Use of single-slice thick slab phase-contrast angiography for the diagnosis of dural venous sinus thrombosis

The aim of this study was to examine the reliability of single-slice phase-contrast angiography (SSPCA) as a rapid technique for the investigation of suspected dural venous sinus occlusion. Images were obtained on 25 normal volunteers to document the accuracy of SSPCA in the demonstration of slow flow states. Normal volunteers were imaged using sagittal and coronal SSPCA (slice thickness 13 cm, matrix 256 × 256, TR 14 ms, TE 7 ms, flip angle 20 °, peak velocity encoding rate 30 cm/s). Sinus patency and flow rate were confirmed by measurement of flow in the superior sagittal and transverse sinuses using quantified single-slice phase difference images. Imaging was performed in 50 patients undergoing routine brain scans in order to determine the optimal slice orientation for clinical use. Twenty-one patients with suspected dural venous sinus thrombosis were also investigated with SSPCA and the diagnosis confirmed by one or more alternative imaging techniques. Imaging time was 29 s per acquisition and image quality was good in all cases. Variations in dural sinus patency and flow in normal volunteers were accurately predicted by SSPCA (kappa = 0.92). Use of a single angulated slice (130 mm thick, para-sagittal image angled 30 ° towards coronal and 30 ° towards transverse) provided sufficient separation of right- and left-sided venous structures to allow use of a single projection. The presence and extent of sinus occlusions in 14 patients and the absence of thrombosis in 7 were accurately identified by SSPCA. Sensitivity and specificity in this limited study were both 100 %. The SSPCA technique takes less than 30 s and provides a reliable and rapid technique for the diagnosis of dural venous sinus thrombosis. Received: 10 July 1998; Revision received: 16 November 1998; Accepted: 11 January 1999     

窦汇区解剖形态的MR血管成像表现

目的 探讨窦汇区解剖形态的MR血管成像(MRA)表现及其临床意义。方法 对123例受检者常规进行T1WI和T2WI磁共振检查(1．5T)，以排除颅内占位性病变和血管畸形。然后进行窦汇区MR血流成像。其中72例采用了二维时间飞跃(2D TOF)磁共振静脉成像(MRV)方法，44例采用了三维相位对比(3D PC)MRA方法，7例志愿者同时采用了上述2种方法。结果 (1)横窦引流优势表现为右侧为主84例，左侧为主23例，基本相等16例。(2)按照上矢状窦、直窦和双侧侧窦吻合关系，全部病例可分为4型：第1型，包括2种情况：①上矢状窦和直窦汇合成一个真正的总池，从总池发出左右横窦；②上矢状窦和直窦在终末端分成2股，左右分支构成两侧侧窦。第2型，上矢状窦引流至一侧横窦，直窦引流至对侧横窦。第3型，上矢状窦和直窦汇合后主要向右侧横窦引流。第4型，上矢状窦和直窦汇合后主要向左侧横窦引流。结论 MRA是显示窦汇区解剖形态的有效方法，对窦汇区解剖形态分类有助于判断横窦引流优势和现存的和(或)潜在的代偿通道，可能对临床诊断和手术过程有所帮助。     

Preliminary evaluation of volume-rendered three-dimensional display of time-of-flight MR angiography in the diagnosis of intracranial aneurysms

We assessed the value of the volume-rendering method of displaying images of three-dimensional (3D) time-of-flight MR angiography (MRA) in the diagnosis of intracranial aneurysms. We obtained three-dimensional volume-rendered MRA from 21 patients with intracranial aneurysms. The images were evaluated in comparison with maximum-intensity-projection images (in 21 patients), conventional angiograms (in 21 ) and CT angiography (in nine). In 17 patients, 3D volume-rendered images were thought to show morphological features most clearly. They were superior to the other methods for demonstrating the precise location of the aneurysm in three patients and in showing the shape of the bleb in another three. 3D volume-rendered MRA can be effectively added to conventional imaging techniques for diagnosis of intracranial aneurysms. Received: 12 October 2000 Accepted: 12 December 2000     

2D time-of-flight MR angiography using concatenated saturation bands for determining direction of flow in the intracranial vessels

