Dynamic 1H-MRS assessment of brain tumors: A novel approach for differential diagnosis of glioma

// Tong Tong 1 , Zhong Yang 2 , John W. Chen 3 , Jianming Zhu 4 , Zhenwei Yao 2 1 Department of Radiology, Fudan University Shanghai Cancer Center, Shanghai, China 2 Department of Radiology, Fudan University Huashan Hospital, Shanghai, China 3 Institute for Innovation in Imaging, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA 4 Department of Radiation Oncology, The University of North Carolina, Chapel Hill, NC, USA Correspondence to: Zhenwei Yao, e-mail: aocnhnr@126.com John W. Chen, e-mail: jwchen@mgh.harvard.edu Keywords: clinical paper, magnetic resonance imaging, magnetic resonance spectroscopy, glioma, differential diagnosis Received: May 18, 2015 Accepted: August 07, 2015 Published: August 20, 2015 ABSTRACT Purpose: To determine whether the changes of [Cho/NAA] ratio in patients with glioma, measured by dynamic 1 H-MRS can be used to differentiate between high-grade and low-grade gliomas. Materials and Methods: This prospective study was approved by the institutional ethics committee. Written informed consent was obtained. Forty-nine patients with biopsy-proven glioma and 20 normal control subjects were recruited in this study. The maximum [Cho/NAA] ratios, acquired at 0 min, and at 6 min, were calculated and assessed from volume of interests (VOI) in the tumor areas and in the surrounding normal tissue for each patient. Absolute difference in the [Cho/NAA] ratios, from MRS acquired at 0 and 6 min, in high-grade glioma, low-grade glioma, and control subjects were compared. Results: The maximum [Cho/NAA] ratio acquired from the tumor area at the 0 min is 6.08 ± 2.02, which was significantly different ( p = .017) from that acquired after 6 min, 4.87 ± 2.13. The [Cho/NAA] ratio from the surrounding normal tissue area did not change significantly from spectra acquired at different times (0 min, 6 min). Absolute difference in [Cho/NAA] ratios acquired at 0 and 6 min time points were significantly higher ( P < 0.001) in high-grade glioma (= 3.86 ± 3.31) than in low-grade glioma (= 0.81 ± 0.90), and control subjects (0.061 ± 0.026, P = 0.000), while there was no significantly difference in low-grade glioma and control subjects. Conclusions: Dynamic 1 H-MRS can be useful for differential diagnosis between high-grade and low-grade gliomas as well as insight into the heterogeneity within the tumor.