High-resolution MRI identifying the terminal segment of the intracranial vertebral artery fine and atherosclerotic lesions / 中国脑血管病杂志

Objective To evaluate the terminal segment of the intracranial vertebral artery (tICVA) fine and atherosclerotic lesions using high-resolution MRI (HRMRI) in order to guide endovascular interventional therapy.Methods From October 2015 to October 2016,4 patients with bilateral tICVA diagnosed with digital subtraction angiography (DSA) and admitted to Xuanwu Hospital,Capital Medical University were analyzed retrospectively.At the same time,time of flight (TOF) and black blood imaging were used.The bilateral tICVA imaging features in 4 patients were analyzed.Congenital dysplasia of vertebral artery and atherosclerotic lesions were identified.Results DSA revealed that bilateral tICVA fine or occlusion.HRMRI evaluation of the vascular wall structure showed that vascular dysplasia in 4 cases were all located on the right sides,showing no obvious thickening of the wall thickness,and the diameter was less than 1/2 of the contralateral side.One patient had atherosclerotic stenosis on the left and 3 had occlusion,showing local wall thickening,plaque formation,and resulting in the narrowing of the corresponding lumen and even occlusion.Three of the patients were treated with endovascular intervention.Conclusion HRMRI is helpful to differentiate hypoplasia in terminal intracranial vertebral artery and atherosclerotic stenosis or occlusion,identifying the dominant side of the vertebral artery and providing image basis for endovascular treatment of vertebral artery.

Hemodynamic evaluation of vascular ultrasonography for severe intracranial vertebral artery stenosis before and after stenting / 中国脑血管病杂志

Objective To investigate color Doppler flow imaging (CDFI)and transcranial color-coded sonography (TCCS)for detection and evaluation of severe stenosis of intracranial vertebral artery (IVA) before and after stenting,as well as the hemodynamic changes of restenosis and their clinical value. Methods A total of 102 patients with severe stenosis of IVA confirmed by CDFI plus TCCS and DSA from November 2011 to November 2013 were analyzed retrospectively. Extra- and intracranial segments peak systolic velocity (PSV),end-diastolic velocity (EDV),IVA pulsatility index (PI),extracranial resistance index (RI),tube diameter,spectrum morphology,and hemodynamic parameters before stenting and 1 week, 3,6 and 12 months after stenting were compared. According to the results of TCCS,they were further divided into either a restnosis group (n=16 )or a non-restnosis group (n=86 ). Results (1 )The results of TCCS detection showed:PSV,EDV,and PI of the stenotic segments were improved significantly at 1 week after stenting,they were 109 ± 40 cm/s vs. 258 ± 63 cm/s,47 ± 18 cm/s vs. 132 ± 45 cm/s,0. 91 ± 0. 15 vs. 0.75 ± 0. 18,respectively. There were significant differences (all P0. 05). (2)The results of CDFI showed:PSV and EDV of the ipsilateral extracranial segment were improved significantly after procedure compare with those before procedure, they were 64 ± 15 cm/s vs. 51 ± 15 cm/s and 24 ± 6 cm/s vs. 19 ± 7 cm/s (all P<0. 05). The RI value and vertebral artery diameter of the extracranial segment were improved gradually,and they reached the peak at 12 months after procedure (0. 61 ± 0. 07 vs. 0. 63 ± 0. 12,P=0. 038;3. 6 ± 0. 4 mm vs. 3. 4 ± 0.5 mm,P=0. 009). Conclusion CDFI in combination with TCCS can objectively evaluate the extra-and intracranial hemodynamic changes before and after IVA stenting,and provide reference information for the effectiveness of stenting and the imaging evaluation of restenosis.

Evaluation criteria of transcranial color-coded sonography for the hemodynamics of intracranial segment vertebral artery stenosis / 中国脑血管病杂志