We prospectively studied 15 patients to assess 2D time-of-flight (TOF) magnetic resonance angiography (MRA) with concatenated saturation bands for determining the direction of intracranial blood flow. This MRA sequence was compared to T2-weighted spin-echo MRI, 3D-TOF MRA, and intra-arterial angiography (IAA) as regards demonstration of vessels and determination of the direction of flow in the circle of Willis and its branches. The 2D-TOF MRA sequence demonstrated flow in 98.5 % vessel segments identified on IAA, 3D-TOF demonstrating 92 % and spin-echo images 77 %. The direction of flow shown on the 2D-TOF sequence was correct in 94 % when compared to conventional angiography, the remaining six segments not demonstrating flow. In ten patients, the flow abnormalities demonstrated by this MRA technique provided clinical information similar to that of conventional angiography in nine, but it was incomplete in three, and misleading in one. Slow retrograde flow in ophthalmic artery collaterals and differentiation of arteries and veins presented some problems. 2D-TOF MRA with concatenated saturation bands provides flow direction information using widely available, easily applicable TOF techniques, and can be a useful adjunct to MRI and MRA if information on flow direction is needed. Received: 18 October 1995 Accepted: 16 August 1996     

Phase-contrast MR angiography of intracranial dural arteriovenous fistulae

MRI and phase-contrast MR angiography (PC MRA) were obtained in 13 patients with angiographically confirmed intracranial dural arteriovenous fistulae (DAVF). Three- and two-dimensional PC MRA was obtained with low (6–20 cm/s) and high (> 40 cm/s) velocity encoding along the three main body axes. MRI showed focal or diffuse signal abnormalities in the brain parenchyma in six patients, dilated cortical veins in seven, venous pouches in four with type IV DAVF and enlargement of the superior ophthalmic vein in three patients with DAVF of the cavernous sinus. However, it showed none of the fistula sites and did not allow reliable identification of feeding arteries. 3D PC MRA enabled identification of the fistula and enlarged feeding arteries in six cases each. Stenosis or occlusion of the dural sinuses was detected in six of eight cases on 3D PC MRA with low velocity encoding. In six patients with type II DAVF phase reconstruction of 2D PC MRA demonstrated flow reversal in the dural sinuses or superior ophthalmic vein. Received: 14 May 1998 Accepted: 15 December 1998     

Anterior cerebral artery variations detected by MR angiography

Introduction From anatomical and angiographic studies, it is well known that there are several variations of the anterior cerebral artery (ACA). However, ACA variations have rarely been studied by magnetic resonance (MR) angiography. The purpose of this study was to investigate not only the type, location, configuration, and incidence of ACA variations, but also coexisting arterial pathology such as aneurysms detected by cranial MR angiography.Methods We retrospectively reviewed cranial MR angiography images of 891 patients at our institution. All images were obtained with one of two 1.5-T scanners using the three-dimensional time-of-flight technique. Maximum intensity projection (MIP) images in the horizontal rotation view were displayed stereoscopically. We reviewed these horizontal MIP images, inferosuperior MIP images, and source images, and identified variations of the ACA.Results We found 50 instances (5.6%) of unilateral A1 segment aplasia, 27 (3.0%) of three A2 segments, 18 (2.0%) of an unpaired A2 segment, and 11 (1.2%) fenestrations of the A1 and/or A2 segment. Seven anterior communicating artery (ACoA) aneurysms and one ACA territory embolic infarction were found among the 50 patients with unilateral A1 segment aplasia. One ACoA aneurysm and one pericallosal infarction were found in the 27 patients with three A2 segments. Two distal ACA aneurysms were detected among the 18 patients with an unpaired A2 segment. No associated aneurysm was seen at the fenestrations.Conclusion Although the clinical significance of ACA variations is usually minor, an associated aneurysm is found relatively frequently. Thus, recognizing ACA variations during the interpretation of cranial MR angiograms is important.     

Three-dimensional time-of-flight MR angiography in trigeminal neuralgia on a 0.5-T system

