Author/Authors :
Firouznia Kavous نويسنده , Ghanaati Hossein نويسنده , Azmoudeh Ardalan Farid نويسنده , Taslimi Reza نويسنده Assistant Professor, Department of Internal Medicine, Division of gastroenterology , Miri Mojtaba نويسنده Department of Neurosurgery, Emam Khomeini Hospital, Tehran University of Medical Sciences, Tehran, Iran , Mohseni Meysam نويسنده Department of Neurosurgery, Imam Khomeini Hospital, Tehran
University of Medical Sciences, Tehran, IR Iran , Saligheh Rad Hamidreza نويسنده Medical Physics and Biomedical Engineering Department,
Tehran University of Medical Sciences, Tehran, Iran , Madadi Alireza نويسنده Quantitative Magnetic Resonance Imaging and Spectroscopy
Group, Research Center for Cellular and Molecular Imaging, Tehran
University of Medical Sciences, Tehran, Iran , Fathi Kazerooni Anahita نويسنده Department of Medical Physics and Biomedical Engineering,
Tehran University of Medical Sciences, Tehran, Iran , Haidari Ali نويسنده Department of Pathology, Tehran University of Medical
Sciences, Tehran, Iran
Abstract :
Background Distinguishing low-grade from high-grade gliomas can
aid in optimal treatment planning and prognostication.
Diffusion-weighted imaging (DWI) and magnetic resonance spectroscopy
(MRS) have been applied in several studies for non-invasive glioma
grading. However, these studies focused on limited aspects of these
imaging techniques and used different study setups, resulting in
occasionally inconsistent and incomparable conclusions in the
literature. Objectives This study was designed to introduce the optimal
imaging setup and the most reliable and applicable imaging parameters in
glioma grading, using DWI and MRS. Patients and Methods During this
prospective study, using a 3T-MR scanner, 55 glioma patients underwent
brain MRS with short, intermediate, and long echo times (TEs), as well
as DWI using low, intermediate, and high b-values. Postoperatively, all
of the specimens were graded pathologically using light microscopy.
Results We found that Max (Chol/Cr)/ Min (NAA/Cr) ((maximum choline to
creatine ratio)/(minimum N-acetyl aspartate to creatine ratio)),
followed by Max (Chol/ Cr), both in long-TE, were the most reliable
metabolite ratios on MRS for accurate glioma grading. These had values
for area under the curve (AUC) of 0.92 (P < 0.05) and 0.89 (P =
0.001), respectively, compared to conventional MR imaging (cMRI), which
had an AUC of 0.83 (P < 0.05). DWI at maximal accuracy showed an
AUC of 0.80 (P < 0.05). Conclusion Max (Chol/Cr)/Min (NAA/Cr) in
long-TE was the most reliable of all of the MRS parameters studied,
while DWI showed no superiority over cMRI in glioma grading. No
significant differences existed among the various b-values applied, or
between the minimum and mean tumor apparent diffusion coefficient values
used in DWI-based glioma grading.
