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Nuclear overhauser enhancement mediated chemical exchange saturation transfer imaging at 7 Tesla in glioblastoma patients.

Paech D, Zaiss M, Meissner JE, Windschuh J, Wiestler B, Bachert P, Neumann JO, Kickingereder P, Schlemmer HP, Wick W, Nagel AM, Heiland S, Ladd ME, Bendszus M, Radbruch A - PLoS ONE (2014)

Bottom Line: Mean NOE mediated CEST signal based on MTR(asym) values over all patients was significantly increased (p<0.001) in CE-T1 tumor (-1.99 ± 1.22%), tumor necrosis (-1.36 ± 1.30%) and peritumoral CEST hyperintensities (PTCH) within T2 edema margins (-3.56 ± 1.24%) compared to contralateral normal appearing white matter (-8.38 ± 1.19%).In CE-T1 tumor (p = 0.015) and tumor necrosis (p<0.001) mean MTR(asym) values were significantly higher than in PTCH.In all patients, isolated high intensity regions (0.40 ± 2.21%) displayed on CEST within the CE-T1 tumor that were not discernible on CE-T1 or T2-weighted images.

View Article: PubMed Central - PubMed

Affiliation: Department of Neuroradiology, University of Heidelberg Medical Center, Heidelberg, Germany; Neurooncologic Imaging, Department of Radiology, Deutsches Krebsforschungszentrum (DKFZ), Heidelberg, Germany.

ABSTRACT

Background and purpose: Nuclear Overhauser Enhancement (NOE) mediated chemical exchange saturation transfer (CEST) is a novel magnetic resonance imaging (MRI) technique on the basis of saturation transfer between exchanging protons of tissue proteins and bulk water. The purpose of this study was to evaluate and compare the information provided by three dimensional NOE mediated CEST at 7 Tesla (7T) and standard MRI in glioblastoma patients.

Patients and methods: Twelve patients with newly diagnosed histologically proven glioblastoma were enrolled in this prospective ethics committee-approved study. NOE mediated CEST contrast was acquired with a modified three-dimensional gradient-echo sequence and asymmetry analysis was conducted at 3.3 ppm (B1 = 0.7 µT) to calculate the magnetization transfer ratio asymmetry (MTR(asym)). Contrast enhanced T1 (CE-T1) and T2-weighted images were acquired at 3T and used for data co-registration and comparison.

Results: Mean NOE mediated CEST signal based on MTR(asym) values over all patients was significantly increased (p<0.001) in CE-T1 tumor (-1.99 ± 1.22%), tumor necrosis (-1.36 ± 1.30%) and peritumoral CEST hyperintensities (PTCH) within T2 edema margins (-3.56 ± 1.24%) compared to contralateral normal appearing white matter (-8.38 ± 1.19%). In CE-T1 tumor (p = 0.015) and tumor necrosis (p<0.001) mean MTR(asym) values were significantly higher than in PTCH. Extent of the surrounding tumor hyperintensity was smaller in eight out of 12 patients on CEST than on T2-weighted images, while four displayed at equal size. In all patients, isolated high intensity regions (0.40 ± 2.21%) displayed on CEST within the CE-T1 tumor that were not discernible on CE-T1 or T2-weighted images.

Conclusion: NOE mediated CEST Imaging at 7 T provides additional information on the structure of peritumoral hyperintensities in glioblastoma and displays isolated high intensity regions within the CE-T1 tumor that cannot be acquired on CE-T1 or T2-weighted images. Further research is needed to determine the origin of NOE mediated CEST and possible clinical applications such as therapy assessment or biopsy planning.

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Related in: MedlinePlus

Peritumoral hyperintensity on NOE mediated CEST compared to standard MRI.Left frontal glioblastoma in a 59 year old man at 3 Tesla, CE-T1 (A) and T2-weighted images (B). On the selected slice the CEST contrast at 7 Tesla, based on MTRasym (C), displays peritumoral hyperintensities at equal extent compared to the edema on T2-weighted images. In contrast to T2-weighted images, the CEST peritumoral hyperintensity displays an irregular border and subareas of different signal intensity.
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pone-0104181-g001: Peritumoral hyperintensity on NOE mediated CEST compared to standard MRI.Left frontal glioblastoma in a 59 year old man at 3 Tesla, CE-T1 (A) and T2-weighted images (B). On the selected slice the CEST contrast at 7 Tesla, based on MTRasym (C), displays peritumoral hyperintensities at equal extent compared to the edema on T2-weighted images. In contrast to T2-weighted images, the CEST peritumoral hyperintensity displays an irregular border and subareas of different signal intensity.

Mentions: In eight out of 12 patients, the peritumoral hyperintensity on CEST was smaller than on T2-weighted images. In four patients, CEST displayed congruent areas. In two of the eight patients with smaller peritumoral hyperintensity, the CEST hyperintensity moderately exceeded the T2 edema in one direction. In comparison to the edema on T2-weighted sequences, peritumoral hyperintensities on CEST displayed an irregular border and subareas of different signal intensity. Furthermore, stria like structures could be identified on CEST images within peritumoral hyperintensities (Fig. 1).


