磁共振成像与磁共振静脉血管成像对脑静脉窦血栓形成的诊断价值

目的探讨磁共振成像（MRI）及磁共振静脉成像（MRV）对脑静脉窦血栓形成（CVST）的诊断价值。方法收集CVST患者22例。使用PHILPSNT-5型0．5T超导磁共振扫描仪,采用常规SE序列、TSE序列及PC法2D静脉血管成像。结果MRI可显示直接征象：静脉窦流空效应消失,静脉窦内出现各期信号不同的血栓。间接征象：脑水肿、脑梗死、脑出血等。MRV可更好的显示阻塞静脉窦。结论MRI结合MRV对脑静脉窦血栓形成高度敏感,可早期显示直接征象、间接征象,反映病理演变及评价治疗效果,两者结合是无创的、较理想的诊断方法。     

高血压病患者的脑磁共振成像改变

目的　评价高血压病患者脑磁共振成像 (MRI)异常的现患率 ,以及血压水平与脑MRI异常的关系。方法　对95例高血压病患者及与其在年龄、性别等方面 1 1匹配的正常人 ,进行脑MRI及血压、血脂、颈动脉B超等危险因素的检查。结果　高血压病组的脑白质疏松 (LA)现患率为 4 3.2 % (4 1 95 ) ,明显高于对照组 2 5 .8% (2 4 93) ;高血压病组腔隙性脑梗死 (LI)现患率为 13.7% (13 95 ) ,对照组未发现。进行条件logistic回归分析显示 ,舒张压是LA发生的预测因子 ,收缩压和舒张压是LI发生的预测因子。结论　高血压是LA和LI的独立危险因素 ,血压水平与脑MRI异常的发生之间有一定的量效关系     

缺血性脑卒中患者脑内微出血的磁共振成像研究

目的分析缺血性脑卒中患者脑内微出血(CBMs)的分布特点及其与陈旧性腔隙性脑梗死和脑白质改变严重程度的关系。方法连续选取住院的缺血性脑卒中患者247例,分析其MRI表现。根据有无CMBs将患者分为CMBs组(72例)和无CMBs组(175例)。记录CMBs的位置和个数、陈旧性腔隙性脑梗死的个数和脑白质改变的严重程度。结果与无CMBs组患者比较,CMBs组患者年龄大、高血压、脑梗死病史、脑白质改变比例均高。CMBs组患者CMBs常见的部位依次为:基底节、皮质及皮质下区、丘脑、脑干及小脑。CMBs的分级与陈旧性腔隙性脑梗死及脑白质改变的严重程度之间具有显著相关性。结论CMBs与脑微血管病变之间有密切关系,其可能是晚期脑微血管病变的标志。     

老年性脑微出血的磁共振成像研究

目的探讨老年性脑微出血(CMB)的检出率及分布特征。方法回顾性分析2012年1月²013年12月行头颅磁共振检查的老年受试者638例,按年龄分为602013年12月行头颅磁共振检查的老年受试者638例,按年龄分为60⁶9岁357例,7069岁357例,70⁷9岁244例和≥80岁37例。采用常规MRI扫描和磁敏感加权成像序列,分别记录皮质及皮质下区、基底节、丘脑、小脑、脑干CMB的个数并进行分级。结果 638例中伴有CMB者195例,CMB检出率为30.6%,CMB的检出率随年龄增长而增加(χ2=10.963,P=0.000),CMB分级与年龄呈正相关(r=0.153,P<0.01);与6079岁244例和≥80岁37例。采用常规MRI扫描和磁敏感加权成像序列,分别记录皮质及皮质下区、基底节、丘脑、小脑、脑干CMB的个数并进行分级。结果 638例中伴有CMB者195例,CMB检出率为30.6%,CMB的检出率随年龄增长而增加(χ2=10.963,P=0.000),CMB分级与年龄呈正相关(r=0.153,P<0.01);与60⁶9岁和7069岁和70⁷9岁比较,≥80岁患者脑干CMB发生率明显升高,差异有统计学意义(23.58%vs 15.42%和12.78%,P<0.05)。结论 CMB发生率及分级与年龄呈正相关,磁共振成像对老年人群CMB的检出具有重要的临床意义。     

