MR动态减影血管造影在脑动静脉畸形治疗前后中的评价

目的评价MR动态减影血管造影（MR-DSA）在脑动静脉畸形（AVM）栓塞治疗前后的价值和限度。方法22例AVM患者，在栓塞前后均行MR—DSA、三维增强MR血管造影（3D—CEMRA）、MR质子加权成像（PWI）和DSA检查，同时由2名有经验的医生独立进行双盲对照研究。结果MR-DSA和DSA在22例AVM栓塞前后的瘤巢大小及分类上结果一致，MR—DSA能够显示AVM栓塞后的血液动力学改变，瘤巢及引流静脉显影推迟17例，瘤巢变小13例（其中完全消失4例），与DSA符合率为100％。与DSA相比，MR-DSA没有显示瘤巢内动脉瘤和栓塞后引流静脉及供血动脉直径变小各1例，而3D-CEMRA对此显示清晰。栓塞后的PWI与栓塞前相比，22例均可见不同程度的高信号。结论MR—DSA是1种快速、有效、无创的血管造影检查方法，能提供AVM栓塞前后的血流动力学信息，MR—DSA、3D-CEMRA和PWI应在AVM的随访中相互结合，综合运用。     

脊髓血管畸形的快速增强MRA与DSA诊断的比较研究

目的 评价椭圆形中心顺序(elliptic centric ordered)的快速增强磁共振血管成像(fastcontrast-enhanced MR angiography,CE-MRA)在脊髓血管畸形中的诊断和临床应用价值.方法 25例临床怀疑脊髓血管畸形的患者在1.5T MR机上接受了椭圆形中心顺序的快速CE-MRA检查,所有病例行选择性全脊椎动脉造影,18例施行了外科手术,其中2例术前行血管内栓塞,术后MRA随访了10例;以选择性全脊椎动脉造影为金标准,就病变诊断、供养动脉起源、供养动脉、瘘口或瘤巢、引流静脉和血管的图像质量(包括血管的连续性、强化程度和清晰度)进行MRA和DSA的比较.结果 经外科手术证实18例,包括脊髓动静脉畸形3例、髓周动静脉瘘5例、硬膜动静脉瘘7例、椎旁动静脉瘘1例、自发性椎管内硬膜外血肿2例;MRA显示脊髓血管畸形的诊断、供养动脉起源、供养动脉、瘤巢或瘘口、引流静脉与DSA的符合率分别为93.8%、92%、96.2%、100%和100%,MRA显示血管强化和清晰度类似于DSA(P＞0.05),DSA显示血管的连续性优于MRA(P＜0.05);9例MRA未见椎管内异常血管,与DSA完全符合.术后MRA随访的10例原异常血管未再显示.结论 椭圆形中心顺序的快速CE-MRA能够初步诊断脊髓血管畸形的亚型,能够显示脊髓血管畸形的供养动脉起源、供养动脉、瘤巢或瘘口、引流静脉,能够指导选择性脊椎动脉造影和手术治疗,是脊髓血管畸形术前诊断和术后随访的重要手段.     

螺旋CT血管造影在诊断脑动静脉畸形中的应用

目的探讨脑动静脉畸形(AVM)CT血管造影(CTA)的价值.材料与方法19例脑AVM病例行CTA检查,其中MRA、DSA检查各5例、8例.12例手术证实,7例保守治疗.CTA、MRA经工作站处理,获得三维血管图像;DSA通过股动脉插管技术,获得减影后血管图像.结果CTA能显示AVM的病变形态及准确部位,有效显示供养动脉、引流静脉及血管巢.但供养动脉显示不及MRA,引流静脉的显示较MRA为佳.结论CTA诊断脑AVM的图像质量、病变显示接近MRA、DSA,对制定治疗方案、指导手术和预后有重要意义.     

