintense signal covered by the PRESS box. In average, the segmented tumor area of the pathological 1H MRSI voxels was 24% larger than the manually segmented tumor area according to the T2 signal changes (range 6 – 33%). 4. Conclusion Our preliminary data suggest that 1H MRSI might be useful in conjunction with frameless stereotaxy to define more exactly the tumor infiltration zone in glioma surgery than in conventional anatomic MR imaging alone.
* Corresponding author. Tel.: +49-9131-8533001; fax: +49-9131-8534551. E-mail address: [email protected] (O. Ganslandt). 0531-5131/ D 2004 CARS and Elsevier B.V. All rights reserved. doi:10.1016/j.ics.2004.03.216
Proton magnetic resonance imaging combined with frameless stereotaxy in glioma surgery O. Ganslandt *, Ch. Nimsky, R. Fahlbusch, E. Moser, A. Stadlbauer Department of Neurosurgery, University Erlangen-Nuremberg, Schwabachanlage 6, Erlangen 91054, Germany
1. Purpose We improved the delineation of the infiltration zone in gliomas using proton magnetic resonance imaging (1H MRSI). Our purpose was to correlate tumor cell density from histopathologic specimens obtained by stereotactic guided procedures with the co-registered metabolic maps. 2. Methods All studies were performed on a 1.5 T scanner. MRSI parameters were TR/TE 1600/135 ms, 24 24 circular phase-encoding scheme across a 16 16 cm FOV, slice thickness 10 mm, 50% Hamming-filter and 2 NEX, spectral width 1000 Hz and 1024 complex points acquisition size. The nominal voxel size was 1.0 0.67 0.67 cm3 (approximately 0.45 cm3 resolution). An algorithm was developed that user-independently calculates pathologic voxels and displays them as metabolic maps. These maps were integrated into a 3D MR data set used for frameless stereotaxy. Stereotactic biopsies were taken from three different areas around the tumor involving the maximum pathologic change, the border zone and an area from outside the spectroscopically suspicious area and were then further evaluated histopathologically. We applied this method in 10 patients with gliomas (WHO grade II – III). 3. Results In all cases 1H MRSI correctly predicted areas of high tumor invasion in the center of the glioma and regions of low tumor invasion at the border zone defined by the metabolic map overlaid onto the anatomical T1 and T2 weighted MR studies. When comparing the area of T2 weighted signal and the area of the spectroscopically pathological area, we found that all patients had segmented 1H MRSI tumor areas that exceeded the T2 weighted hyperintense signal covered by the PRESS box. In average, the segmented tumor area of the pathological 1H MRSI voxels was 24% larger than the manually segmented tumor area according to the T2 signal changes (range 6 – 33%). 4. Conclusion Our preliminary data suggest that 1H MRSI might be useful in conjunction with frameless stereotaxy to define more exactly the tumor infiltration zone in glioma surgery than in conventional anatomic MR imaging alone.
* Corresponding author. Tel.: +49-9131-8533001; fax: +49-9131-8534551. E-mail address: [email protected] (O. Ganslandt). 0531-5131/ D 2004 CARS and Elsevier B.V. All rights reserved. doi:10.1016/j.ics.2004.03.216