钙拮抗剂对脑血管痉挛的治疗作用

重点阐述了某些血管活性物质如5-羟色胺、儿茶酚胺、前列腺素等在蛛网膜下腔出血后脑血管痉挛产生方面的作用和钙拮抗剂对抗血管痉挛的机理及其临床应用。     

脑血管痉挛的机制和防治

脑血管痉挛(CVS)是导致动脉瘤性蛛网膜下腔出血(SAH)患者死亡和残疾的主要原因之一。尽管对SAH后CVS进行了广泛的研究,但其发病机制仍未完全阐明,红细胞分解产物、血管内皮功能障碍以及炎症反应在其中起关键作用。脑血管造影仍然是诊断CVS的金标准,但随着检测技术的发展,经颅多普勒、MRI和CT等无创性手段在SAH和CVS诊断中的地位越来越重要。对CVS的处理包括5个层面(1)在SAH后尽早预防CVS;(2)在发生CVS后纠正动脉狭窄;(3)预防动脉狭窄引起的脑缺血;(4)治疗动脉狭窄引起的脑缺血;(5)保护脑组织免受缺血损伤。     

蛛网膜下腔出血致脑血管痉挛的机制和临床治疗进展

脑血管痉挛是蛛网膜下腔出血最严重的并发症之一,其发生率高达30%~90%,常引起严重局部脑组织缺血或迟发性缺血性脑损害,甚至导致脑梗死,成为致死和致残的主要原因。近年来随着研究的不断深入,已经认识到氧合血红蛋白、炎症反应、缩血管物质增多、细胞凋亡、血液高凝状态和血管细胞增殖等在脑血管痉挛发病中起重要作用。尽管其机制尚未完全阐明,但根据已知的发病机制采取相应的临床治疗方法均取得了较好的效果。     

脑囊虫病磁共振成像分析

本文报告３４例脑囊虫病患者的磁共振成像（ＭＲＩ）表现。其中脑实质型２６例，脑室型６例，混合型２例。脑实质型７例为单发病灶，６例为多发病灶，其余１３例为数量较多的多发病灶，此型ＭＲＩ表现常为小的Ｔ１低信的号与长Ｔ２高信号囊肿，脑室型显示脑室扩大，可见脑室内囊肿壁，有３例可见头节，１６例ＭＲＩ与ＣＴ作发对比分析，对于病变大小，范围，数目及部位及的显著，ＭＲＩ均优于ＣＴ，特别是微小病灶。     

脑型血吸虫病磁共振成像诊断11例报告

目的分析脑型血吸虫病磁共振成像(MRI)的表现特点,探讨MRI在本病中的诊断价值。方法对11例脑型血吸虫病MRI表现及8例磁显葡胺(Gd-DTPA)强化特点进行回顾性分析。对T1WI和T2WI信号强度与正常脑灰质进行比较。结果8例表现为与脑灰质信号一致的等T1、等T2信号;2例呈等长T1、等长T2信号,提示为灶性软化;1例呈长T1、短T2信号,提示病灶钙化。9例灶周水肿影将病灶包绕成“岛”状。4例水肿累及脑室旁白质时,水肿影呈“佛手状”。8例增强扫描,7例表现为数个小结节呈簇状聚集且融合成团块样强化。8例抗病原治疗后,7例MRI复查异常信号范围缩小或数目减少、消失。结论平扫T1WI和T2WI均与脑灰质等信号,增强扫描数个小结呈簇状聚集且融合成团块样强化是脑型血吸虫病的主要MRI表现。MRI可用于发现病变,帮助确诊,并在评价疗效方面也有重要意义。     

北京市急性缺血性脑卒中磁共振成像分型研究

目的研究北京市急性脑梗死磁共振显示的亚型分布情况,使北京市急性缺血性脑卒中患者得到更加准确的病因学和个体化治疗。方法回顾分析北京市东城、西城、朝阳、海淀等4个区6家医院2004年接诊的647例急性缺血性脑卒中的分型情况及影像学特征。结果北京市五家医院急性脑梗死的亚型构成为:腔隙性脑梗死46.5%,小梗死38.1%,中梗死9.4%,大梗死6.0%。结论北京市急性脑梗死的分布以腔隙性脑梗死为多发,提示小动脉病变是北京市缺血性脑卒中的最主要病理改变。根据影像学的分型法可用于急性缺血性脑卒中的早期分型、指导治疗、评估预后。     