Nuclear overhauser enhancement mediated chemical exchange saturation transfer imaging at 7 Tesla in glioblastoma patients.

Paech D, Zaiss M, Meissner JE, Windschuh J, Wiestler B, Bachert P, Neumann JO, Kickingereder P, Schlemmer HP, Wick W, Nagel AM, Heiland S, Ladd ME, Bendszus M, Radbruch A - PLoS ONE (2014)

Peritumoral hyperintensity on NOE mediated CEST compared to standard MRI.Left frontal glioblastoma in a 59 year old man at 3 Tesla, CE-T1 (A) and T2-weighted images (B). On the selected slice the CEST contrast at 7 Tesla, based on MTRasym (C), displays peritumoral hyperintensities at equal extent compared to the edema on T2-weighted images. In contrast to T2-weighted images, the CEST peritumoral hyperintensity displays an irregular border and subareas of different signal intensity.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4128651&req=5

pone-0104181-g001: Peritumoral hyperintensity on NOE mediated CEST compared to standard MRI.Left frontal glioblastoma in a 59 year old man at 3 Tesla, CE-T1 (A) and T2-weighted images (B). On the selected slice the CEST contrast at 7 Tesla, based on MTRasym (C), displays peritumoral hyperintensities at equal extent compared to the edema on T2-weighted images. In contrast to T2-weighted images, the CEST peritumoral hyperintensity displays an irregular border and subareas of different signal intensity.
Mentions: In eight out of 12 patients, the peritumoral hyperintensity on CEST was smaller than on T2-weighted images. In four patients, CEST displayed congruent areas. In two of the eight patients with smaller peritumoral hyperintensity, the CEST hyperintensity moderately exceeded the T2 edema in one direction. In comparison to the edema on T2-weighted sequences, peritumoral hyperintensities on CEST displayed an irregular border and subareas of different signal intensity. Furthermore, stria like structures could be identified on CEST images within peritumoral hyperintensities (Fig. 1).

Bottom Line: Mean NOE mediated CEST signal based on MTR(asym) values over all patients was significantly increased (p<0.001) in CE-T1 tumor (-1.99 ± 1.22%), tumor necrosis (-1.36 ± 1.30%) and peritumoral CEST hyperintensities (PTCH) within T2 edema margins (-3.56 ± 1.24%) compared to contralateral normal appearing white matter (-8.38 ± 1.19%).In CE-T1 tumor (p = 0.015) and tumor necrosis (p<0.001) mean MTR(asym) values were significantly higher than in PTCH.In all patients, isolated high intensity regions (0.40 ± 2.21%) displayed on CEST within the CE-T1 tumor that were not discernible on CE-T1 or T2-weighted images.

View Article: PubMed Central - PubMed

Affiliation: Department of Neuroradiology, University of Heidelberg Medical Center, Heidelberg, Germany; Neurooncologic Imaging, Department of Radiology, Deutsches Krebsforschungszentrum (DKFZ), Heidelberg, Germany.

ABSTRACT

Background and purpose: Nuclear Overhauser Enhancement (NOE) mediated chemical exchange saturation transfer (CEST) is a novel magnetic resonance imaging (MRI) technique on the basis of saturation transfer between exchanging protons of tissue proteins and bulk water. The purpose of this study was to evaluate and compare the information provided by three dimensional NOE mediated CEST at 7 Tesla (7T) and standard MRI in glioblastoma patients.

Patients and methods: Twelve patients with newly diagnosed histologically proven glioblastoma were enrolled in this prospective ethics committee-approved study. NOE mediated CEST contrast was acquired with a modified three-dimensional gradient-echo sequence and asymmetry analysis was conducted at 3.3 ppm (B1 = 0.7 µT) to calculate the magnetization transfer ratio asymmetry (MTR(asym)). Contrast enhanced T1 (CE-T1) and T2-weighted images were acquired at 3T and used for data co-registration and comparison.

Results: Mean NOE mediated CEST signal based on MTR(asym) values over all patients was significantly increased (p<0.001) in CE-T1 tumor (-1.99 ± 1.22%), tumor necrosis (-1.36 ± 1.30%) and peritumoral CEST hyperintensities (PTCH) within T2 edema margins (-3.56 ± 1.24%) compared to contralateral normal appearing white matter (-8.38 ± 1.19%). In CE-T1 tumor (p = 0.015) and tumor necrosis (p<0.001) mean MTR(asym) values were significantly higher than in PTCH. Extent of the surrounding tumor hyperintensity was smaller in eight out of 12 patients on CEST than on T2-weighted images, while four displayed at equal size. In all patients, isolated high intensity regions (0.40 ± 2.21%) displayed on CEST within the CE-T1 tumor that were not discernible on CE-T1 or T2-weighted images.

Conclusion: NOE mediated CEST Imaging at 7 T provides additional information on the structure of peritumoral hyperintensities in glioblastoma and displays isolated high intensity regions within the CE-T1 tumor that cannot be acquired on CE-T1 or T2-weighted images. Further research is needed to determine the origin of NOE mediated CEST and possible clinical applications such as therapy assessment or biopsy planning.

Show MeSH
Related in: MedlinePlus