Objective To investigate the criteria of hemodynamic parameters for diagnosis of intracranial segment vertebral artery stenosis with transcranial color-coded sonography (TCCS ). Methods A total of 622 outpatients or inpatients with suspected posterior circulation ischemia were enrolled retrospectively,from which 216 patients were selected with TCCS,color Doppler flow imaging (CDFI)screen,and digital subtraction angiography (DSA)examination,including 33 patients (15. 3%) had normal intracranial vertebral arteries,the stenosis rates<50% were 45 cases (20. 8%),50%-69%were 44 cases (20. 4%),and 70%-99% were 94 cases (43. 5%). The mean velocity (MV)of intracranial segment,the ratios SPRP (PSV1/PSV2 ),SPRE (EDV1/EDV2 )of the systolic and end diastolic flow velocity between the intracranial segment and the intervertebral space segment were calculated respectively by detecting the intracranial segment of vertebral artery,the intervertebral space segment peak systolic velocity (PSV1 ,PSV2 )and end diastolic velocity (EDV2 ,EDV1 ). The DSA findings were used as the criteria,the area under the receiver operating characteristic (ROC ) curve was calculated and the optimal cut-off points were obtained. Results The optimal cut-off points of TCCS diagnosis of intracranial vertebral artery stenosis were as follows:the parameter standards of stenosis rate <50% were 110 cm/s≤PSV1≤145 cm/s and 65 cm/s≤MV≤85 cm/s,the parameter standards of stenosis rate 50%-69%were 145 cm/s≤PSV1≤190 cm/s and 85 cm/s≤MV≤115 cm/s,and the parameter standards of stenosis rate 70%-99% were PSV1≥190 cm/s and MV≥115 cm/s. Conclusion TCCS may effectively evaluate the hemodynamic changes of intracranial vertebral artery stenosis and provide reference for the ultrasound evaluation criteria of intracranial vertebral artery stenosis.

High-Resolution Contrast-Enhanced 3D-Spoiled Gradient-Recalled Imaging for Evaluation of Intracranial Vertebral Artery and Posterior Inferior Cerebellar Artery in Lateral Medullary Infarction

PURPOSE: To determine whether high-resolution contrast-enhanced three dimensional imaging with spoiled gradient-recalled sequence (HR-CE 3D-SPGR) plays a meaningful role in the assessment of intracranial vertebral artery (ICVA) and posterior inferior cerebellar artery (PICA) in lateral medullary infarction (LMI). MATERIALS AND METHODS: Twenty-five patients confirmed with LMI were retrospectively enrolled with approval by the IRB of our institute, and 3T MRI with HR-CE 3D-SPGR and contrast-enhanced magnetic resonance angiography (CE-MRA) were performed. Two radiologists who were blinded to clinical information and other brain MR images including diffusion weighted image independently evaluated arterial lesions in ICVA and PICA. The demographic characteristics, the area of LMI and cerebellar involvement were analyzed and compared between patients with arterial lesion in ICVA only and patients with arterial lesions in both ICVA and PICA on HR-CE 3D-SPGR. RESULTS: Twenty-two of twenty-five LMI patients had arterial lesions in ICVA or PICA on HR-CE 3D SPGR. However twelve arterial lesions in PICA were not shown on CE-MRA. Concurrent cerebellar involvement appeared more in LMI patients with arterial lesion in ICVA and PICA than those with arterial lesion in ICVA alone (p = 0.069). CONCLUSION: HR-CE 3D-SPGR can help evaluate arterial lesions in ICVA and PICA for LMI patients.

Spontaneous Dissecting Aneurysm of the Intracranial Vertebral Artery: Management Strategies

PURPOSE: Pathogenesis and treatment of spontaneous dissecting aneurysm of the intracranial vertebral artery (VA) remain controversial. This study was designed to provide management strategies and to improve management outcome in patients with these aneurysms. MATERIALA AND METHODS: Among a total of 1,990 patients treated for intracranial aneurysms from February 1992 to June 2005, 28 patients (1.4%) were treated either by surgery (8 patients) or neurointervention (20 patients) for spontaneous dissecting aneurysms of the intracranial VA. Twenty-two patients had ruptured aneurysms. We analyzed indications of surgery or neurointervention for each case, and assessed the management outcome at a 6-month follow-up. RESULTS: For selection of therapeutic options, patients were initially evaluated as possible candidates for neurointervention using the following criteria: 1) poor clinical grade; 2) advanced age; 3) medical illness; 4) unruptured aneurysm; 5) equal or larger opposite VA; 6) anticipated surgical difficulty due to a deep location of the VA-posterior inferior cerebellar artery (PICA) junction. Surgery was considered for patients with: 1) high-risk aneurysms (large or irregular shaped); 2) smaller opposite VA; 3) failed neurointervention; or 4) dissection involving the PICA. Management outcomes were favorable in 25 patients (89.3%). Causes of unfavorable outcome in the remaining 3 patients were the initial insult in 2 patients, and medical complications in one patient. CONCLUSION: Ruptured aneurysms must be treated to prevent rebleeding. For unruptured aneurysms, follow-up angiography would be necessary to detect growth of the aneurysm. Treatment modality should be selected according to the clinical characteristics of each patient and close collaboration between neurosurgeons and neurointerventionists is essential.