Quantitative evaluation of coronary stenosis by coronary magnetic resonance angiography

Coronary magnetic resonance angiography (coronary MRA) can detect, noninvasively, a high proportion of severe stenotic lesions found on coronary angiograms. However, quantitative evaluation of coronary artery stenosis by coronary MRA has been performed only in a small number of patients. This study was designed to determine whether coronary MRA can assess the degree of stenosis using the two-dimensional segmented turbo-FLASH method (2D method). We studied 108 patients with technically adequate coronary MRA images. The blood flow signal intensity on coronary MRA was classified as markedly decreased, moderately decreased, or normal. The severity of coronary artery stenosis was determined by the caliper method, and coronary stenosis was rated using a seven-point scale (0%, 25%, 50%, 75%, 90%, 99%, and 100%) in accordance with the American Heart Association classification system. Patients were classified into three groups: normal coronary artery (0%–25% stenosis), moderate stenosis (50%–75% stenosis), and severe stenosis (90%–100% stenosis). The degree of stenosis on coronary angiography and the decrease in coronary MRA signal intensity were compared. The right coronary artery was evaluated in 64 patients and the left coronary artery in 73 patients. When a marked or moderate decrease in coronary MRA blood flow signal intensity was defined as indicating stenosis, the sensitivity and specificity of coronary MRA for detecting angiographically severe stenosis were 85% and 80%, respectively. A moderate decrease in coronary MRA blood flow signal intensity detected angiographically moderate stenoses with a sensitivity of 38% and a specificity of 83%. Coronary MRA can detect a high proportion of severe stenoses but only a low proportion of moderate stenoses. Technical improvements are required before coronary MRA can be used clinically. Received: June 23, 2000 / Accepted: December 16, 2000     

颅内静脉窦血栓形成的临床和磁共振血管成像

目的　探讨颅内静脉窦血栓形成 (IVST)的临床表现和MRA诊断价值。方法　回顾性分析 8例经MRA证实的IVST的临床表现、病因、预后及MRA特点。结果　 8例患者中 ,7例有明确的病因 ,表现以高颅内压症状为主 ,可伴意识障碍、抽搐、偏瘫。MRA示 7例患者为多静脉窦、1例为单静脉窦血栓形成 ,经保守治疗 ,7例治愈 ,1例死亡。结论　IVST少见 ,常累及多静脉窦 ,临床表现虽复杂 ,但以高颅内压症状为主 ,MRA有助于确诊 ,早期治疗可改善预后。     

磁共振血管造影在诊断老年人下肢动脉病变中的应用

目的：探讨磁共振血管造影（MRA）在老年人下肢动脉病变诊断中的应用价值。方法：采用1．5T超导MR扫描对疑急、慢性下肢动脉病变的老年患者70例进行检查,平扫用二维时飞法序列（2D－TOF）52例、2D－TOF加三维增强序列（3D－CE）18例。32例行彩色多普勒超声（彩超）检查,4例急诊手术。结果：70例老年患者经MRA诊断,动脉硬化伴狭窄52例,动脉硬化闭塞症17例,动脉瘤样扩张1例。MRA共显示血管997条,其中52例2D－TOF平扫显示腹主动脉下段、髂总、髂外、髂内、股、Guo动脉及小腿动脉,平均显示率为91％;18例增强扫描上述血管显示率100％。70例显示动脉狭窄共600条,其中轻、中度动脉狭窄486条,占81％;重度狭窄114条,占19％。32例老年患者经彩超检查,两者诊断符合率为915,病变程度符合率为96％。彩超显示血管壁钙化40条,粥样斑块32条。结论：MRA与临床、手术、彩超有良好的相关性,是下肢动脉病变的有效检查方法之一。2D－TOF有对病变“高估”、检查时间较长的不足。     

