pCASL、3D-TOF-MRA与DSA在缺血性脑血管疾病诊断中的应用研究

发布时间：2018-07-12 09:31

本文选题：准连续式动脉自旋标记 + pCASL　；参考：《南方医科大学》2017年硕士论文

【摘要】：研究背景脑血管意外(CVA),又称脑卒中,是指脑血管疾病的患者因各种诱发因素引起脑内动脉狭窄、闭塞或破裂,而造成急性脑血液循环障碍,临床上表现为一次性或永久性脑功能障碍的症状和体征。是危害人类健康的常见疾病之一,具有发病率高、死亡率高、致残率高等特点。据我国流行病学调查结果推算,脑卒中年发病率约为210/10万,死亡率约为65/10万,幸存者中有70%-80%遗留有不同程度的残疾,近一半患者生活不能自理,给社会和家庭带来沉重的负担。其中,缺血性脑血管疾病(ICVD)约占70%,包括短暂性脑缺血发作、脑梗死。究其原由,主要因脑供血血管狭窄或闭塞等,致所灌注的脑组织区域供血失代偿,出现中枢神经系统病变有关。因此,及早发现并明确供血血管病变是控制疾病危害性的关键,为患者早期诊断、及时治疗提供方向。目前主要采取数字减影血管造影(DSA)、CT血管成像(CTA)、磁共振血管造影(MRA)等方法进行诊断。数字减影血管造影(Digital Subtraction Angiography,DSA)通过导管注入显影剂血管浓性碘,在显影剂到达目标血管之前至目标血管内对比剂浓度达最高峰及显影剂被廓清的时间段内,对检查部位连续成像,并将该连续成像结果中不含显影剂图像为蒙片,与含有显影剂图像形成减影对,通过采用计算机对其组成的图像数字矩阵进行减影成像,抵消掉骨骼与软组织部分,最后形成血管影像。DSA是目前诊断血管形态异常的金标准,但因其费用昂贵、有创、存在放射线暴露、操作复杂且耗时等缺陷,不适于作为初筛及普查。电子计算机断层扫描血管成像(Computed Tomography angiography,CTA)是经周围静脉快速注射碘对比剂,并在注入对比剂的充盈高峰期,采用螺旋CT对靶血管进行高速多层次连续CT扫描,采集数据。扫描结束后,通过容积再现(volume rendering,VR)、曲面重建(curved planner reconstruction,CPR)等计算机软件技术对图像进行后处理,重建合成三维立体血管图像。CTA也需要对比剂进行成像,也存在有辐射、碘对比剂过敏等缺陷。相比之下,具有无创、无对比剂、设备和后处理技术不断地发展等特点的MRI技术,在血管病变诊断的应用越来越广泛。磁共振血管造影(magnetic reconanceangiorgraphy,MRA)利用相位位移、流动增强效应等磁共振成像技术,以周围静止的机体组织为参考物象,根据流动的血液来显示出被检查者的血管情况。时间飞跃法磁共振血管成像(3D-TOF-MRA)是临床常用的一种MRA技术,具有很高的空间分辨力、定位准确、任意方向、任意角度、扫描范围广、多种重建、成像序列多等特点,可以连续完整的显示病变血管的部位及范围。在评估血管狭窄程度方面,3D-TOF-MRA与DSA具有很好的一致性。但是3D-TOF-MRA也有缺陷,例如通常只对颅内较大动脉及其Ⅰ～Ⅱ级分支的血管病变敏感,血流动力学变化产生的涡流会夸大血管狭窄的程度等。于1992年由Detre JA等首次提出一种以动脉血内自由弥散的水质子作为内源性示踪剂的新型的测量脑灌注的MRI技术——动脉自旋标记(ASL)脑灌注MRI技术。该技术通过利用反转脉冲标记兴趣区(ROI)上游的动脉血,当被标记的血流进入ROI血管后,开始采集图像,对标记前、后的图像进行减影,获得ROI的血流图像;同时利用成像层的毛细血管区与组织水进行自旋交换引起变化的局部组织纵向弛豫时间T1,将标记前、后的ROI组织T1信号相减,获得脑血流量。近年,ASL技术得到改良,推出准连续式(pCASL)。pCASL具有标记效能较高,无需注入钆对比剂;无需额外硬件设备;磁化传递效应轻;射频能量沉积少;图像信噪比高等特点。有研究用其判断颅内血管狭窄情况,发现pCASL与3.0T高分辨率磁共振(HR-MRI)在脑血管评估有较好的一致性,也有研究指出ASL较3D-TOF-MRA灵敏度和特异性更高,临床选择上存在争议。为更好探讨ASL在缺血性脑血管疾病诊断中的价值,以DSA为金标准,探讨pCASL和3D-TOF-MRA的灵敏性和特异性,并比较两种诊断方法与DSA的吻合程度,以求为临床应用提供依据。目的研究比较准连续式动脉自旋标记(pCASL)脑灌注MRI技术、时间飞跃法磁共振血管成像(3D-TOF-MRA)和数字减影血管造影(DSA)在缺血性脑血管疾病诊断中的价值。方法(1)病例来源患者来源于2016年1月至2017年1月间经我院神经外科诊治考虑缺血性脑血管疾病者。(2)纳入标准①突然出现以下症状:一侧肢体(伴或不伴面部)无力或麻木;或一侧面部麻木或口角歪斜;或说话不清或理解语言困难;或双眼向一侧凝视;或一侧或双眼视力丧失或模糊;或眩晕伴呕吐;或既往少见的严重头痛、呕吐;或意识障碍或抽搐者;②病情稳定者,配合检查者;③签署知情同意书者。(3)排除标准① 烟雾病、血管炎等非动脉粥样硬化性血管疾病者;②脑内出血、脑内肿瘤、颅脑外伤等其他神经系统疾病的患者;③体内无金属类物质(心脏起搏器或颅内动脉夹),且无幽闭空间恐惧症者;④对造影剂过敏者;⑤有严重心、肺、肝、肾疾病者;⑥图像质量差者。(4)中止标准患者依从性差,或发生严重不良事件,或出现其他病证不宜继续接受观察者,予以中止。(5)病例详细资料最终纳入88例,其中男53例,女35例,平均年龄(67.82±5.35)岁,既往有高血压病史者67例,有糖尿病病史者13例。(6)检查设备与方法所有纳入88例患者均进行pCASL、3D-TOF-MRA和DSA检查,检查时间:pCASL、3D-TOF-MRA均于发病后24h内进行,DSA于MRI检查后24h内进行。①DSA检查要求所有检查者手术前6小时禁食。使用数字减影血管造影机(西门子公司,德国)进行DSA检测:采用Seldinger技术,经股动脉穿刺,选择性插管入颈内动脉和椎动脉后,注入适量非离子型造影剂,依次造影,获取图像。② 3D-TOF-MRA 和 pCASL 检查所有研究对象的MR扫描均采用Philips Ingenia 3.0T磁共振成像系统。T1W1扫描参数:重复时间(repetition time,TR)2045 ms,回波时间(echo time,TE)20 ms,视野(Field of view,FOV)230 × 230 mm,矩阵(Matrix)356× 215,层厚(slice thickness)5.5 mm,层间隔(intersectiongap)1 mm,层数(slices)21。T2W1 扫描参数:TR 9000 ms,TE 120ms,FOV 230 × 230 mm,Matrix 328 ×201,slice thickness 5.5,intersection gap 1 mm,slices 21。3D-TOF-MRA 扫描参数:TR23 ms,TE 3.5 ms,翻转角(flipangle,FA)18 °,FOV 201 × 201 mm,Matrix 404 × 256,slice thickness 0.8 mm,intersection gap 0 mm,slices 160。pCASL 扫描参数:FFE 技术,TR4000ms,TE16ms,FA90°,FOV240×240 mm,Matrix 88 × 88,slice thickness 6 mm,intersection gap 1 mm,slices 16。(7)血管狭窄程度测定以及影像学分析在MR后处理工作站对ASL图像数据依次进行校正、获取脑血流量(CBF)图、获取感兴趣区(ROI)、测量CBF值。通过与镜侧血管比较,判断患侧脑血流量灌注是否异常。