The goal of this study was to analyze the diagnostic value of three-dimensional time-of-flight magnetic resonance angiography (3D TOF MRA), performed on a 0.5-T system in the detection of neurovascular compression in patients with trigeminal neuralgia (TN). One hundred seventy-two TN patients were examined using plain and contrast-enhanced 3D TOF MRA on a 0.5-T system. Maximum intensity projection (MIP) reconstruction was performed in three standard planes. Both the original and the reconstructed images were studied to search for vascular compression shown by close neurovascular contact and/or dislocation of the trigeminal nerve. Forty-two TN patients underwent surgical exploration of the posterior fossa. Results of MRA were compared with clinical data in all cases and to results of surgery in the surgically treated cases. Neurovascular contact at the root entry zone of the trigeminal nerve was detected on the symptomatic side in 94 patients, and on the asymptomatic side in 12 patients. Sensitivity, specificity, accuracy, as well as positive and negative predictive value of 3D TOF MRA in the detection of neurovascular compression in the patient group undergoing surgery, were 97.6, 92.5, 95.0, 93.0, and 97.4 %, respectively. Three-dimensional TOF MRA performed on a 0.5-T system appears to be not less effective than similar examinations by higher field strength devices in the detection of neurovascular contact. This sequence accurately demonstrates the presence of neurovascular compression, and in this way valuable information may be achieved for the planning of surgical therapy of patients with trigeminal neuralgia. Received: 25 February 1999 Revised: 29 March 2000 Accepted: 4 July 2000     

Acute subarachnoid Haemorrhage: 3D time-of-flight MR angiography versus intra-arterial digital angiography

To evaluate the efficacy and reliability of 3D time-of-flight MR angiography (TOF MRA) as a noninvasive procedure, 27 patients with acute subarachnoid haemorrhage (SAH) were studied with MRA immediately before or after intra-arterial digital subtraction angiography (DSA). 3DTOF MRA was performed with an axial slab of 60 mm centred on the circle of Willis and isotropic voxels. DSA showed 22 aneurysms and 1 dural arteriovenous fistula in 21 patients; the aneurysms ranged in size from 2 to 8 mm. MRA failed to show 2 small aneurysms, at the origin of the posterior and anterior communicating arteries. The 3D display of the intracranial vessels obtained with maximum intensity projection (MIP) or targetted MIP sometimes rendered the aneurysms better than DSA. However, due to its high spatial resolution, DSA more clearly defined the overall anatomy of the walls of the normal and abnormal vessels.1992 Scientific Award of the ESNR     

Takayasu's arteritis: evaluation with three-dimensional time-of-flight MR angiography

Three-dimensional time-of-flight MR angiography was performed in 16 patients with Takayasu's arteritis. Two regions were evaluated, the arch of aorta and its intrathoracic major branches, and the abdominal aorta with proximal portions of its major visceral and renal branches. Individual arteries and aortic segments, i. e. aortic arch and abdominal aorta, were evaluated for abnormalities such as stenosis, occlusion, dilatation and aneurysm formation. The results were compared with contrast angiography. Follow-up MR angiography was performed in three patients after 9–12 months. MR angiography demonstrated steno-occlusive lesions in all the patients and aneurysms in 2. In comparison with contrast angiography, good correlation was found in 129 of the 145 arteries and aortic segments. For the 12 false-positive results, incorrect slab placement and overestimation of stenosis were implicated. Interestingly, there were three false-negative results and one occlusion was underestimated as stenosis. A new lesion developed in 1 patient and one stenosis progressed in another patient upon follow-up. Three-dimensional time-of-flight MR angiography is a simple and fairly accurate method for documenting the lesions in Takayasu's arteritis and for its follow-up. Received 12 April 1995; Revision received 30 August 1995; Accepted 15 September 1995     

Head and neck haemangiomas: contrast-enhanced three-dimensional MR angiography

We evaluated the clinical effectiveness of contrast-enhanced three-dimensional (3D) magnetic resonance angiography (MRA) for diagnosing head and neck haemangiomas. We studied six patients using a magnetization prepared rapid acquisition gradient-echo (MP-RAGE) sequence on a 1.5-T system. Conventional T1- and T2-weighted and contrast-enhanced images were also obtained. The images were compared with histological findings. In four cavernous haemangiomas, a mass was partially visible as an enhancing lesion on the early phase of MRA, and was completely visible as a larger enhancing lesion in the late phase, showing slow blood flow. In two capillary haemangiomas, a mass was completely visible in the early phase showing fast flow. In all patients, MRA clearly showed both the haemangiomas and the external carotid artery branches. MRA allowed assessment of the relationship between the haemangiomas and the feeding arteries, and of the haemodynamics. Received: 17 April 1998 Accepted: 5 June 1998     

Follow-up MRI in dural arteriovenous malformations involving the cavernous sinus: emphasis on detection of venous thrombosis