Three-dimensional magnetic resonance angiography of vascular lesions in children

We applied three-dimensional (3D) magnetic resonance (MR) angiography to vascular lesions in children and evaluated the clinical usefulness of this technique. Ten patients, whose ages ranged from 1 month to 16 years, underwent 3D MR angiography for 12 vascular lesions, including lesions in seven pulmonary arteries, two thoracic aortae, a pair of renal arteries, and one iliac artery. Three-dimensional MR angiography was performed with body- or pelvic-phased array coils on a 1.5-T scanner using fast spoiled gradient echo sequence. Data were acquired with the following parameters: TE, 1.9 ms; TR, 10.1 ms; flip angle, 20–60°; 1 or 2 NEX; field of view, 24–48 × 18–40 cm; matrix, 256 or 512 × 128 or 256; slice thickness, 1.2–7.5 mm; and 12, 28, or 60 partitions. Vascular imaging was enhanced with 20% gadolinium–diethylenetriaminepentaacetic acid. The examination was performed under breath-holding in six patients and with shallow breathing in four patients. In a comparative study with other noninvasive methods, 3D MR angiography was superior in seven of nine cases to other noninvasive examinations and in two cases, all methods evaluated the lesions. Furthermore, six cases were compared with conventional angiography. In five of the six cases, both methods depicted the lesions similarly, and in one case, MR angiography was more effective. A quantitative comparison of vascular diameter in the MR image was made with that in the conventional angiographic image. The correlation between them was excellent: y = 1.145x− 2.090 (r = 0.987; P < 0.0001), where x is the diameter in the conventional angiographic images, y is the diameter in the MR images, and r is the correlation coefficient. In conclusion, 3D MR angiography is useful for depicting peripheral vascular lesions in children. Received: March 1, 1999 / Accepted: March 30, 2000     

Contrast enhanced body magnetic resonance angiography

The use of gadolinium contrast for body MRA is reviewed. Considerations for timing of the bolus of contrast are discussed. The utility of this technique is illustrated through clinical examples. Contrast enhanced MRA is rapidly replacing conventional angiography for many applications.     

Clinical utility of two-dimensional magnetic resonance angiography in detecting coronary artery disease

AIMS: The accuracy of magnetic resonance angiography in detectingproximal coronary artery stenoses is unclear. We postulatedthat fast magnetic resonance angiography is capable of (1) imagingproximal coronary arteries, and (2) detecting stenoses of 50%of their luminal diameter. METHODS AND RESULTS: Thirty-five patients, referred for analysis of angina pectoris,underwent both conventional angiography and magnetic resonanceangiography of coronary arteries. A fast k-space segmented gradient-echotechnique was used during breath-holds. Two observers, blindedto the results of conventional angiography, independently analysedthe magnetic resonance studies for (1) length of visualizedsegments, and (2) presence of signal voids indicative of stenoses.From 140 proximal arteries, 15 (11%) were excluded because ofincomplete imaging or degraded image quality. Mean length ofthe visualized segments was 9±4 mm for the left main,62±16 mm for the left anterior descending, 21±9mm for the left circumflex and 89±32 mm for the rightcoronary artery. Sensitivity for detecting 50% luminal diameterstenoses was 0·00 for the left circumflex, 0·53for the left anterior descending coronary artery, 0·71for the RCA and 1·00 for the left main artery. Specificityvaried from 0·73 for the left anterior descending coronaryartery to 0·96 for the left circumflex. Inter-observeragreement was 0·90. CONCLUSION: Thus, segmented magnetic resonance angiography is capable ofnon-invasive imaging of proximal coronary anatomy. Its goodaccuracy in detecting left main coronary artery disease, intermediateaccuracy in detecting right coronary artery and left anteriordescending coronary artery stenoses, and low accuracy in detectingleft circumflex lesions fit within a range of sensitivitiesand specificities found by others. Further technical advancesare necessary to make the technique clinically robust.     

