Effective performance of contrast enhanced SPACE imaging in clearly depicting the margin of pituitary adenoma.

PURPOSE

The aim of this study is to determine if contrast enhanced (CE) sampling perfection with application-optimized contrasts using different flip-angle evolutions (SPACE) images can provide clearer pituitary adenoma margin than conventional CE T1-weighted spin echo (T1-SE) sequence for cavernous sinus (CS) invasion evaluation.

METHODS

21 healthy volunteers were preformed with SPACE scans before and after administration of gadopentetate dimeglumine at different time points (1, 7 and 13 min). Signal intensity (SI) of regions of interest was plotted in SI/time curves for bilateral CS, pituitary and temporal lobe. 35 patients with pituitary adenoma (≥1 cm) were performed CE T1-SE and CE SPACE scans. Two observers made the visual assessment of the tumor margin delineation and CS invasion evaluation on both SPACE and T1-SE images. Surgical findings were compared with the invasion assessment results.

RESULTS

At 1, 7 and 13 min after enhancement, SI of left CS increased 6.7, 9.5 and 11.2% respectively compared with unenhanced images (all p < 0.05). Right CS increased 7.2, 9.3 and 11.3% (all p < 0.05%). Within pituitary, a decline (6.3%, p < 0.05) of SI was measured at 1 min after enhancement. CE SPACE performed superior to those of CE T1-SE sequence in visual assessment of tumor edge (assessment score, 1.66 ± 0.42 vs. 1.23 ± 0.65, p < 0.05), as well as the specificity (86.8 vs. 66.0%, p < 0.05) and accuracy (85.7 vs. 68.6%, p < 0.05) for CS invasion evaluation.

CONCLUSION

CE SPACE could provide better contrast of pituitary adenoma with surrounding CS and clear demonstration of tumor edge for CS invasion evaluation than conventional CE T1-SE sequence.