Brilliance ct big bore

All CT scans were acquired using a Philips Brilliance CT Big Bore or a GE LightSpeed RT CT scanner. Patients were positioned in the supine position and immobilized with a thermoplastic mask. High-resolution contrast-enhanced helical CT scans were then obtained with an x-ray tube voltage of 120 kV. The slice thickness was set as 3 mm or 5 mm in the Philips CT scanner and 2.5 mm or 5 mm in the GE CT scanner.

The patient was immobilized with a thermoplastic mask to cover the whole head. CT images were collected using multi-slice computed tomography (Brilliance CT, Big Bore, GE, USA) with a 1-mm slice thickness. A plain CT image without an intravenous contrast agent was scanned first, and then the patient underwent enhanced CT scanning immediately after the first scan at the same supine and head position. According to the age and cardiac output among patients, the contrast agent administration technique was individually applied. The computed tomographic angiography principle and parameter range employed in our study are listed in Table 2. The two sets of CTs were imported into the MultiPlan TPS of CyberKnife.