3T磁共振增强全心冠状动脉成像技术临床应用价值

目的 探讨自由呼吸导航门控3 T磁共振增强全心冠状动脉三维成像技术临床应用可行性及其价值.方法应用自由呼吸导航3 T磁共振增强全心冠状动脉三维成像方法对临床疑似冠心病患者行全心冠状动脉成像,增强采用钆贝葡胺注射液(0.2 mmol/kg)静脉缓慢注射,流率0.3ml/s.数据经后处理获得冠状动脉主要分支图像,评价图像质量,并以选择性冠状动脉造影检查结果为参照标准,采用9段划分法评价冠状动脉主要分支的有意义狭窄(＞50%),判断磁共振增强冠状动脉成像对冠心病的诊断准确性及其价值.结果26例病例中23例顺利完成磁共振检查,平均扫描时间为(10.4±2.1)min.选择性冠状动脉造影显示的202个节段中,磁共振增强冠状动脉成像显示可评价节段178个(88.1%),以近、中段图像质量较好.与选择性冠状动脉造影比较,磁共振增强冠状动脉成像在显示近段及中段可评价节段上差异无统计学意义(P＞0.05).磁共振冠状动脉成像显示阳性9例,阴性14例.选择性冠状动脉造影显示11例阳性,12例阴性.磁共振冠状动脉成像有意义的狭窄总体诊断符合率91.3%(21/23),灵敏度81.8%(9/11),特异度88.5%(169/191),阴性预测值98.8%(9/31).结论自由呼吸导航门控3 T磁共振增强全心冠状动脉三维成像技术能够对冠状动脉近中段有意义的狭窄进行初步评估,一致性较好.但对冠状动脉远段及小分支狭窄的评估有一定限度.

Abstract：

Objective To investigate the clinical application, feasibility and value of 3 T wholeheart contrast enhanced free-breathing navigator-gated three-dimensional coronary magnetic resonance angiography (CE-CMRA). Methods 3 T CE-CMRA was used to examine patients with suspected coronary heart disease (CAD). Gd-BOPTA(0. 2 mmol/kg) was injected intravenously with slow infusion rate(0. 3ml/s) to perform enhancement. Data were post-processed to obtain principal branches of coronary artery and picture quality was evaluated. According to results of selective coronary arteriography ( SCAG ), the diagnostic accuracy of CE-CMRA for diagnosing CAD was judged by means of detecting significant stenosis ( ＞50% ) of the principal branches based on the 9 segments of coronary artery. Results Twenty-three out of 26 patients successfully completed the examination. The mean scanning time was ( 10. 4 ± 2. 1 ) minutes,178 out of 202 (88. 1% ) SCAG demonstrated segments could be evaluated by CE-CMRA. The imaging quality was superior in proximal and middle segments of coronary artery principal branches than in distal segments. Based on patient-level, there were 9 positive cases and 14 negative cases examined by CE-CMRA compared with 11 positive cases and 12 negative cases examined by SCAG, respectively. The whole diagnose accordance rate of CE-CMRA was 91.3% (21/23)compared with SCAG. The sensitivity, specificity and negative predictive values were 81.8% (9/11), 88.5% (169/191) and 98.8% (9/31)respectively. Conclusions 3 T CE-CMRA is a feasible non-invasive imaging modality for diagnosing CAD,especially to detect significant stenosis in proximal and middle segments of coronary artery principal branches. However, the detecting efficacy is limited in assessing stenosis of distal segment and small branches of coronary artery.     

CT血管造影和磁共振血管成像在颅内动脉瘤诊治中的价值

目的 评价CT血管造影(CTA)、磁共振血管成像(MRA)在颅内动脉瘤诊断及治疗中的临床应用价值。方法 运用CTA、MRA和数字减影血管造影(DSA)影像学方法，对302例颅内动脉瘤患者及18例非动脉瘤自发性蛛网膜下腔出血患者进行了单独或联合检查。单独检查CTA、MRA或DSA的患者分别为203例、12例及88例，CTA DSA联合检查为11例，CTA MRA联合检查为4例，检测出的颅内动脉瘤均经手术证实；对18例非动脉瘤自发性蛛网膜下腔出血患者进行CTA DSA联合检查，并对CTA、MRA、DSA检查结果进行回顾性分析，结果 通过CTA、DSA检查单独确诊的动脉瘤分别为203个和88个，与术中结果相一致。仅行MRA检查的12例患者，其中10例与手术结果完全一致，1例术前MRA诊断为右侧大脑中动脉瘤，术中证实为右侧颈内后交通动脉瘤，1例术前MRA正常，术中证实为巨大前交通动脉瘤。10例先行CTA检查，怀疑为动脉瘤，后经DSA检查确诊，并经手术证实，1例DSA检查正常，后行CTA检查确诊并经手术证实。4例行MRA检查，怀疑为动脉瘤，后行CTA检查确诊，并经手术证实。另有18例自发性蛛网膜下腔出血患者，行CTA DSA检查均未见动脉瘤及其他脑血管病征象。CTA、MRA和DSA对颅内动脉瘤的检出率(与手术相比较)分别为100％、87．5％、98．9％。结论 CTA可以作为检查颅内动脉瘤的首选方法，MRA可以用于诊断颅内动脉瘤，但其检出率低于CTA、DSA。     

