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Updated: Mar 16, 2026
Diffusion Tensor Magnetic Resonance Imaging in the Analysis of Neurodegenerative Diseases
Published on: July 28, 2013
Multiparametric evaluation of low grade gliomas at follow-up: comparison between diffusion and perfusion MR with
Maria C Rossi Espagnet1,2, Andrea Romano1, Valeria Mancuso1
11 NESMOS Department, Sant'Andrea Hospital, Sapienza University of Rome, Rome, Italy.
Objective:
To compare MRI using perfusion and diffusion techniques with 6-[(18)F]-fluoro-L-3,4-dihydroxyphenylalanine ((18)F-FDOPA) positron emission tomography (PET) in the follow-up of low-grade gliomas (LGGs) and to identify the best imaging parameter to differentiate patients with different prognosis.
Methods:
Between 2010 and 2015, 12 patients with a pathology-proven diagnosis of LGG and MR (with perfusion and diffusion sequences) and a PET study during their follow-up were retrospectively included in our study. Cerebral blood volume (CBV) and apparent diffusion coefficient (ADC) maps on MR studies and PET images were evaluated using a region of interest-based method. All patients were categorized as stable or as having progressive disease at 1-year follow-up. Statistical analysis was performed using Pearson's correlation test and multivariate analysis of variance (p < 0.05).
Results:
No significant correlations were found between PET parameters [maximum tumour-to-controlateral normal brain ratio (T/Nmax) and tumour-to-striatum ratio] and ADC or relative CBV values measured in both PET hotspot regions and areas of maximum signal alterations. T/Nmax demonstrated a good sensitivity (83%) and specificity (100%) for differentiating two subgroups of patients with different outcomes at 1-year-follow-up (p < 0.05).
Conclusion:
Perfusion and diffusion MR images provide different information compared with (18)F-FDOPA PET in LGGs during follow-up and therefore, they should be considered as complementary tools in the evaluation of these tumours. (18)F-FDOPA PET showed a significant prognostic role in the follow-up of LGGs and appeared to be a better tool than MR advanced techniques for outcome prediction. These results need to be confirmed with longitudinal studies on a larger population.
Advances In Knowledge:
This is the first study that compared (18)F-FDOPA PET with perfusion and diffusion MR in LGGs during follow-up. These preliminary results highlight the importance of a multimodality approach in this field and evidence a potential role for (18)F-FDOPA PET to predict patients at risk for tumour progression.
Insights
6-[(18)F]-fluoro-L-3,4-dihydroxyphenylalanine (18F-FDOPA) positron emission tomography (PET) shows prognostic value in low-grade glioma (LGG) follow-up. This study suggests 18F-FDOPA PET is superior to MRI for predicting patient outcomes.
Area of Science:
- Neuro-oncology
- Diagnostic imaging
- Radiochemistry
Background:
- Low-grade gliomas (LGGs) require accurate follow-up imaging to assess disease progression.
- Advanced MRI techniques like perfusion and diffusion imaging offer insights into tumor biology.
- 6-[(18)F]-fluoro-L-3,4-dihydroxyphenylpyrazine (18F-FDOPA) positron emission tomography (PET) assesses metabolic activity.
Purpose of the Study:
- To compare the efficacy of MRI (perfusion and diffusion) with 18F-FDOPA PET in monitoring LGGs.
- To identify the optimal imaging parameter for differentiating patient prognosis in LGG follow-up.
- To evaluate the role of multimodality imaging in predicting tumor progression.
Main Methods:
- Retrospective analysis of 12 LGG patients (2010-2015) with both MRI and 18F-FDOPA PET during follow-up.
- Quantitative analysis of MRI parameters (cerebral blood volume [CBV], apparent diffusion coefficient [ADC]) and PET parameters (tumor-to-contralateral normal brain ratio [T/Nmax], tumor-to-striatum ratio).
- Statistical correlation and multivariate analysis to compare imaging findings with 1-year follow-up outcomes (stable vs. progressive disease).
Main Results:
- No significant correlations were found between 18F-FDOPA PET parameters and MRI-derived CBV or ADC values.
- The T/Nmax ratio from 18F-FDOPA PET demonstrated high sensitivity (83%) and specificity (100%) in distinguishing patients with different prognoses at 1 year.
- MRI perfusion and diffusion techniques provided distinct information compared to 18F-FDOPA PET.
Conclusions:
- 18F-FDOPA PET is a valuable prognostic tool in LGG follow-up, potentially outperforming advanced MRI techniques for outcome prediction.
- MRI and 18F-FDOPA PET should be considered complementary in the comprehensive evaluation of LGGs.
- Further longitudinal studies with larger cohorts are needed to validate these findings and the prognostic role of 18F-FDOPA PET.
