This diagnostic image is a contrast-enhanced MRI of the brain, specifically focusing on a sagittal view of the sellar and suprasellar regions. The image demonstrates the pituitary gland situated within the sella turcica. A key finding is the heterogeneous enhancement of the pituitary parenchyma, characterized by non-uniform signal intensity following intravenous contrast administration. Instead of the typical homogeneous bright signal, the gland shows patchy areas of varying brightness and relative hypoenhancement. The overall morphology of the gland appears slightly enlarged or distorted with poorly defined margins in certain sections. This visual pattern is a significant clinical indicator of hypophysitis, potentially secondary to immune checkpoint inhibitor (ICI) therapy. The image serves as an educational example of how inflammatory processes can alter the vascular and structural integrity of the pituitary gland, leading to abnormal contrast uptake patterns compared to normal glandular tissue.

Contrast-enhanced brain magnetic resonance imaging (MRI) scans in sagittal (a) and coronal (b) views demonstrating a significant pituitary lesion. Red arrows point to a markedly enlarged pituitary gland that expands the sella turcica. The lesion exhibits heterogeneous signal intensity, characterized by varying degrees of contrast enhancement and distinct areas of intrinsic high signal, which are visually suggestive of intra-lesional hemorrhage or necrosis. In the sagittal view, superior expansion of the mass is visible relative to the sphenoid sinus and brainstem. The coronal view highlights the horizontal extension and proximity to the cavernous sinuses. These neuroimaging findings are clinically significant for diagnosing pituitary apoplexy, often occurring in the setting of a preexisting macroadenoma. The images serve as an educational example of sellar pathology, demonstrating the diagnostic utility of multi-planar MRI in evaluating the hypothalamic-pituitary axis and identifying complications such as hemorrhage within a pituitary mass.

This diagnostic image series consists of four T1-weighted sagittal dynamic contrast-enhanced (DCE) MRI frames of the pituitary gland, progressing from an arterial/early phase (left) to a late venous phase (right). The red arrow indicates the pituitary gland situated within the sella turcica. The sequence demonstrates normal contrast wash-in, where the pituitary stalk and posterior pituitary enhance initially, followed by diffuse, homogeneous enhancement of the adenohypophysis. Visible anatomical landmarks include the sphenoid sinus (inferior), the optic chiasm (superior), and the pons (posterior). The images are used to assess the pituitary for secondary signs of pathology, such as hypophysitis or microadenomas, which may present with delayed or altered enhancement patterns. In this specific case, the pituitary appears normal in size and morphology with appropriate contrast kinetics, providing radiographic evidence against structural causes in patients presenting with hormonal deficiencies like isolated ACTH deficiency.

Contrast-enhanced T1-weighted MRI of the head in coronal (A) and sagittal (B) planes, focused on the sellar and suprasellar regions. The imaging reveals a significant homogeneous enhancement of an enlarged pituitary stalk, measuring approximately 12 x 15 x 16 mm. This mass and the normal pituitary gland are both bounded superiorly by the diaphragma sellae. Notable mass effect includes slight compression of the optic chiasm and a focal depression of the sellar floor toward the left side. The cavernous sinuses bilaterally appear clear of tumor invasion. Additionally, the images show mucosal thickening in the ethmoid and left maxillary sinuses. This diagnostic imaging is indicative of pathology involving the infundibulum, such as lymphocytic hypophysitis or a primary pituitary stalk tumor like marginal zone lymphoma (MZL). The study demonstrates key landmarks for neurosurgical planning, including the relationship between the lesion, the sella turcica, and the visual pathways.