全脑一站式CTA-CTP对脑动静脉畸形的临床价值探讨

目的：探讨全脑一站式CT血管成像-CT灌注成像(CTA-CTP)对脑动静脉畸形(cAVM)的临床应用价值。方法回顾性分析15例经一站式CTA-CTP诊断为 cAVM患者的临床及影像学资料。记录四维CT血管成像(4D-CTA)所示病灶瘤巢、供血动脉及引流静脉的解剖细节;比较13例4D-CTA与数字减影血管造影(DSA)的影像学表现,判断其诊断价值。定量测定瘤巢及瘤周脑实质的灌注参数。分析病灶解剖构筑、血流灌注特征与颅内出血的相关性。结果4D-CTA能够动态显示 cAVM病灶的解剖构筑细节及对比剂进出瘤巢的整个过程,与DSA诊断一致性较高,但对一些细小供血动脉或引流静脉显影欠佳。13例瘤巢呈高灌注,瘤周“盗血”呈低灌注;2例病灶因局部血肿存留呈低灌注。9例患者既往发生颅内出血,出血组瘤巢最大径<3 cm、单支动脉供血、深静脉引流、瘤巢平均通过时间(MTT)延长、瘤周 MTT 缩短的比例高于未出血组(P<0.05)。结论全脑一站式 CTA-CTP在 cAVM无创性诊断及出血高危因素预测方面具有潜在的临床价值。     

脑动静脉畸形手术前后电子束CT三维血管造影的评价

目的：探讨电子束CT三维血管造影（3D-EBCTA）在评价脑动静脉畸形手术前后中的价值与限度。材料和方法：选择11例不同部位、不同类型的脑动殂脉畸形进行术前和术后的3D-EBCTA和DSA对照研究,采用最大信号强度投影（MIP）和表面遮盖法（SSD）进行重建。结果：与DSA相比,术前3D-EBCTA对瘤巢、供血动脉（来源、数目及形态）和引流静脉的显示率分别为100%、100%和81.8%。术后瘤巢及供血动脉和引流静脉的处理情况显示满意率为100%。结论：3D-EBCTA无创、价廉,是诊断脑动静脉畸形的好方法。在术后随访方面可替代DNA,但在术前诊断上尚不能取代DNA。     

胼胝体区脑动静脉畸形

目的 :探讨颅内胼胝体区脑动静脉畸形的病理基础、临床表现、脑血管影像特点及治疗效果。方法 :6例患者在数字减影血管造影 (DSA)监视下进行全脑血管造影 ,了解畸形血管团的位置、大小、供血动脉及引流静脉情况 ,然后给予血管内栓塞治疗或放射治疗。结果 :6例患者 ,4例应用漂浮导管技术行血管内栓塞治疗治愈 ;2例行X—刀治疗 ,1例治愈 ,1例因治疗时间短 ,未复查。结论 :胼胝体区脑动静脉畸形 ,发病年龄轻 ,出血危险性大 ,畸形团小 ,位置深 ,供血动脉少 ,引流静脉单一 ,治疗效果好     

MR血管成像诊断脊髓动静脉畸形的价值

目的 探讨磁共振血管成像(包括快速3D增强MRA技术和常规MRA)在脊髓动静脉畸形的诊断价值.方法 回顾分析10例脊髓动静脉畸形MRA资料,均由选择性脊髓血管造影确诊,全部病例均使用3D增强MRA技术(CE-MRA),头颈部另外还使用常规MRA(3D-TOF MRA).结果 髓内动静脉畸形3例,AVM血管巢的MRA表现为血管粗细不一,扭曲成团,并显示1条或多条供血动脉及增粗的引流静脉.髓外硬膜内动静脉畸形5例,其中3例为AVM,MRA显示有血管巢、供血动脉及引流静脉;2例为AVF,MRA可以显示供血动脉及引流静脉,并可推断瘘口的位置.硬脊膜动静脉瘘2例,MRA只表现为髓周血管扩张.结论 MRA不仅可以对脊髓动静脉畸形作定性诊断,而且还可以显示病灶的内部结构,已成为无创性诊断脊髓血管畸形的理想方法.     

