Brilliance 256

Baseline multimodal CT imaging included brain NCCT, head and neck CT angiography (CTA), and brain CT perfusion (CTP). All baseline multimodal CT images were acquired using a 256-channel scanner (Brilliance 256; Philips Healthcare). Follow-up CT/MRI was obtained 24 h after the baseline NCCT. The scanning parameters for NCCT were: 120 kV, 200 mAs. The scanning parameters for CTP were 80 kV, 80 mAs, and 64 mm × 1.25 mm detector collimation and scan duration of 60 s. The scanning parameters for CTA were 100 kV, 266 mAs.

Renal vessel imaging in the Renal group was performed using contrast-enhanced spiral CT (Brilliance 256; Philips Medical Systems, Cleveland, OH). All patients underwent craniocaudal scanning in the supine position while holding a single-held breath. A non-ionic contrast agent (Ultrafine, Bayer Schering Pharma AG, German) was injected into the antecubital vein using a dual-cylinder high-pressure syringe at 1.2 ml/kg, 4 ml/s. The venous phase acquisition was set to 80 s after intravenous injection, followed by a flush of 40 mL saline. The scanning range extended from the diaphragmatic roof to the superior border of the pubic symphysis. Scanning parameters were 250 mA at 120 kV, 0.5 mm reconstruction interval, and 0.625 mm increment.

All patients were scanned with a 256-slice MDCT scanner (Brilliance 256; Philips Medical Systems, OH, USA), as previously described^{19 (link)}. Orbital CT scans were obtained using contiguous axial slices, with the patient’s head positioned parallel to the Frankfurt plane. Patients were asked to look at a fixed point, and the scanning parameters were as follows: 120 kV, 150 mAs, 64 × 0.625 mm detector configuration, 1 mm slice thickness, and 1 mm slice increment. Measurement of proptosis was performed on the CT image by drawing a horizontal line between the lateral orbital rims on an axial plane that bisects the lens and then drawing a perpendicular line forward to the posterior surface of the cornea^{18 (link)}. The posterior surface of the cornea was chosen because it can be difficult to define the anterior surface of the cornea on CT.