3D-TOF-MRA和DSA图像由两名高年资医师分别独立在工作站上人工勾画测量获得血管狭窄率,并根据北美症状性颈动脉狭窄内膜切除协作研究组提出计算狭窄率的测量标准对图像进行分析,二者结论不一致时,协商判定,若不能解决,请第三方进行裁定。狭窄率(%)=(1—动脉最狭窄处血管宽度/狭窄病变远端的正常血管直径)×100%。当狭窄率50%,为轻度狭窄;在50%-69%,为中度狭窄;在70%-99%,为重度狭窄;管壁完全闭塞或未见显影,为100%狭窄或闭塞。若1个病例中有多处狭窄者,只选择一处最严重的进行判定,且各方法评价部位为同一部位。以DSA为参照标准,若DSA显示为供血血管狭窄,且pCASL显示为患侧同一供血血管灌注异常,或者都为未见异常,二者诊断一致,否则为不一致;MRA则需显示同一供血血管狭窄,或者都是未见异常,二者方为诊断一致,否则为不一致。计算3D-TOF-MRA和pCASL判断颅内血管狭窄的敏感性、特异性、准确度。(8)试验过程中患者不良事件发生情况(9)统计方法使用SPSS20.0 for windows软件包进行统计学分析,以P0.05为有统计学差异。结果(1)DSA检出颅内动脉狭窄79例,9例为其它脑血管疾病,发生率为89.77%。pCASL检出颅内动脉狭窄74例,14例为其它脑血管疾病,发生率为84.09%。3D-TOF-MA检出73例,5例为其它脑血管疾病,发生率为82.95%。(2)以DSA为对照,pCASL检出颅内动脉狭窄灵敏度为91.14%,特异性为77.78%,准确度为89.77%,两种方法比较,差异无统计学意义(P0.05),两种方法吻合度一般(K=0.553,P0.05)。(3)以DSA为对照,3D-TOF-MRA检出颅内动脉狭窄灵敏度为87.34%,特异性为55.56%,准确度为84.09%,两种方法比较,差异无统计学意义(P0.05),两种方法吻合度较弱(K=0.331,P0.05)。(4)观察过程中患者无不良事件发生。结论(1)尽管pCASL、3D-TOF-MRA分别与DSA在缺血性脑血管疾病患者颅内动脉狭窄判断上具有较高的一致性,但是pCASL和DSA吻合度更高。而且在评估急性缺血性脑血管疾病时,影像检查需要快速高效,pCASL可以在较短的时间内提供重要的血流动力学信息,与3D-TOF-MRA相比,优势突出。(2)但pCASL无法获取动脉影像,因此,在缺血性脑血管疾病的影像学检查时,建议在3D-TOF-MRA上,加扫pCASL以进行观察判断,提高阳性发现。
[Abstract]:Background cerebral vascular accident (CVA), also known as stroke, refers to the patients with cerebrovascular disease caused by various inducing factors that cause cerebral artery stenosis, occlusion or rupture, and cause acute cerebral blood circulation disorder. Clinical manifestations are symptoms and signs of one-time or permanent cerebral dysfunction. It is one of the common diseases endangering human health. It is characterized by high morbidity, high mortality and high disability rate. According to the results of epidemiological investigation in China, the incidence of cerebral death is about 210/10 million and the mortality rate is about 65/10 million. Among the survivors, 70%-80% has a different degree of disability, nearly half of the patients can't take care of themselves and bring a heavy burden to the society and family. Vascular disease (ICVD) accounts for about 70%, including transient ischemic attack, cerebral infarction, which is mainly due to the stenosis or occlusion of blood supply vessels in the brain, resulting in blood supply decompensation and central nervous system lesion in the cerebral region of the perfusion. Therefore, early detection and clear blood vessel disease are the key to control the disease harm. Early diagnosis and timely treatment provide direction. Currently, digital subtraction angiography (DSA), CT angiography (CTA), magnetic resonance angiography (MRA) and other methods are used to diagnose. Digital subtraction angiography (Digital Subtraction Angiography, DSA) is injected into the vascular concentration iodine through the catheter through the catheter, before the developer reaches the target vessel. In the time segment of the target intravascular contrast agent concentration and the developer to be cleared, continuous imaging of the inspection site, and the continuous imaging results without the developer image as the mask, and the subtraction image containing the developer image, are subtracted by the image digital matrix made up of the computer to offset the bone loss. The soft tissue section and the final formation of vascular image.DSA is the gold standard for the diagnosis of vascular abnormalities, but because of its expensive, invasive, radiological exposure, complicated operation and time-consuming defects, it is not suitable