Image-fusion of MR spectroscopic images for treatment planning of gliomas Journal Article

Authors: Chang, J.; Thakur, S.; Perera, G.; Kowalski, A.; Huang, W.; Karimi, S.; Hunt, M.; Koutcher, J.; Fuks, Z.; Amols, H.; Narayana, A.
Article Title: Image-fusion of MR spectroscopic images for treatment planning of gliomas
Abstract: 1H magnetic resonance spectroscopic imaging (MRSI) can improve the accuracy of target delineation for gliomas, but it lacks the anatomic resolution needed for image fusion. This paper presents a simple protocol for fusing simulation computer tomography (CT) and MRSI images for glioma intensity-modulated radiotherapy (IMRT), including a retrospective study of 12 patients. Each patient first underwent whole-brain axial fluid-attenuated- inversion-recovery (FLAIR) MRI (3 mm slice thickness, no spacing), followed by three-dimensional (3D) MRSI measurements (TE/TR: 144/1000 ms) of a user-specified volume encompassing the extent of the tumor. The nominal voxel size of MRSI ranged from 8 X 8 X 10 mm3 to 12 X 12 X 10 mm 3. A system was developed to grade the tumor using the choline-to-creatine (Cho/Cr) ratios from each MRSI voxel. The merged MRSI images were then generated by replacing the Cho/Cr value of each MRSI voxel with intensities according to the Cho/Cr grades, and resampling the poorer-resolution Cho/Cr map into the higher-resolution FLAIR image space. The FUNCTOOL processing software was also used to create the screen-dumped MRSI images in which these data were overlaid with each FLAIR MRI image. The screen-dumped MRSI images were manually translated and fused with the FLAIR MRI images. Since the merged MRSI images were intrinsically fused with the FLAIR MRI images, they were also registered with the screen-dumped MRSI images. The position of the MRSI volume on the merged MRSI images was compared with that of the screen-dumped MRSI images and was shifted until agreement was within a predetermined tolerance. Three clinical target volumes (CTVs) were then contoured on the FLAIR MRI images corresponding to the Cho/Cr grades. Finally, the FLAIR MRI images were fused with the simulation CT images using a mutual-information algorithm, yielding an IMRT plan that simultaneously delivers three different dose levels to the three CTVs. The image-fusion protocol was tested on 12 (six high-grade and six low-grade) glioma patients. The average agreement of the MRSI volume position on the screen-dumped MRSI images and the merged MRSI images was 0.29 mm with a standard deviation of 0.07 mm. Of all the voxels with Cho/Cr grade one or above, the distribution of Cho/Cr grade was found to correlate with the glioma grade from pathologic finding and is consistent with literature results indicating Cho/Cr elevation as a marker for malignancy. In conclusion, an image-fusion protocol was developed that successfully incorporates MRSI information into the IMRT treatment plan for glioma. © 2006 American Association of Physicists in Medicine.
Keywords: clinical article; controlled study; retrospective studies; intensity modulated radiation therapy; treatment planning; disease marker; comparative study; radiation dose; nuclear magnetic resonance imaging; glioma; brain neoplasms; magnetic resonance imaging; sensitivity and specificity; reproducibility of results; computer assisted tomography; image interpretation, computer-assisted; tomography, x-ray computed; retrospective study; simulation; correlation analysis; algorithm; subtraction technique; magnetic resonance spectroscopy; choline; creatine; nuclear magnetic resonance spectroscopy; radiotherapy planning, computer-assisted; phantoms, imaging; computer program; image fusion; imrt dose painting; magnetic resonance spectroscopy imaging (mrsi)
Journal Title: Medical Physics
Volume: 33
Issue: 1
ISSN: 0094-2405
Publisher: American Association of Physicists in Medicine  
Date Published: 2006-01-01
Start Page: 32
End Page: 40
Language: English
DOI: 10.1118/1.2128497
PUBMED: 16485406
PROVIDER: scopus
Notes: --- - "Cited By (since 1996): 17" - "Export Date: 4 June 2012" - "CODEN: MPHYA" - "Source: Scopus"
Altmetric Score
MSK Authors
  1. Zvi Fuks
    342 Fuks
  2. Gerard Mark Perera
    7 Perera
  3. Jenghwa Chang
    63 Chang
  4. Sasan Karimi
    97 Karimi
  5. Howard I Amols
    157 Amols
  6. Sunitha Bai Thakur
    49 Thakur
  7. Jason A Koutcher
    241 Koutcher
  8. Margie A Hunt
    251 Hunt
  9. Wei Huang
    24 Huang