Utility of contrast-enhanced 3D STIR FLAIR imaging for evaluating pituitary adenomas at 3 Tesla

PURPOSE: To assess the usefulness of contrast-enhanced 3D STIR FLAIR imaging for evaluation of pituitary adenomas. METHODS: Patients with pituitary adenomas underwent MR examinations including contrast-enhanced 3D STIR FLAIR and 2D T1-weighted (T1W) imaging. We subjectively compared the two techniques in terms of 10 categories. In addition, images were rated by side-by-side comparisons into three outcomes: 3D STIR FLAIR imaging superior, equal, or 2D T1W imaging superior. Additionally, the added value of 3D STIR FLAIR imaging for adenoma detection over conventional MR imaging was assessed. RESULTS: Twenty-one patients were included in this study. 3D STIR FLAIR imaging offered significantly better images than 2D T1W imaging in terms of three categories, including overall visualization of the cranial nerves in the cavernous sinus (mean 4.0 vs. 2.8, p < 0.0001), visualization of the optic nerves and chiasm (mean 4.0 vs. 2.6, p < 0.0001), and severity of susceptibility artifacts (mean 0.0 vs. 0.4, p = 0.004). In the side-by-side comparison, 3D STIR FLAIR imaging was judged to be significantly superior to 2D T1W imaging for overall lesion conspicuity (62% vs. 19%, p = 0.049) and border between the adenoma and the pituitary gland (67% vs. 19%, p = 0.031). The addition of 3D STIR FLAIR imaging significantly improved the adenoma detection of conventional MR imaging. CONCLUSION: 3D STIR FLAIR imaging improved overall lesion conspicuity compared to 2D T1W imaging. We suggest that 3D STIR FLAIR imaging is recommended as a supplemental technique when pituitary adenomas are invisible or equivocal on conventional imaging.