三维时间飞跃法MR血管造影血液铸型诊断颈内动脉系颅内动脉瘤的优势

Preliminary evaluation of 3D TOF MRA fly-around advantages in the diagnosis of internal carotid artery aneurysms

目的 与多层面螺旋CT三维血管造影 (MS 3D CTA)和DSA比较 ,探讨三维时间飞跃法MR血管造影 (threedimensionaltimeofflightMRA ,3DTOFMRA)图像后处理血液铸型技术 (fly around)诊断颈内动脉系颅内动脉瘤的优势和临床应用价值。方法 18名疑诊颈内动脉系颅内动脉瘤病人 ,男 4例 ,女 14例 ;年龄 17～ 76岁 ,平均 4 9 8岁 ;其中蛛网膜下腔出血 (SAH) 14例、动眼神经麻痹 4例。所有病人均接受 3DTOFMRA和MS 3D CTA检查 ,17名接受DSA检查 ,确诊后均经手术治疗。 3DTOFMRA用Toshiba 1 5T超导型MR系统VISART的 3D TOF序列采集原始数据。其参数为 :TR 30ms,TE 6 8ms ,反转角 2 0° ,视野 (FOV) 17cm× 19cm ,矩阵 16 0× 2 5 6 ,采集层块厚度 5 0～ 6 0mm ,层厚 1 2mm ;原始图像后处理方法采用最大密度投影 (MIP)和血液铸型。MS 3D CTA用Toshiba多层螺旋CT Aquilion采集原始数据。其参数为 :扫描速度 0 5s/r,层厚 1 0mm ,螺距 3 5 ;用高压注射器静脉注射非离子型对比剂 ,注射剂量 2 0ml/kg体重 ,注射流率 4 0～ 5 0ml/s ,延迟时间 15～ 18s ;原始图像后处理方法同 3DTOFMRA。图像后处理工作站均用SGIO2 ,后处理软件为Alatoview ,版本 1 4 2。DSA用SiemensMulti

Objective To assess the advantages and the clinical application value of 3D TOF MR angiography fly-around in diagnosing internal carotid artery aneurysms in comparison with multi-slice helical CT three dimensional angiography (MS 3D-CTA) and digital subtraction angiography (DSA). Methods Eighteen patients with clinical suspected internal carotid artery aneurysms were involved in the study.There were 4 males and 14 females,and their age ranged from 17 to 76 years.14 patients were with subarachnoid hemorrhage and 4 patients with oculomotor nerve palsy.All these patients underwent 3D TOF MRA and MS 3D-CTA,and 17 patients underwent DSA.All of them accepted operation treatment.3D TOF MRA was performed with Toshiba 1.5 T MRI system and the parameters of 3D-TOF sequence were: TR 30 ms,TE 6.8 ms,field of view 17 cm×19 cm,matrix 160×256,slab thickness 50-60 mm,section thickness 1.2 mm,flip angle 20°.Row data of MS 3D-CTA was acquired by Multi-slice helical CT-Aquilion (Toshiba).The scanning parameters were: image slice thickness 1.0 mm,scan speed 0.5 s/r,helical pitch 3.5,delay time 15-18 sec.Nonionic contrast agent was injected intravenously (2.0 ml/kg) at the speed of 4.0-5.0 ml/s using a power injector.Source images of 3D TOF MRA and MS 3D-CTA were processed into MIP and fly-around using a workstation SGI-O2,with the post-processing software Alatoview (Ver: 1.42).Conventional four-vessel digital subtraction angiography was performed with Siemens Multi-Start OT. Results 22 aneurysms were detected by both 3D TOF MRA and MS 3D-CTA (1 ACA aneurysm,3 ACoMA aneurysms,1 left MCA aneurysm,2 ICA-cavernous aneurysms,3 left ICA-PCoM aneurysms,8 right ICA-PCoM aneurysms,1 left ICA-AChA aneurysms,2 right ICA-AChA aneurysms,and 1 superior pituitary artery aneurysm).Among those aneurysms,one was not detected by DSA,and another aneurysm′s neck was not clear on the image of DSA.1 right ICA-PCoM aneurysm was surgically treated according to 3D TOF MRA and MS 3D-CTA only.All of the 22 Aneurysms were detected by 3D TOF MRA fly-around,with the body′s diameter ranging from 2.5 mm to 24 mm.Seven of those aneurysms were less than 4 mm in diameter (31.8%, 7/22).Detecting rate of 3D TOF MRA was 100%.On images of 3D TOF MRA,aneurysm′s body,neck,source vessel,and the relationship between the aneurysms and the surrounding structures were clearly and surely displayed.Conclusion 3D TOF MRA fly-around should be a very effective procedure in diagnosing internal carotid artery aneurysms,especially in those who are close to the bony structures of the skull base and the cavernous sinus.