The solitary enhancing cerebral lesion: can FLAIR aid the differentiation between glioma and metastasis?
1Department of Radiology, Princess Alexandra Hospital, Brisbane, Qld, Australia.
Background And Purpose:
The purpose of this study is to investigate the diagnostic utility of fluid-attenuated inversion recovery (FLAIR) in differentiating between glioma and metastasis by assessing for nonenhancing adjacent cortical signal intensity abnormality in patients who present with a solitary enhancing cerebral lesion.
Methods:
After approval from the institutional ethics committee was obtained, the MR imaging studies of 70 patients with a solitary enhancing lesion, without previous surgery or treatment, were reviewed. The axial FLAIR studies were initially reviewed for cortical involvement. If cortex involvement was detected, comparison with the axial T1, with and without gadolinium enhancement, was made to determine whether the cortex involvement was in an area without enhancement. If this was the case, the study was considered positive for glioma. Statistical analysis consisted of binary logistic regression and a 2 x 2 contingency table.
Results:
Involvement of the adjacent cortex with FLAIR signal intensity abnormality but without enhancement was seen in 19 of 70 patients; 16 were gliomas and 3 were solitary metastasis. The sensitivity and specificity of this finding were 44% and 91%, respectively. The positive predictive value for glioma was 84%.
Conclusion:
FLAIR, when interpreted in concert with pre- and postgadolinium T1-weighted images, may be useful in differentiating glioma from metastasis when a solitary enhancing cerebral lesion is present. The presence of nonenhancing adjacent cortical involvement in a solitary enhancing lesion is a frequent and relatively specific sign.
Insights
Fluid-attenuated inversion recovery (FLAIR) MRI can help differentiate glioma from metastasis in solitary enhancing brain lesions. Nonenhancing cortical involvement on FLAIR is a frequent and specific sign for glioma.
Area of Science:
- Neuroradiology
- Neuro-oncology
- Medical imaging
Background:
- Differentiating solitary enhancing cerebral lesions between glioma and metastasis is clinically important.
- Conventional MRI sequences can sometimes be ambiguous in these cases.
Purpose of the Study:
- To evaluate the diagnostic utility of fluid-attenuated inversion recovery (FLAIR) in distinguishing glioma from metastasis.
- To assess the significance of nonenhancing adjacent cortical signal intensity abnormality in solitary enhancing cerebral lesions.
Main Methods:
- Retrospective review of 70 patients with solitary enhancing cerebral lesions.
- Analysis of axial FLAIR and T1-weighted (pre- and post-gadolinium) MRI studies.
- Statistical analysis including binary logistic regression and contingency tables.
Main Results:
- Nonenhancing adjacent cortical involvement on FLAIR was observed in 19 of 70 patients.
- Of these 19 patients, 16 had gliomas and 3 had metastasis.
- The sensitivity and specificity for detecting glioma were 44% and 91%, respectively, with a positive predictive value of 84%.
Conclusions:
- FLAIR, in conjunction with T1-weighted images, aids in differentiating glioma from metastasis in solitary enhancing lesions.
- Nonenhancing adjacent cortical involvement on FLAIR is a relatively specific indicator for glioma.
