As pituitary apoplexy may clinically present with sudden headache and oculomotor palsies; CT may be considered as part of the initial diagnostic evaluation to exclude intracranial hemorrhage or mass lesion, particularly when rapid diagnosis is needed, such as in an emergency department setting. CTA Head CTA may be part of operative planning or image guidance; however, CTA is not routinely used for initial evaluation of pituitary apoplexy [20]. MRA Head There is no relevant literature regarding the use of MRA in the evaluation of pituitary apoplexy. Neuroendocrine Imaging MRI Sella MRI using high-resolution pituitary protocols is the primary modality for the evaluation of suspected pituitary apoplexy [83]. Tumor enlargement, sellar expansion, and intratumoral hemorrhage are well demonstrated on MRI. Noncontrast imaging is sensitive to the detection of hemorrhage and may show T1 signal hyperintensity, low T2 signal, or a hemorrhage fluid level within the pituitary gland [84]. Not all cases of intrapituitary hemorrhage (ie, subacute/necrotic adenoma) are associated with symptomatic pituitary apoplexy; however, caution is needed in interpreting pituitary hemorrhage in the context of clinical symptoms [85]. While pituitary apoplexy is most commonly caused by hemorrhage into an existing pituitary macroadenoma, other soft-tissue masses may have overlapping imaging features. For example, craniopharyngioma or Rathke cleft cysts can have intrinsic T1-signal hyperintensity that is due to proteinaceous content, and a dermoid or teratoma may show high T1 signal because of fat. Inclusion of T1 fat saturation sequences may aid in differentiation of fat from blood products. Ischemic pituitary apoplexy can be detected on contrast-enhanced MRI in the appropriate clinical context by central nonenhancement of the enlarged pituitary, indicating central tumoral necrosis or ischemia. MRI with IV contrast may only be performed for use in operative guidance and should not be considered a first-line imaging test.
Neuroendocrine Imaging. As pituitary apoplexy may clinically present with sudden headache and oculomotor palsies; CT may be considered as part of the initial diagnostic evaluation to exclude intracranial hemorrhage or mass lesion, particularly when rapid diagnosis is needed, such as in an emergency department setting. CTA Head CTA may be part of operative planning or image guidance; however, CTA is not routinely used for initial evaluation of pituitary apoplexy [20]. MRA Head There is no relevant literature regarding the use of MRA in the evaluation of pituitary apoplexy. Neuroendocrine Imaging MRI Sella MRI using high-resolution pituitary protocols is the primary modality for the evaluation of suspected pituitary apoplexy [83]. Tumor enlargement, sellar expansion, and intratumoral hemorrhage are well demonstrated on MRI. Noncontrast imaging is sensitive to the detection of hemorrhage and may show T1 signal hyperintensity, low T2 signal, or a hemorrhage fluid level within the pituitary gland [84]. Not all cases of intrapituitary hemorrhage (ie, subacute/necrotic adenoma) are associated with symptomatic pituitary apoplexy; however, caution is needed in interpreting pituitary hemorrhage in the context of clinical symptoms [85]. While pituitary apoplexy is most commonly caused by hemorrhage into an existing pituitary macroadenoma, other soft-tissue masses may have overlapping imaging features. For example, craniopharyngioma or Rathke cleft cysts can have intrinsic T1-signal hyperintensity that is due to proteinaceous content, and a dermoid or teratoma may show high T1 signal because of fat. Inclusion of T1 fat saturation sequences may aid in differentiation of fat from blood products. Ischemic pituitary apoplexy can be detected on contrast-enhanced MRI in the appropriate clinical context by central nonenhancement of the enlarged pituitary, indicating central tumoral necrosis or ischemia. MRI with IV contrast may only be performed for use in operative guidance and should not be considered a first-line imaging test.