Diffusion tensor imaging for preoperative evaluation of tumor grade in gliomas

https://doi.org/10.1016/j.clineuro.2004.06.011Get rights and content

Abstract

The relationship between water diffusion parameters measured using diffusion tensor imaging (DTI) and histological malignancy of gliomas was investigated.

DTI was performed using a 3.0 T MR scanner in 41 consecutive patients with histologically proven gliomas. Fractional anisotropy (FA) and mean diffusivity (MD) were calculated and compared with the WHO classification of the gliomas.

The FA values of grade 1 gliomas (0.150 ± 0.017) were significantly lower than those of grade 3 (0.23 ± 0.033) or grade 4 gliomas (0.229 ± 0.033) (P < 0.0001, respectively). The FA values of grade 2 gliomas (0.159 ± 0.018) were significantly lower than those of grade 3 or grade 4 gliomas (P = 0.0002, P < 0.0001, respectively). The FA threshold between low grade and high grade gliomas was 0.188. The MD values of grade 1 gliomas (1619.1 ± 157.4 × 10−6 mm2/s) were significantly higher than those of grade 3 (1084.5 ± 218.9 × 10−6 mm2/s) (P = 0.0036) or grade 4 gliomas (1098.0 ± 291.6 × 10−6 mm2/s) (P = 0.0002). The MD values were not correlated with the other grades of glioma.

FA values can distinguish between high grade and low grade gliomas. This is useful in deciding the surgical strategy or selecting the site of stereotactic biopsy.

Introduction

Gliomas are the most common primary neoplasms of the central nervous system [1]. The prognosis for patients with high grade gliomas has remained poor despite improvements in radiation and chemotherapy [2], [3]. Accurate preoperative diagnosis of the tumor grade is important for the determination of appropriate treatment strategies [4]. Magnetic resonance (MR) spectroscopy [5], [6], [7], [8], single photon emission computed tomography [9], [10], [11], [12], [13], or positron emission tomography [9], [10], [11] have all been used for the preoperative evaluation of glioma malignancy. However, MR spectroscopy has limitations in spatial resolution and heterogeneous lesions are difficult to assess [7], whereas imaging methods using radioactive isotopes are invasive and involve handling problems.

Diffusion tensor imaging (DTI) can measure the directionality (anisotropy) and the magnitude (diffusivity) of water diffusion in vivo [14]. Fractional anisotropy (FA) and mean diffusivity (MD) are the quantitative indices for anisotropy and diffusivity, respectively [15]. The microstructural organization of the brain tissue affects the molecular motion of water. Therefore, the FA and MD reflect microstructural changes of tissue caused by damage from degenerative disease, brain ischemia and brain tumors [16], [17], [18], [19], [20], [21]. The histological diagnosis of glioma malignancy is based on the presence of nuclear heteromorphism, nuclear mitosis, endothelial proliferation, and necrosis [22]. These characteristics may affect the FA and MD values of gliomas.

This study evaluates the relationship between the findings of DTI and the histological malignancy of gliomas.

Section snippets

Patient population

This study included 41 consecutive patients (18 females and 23 males) aged 2–77 years (mean 46 years) treated at our institute between October 2000 and December 2002, who underwent DTI and had a histological diagnosis. No medical therapy was received for their tumor prior to imaging. The patient characteristics and tumor grades, using the WHO classification [23], are listed in Table 1. The study protocol was approved by the local ethical committee. All subjects gave written informed consent

Results

DTI demonstrated the tumor mass and cystic lesions in all patients. Representative FA maps and T1-weighted images with contrast medium are shown in Fig. 2. The relationships between the FA or MD values and the tumor grade are shown in Fig. 3, Fig. 4, respectively.

The FA values of grade 1 gliomas (0.150 ± 0.017) were significantly lower than those of grade 3 (0.23 ± 0.033) or grade 4 gliomas (0.229 ± 0.033) (P < 0.0001, respectively). The FA values of grade 2 gliomas (0.159 ± 0.018) were

Discussion

The primary finding of the present study was that the FA value could be used to distinguish high grade glioma from low grade glioma.

FA values have been investigated in patients with multiple sclerosis, amyotrophic lateral sclerosis, or leukoaraiosis, showing that the FA value is an indicator of the tissue damage of white matter [17], [18], [19], [20], [24]. The molecular movement of water is restricted by membranes in the brain [25]. The presence of myelinated fibers is an important factor in

Conclusion

Investigation of the relationship between DTI and histological malignancy of gliomas found that the FA value can distinguish high grade glioma from low grade glioma. This may be useful in deciding the surgical strategy or selecting the site of stereotactic biopsy.

Acknowledgement

This work was supported in part by Grants-in-Aid for Advanced Medical Science Research by the Ministry of Education, Culture, Sports, Science, and Technology, Japan.

References (38)

  • G. Sfakianakis

    Preoperative grading of gangliogliomas using FDG PET and Tl-201 SPECT: comments from a nuclear medicine view

    AJNR Am J Neuroradiol

    (1998)
  • P.K. Kincaid et al.

    Cerebral gangliogliomas: preoperative grading using FDG-PET and 201Tl-SPECT

    AJNR Am J Neuroradiol

    (1998)
  • M. Tamura et al.

    Assessment of malignancy of glioma by positron emission tomography with 18F-fluorodeoxyglucose and single photon emission computed tomography with thallium-201 chloride

    Neuroradiology

    (1998)
  • K. Kallen et al.

    Evaluation of malignancy in ring enhancing brain lesions on CT by thallium-201 SPECT

    J Neurol Neurosurg Psychiatry

    (1997)
  • T. Kumabe et al.

    Thallium-201 single-photon emission computed tomographic and proton magnetic resonance spectroscopic characteristics of intracranial ganglioglioma: three technical case reports

    Neurosurgery

    (1999)
  • C. Pierpaoli et al.

    Toward a quantitative assessment of diffusion anisotropy

    Magn Reson Med

    (1996)
  • R. Bammer et al.

    Magnetic resonance diffusion tensor imaging for characterizing diffuse and focal white matter abnormalities in multiple sclerosis

    Magn Reson Med

    (2000)
  • O. Ciccarelli et al.

    Investigation of MS normal-appearing brain using diffusion tensor MRI with clinical correlations

    Neurology

    (2001)
  • C.M. Ellis et al.

    Diffusion tensor MRI assesses corticospinal tract damage in ALS

    Neurology

    (1999)
  • Cited by (0)

    View full text