脑动静脉畸形供血方式与栓塞的关系研究

目的探讨脑动静脉畸形供血方式与栓塞的关系。方法回顾性分析12 4例4 0 0次超选择性微导管造影所显示的脑动静脉畸形的供血方式及其栓塞后并发症的发生率。结果4 0 0次微导管超选择性造影显示终末型供血方式2 92次,占73% ,穿枝型供血方式2 8次,占7% ,动静脉直接交通型36次,占9%。畸形血管团内伴有动脉瘤2 4例,占6 %。畸形血管团内含有静脉瘤或引流静脉呈瘤样扩张者2 0例,占5 %。除穿枝型供血方式16例未行栓塞外,余者栓塞后无严重并发症发生。结论了解脑动静脉畸形供血方式便可知道能否安全的进行栓塞,而测定脑动静脉畸形的动静脉循环时间可指导栓塞用胶的配制浓度。     

磁敏感加权成像在脑血管畸形显像中的初步应用研究

目的 初步分析磁敏感加权成像(SWI)在脑血管畸形显像中的应用价值. 资料与方法 2006年5月至9月间对11例颅内血管畸形患者资料进行前瞻性研究,11例中男7例,女4例,平均年龄25岁.其中6例为海绵状血管瘤,3例为脑动静脉畸形,2例为静脉畸形.SWI所得图像应用10 mm厚度的最小密度投影重组.与手术所见和DSA对比,将SWI图像与常规MR序列比较. 结果 SWI对11例血管畸形患者的病灶均显示清楚.其中6例海绵状血管瘤患者常规MR序列发现10个海绵状血管瘤,而SWI发现了15个;3例脑动静脉畸形患者中,2例SWI较常规序列发现更多病灶.SWI发现了DSA所见的4支引流静脉中的3支,而常规MR序列仅可以显示1支,且更易与动脉区分,常规序列和SWI均可发现2支供血动脉,SWI还可以显示其中1例动静脉畸形的钙化; 2例静脉畸形均可清晰显示扩张的髓静脉和粗大的引流静脉,而常规序列显示欠佳. 结论 SWI应作为脑血管畸形尤其慢流速血管畸形诊断的常规序列应用于临床,结合其他序列对脑血管畸形能提供更全面、精确的信息.     

有孔型椎基底动脉的MR血管成像诊断

目的 描述有孔型椎基底动脉的MR血管成像(MRA)表现，以提高对该血管异常的认识。方法 回顾分析178例头颈部增强磁共振血管造影(CEMRA)中10例诊断为有孔型椎基底动脉病例，其中7例行颅脑CEMRA，3例行颈部CEMRA，钆喷替酸葡甲胺(Gd-DTPA)0．2mmol／kg高压注射，小剂量团注测试延迟时间，增强前后行连续动态扫描。原始和减影图像经SGI02工作站后处理，经容积重建(实时三维，R13D)、最大信号强度投影(MLP)、薄层最大信号强度投影多平面或曲面重建血管图像(TS MIP)，比较各组图像对血管异常的显示情况。5例患者同时行三维时间飞跃法(3D TOF)MRA，3例经DSA证实。结果 有孔型基底动脉7例(检出率3．9％，7／178)全部位于基底动脉下1／2段，4例位于基底动脉干，3例位于椎基底动脉吻合部；3例有孔型椎动脉(检出率1．7％，3／178)中2例位于左侧V4段，1例位于右V3段。4例有孔型异常2支血管间形成小圆孔状充盈缺损，6例呈部分重复形。4例有孔型血管异常合并其他血管异常，2例有孔型基底动脉合并脑动静脉畸形；2例有孔型椎动脉合并对侧永存三叉动脉，其中1例还合并同侧远端椎动脉瘤，另1例有孔型椎动脉同时伴有颈、基底动脉粥样硬化。RT3D能显示血管立体空间和毗邻关系，兴趣区MIP和TS MIP可清楚显示异常血管细节。结论 CEMRA结合图像工作站后处理能清楚显示和诊断有孔型椎基底动脉这一少见的血管异常。     

Novel technique for evaluating complex pelvic arteriovenous malformations with catheter-directed subtracted MR angiography

Residual or recurrent arteriovenous malformation (AVM) nidal filling is not uncommon after embolization of complex peripheral AVMs. The major reason for this is incomplete embolization of the nidus owing to failure to detect all feeder vessels other than the dominant one. Herein, the authors describe a novel "intravenous minus intraarterial" subtraction magnetic resonance (MR) angiography technique that enabled the delineation of additional feeding branches not clearly identifiable at intravenous contrast-enhanced MR angiography or nonselective pelvic angiography. This technique may be particularly useful in the evaluation of complex AVMs and their subsequent management with embolization.     