for screening and screening. Computed tomography angiography (Computed Tomography angiography, CTA) is the peripheral vein. Fast injection of iodine contrast agent, and at the peak period of filling the contrast agent, spiral CT is used to carry out high speed and multilevel continuous CT scan on the target vessel and collect data. After the scan, the image is reprocessed and reconstructed by the volume reproduction (volume rendering, VR), surface reconstruction (curved planner reconstruction, CPR) and so on. .CTA also needs contrast agents to be imaging, and there are also defects such as radiation and iodized contrast. In contrast, MRI technology with non-invasive, non contrast, equipment and post-processing technology is becoming more and more widely used in the diagnosis of vascular disease. Magnetic reconancea Ngiorgraphy, MRA) using the phase displacement, the flow enhancement effect and other magnetic resonance imaging techniques, using the surrounding body tissue as the reference image, according to the flow of blood to show the condition of the blood vessel of the examiner. The time leap method magnetic resonance angiography (3D-TOF-MRA) is a common MRA technique in the bed, and has a high spatial resolution. 3D-TOF-MRA is well consistent with DSA in assessing the degree of vascular stenosis. However, 3D-TOF-MRA is also defective, for example, only the larger intracranial arteries and their ones are usually limited. The vascular lesions of class I to class II branches are sensitive, and the eddy current produced by hemodynamic changes will exaggerate the degree of vascular stenosis. In 1992, a new type of MRI technique for measuring cerebral perfusion, including arterial spin labeling (ASL) cerebral perfusion MRI, was first proposed by Detre JA and so on as an endogenous tracer. The technique uses the reverse pulse to mark the arterial blood upstream of the region of interest (ROI). When the labeled blood flow enters the ROI blood vessel, it begins to collect the image, subtracting the image before and after the marking, and obtaining the blood flow image of the ROI, and using the capillary zone of the imaging layer and the tissue water to make the local tissue longitudinal change caused by the spin exchange. In recent years, the ASL technology has been improved, and the ASL technology has been improved, and the ASL technology has been improved in recent years. In recent years, the quasi continuous (pCASL).PCASL has high labeling efficiency and no need to be injected into the gadolinium contrast agent; no additional hardware equipment is needed; the magnetization transfer effect is light; the radio frequency energy deposition is low; the image signal to noise ratio is high. The research is used for research. In judging the situation of intracranial vascular stenosis, it is found that pCASL and 3.0T high resolution magnetic resonance (HR-MRI) have good consistency in cerebrovascular evaluation. There are also studies pointing out that ASL is more sensitive and specific than 3D-TOF-MRA, and there is a dispute in clinical selection. In order to better explore the value of ASL in the diagnosis of ischemic cerebrovascular disease, DSA is the gold standard. To discuss the sensitivity and specificity of pCASL and 3D-TOF-MRA, and to compare the two diagnostic methods with DSA in order to provide