Differentiation of high-grade and low-grade intra-axial brain tumors by time-dependent diffusion MRI

Tomoko Maekawa; Masaaki Hori; Katsutoshi Murata; Thorsten Feiweier; Kouhei Kamiya; Christina Andica; Akifumi Hagiwara; Shohei Fujita; Saori Koshino; Toshiaki Akashi; Koji Kamagata; Akihiko Wada; Osamu Abe; Shigeki Aoki

doi:10.1016/j.mri.2020.06.018

Differentiation of high-grade and low-grade intra-axial brain tumors by time-dependent diffusion MRI

Magn Reson Imaging. 2020 Oct:72:34-41. doi: 10.1016/j.mri.2020.06.018. Epub 2020 Jun 26.

Authors

Affiliations

¹ Department of Radiology, Graduate School of Medicine and Faculty of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8655, Japan; Department of Radiology, Juntendo University School of Medicine, 2-1-1 Hongo, Bunkyo-ku, Tokyo 113-8421, Japan. Electronic address: t-maekawa@juntendo.ac.jp.
² Department of Radiology, Juntendo University School of Medicine, 2-1-1 Hongo, Bunkyo-ku, Tokyo 113-8421, Japan; Department of Diagnostic Radiology, Toho University Omori Medical Center, 6-11-1, Omorinishi, Ota-ku, Tokyo 143-8541, Japan.
³ Siemens Healthcare Japan KK, Gate City Osaki West Tower, 11-1 Osaki 1-Chome, Shinagawa-ku, Tokyo 141-8644, Japan.
⁴ Siemens Healthcare GmbH, Henkestrasse 127, 91052 Erlangen, Germany.
⁵ Department of Radiology, Graduate School of Medicine and Faculty of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8655, Japan; Department of Radiology, Juntendo University School of Medicine, 2-1-1 Hongo, Bunkyo-ku, Tokyo 113-8421, Japan.
⁶ Department of Radiology, Juntendo University School of Medicine, 2-1-1 Hongo, Bunkyo-ku, Tokyo 113-8421, Japan.
⁷ Department of Radiology, Graduate School of Medicine and Faculty of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8655, Japan.

PMID: 32599021
DOI: 10.1016/j.mri.2020.06.018

Abstract

Introduction: Oscillating gradient spin-echo (OGSE) sequences enable acquisitions with shorter diffusion times. There is growing interest in the effect of diffusion time on apparent diffusion coefficient (ADC) values in patients with cancer. However, little evidence exists regarding its usefulness for differentiating between high-grade and low-grade brain tumors. The purpose of this study is to investigate the utility of changes in the ADC value between short and long diffusion times in distinguishing low-grade and high-grade brain tumors.

Material and methods: Eleven patients with high-grade brain tumors and ten patients with low-grade brain tumors were scanned using a 3 T magnetic resonance imaging with diffusion-weighted imaging (DWI) using OGSE and PGSE (effective diffusion time [Δ_eff]: 6.5 ms and 35.2 ms) and b-values of 0 and 1000 s/mm². Using a region of interest (ROI) analysis of the brain tumors, we measured the ADC for two Δeff (ADC_Δeff) values and computed the subtraction ADC (ΔADC = ADC_{6.5 ms} - ADC_{35.2 ms}) and the relative ADC (ΔADC = (ADC_{6.5 ms} - ADC_{35.2 ms}) / ADC_{35.2 ms} × 100). The maximum values for the subtraction ADC (ΔADC_max) and the relative ADC (rADC_max) on the ROI were compared between low-grade and high-grade tumors using the Wilcoxon rank-sum test. A P-value <.05 was considered significant. The ROIs were also placed in the normal white matter of patients with high- and low-grade brain tumors, and ΔADC_max values were determined.

Results: High-grade tumors had significantly higher ΔADC_max and rADC_max than low-grade tumors. The ΔADC_max values of the normal white matter were lower than the ΔADC_max of high- and low-grade brain tumors.

Conclusion: The dependence of ADC values on diffusion time between 6.5 ms and 35.2 ms was stronger in high-grade tumors than in low-grade tumors, suggesting differences in internal tissue structure. This finding highlights the importance of reporting diffusion times in ADC evaluations and might contribute to the grading of brain tumors using DWI.

Keywords: Brain tumor; Diffusion time; Diffusion-weighted imaging; OGSE; Oscillating gradient spin-echo.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Adult
Aged
Brain Neoplasms / diagnostic imaging*
Brain Neoplasms / pathology*
Diagnosis, Differential
Diffusion Magnetic Resonance Imaging*
Female
Humans
Male
Middle Aged
Neoplasm Grading
Time Factors