Evaluation of the 80 mm volume shuttle CT cerebral perfusion imaging and 4D-CT angiography in patients with stenosis or occlusion of internal carotid artery

Objective To evaluate the 80 mm volume shuttle cerebral CT perfusion(CTP) and 4D-CT angiography (CTA) in patients with stenosis or occlusion in Willis circle.Methods Conventional cerebral plain CT, 80 mm CTP and dynamic 4D-CTA were performed in 55 patients with unilateral MCA/ ICA stenosis or occlusion.The parameter maps of cerebral blood flow (CBF), cerebral blood volume (CBV), mean transit time (MTT) and time to peak (TTP) were analyzed.Meanwhile dynamic 4D-CTA images were also obtained.The significance of the differences of CBF, CBV, MTT and TTP between the affected side and the contralateral side was assessed using K Independent Samples analysis.Results In 40 patients with unilateral stenosis or occlusion of MCA/ICA, CTP was found abnormal in 36 patients.MTT and TTP of affected side [(7.18 ±1.34), (19.65 ±1.81) s] were significantly prolonged compared to contralateral side [(5.22±1.14) s, (17.62±1.65) s, X~2 =30.833,25.817, P<0.017].Centrum ovale or parietal lobe ischemic lesions were observed in 16 patients on CTP.In 15 patients with bilateral stenosis or occlusion of MCA/ICA, CTP was observed abnormal in 10 patients.CBF, CBV, MTT and TTP of affected side [(42.85 ±6.09) ml·100 g~(-1)·min~(-1), (2.63 ±0.42) ml·100 g~(-1), (11.27 ±1.43) s, (21.07 ±1.44) s)] were significantly different from those of contralateral side [(71.20 ±6.30) ml·100 g~(-1)·min~(-1), (2.29 ±0.15) ml·100 g~(-1), (3.38 ±0.61) s, (17.64 ±1.70) s (X~2 =17.314, 5.913,17.334,13.834,P<0.017)].On 4D-CTA covering 80 mm (0.625 mm×l28), unilateral stenosis of MCA were observed in 22 patients (13 right MCA and 9 left MCA), unilateral occlusion were observed in 5 patients (1 right MCA and 4 left MCA) and bilateral MCA stenosis/occlusion were observed in 9 patients.4D-CTA covering Willis cycle can display stenosis/occlsion of MCA as same as conventional CTA and DSA.Conclusion 80 mm volume shuttle CTP and 4D-CTA provide valuable information about the hemodynamic changes and the abnormalities of intracranial artery in patients with MCA/ICA stenosis or occlusion. Key words: Middle cerebral artery;  Internal carotid artery;  Tomography, X-ray computed;  Angiography