the basis for clinical application. Objective to compare the quasi continuous arterial spin labeling (pCASL) cerebral perfusion MRI, the time leap method magnetic resonance angiography (3D-TOF-MRA) and the digital subtraction angiography (DSA) in the ischemic brain. The value of the diagnosis of vascular disease. Method (1) the patients were derived from January 2016 to January 2017 with the treatment of ischemic cerebrovascular disease in the Department of Neurosurgery of our hospital. (2) the following symptoms were included in the standard: one limb (with or without facial) weakness or numbness; or one side facial numbness or angular skewness; or an indistinct speech. Or to understand language difficulties; or to gaze to one side; or the loss or blurring of vision or blur on one side or both eyes; or dizziness and vomiting; or previously uncommon severe headache, vomiting, or conscious disturbance or convulsion; (2) patients with stable condition, who cooperate with the examiners; (3) sign informed consent. (3) exclude the standard of moyamoya disease, vasculitis, and other non atherosclerosis Patients with sexual vascular diseases; (2) patients with intracerebral hemorrhage, intracerebral tumor, craniocerebral trauma and other nervous system diseases; (3) the body without metal substances (cardiac pacemaker or intracranial artery clip), and no claustrophobic space phobias; (4) allergic to contrast agents; (5) patients with serious heart, lung, liver and kidney disease; (6) poor image quality. (4) terminate standard patients dependent (5) the case detailed information was finally included in 88 cases, including 53 men, 35 women, average age (67.82 + 5.35), 67 patients with past history of hypertension, and 13 patients with a history of hypertention. (6) all the examination equipment and methods were included in 88 patients. All the pCASL, 3D-TOF-MRA and DSA examinations were performed: pCASL, 3D-TOF-MRA were performed within 24h after the onset of the disease. DSA was performed in 24h after MRI examination. (1) DSA examination required all examiners to fasting 6 hours before operation. Use digital subtraction angiography (SIEMENS, Germany) for DSA detection: Seldinger technique, femoral artery puncture, selection After the selective intubation into the internal carotid artery and the vertebral artery, an appropriate amount of nonionic contrast media was injected, and the images were obtained in turn. (2) all the MR scans of the 3D-TOF-MRA and pCASL examinations were examined by the.T1W1 scanning parameters of the Philips Ingenia 3.0T magnetic resonance imaging system: the repetition time (repetition time, TR) 2045 MS, and the echo time (echo, 20) MS, Field of view (FOV) 230 x 230 mm, matrix (Matrix) 356 x 215, layer thickness (slice thickness) 5.5 mm, layer interval (intersectiongap) 1 mm. MS, TE 3.5 ms, flipangle, FA 18 degrees, FOV 201 x 201 mm, Matrix 404 x 256, slice thickness 0.8 mm, intersection 0, 88 * 88, 88 * 88 And imaging analysis in order to correct the ASL image data in sequence at the post processing station of MR, obtain the brain blood flow (CBF) map, obtain the region of interest (ROI) and measure the CBF value. By comparing with the mirror side blood vessels, it is judged whether the abnormal.3D-TOF-MRA and DSA images of the blood flow perfusion in the affected side of the brain