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Updated: Dec 10, 2025
Radiotracer Administration for High Temporal Resolution Positron Emission Tomography of the Human Brain: Application to FDG-fPET
Published on: October 22, 2019
Focal cortical dysplasia imaging discrepancies between MRI and FDG-PET: Unique association with temporal lobe
Hajime Yokota1, Hiroyuki Uetani2, Hiroyuki Tatekawa3
1Department of Radiological Sciences, David Geffen School of Medicine at UCLA, Los Angeles, CA, United States; Department of Diagnostic Radiology and Radiation Oncology, Graduate School of Medicine, Chiba University, Chiba, Japan.
Purpose:
Although magnetic resonance imaging (MRI) and 18F-2-fluorodeoxyglucose-positron emission tomography (FDG-PET) are used for pre-surgical assessment of focal cortical dysplasia (FCD), they often disagree. This study aimed to identify factors that contribute to discrepancies in FCD imaging between MRI and FDG-PET.
Methods:
Sixty-two patients (mean age, 18.9 years) with a FCD type I or II were retrospectively selected. These patients were visually categorized into two groups: 1) extent of PET abnormality larger than MRI abnormality and 2) vice versa or equivalent. Predictive factors of these two groups were analyzed by multivariate logistic regression. The extent of hypometabolic transient zone surrounding FCDs and their mean standardized uptake values were measured and compared by the Mann-Whitney U-test.
Results:
FCDs were detected on MRI and PET in 46 and 55 patients, respectively, whereas no abnormality was detected in 4 patients. The PET hypometabolic areas were larger than the MRI abnormal areas in 26 patients (88 % in the temporal lobe), whereas the PET hypometabolic areas were equivalent or smaller than the MRI abnormal areas in 32 patients (69 % in the frontal lobe). The temporal lobe location was an independent predictor for differentiating the two groups (OR = 35.2, 95 % CI = 6.81-168.0, P < .001). The temporal lobe lesions had significantly wider transient zones and lower standardized uptake values than those in the other lobes (P < .001, both).
Conclusion:
The discrepancies between MRI and FDG-PET findings of FCD were associated with temporal lobe location.
Insights
Discrepancies between MRI and 18F-2-fluorodeoxyglucose-positron emission tomography (FDG-PET) in focal cortical dysplasia (FCD) imaging are linked to temporal lobe location. Temporal lobe FCDs show larger PET abnormalities and wider hypometabolic zones.
Area of Science:
- Neuroimaging
- Epilepsy Surgery
- Neuroradiology
Background:
- Magnetic resonance imaging (MRI) and 18F-2-fluorodeoxyglucose-positron emission tomography (FDG-PET) are crucial for pre-surgical assessment of focal cortical dysplasia (FCD).
- Discrepancies between MRI and FDG-PET findings are common, potentially impacting surgical planning.
Purpose of the Study:
- To identify factors contributing to imaging discrepancies between MRI and FDG-PET in patients with FCD.
- To investigate the influence of lesion location on the agreement between MRI and FDG-PET findings.
Main Methods:
- Retrospective analysis of 62 patients with FCD type I or II, comparing MRI and FDG-PET findings.
- Categorization of patients based on the relative extent of PET vs. MRI abnormalities.
- Multivariate logistic regression to identify predictive factors; Mann-Whitney U-test for comparing hypometabolic zone extent and standardized uptake values.
Main Results:
- FCDs were detected in 46 patients by MRI and 55 by FDG-PET.
- PET hypometabolic areas were larger than MRI abnormalities in 26 patients (88% in the temporal lobe).
- Temporal lobe location independently predicted larger PET abnormalities (OR = 35.2) and was associated with wider transient zones and lower SUV values.
Conclusions:
- Discrepancies between MRI and FDG-PET in FCD assessment are significantly associated with temporal lobe location.
- Temporal lobe FCDs exhibit distinct imaging characteristics on FDG-PET compared to other locations.
- Understanding these location-specific differences is vital for accurate pre-surgical evaluation of FCD.