Summary Six patients with a dural arteriovenous malformation (dural AVM) involving the cavernous sinus were followed up with magnetic resonance imaging in order to assess change in the lesions. Spin-echo (SE) imaging of three patients in whom the AVM appeared to have closed at least 1 month earlier (two of them spontaneously, and one after external carotid artery embolization) showed neither apparent flow void in the involved cavernous sinus nor evidence of venous thrombosis. SE images of the other three patients who had not been cured by external carotid artery embolization (two of whom were examined within a week of treatment), detected persisting arteriovenous shunts, including high-flow cortical venous drainage, seen as flow void. Two-dimensional time-of-flight MR angiography (2D TOF MRA) was performed simultaneously in three patients. Whereas shunting blood and the normal cavernous sinus were of high intensity, presumed thrombosed cavernous sinuses were isointense with stationary brain tissue. SE imaging can confirm the resolution of arteriovenous shunts, but poorly delineates ver acute and chronic thrombosis of the draining veins. In contrast, 2D TOF MRA directly demonstrates flowing blood, permitting the diagnosis of venous thrombosis; it should be included in follow-up of a dural AVM involving the cavernous sinus when venous thrombosis is suspected.     

三维对比剂增强MR血管成像诊断布加综合征的价值

目的观察三维对比剂增强MR血管成像（3DCEMRA）上布加综合征（BCS）的各种表现,并初步评价该项新技术的价值。方法33例BCS患者行3DCEMRA检查。23例为继发性BCS,分别继发于肝细胞癌（21例）、右肾上腺癌（1例）或血栓性静脉炎（1例）。10例为原发性BCS。观察肝静脉、下腔静脉（IVC）和门静脉的开放性,观察有无肝内外侧支、肝实质病变和门静脉一体静脉间曲张静脉。10例患者行下腔静脉造影术,2例行肝右静脉穿刺造影术,把3DCEMRA所获的诊断结果与造影相对照。结果3DCEMRA可显示BCS的各种表现。肝静脉表现包括：癌栓形成（19例）、肿瘤压迫（2例）、肝静脉未显示（4例）和局限性狭窄（4例）。IVC表现为严重狭窄或闭塞（10例）、肿瘤直接侵犯（2例）、癌栓形成（3例）、血栓性静脉炎（1例）和隔膜形成（3例）。9例显示肝内侧支形成,其中2例显示“蜘蛛网”征象。所见的肝外侧支包括扩张的奇静脉和半奇静脉（13例）,以及左肾一膈下一心包膈静脉侧支（2例）形成。2例患者发现门静脉左支闭塞,10例患者发生门静脉．体静脉间静脉曲张。3DCEMRA发现的肝实质病变有：尾叶增大（7例）、不均匀强化（18例）和并发肿瘤（18例）。12例3DCEMRA诊断结果均与造影结果一致。结论3DCEMRA能显示BCS的各种征象,并能帮助提供正确诊断。     

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。     

磁共振三维血流成像在小儿腹部疾病诊断中的价值

目的：探讨对比剂增强自动触发磁共振三维血流成像(3D CE MRA)技术在小儿腹部疾病诊断中的价值。方法：2001年3月～2003年6月对临床拟诊腹部实体肿瘤和腹腔大血管病变的46例患儿行常规MRI扫描和3D CEMRA检查，年龄生后1天～14岁，平均4．8岁。腹部实体肿瘤40例，腹腔大血管病变6例。全部患者检查前行肘静脉穿刺并保留静脉通道．镇静睡眠后注射2～3倍剂量非离子型对比剂。扫描采用Smart Prep Angio。对比剂智能捕捉技术。结果：本组检查成功率97．83％。40例实体肿瘤中,3D CEMRA显示肿瘤起源2例，肿瘤侵犯和包绕腹主动脉11例，下腔静脉闭塞3例，肾动静脉受侵蚀闭塞6例，肾蒂受肿瘤牵拉变细3例，腹腔动脉干、肠系膜上动静脉及睥静脉移位共12例，门静脉及其左右肝内分支受侵犯3例。腹部大血管病变6例。结论：3D CEMRA技术对巨大腹膜后肿瘤的起源定位具有诊断价值。结合多方位的断面图像不仅可以了解腹腔重要大血管被肿瘤浸润包裹和推挤移位情况，而且可对肾脏受浸润破坏情况进行术前评估，从而为临床制定恰当的治疗方案提供比较可靠的影像学依据。3D CEMRA是无创显示体腔大血管病变的有效方法。     