are artificially ticked on the workstation by two senior physicians. Draw blood vessel stenosis rate, and analyze the image according to the North American Symptomatic Carotid Stenosis endarterectomy cooperative research group to calculate the stenosis rate. When the two conclusions are inconsistent, the third parties are asked to decide. The narrowing rate (%) = (1 - the narrowest artery width / stenosis of the artery is far away). The normal vascular diameter at the end) * 100%. was 50%, mild stenosis, mild stenosis in 50%-69%, moderate stenosis, severe stenosis in 70%-99%, complete occlusion of the wall or no development, 100% stenosis or occlusion. If there were many stenosis in 1 cases, only one of the most serious criteria was selected and the evaluation sites were in the same site. DSA for the same site. For reference, if DSA showed stenosis of blood supply, and pCASL showed abnormal perfusion of blood vessels of the same blood vessel on the side of the affected side, or no abnormality, the two diagnosis was consistent, otherwise, MRA should show the same blood vessel stenosis or no abnormality, and the two is the same diagnosis, otherwise it is inconsistent. Calculation of 3D-TOF-MRA and pCASL To judge the sensitivity, specificity and accuracy of intracranial vascular stenosis (8) the occurrence of adverse events in the patients (9) statistical methods were statistically analyzed using SPSS20.0 for Windows software package, with statistical differences in P0.05. Results (1) 79 cases of intracranial artery stenosis were detected by DSA, 9 cases were other cerebrovascular diseases, and the incidence was 89.77%.pC ASL detected 74 cases of intracranial artery stenosis and 14 cases of other cerebrovascular diseases, 73 cases were detected by 84.09%.3D-TOF-MA, 5 were other cerebrovascular diseases, the incidence was 82.95%. (2) with DSA as the control, the sensitivity of intracranial artery stenosis detected by pCASL was 91.14%, the specificity was 77.78%, the accuracy was 89.77%, and the difference was not statistically significant. The difference was not statistically significant. (P0.05) the two methods were in general (K=0.553, P0.05). (3) the sensitivity of 3D-TOF-MRA in the detection of intracranial artery stenosis was 87.34%, the specificity was 55.56%, the accuracy was 84.09%, and the two methods were compared, the difference was not statistically significant (P0.05), and the two square methods were weak (K=0.331, P0.05). (4) there was no adverse event in the observation process. Conclusions (1) although pCASL, 3D-TOF-MRA and DSA have higher consistency in judging intracranial artery stenosis in patients with ischemic cerebrovascular disease, pCASL and DSA are more anastomosed. And in assessing acute ischemic cerebrovascular disease, imaging needs to be fast and efficient, and pCASL can provide important blood flow in a shorter time. Dynamic information, compared with 3D-TOF-MRA, has a prominent advantage. (2) but pCASL is unable to obtain arterial images. Therefore, in the imaging examination of ischemic cerebrovascular disease, it is suggested that on 3D-TOF-MRA, the scanning of pCASL can be used for observation and judgment to improve the positive discovery.
【学位授予单位】：南方医科大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：R743

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