Neurovascular lesions and endovascular therapy: the role of MR

Summary Magnetic resonance imaging (MRI) studies were performed on 27 patients with vascular lesions of the central nervous system before and after embolization with either IBCA, polyvinyl alcohol foam particles, Avitene (microfibrillar collagen) or balloons. Thirteen pial brain arteriovenous malformations (AVMs), 3 brain AV fistulas, 2 giant aneurysms, 5 dural AVMs, 1 vertebro-vertebral fistula and 3 meningiomas were studied. The pre-embolization MR demonstrated the nidus and venous drainage of all pial AVMs. MR failed to detect 3 out of 5 dural AVMs using only spin echo sequences. A draining vein alone was seen in the remaining two cases. MR was superior to CT in detecting contiguous parenchymal changes such as atrophy, reversible ischemia, and mass effect in the pre-embolization studies. Following embolization, MR demonstrated partial or complete obliteration of the vascular nidus in all 13 pial AVMs. The embolized area was seen as an area of increased signal consistent with thrombus where previously there had been signal void. Ischemic or edematous changes in the brain parenchyma following embolization were seen on MR more easily than on CT scans. MR was accurate in the assessment of aneurysm patency, degree of thrombosis and balloon position in both giant aneurysms, and AV fistulae. These MR findings had an impact on patient management. MR will be an increasingly useful tool in the diagnosis and management of a number of neurovascular diseases requiring endovascular intervention.     

A comprehensive approach using MR imaging to diagnose acute segmental mesenteric ischemia in a porcine model.

OBJECTIVE: Acute mesenteric ischemia is a lethal disease that lacks a noninvasive diagnostic test. We evaluated the abilities of contrast-enhanced MR angiography, MR oximetry, and real-time interactive MR imaging to diagnose segmental mesenteric ischemia in a porcine model. MATERIALS AND METHODS: Segmental mesenteric ischemia was created by subselective Gelfoam embolization of the mesenteric circulation in eight pigs. Conventional digital subtraction angiography (DSA), MR oximetry, and real-time interactive MR imaging of the small bowel were performed before and after embolization. Changes in the perfusion pattern seen on DSA established the regions of true ischemia. Postembolization DSA and MR angiography were compared with this gold standard. RESULTS: Both MR angiography and DSA had high sensitivity (91% and 100%, respectively) for detecting ischemic regions. The difference was not statistically significant (p > .2). MR angiography yielded lower specificity than DSA (80% and 90%, respectively; p < .01). After embolization, the oxygen saturation in the superior mesenteric vein (SMV) dropped significantly (p < .005). After embolization, the SMV also showed oxygen saturation significantly lower than that in the inferior vena cava (p < .005). In two of the animals, segmental hypomotility of the small bowel was observed. CONCLUSION: MR oximetry is capable of detecting oxygen desaturation caused by segmental ischemia. A loss of oxygen saturation in the SMV relative to that in the inferior vena cava provides a convenient marker of mesenteric ischemia. Contrast-enhanced MR angiography has sensitivity and specificity approaching those of DSA. Both MR techniques hold promise for the detection of acute mesenteric ischemia.     

Exceptional multiplicity of cerebral arteriovenous malformations associated with hereditary hemorrhagic telangiectasia (Osler-Weber-Rendu syndrome).

PURPOSETo describe the clinical and imaging features of seven patients with hereditary hemorrhagic telangiectasia and an exceptional number of cerebral arteriovenous malformations (AVMs).METHODSOne hundred thirty-six patients from a dedicated hereditary hemorrhagic telangiectasia clinic were screened systematically for cerebral AVMs by means of MR imaging. Thirty-one were found to have abnormalities suggestive of a vascular malformation. Eighteen of these 31 patients subsequently underwent diagnostic cerebral angiography.RESULTSOf the 18 patients who had cerebral angiography, all were found to have at least one AVM and seven were found to have three or more AVMs. The number of cerebral AVMs detected ranged from three to nine. At angiography, the AVMs varied in size from 3 to 25 mm in maximal dimension and consisted of a poorly defined plexiform nidus that typically had a single arterial feeding pedicle and a single draining vein. The two largest AVMs (20- and 25-mm nidus, respectively) contained intranidal aneurysms. Treatment included embolization, surgical excision, or follow-up management.CONCLUSIONSMultiple cerebral AVMs are associated with hereditary hemorrhagic telangiectasia and further highlight the uniqueness of central nervous system involvement by this systemic angiodysplasia. MR imaging can underestimate the number and size of cerebral AVMs; therefore, catheter angiography is necessary to establish the extent of central nervous system involvement in this disorder.     

