Hypopituitarism MRI

MRI is the imaging procedure of choice in the diagnosis of hypopituitarism. It is preferred over the CT scan as optic chiasm, pituitary stalk, and cavernous sinuses can be seen in MRI. An MRI lesion needs to be related to clinical and lab findings. The absence of an MRI lesion mostly indicates a non-organic etiology. Cystic lesions, such as Rathke’s cleft cysts may have a low-intensity signal on T1-weighted images and a high-intensity signal on T2-weighted images. Meningiomas have a homogenous postcontrast enhancement than pituitary adenomas and have a suprasellar attachment. Hemorrhage into the pituitary gland results in a high-intensity signal on both T1- and T2-weighted images.

• MRI scan with intravenous gadolinium is the imaging procedure of choice in the diagnosis of hypopituitarism. It is preferred over the CT scan as optic chiasm, pituitary stalk, and cavernous sinuses can be seen in MRI^[1]
• MRI is the single best imaging modality in the evaluation of sellar masses as certain findings are suggestive of some specific sellar masses and help to differentiate them
• If MRI is not possible due to any reason, high-resolution CT scan with contrast administration, in coronal plane, may be used as an alternative
• An magnetic resonance imaging (MRI) scan may show a three-dimensional image of pituitary gland, hypothalamus, and the surrounding intracranial structures
• MRI is used to detect the underlying cause of pituitary adenoma that can be seen as a mass with hormonal hypersecretion
• There is a positive correlation between MRI findings and the number of pituitary hormonal deficiencies^[2][3]
• An MRI lesion needs to be related to clinical and lab findings. The absence of an MRI lesion mostly indicates a non-organic etiology
• MRI scan may show the following findings in cases of hypopituitarism:^[4]
  • Decreased size of the pituitary gland
  • Empty sella may be noticed in some cases
  • Pituitary stalk may be visible, thin, or totally absent
  • Posterior lobe of the pituitary may be absent
  • Mass may appear in the pituitary
  • Ectopic posterior lobe of the pituitary gland may be observed in cases of pituitary dwarfism
  • Infiltrative disorders such a sarcoidosis and histiocytosis may present as thickening of infundibulum^[5]
  • In central DI, T1 weighted MR shows absence of high internsity bright spot that is normally seen in posterior pituitary^[6]

• Cystic lesions, such as Rathke’s cleft cysts may have
  • A low-intensity signal on T1-weighted images
  • A high-intensity signal on T2-weighted images

• Meningiomas have a homogenous postcontrast enhancement than pituitary adenomas and have a suprasellar attachment^[7]
• Hemorrhage into the pituitary gland results in a high-intensity signal on both T1- and T2-weighted images

• 
  There is a well defined round lesion noted in the pituitary fossa, the lesion shows homogeneous contrast enhancement.^[9]
• 
  There is a well defined round lesion noted in the pituitary fossa, the lesion is homogeneous and isodense on T1.^[9]

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