Sagittal and axial T1-weighted images, coronal and axial T2-weighted images, coronal and contrast-enhanced Flair images of all subjects were obtained using the Siemens 3.0T MAGNETOM Trio Tim MRI system (Siemens, Munich, Germany). Routine MRI scanning parameters: turbo spin echo (TSE) sequence was used for T1WI, TE = 8-15 ms, TR = 400-500 ms, three times of excitation; TSE sequence was used for T2WI, TE = 83-98 ms, TR = 3000 ms, two times of excitation. Field of view (FOV) = 180×180 mm, matrix = 320-384×240-252, slice thickness and gab of the axial scan were 5 mm and 6.5 mm, respectively; slice thickness and gab of the sagittal and coronal scans were 2.5 mm and 2.75 mm, respectively. After plain scanning, contrast-enhanced scanning was performed using Gd-DTPA (0.2 mmol/kg), using the same parameters as described above.
MRI data of all subjects within 1 week before surgery and after surgery were collected. Two neurosurgeons and one radiologist analyzed these data together and agreed on the definition of tumor invasiveness and cystic changes. The main observation included (1) measurement of tumor volume and preoperative maximum tumor diameter; (2) determination of cystic changes in the tumor; and (3) evaluation of tumor invasiveness.
MRI data of all subjects within 1 week before surgery and after surgery were collected. Two neurosurgeons and one radiologist analyzed these data together and agreed on the definition of tumor invasiveness and cystic changes. The main observation included (1) measurement of tumor volume and preoperative maximum tumor diameter; (2) determination of cystic changes in the tumor; and (3) evaluation of tumor invasiveness.