Whole-body three-dimensional contrast-enhanced magnetic resonance (MR) angiography with parallel imaging techniques on a multichannel MR system for the detection of various systemic arterial diseases

Using a 1.5-T magnetic resonance (MR) imager equipped with 32 receiving channels and integrated parallel acquisition techniques, 37 patients underwent whole-body three-dimensional (3D) contrast-enhanced MR angiography (WB 3D CE MRA). The patients included had clinically documented or suspected peripheral arterial occlusive disease (PAOD, n = 19), Takayasu arteritis (n = 8), polyarteritis nodosa (n = 1), type-B dissection (n = 4), thoracic and/or abdominal aneurysm (n = 5). Sixty-eight surface coils were employed to encompass the whole body. Four 3D CE MRA stations were acquired successively through automatic table moving. The spatial resolution was 1.6 × 1.0 mm and slice thickness was 1.5 mm for all stations. A total scan range of 188 cm was acquired. Overall image quality of each arterial segment and venous overlay were assessed. The depiction of various systemic arterial diseases was evaluated and compared, in 20 patients, with other imaging modalities. This WB 3D CE MRA yielded a detailed display of the arterial system with an average MR room time of 17.4 min. The image quality was considered diagnostic in 99.3% of the arterial segments. In 7 of 19 patients with PAOD, WB MRA showed additional vascular narrowing apart from peripheral arterial disease. In nine patients with vasculitis, WB MRA depicted luminal irregularity, narrowing or occlusion, aneurysm, and collateral circulation involving multiple vascular segments. WB MRA also clearly revealed the severity and extent of dissection and aortic aneurysm. In 20 cases where additional imaging investigations have been carried out, the vascular pathologies demonstrated by WB MRA agree with these additional imaging investigations.     

3.0T三维时间飞跃法无增强磁共振血管造影术诊断颅内微小动脉瘤

目的评价3.0 T三维时间飞跃法无增强磁共振血管造影术(3D-TOF-MRA)诊断颅内微小动脉瘤(直径≤3 mm)的准确性。方法选择513例疑似动脉瘤或因其他脑血管疾病行3D-TOF-MRA检测的患者。经DSA确诊131例患有微小动脉瘤(143个),170例无动脉瘤。以该301例为研究对象,容积重建DSA(VR-DSA)为金标准,评估3D-TOF-MRA在诊断微小动脉瘤中的价值。评价蛛网膜下腔出血(SAH)、动脉瘤的数目及动脉瘤位置对诊断准确性的影响。结果 301例中,3D-TOF-MRA共检测出动脉瘤患者135例(149个)。①以患者为样本数,3D-TOF-MRA检测颅内微小动脉瘤的准确性、敏感性、特异性、阳性预测值、阴性预测值分别为97.3%、98.5%、94.7%、95.6%及97.0%。以动脉瘤为样本数,上述指标分别为96.8%、98.6%、95.3%、94.6%及98.9%。②与无SAH患者比较,3D-TOF-MRA诊断SAH的假阴性率较高,差异有统计学意义,P=0.042;准确率虽有所下降,但差异无统计学意义。③单发或多发动脉瘤对诊断动脉瘤无影响。④3D-TOF-MRA诊断位于大脑前动脉、椎-基底动脉的微小动脉瘤的准确性最高,均为100%,诊断位于颈内动脉系统、大脑中动脉的动脉瘤的准确性分别为97.3%和98.4%。与大脑前动脉、大脑中动脉及椎-基底动脉的微小动脉瘤比较,3D-TOF-MRA诊断颈内动脉系统动脉瘤的准确性略低,P=0.039。结论 3D-TOF-MRA对微小动脉瘤诊断的准确性高,基本可以替代DSA。