Objective To investigate the pathological basis of CT and MRI image formation of agranulocytic pituitary tumors. Methods CT and MRI plain and enhanced MRI of 26 cases of agranulocytic pituitary tumors were analyzed and compared with intraoperative findings and pathology. The analysis was focused on the invasion of the spongy sinus; the invasion of the bony skull base and the protrusion into the pterygoid sinus; and the invasion of the internal carotid artery adhesions. Results: 22 cases of pituitary tumors were diagnosed preoperatively; cavernous sinus invasion and internal carotid artery adhesion encapsulation invasion were diagnosed, but the false-positive rates were 27.3% and 36.4%, respectively. Three cases of pituitary tumor showed heterogeneity and nuclear division of tumor cells. Conclusion: CT and MRI images can diagnose pituitary tumor hemorrhage and necrosis, cystic changes, and bone invasion lesions at the skull base more clearly. It can sensitively show cavernous sinus invasion and internal carotid artery adhesion wrapping invasion, which can be false positive. It is inaccurate in determining blood supply and does not suggest pituitary tumor biology.
Pituitary tumors are common intracranial tumors, and the widespread use of CT and MRI in medicine has significantly increased the sensitivity and specificity of the diagnosis of pituitary tumors. Preoperative CT and MRI examinations of pituitary tumors are very important to determine the morphology of the tumor and its relationship with the surrounding tissues, and to determine the surgical approach and treatment plan. The most common pituitary tumors are agranulocytic pituitary tumors. The author retrospectively analyzed 26 cases of agranulocytic pituitary tumors confirmed by surgery and pathology to discuss their imaging characteristics.
I. General data Age 27-71 years old 20 male cases, average age 47 years old; 6 female cases, average age 39.7 years old. All of them had surgically confirmed anaplastic pituitary tumors. The main symptom was lactational amenorrhea syndrome in 9 cases; the main symptom was gigantism or acromegaly in 5 cases; the main symptom was Cushing syndrome in 2 cases; headache in 10 cases; visual impairment in 16 cases; decreased sexual function in 5 cases; vomiting in 2 cases; facial paralysis in 2 cases; excessive drinking and eating in 4 cases.
(a) CT examination: 26 cases were examined by CT, all of which were performed by GE CT machine. 12 cases were scanned in coronal plane + cross-sectional plane, and 14 cases were scanned in coronal plane only. The thickness of coronal layer was 2mm, interval 2mm, and the thickness of cross-sectional scan was 3mm. Twenty-four cases were scanned with enhancement. The contrast medium was 80 ml, and the double-phase scans were performed at 20s and 40s respectively after intravenous rapid pressure injection.
(b) MRI examination: 26 cases were examined by MRI, and all were scanned + enhanced. The 1.0T superconducting MRI machine was selected, and the cranial orthogonal coil was used to perform the spin-echo (SE) sequence. Pre-contrast scans were performed in sagittal T1WI ( TR/ TE : 500/ 40), coronal T ( TR/ TE = 500/ 50) and T2 WI ( TR/ TE = 2000/ 40). The contrast agent was gadopentetate at a dose of 0.1 mmol/kg. After intravenous injection of gadolinium, the sagittal and coronal T 1 WI scans were repeated immediately. The layer thickness was 5 mm (3. 5 mm for microadenoma) and the matrix was 256 × 256. (C) The CT and MRI images were diagnostically analyzed by three highly qualified diagnostic physicians. The size, location, signal intensity characteristics, and infiltrative growth pattern into the surrounding tissues of the tumor were analyzed and recorded. The diagnostic analysis was focused on whether there was necrosis and cystic change; hemorrhage; invasion of cavernous sinus; invasion of skull base bone: protrusion into the pterygoid sinus; invasion of internal carotid artery adhesion wrapping and blood supply status. Intraoperative observation of the extent of tumor growth and relationship with surrounding tissues by surgeons. The tumor was compared with the postoperative pathological findings.