TITLE:
Gadolinium Enhancement Ratio in Sellar Region Masses: A Pilot Study of 16 Cases
AUTHORS:
Bénédicte Souho, Géraud Akpo, Salif Djigo, Acyl Idriss, Pihou Gbande, Bidamin N’Timon, Abdoulatif Amadou, Mazamaesso Tchaou, Boucar Ndong, Lantam Sonhaye, Lama Kegdigoma Agoda-Koussema, Komlanvi Adjenou
KEYWORDS:
MRI, Gadolinium, Enhancement Ratio, Macroadenoma, Craniopharyngioma, Meningioma
JOURNAL NAME:
Open Journal of Radiology,
Vol.16 No.3,
September
24,
2026
ABSTRACT: Background: Gadolinium-based contrast agents are paramagnetic and shorten protons’ T1 relaxation time. Quantitative data on T1 signal changes in sellar masses ≥ 1 cm, at 1.5T MRI, are limited. Objective: To quantitatively assess the paramagnetic effect of gadolinium chelate on T1 signal intensity in sellar and suprasellar masses ≥ 1 cm using 1.5T MRI, and to describe enhancement patterns according to histological type in a pilot cohort. Methods: Retrospective cross-sectional study of 16 patients with histologically confirmed sellar/suprasellar masses ≥ 1 cm on 1.5T MRI, between April 2021 and April 2025. Signal intensity was measured before and 4 minutes after 0.1 mmol/kg gadoteric acid injection. ROIs were placed on the solid enhancing portion of the lesion and reference white matter for pre-injection signal intensity (SIpre) and enhancement ratio (ER, expressed as percentage) calculation. Results: The cohort included 11 macroadenomas (68.75%), 3 craniopharyngiomas (18.75%) and 2 meningiomas (12.5%). On pre-contrast T1, 87.5% of the lesions were isointense. After gadolinium administration, all lesions showed paramagnetic enhancement. Mean ER was 30.9% ± 5.1% for macroadenomas, 53.4% ± 11.5% for craniopharyngiomas, and 89.2% ± 18.5% for meningiomas. The difference between groups was statistically significant (p = 0.0066, Kruskal-Wallis test). Conclusion: Quantitative analysis of MRI enhancement showed distinct profiles: intense for meningiomas, low for pituitary adenomas, and low and moderate for craniopharyngiomas. These preliminary findings suggest that enhancement ratios may add to the characterization of sellar masses and should be confirmed in larger series.