64 slice spiral ct device

All patients underwent multidetector brain CTA using a 64-slice spiral CT device (GE Healthcare, Milwaukee, WI, USA). The parameters were as follows:120 kVp, 140 mA, 0.9-mm section thickness, 0.9-mm slice acquisition interval, and intravenous administration of 80 mL of iohexol at a rate of 5.0 mL/s^{15 (link)}. Bone window CT images covered the whole brain (from the skull base to the vertex), to identify the presence of IAC. IAC lesions were defined as high density lesions with a median density greater than 130 Hounsfield units^{16 (link)}. We used the 5-point scale semi-quantitative scoring system proposed by Babiarz et al. to evaluate IAC^{17 (link)}. We selected the highest calcification score for each cerebral artery and added the calcification score of all evaluated artery to get the patient’s total calcification score. We distinguished the severity of IAC according to the total calcification score. 0 score for absent, 1–4 for mild, 5–8 for moderate, and 9–12 for severe degree^{18 (link)}. Two experienced neurologists independently reviewed the images from CT angiography and graded the degree of IAC.

All patients underwent multidetector brain CTA using a 64-slice spiral CT device (GE Healthcare, Milwaukee, WI, USA) with the following parameters:120 kVp, 140 mA, 0.9-mm section thickness, 0.9-mm slice acquisition interval, and intravenous administration of 80 mL of iohexol at a rate of 5.0 mL/s. Bone window CT images covered the whole brain (from the skull base to the vertex) to identify IAC. IAC foci were defined as hyperdense foci with a median density greater than 130 Hounsfield units. We used the 5-point scale semi-quantitative scoring system proposed by Babiarz et al. to evaluate IAC^{18 (link)}. The highest calcification score for each cerebral artery was selected and the calcification score of all evaluated arteries were added to obtain the patient’s total calcification score. The severity of IAC was graded based on the total calcification score: 0 was absent, 1–4 was mild, 5–8 was moderate, and 9–12 was severe^{19 (link)}. Two experienced neurologists independently reviewed the images from CT angiography and graded the degree of cerebral artery calcification.