Hemorrhagic and Non-hemorrhagic Pituitary Apoplexy: Imaging Cohort Analysis.

ABSTRACT

Introduction: Patients suffering from pituitary apoplexy present with variable clinical symptoms and imaging findings. Imaging findings may differ between hemorrhagic and non-hemorrhagic apoplexy. Our study aimed to better define imaging findings in both hemorrhagic and non-hemorrhagic apoplexy and is the first cohort study to report a comparison of imaging findings in these two groups. Materials and Methods: 311 consecutive patients admitted with pituitary tumors were retrospectively reviewed for clinical and imaging evidence of pituitary apoplexy. 37 operative cases were included in this cohort. A cohort statistical analysis was performed between the two groups using Chi Square, Fisher exact test, logistic regression, ANOVA, and t-test. Results: Imaging analysis demonstrated a significant difference in the hemorrhagic cohort’s Computed Tomography (CT) finding of hyperdensity within the sella (n = 17, 48.5%, p = 0.02) and sellar Hounsfield units (mean 45 versus 38.1, p=0.05). Sellar HU were higher in the hemorrhagic pituitary apoplexy cohort. Similarly, hyperintensity on magnetic resonance imaging was more indicative of patients with hemorrhagic apoplexy according to T1 (p = 0.004), T2 (p = 0.004), and FLAIR (p = 0.04) imaging sequences. No difference was found in patterns of enhancement (p = 0.69) or restriction based on diffusion-weighted imaging (p = 0.54). Gradient echo (n=4) and susceptibility weighted imaging (n=1), while not performed in all patients, demonstrated hemorrhage within a pituitary adenoma in patients where this technique was used. Conclusions: Our study did not demonstrate a unifying imaging feature in non-hemorrhagic apoplexy cases. Hemorrhagic apoplexy was more likely associated with hyperdensity on CT and hyperintensity on T1, T2 and FLAIR MRI sequences. Because of the variation of imaging findings in hemorrhagic and especially non-hemorrhagic apoplexy, imaging appearance inconsistent with hemorrhage should not be used to exclude the diagnosis of apoplexy.