Related Experiment Videos
MR imaging of the posterior hypophysis in children
F Gudinchet1, F Brunelle, M O Barth
1Service de radiologie, Hopital des Enfants-Malades, Paris, France.
Insights
Magnetic resonance imaging (MRI) reveals that an absent bright signal in the posterior pituitary lobe on T1-weighted images indicates neurohypophyseal dysfunction. This finding is crucial for diagnosing central diabetes insipidus and detecting suprasellar tumors.
Area of Science:
- Radiology
- Pediatric Endocrinology
- Neuroimaging
Background:
- The posterior pituitary lobe normally appears as a high-intensity structure on T1-weighted MRI scans.
- Central diabetes insipidus (CDI) is characterized by impaired antidiuretic hormone secretion.
- Suprasellar tumors can compress or infiltrate the pituitary gland and stalk, affecting function.
Purpose of the Study:
- To evaluate the utility of T1-weighted MRI in assessing the posterior pituitary lobe signal in children.
- To correlate the posterior pituitary lobe signal intensity with neurohypophyseal function in children with and without CDI.
- To investigate the association between pituitary stalk changes and suprasellar tumors.
Main Methods:
- Retrospective analysis of MR imaging in 30 healthy children and 13 children with CDI.
- Comparison of T1-weighted MRI findings of the posterior pituitary lobe between control and patient groups.
- Correlation of MRI findings with clinical diagnosis and tumor presence.
Main Results:
- All 30 healthy children showed a high-intensity signal in the posterior pituitary lobe on T1-weighted images.
- The normal hyperintense signal was absent in all 13 children with central diabetes insipidus.
- Three patients with suprasellar tumors exhibited progressive pituitary stalk enlargement on follow-up MRI.
Conclusions:
- Absence of the normal posterior pituitary lobe hyperintense signal on T1-weighted MRI is a reliable indicator of neurohypophyseal dysfunction.
- Pituitary stalk abnormalities on MRI may suggest the presence or development of suprasellar tumors.
- MRI is a valuable tool for diagnosing and monitoring conditions affecting the posterior pituitary in children.
Abstract:
The posterior lobe of the pituitary gland was studied by MR imaging in 30 children without pituitary gland disease and compared with studies from a group of 13 children with central diabetes insipidus, including eight cases of primary diabetes insipidus and five cases of diabetes insipidus secondary to suprasellar tumors (four proved germinomas, one still unknown tumor). Two components in the sella turcica were identified in all 30 children without pituitary gland disease, and the posterior lobe was identified as a high-intensity structure on T1-weighted images. In all 13 patients with diabetes insipidus, the normal hyperintense signal of the posterior hypophysis was absent on T1-weighted images. Three patients with suprasellar tumors presented with a progressively enlarging pituitary stalk on follow-up. Our findings show that absence of the normal hyperintense signal of the posterior lobe is closely related to a loss of function of the neurohypophysis. Size or signal modification of the pituitary stalk should suggest the development of a suprasellar tumor.