Abstract: Objective　To observe the imaging characteristics of the anterior intercavernous sinus（AICS）in MRI.　Methods　72 patients who took pituitary enhanced MRI examination were collected continuously, including 32 normal physical examinations and 40 pituitary adenomas. The imaging characteristics of AICS were observed by multi-slice MRI, and classified. In the sagittal plane of midbrain aqueduct, an extension line of the sphenoidal planum was line A, line B was a parallel line with line A passing through the highest signal of AICS, and line C was a parallel line with line A at the sellar floor. Value a was the distance between line A and line B, and Value b was the distance between line B and line C. Then the relative position of AICS between sphenoidal planum and sellar floor was analyzed.    Results    Among the 72 cases, the complete AICS group, the incomplete AICS group, and the non-AICS group were 47 cases (accounted for 65.28%), 19 cases (accounted for 26.39%), and 6 cases (accounted for 8.33%) cases, respectively. The complete AICS was located above the anterosuperior pituitary and below the apex of the tuberculum sellae on the T1WI TSE enhanced MRI. a/ (a+b) value of the complete AICS in the normal group was (0.31±0.10), and (0.20±0.16) in the pituitary adenoma group. There were statistical difference between the normal group and the pituitary adenoma group (P<0.05).　Conclusions　In T1WI TSE MRI, AICS imaging has higher imaging in normal medical examinations, but AICS imaging decreases and tends to be discontinuous in pituitary adenomas.

Key words:  , Anterior intercavernous sinus, 　MRI, 　TIWI, 　Pituitary, 　Pituitary adenoma