Noncontrast‐enhanced four‐dimensional MR angiography for the evaluation of cerebral arteriovenous malformation: A preliminary trial

Purpose:

To prospectively evaluate noncontrast‐enhanced (NCE), time resolved, four‐dimensional (4D) magnetic resonance angiography (MRA) for assessment of cerebral arteriovenous malformation (AVM), with intraarterial digital subtraction angiography (DSA) performed as the reference standard.

Materials and Methods:

Fifteen patients (ten men, five women; age range 2–59 years, mean 29.4 years) with 15 untreated cerebral AVMs comprised the study population. NCE 4D MRA was performed on a 3.0 T MR scanner. MR images were reviewed by two independent readers and compared with DSA with respect to arterial feeders, nidus size, and venous drainage. Kappa coefficients of concordance were computed to determine the interobserver and intermodality agreements for the depiction of arterial feeders, nidus, and venous drainage between the two techniques.

Results:

Fifteen AVMs detected in DSA were visualized in NCE 4D MRA. Intermodality agreements were excellent for the arterial feeders (K = 0.918, P = 0.000), good for the nidus size (K = 0.692, P = 0.000), and moderate for the venous drainage (K = 0.495, P = 0.001).

Conclusion:

NCE 4D MRA is a promising and potentially valuable method for noninvasive assessment of angioarchitecture and hemodynamics of cerebral AVMs. Further improvement of labeling persistence is desirable in order to enhance the depiction of draining veins for AVMs. J. Magn. Reson. Imaging 2011;. © 2011 Wiley Periodicals, Inc.     

Intracranial vascular malformations: imaging of charged-particle radiosurgery. Part I. Results of therapy

Twenty-four patients with intracranial vascular malformations were examined before and after helium ion radiosurgical treatment with angiography, computed tomography (CT), and magnetic resonance (MR) imaging. Twenty patients had high-flow arteriovenous malformations (AVMs). After treatment 18 of 20 AVMs (90%) showed a significant reduction in size on angiograms or MR images. Eleven of 20 (55%) had complete resolution on angiograms or MR images, 35% had partial resolution, and 10% showed no size change. Before treatment, the size range of the AVMs was 0.86-383 cm3 (median, 21.7 cm3). Smaller AVMs (less than 8 cm3) were more likely to resolve completely than medium-sized AVMs (8-64 cm3) or larger AVMs (greater than 64 cm3). Four additional patients had slow-flow vascular malformations: One had a venous angioma; one, a probable cavernous hemangioma; and two, malformations that were not seen on angiograms. CT proved inaccurate in demonstrating the boundaries of the AVM after treatment because it showed persistent contrast enhancement even when the AVM was completely obliterated on angiograms. MR imaging and angiography were complementary in the evaluation of therapeutic results and should be the primary modalities in the examination of patients with AVMs.     

Utility of CT angiography and MR angiography for the follow-up of experimental aneurysms treated with stents or Guglielmi detachable coils

