Evaluation of MRI Criteria for Cavernous Sinus Invasion in Pituitary Macroadenoma

BACKGROUND AND PURPOSE This study was designed to evaluate various magnetic resonance imaging (MRI) criteria for cavernous sinus (CS) invasion in preoperative evaluation of pituitary macroadenoma. METHODS The sellar MRIs of 63 patients (47 female, 16 male; age 17-67 years, mean of 42 years) who underwent surgery for pituitary macroadenoma were retrospectively reviewed. The following MR signs were assessed and compared with intraoperative findings, and statistical analyses were performed: (1) presence of hypointense-line suggestive of medial wall of CS on high-resolution coronal T2-weighted image, (2) presence of entire rim-enhancement around the intracavernous internal carotid artery (ICA) (periarterial enhancement), (3) location of the tumor in relation to the lateral intercarotid lines, and (4) angle of tumor encasement around the intracavernous ICA. RESULTS CS invasion was highly probable if periarterial enhancement was not depicted (positive predictive value, 86%; P < .001). Valuable criteria of CS invasion by logistic regression analysis were the absence of periarterial enhancement (P = .043, odds ratio = 5.23) and the angle of intracavernous ICA encased by the tumor (P = .029, odds ratio = 1.017) with a threshold value of 136.5 degrees with a sensitivity of 90% and specificity of 78.3%. CONCLUSIONS MRI criteria may be helpful in evaluating the presence of CS invasion in pituitary macroadenoma.