BACKGROUND AND PURPOSE: Previous studies have depicted arterial and aneurysmal anatomy with three-dimensional time-of-flight (3D-TOF) MR angiography before and after treatment with Guglielmi detachable coils (GDCs) and with CT angiography before and after treatment with stents and stent-grafts. We investigated the ability of time-resolved contrast-enhanced 3D MR angiography (3D MR digital subtraction angiography [DSA]) to accurately depict the anatomy of experimental lateral aneurysms before and after treatment with GDCs and a variety of stents or stent-grafts, and compared these findings with 3D-TOF MR angiography without and with contrast enhancement and CT angiography. METHODS: Two nitinol stents, two nitinol-polytetrafluoroethylene (PTFE) stent-grafts, and two stainless steel stents were deployed in three dogs with experimental carotid aneurysms. In a fourth animal, one of three aneurysms was completely occluded with GDCs. The other two aneurysms were loosely packed to ensure persistence of some residual aneurysmal lumen. Cut-film angiography, CT angiography, 3D-TOF MR angiography without and with contrast enhancement, and 3D MR DSA were performed in all dogs before and 3 weeks after treatment. RESULTS: 3D MR DSA was superior to conventional 3D-TOF MR angiography without and with contrast enhancement in accurately depicting experimental lateral aneurysms and superior to CT angiography in depicting aneurysms treated by GDCs. 3D MR DSA and CT angiography were comparable in depicting vessels treated with nitinol stents and stent-grafts, whereas CT angiography was superior for showing vessels treated by stainless steel stents. CONCLUSION: We recommend further development and clinical evaluation of 3D MR DSA for imaging cerebral aneurysms before and after treatment with GDCs. 3D MR DSA or CT angiography may be useful for evaluating vessels containing nitinol stents or nitinol-PTFE stent-grafts, whereas CT angiography should be used for follow-up of vessels treated by stainless steel stents.     

脊髓血管畸形的影像学特点与介入治疗(附6例报告)

目的：分析６例脊髓ＡＶＭ的影像学表现和评价血管栓塞治疗的效果。方法：６例作了数字减影血管造影检查,并行血管内栓塞治疗,分析术前ＣＴ,脊髓造影和ＭＲ资料。结果：根据病变位置和血管形态,血流动力学改变,本组有３例符合硬膜动静脉瘘（ＳＤＡＶＦ）,１例为髓周的巨大ＡＶＦ,２例为髓内型。栓塞术后随访３￣２４个月,２例完全治愈,４例好转,结论：脊髓ＡＶＭ的影像学特点相对典型,ＤＳＡ为其金标准诊断方法。血管内栓     

Contrast-enhanced MR 3D angiography in the assessment of brain AVMs

BACKGROUND AND PURPOSE: Digital subtraction angiography (DSA) is the current reference standard for the diagnosis, assessment, and management of brain arteriovenous malformations (AVMs). The purpose of this study was to compare the diagnostic utility of three-dimensional (3D) time-of-flight (TOF) magnetic resonance angiography (MRA) and contrast-enhanced 3D MRA in patients with intracranial arteriovenous malformations (AVMs) in different sizes and locations. The AVM diagnosis was proved via DSA and almost half of the patients had also hematoma. MATERIALS AND METHODS: Two radiologists, experienced on neurovascular imaging and independent from each other, retrospectively reviewed two MRA techniques and DSA with regard to the assessment of feeding arteries, AVM nidus, and venous drainage patterns on 20 patients with 23 examinations by scoring system. Disagreements were resolved by consensus. RESULTS: An excellent agreement between contrast-enhanced MRA and DSA was found in order to assess the numbers of arterial feeders and draining veins (Spearman r=0.913, P<0.001). The average scores in contrast-enhanced MRA for feeders, nidi, and drainers were respectively 2.26, 2.69, and 2.48, while in TOF-MRA they are 1.96, 1.35, and 0.89, respectively. CONCLUSION: Compared to TOF-MRA, 3D contrast-enhanced MRA is useful for visualization by subtraction technique of malformation components presented by hematoma or by haem product. On the other hand, for the cases presented by slow or complex flow that is especially in around or nidi or around the venous portion is also advantageous because of the independence from flow-related enhancement. Therapeutic effects were clearly demonstrated in three follow-up patients. A major limitation of this technique is the low spatial resolution. Since there is such a limitation, arterial feeder of a case with micro-AVM is not detected by contrast-enhanced MRA and nidus for the same case was observed retrospectively. In this respect, we believe that 3D contrast-enhanced MRA is a less invasive and inexpensive angiographic tool, but not a safe substitute for DSA. Yet, it can be a beneficial supplement to DSA in patients with cerebral AVMs at both initial diagnosis and at follow-up processes after therapy.