Persistent trigeminal artery variants detected by MR angiography

Persistent trigeminal artery (PTA) variants are cerebellar arteries that originate directly from the precavernous portion of the internal carotid artery (ICA). The goal of our study was to determine the incidence and MR angiographic features of PTA variants. Between April 1996 and September 1999, 523 cranial MR angiographies were performed at our institution. Most of the patients examined had or were suspected of having cerebrovascular disease. We retrospectively reviewed these 523 MR angiograms. A 1.5-T scanner was used in all studies, and maximum intensity projection (MIP) images obtained using the three-dimensional time-of-flight (3D TOF) technique were displayed stereoscopically. Four PTA variants were detected on MR angiograms, at a rate of 0.76 %. At least three of the four PTA variants were anterior inferior cerebellar arteries (AICAs), small tortuous arteries arising from the precavernous portions of the ICAs and taking a posterior course. Although the clinical significance is not great, we found a relatively high incidence of PTA variants on MR angiograms. We stress that knowledge and recognition of these anomalous cerebellar arteries are useful and important in the interpretation of cranial MR angiograms. Received: 4 November 1999; Revised: 16 February 2000; Accepted: 16 March 2000     

单倍剂量三维动态对比增强MR血管成像诊断肢体软组织血管瘤的价值

目的探讨单倍剂量三维动态对比增强MR血管成像（SD 3D DCEMRA）诊断肢体软组织血管瘤的可行性及其意义。方法测试30例健康志愿者注射单倍剂量钆喷替酸葡甲胺（Gd-DTPA）后Gd-DTPA至股、胭和胫前动脉中段的循环时间（TT）、动脉强化峰值信号强度（SPE）和动脉峰值强化持续时间（DPE）。45例肢体软组织血管瘤和9例神经鞘瘤行常规MRI和SD 3D DCEMRA检查，SD 3D DCEMRA扫描时间10～12S，获取动脉早、晚期及静脉期3期图像。观察、比较血管瘤常规MRI与SD 3D DCEMRA表现，比较血管瘤和神经鞘瘤SD 3D DCEMRA的差异。结果（1）股、胭及胫前动脉TT、SPE和DPE依次分别为（15±5）s、（400±50）、（11．9±2．6）s，（19±7）s、（320±45）、（16．8±3．6）s和（27±10）s、（270±39）、（22．0±6．6）s；3条动脉之间的TT（F=6．91，P〈0．01）、SPE（F=21．21，P〈0．01）及DPE（F=12．10，P〈0．01）差异有统计学意义。（2）血管瘤SD 3D DCEMRA表现：瘤体动态显现，自动脉早期至静脉期瘤体信号逐渐增强、瘤体显影范围增大，动脉早、晚期及静脉期平均瘤体信号分别为0．09、0.49和0．74，各期间差异有统计学意义（F=775．60，P〈0．01）；45例中，A型（动脉早期无显影）24例，B型（动脉早期轻微显影）21例，A型SD 3D DCEMRA3期平均瘤体信号0．43、B型0．46，差异无统计学意义（F=4．57，P〉0．01）。肿瘤供血动脉，显示率100％。（3）常规MRI上未能显示的2例血管瘤，SD 3D DCEMRA上动态显现瘤体和显示供血动脉。（4）神经鞘瘤SD 3D DCEMRA无瘤体动态显现和供血动脉显示。结论应用SD 3D DCEMRA诊断肢体软组织血管瘤是可行的，瘤体动态显现和供血动脉显示是其SD 3D DCEMRA特征。     

Pelvic arteriovenous malformations: gadolinium-enhanced three-dimensional MR angiography findings

Pelvic arteriovenous malformations (PAVMs) are rare disorders traditionally diagnosed by conventional angiography. Breath-hold three-dimensional gadolinium-enhanced MR angiography (3D-Gd-MRA) is a state-of-the-art alternative for vascular imaging. We describe the 3D-Gd-MRA findings in two patients with PAVMs. The 3D-Gd-MRA approach provides a noninvasive and versatile method for evaluation of PAVMs that enables both angiographic assessment of the malformations and evaluation of visceral involvement, which can preclude surgical intervention. Received: 15 September 1999; Revised: 27 December 1999; Accepted: 27 December 1999     

三维动态增强MR血管成像对门静脉高压症的评价

目的通过规范扫描时相、增加三维采集厚度及采用减影后处理技术,评价三维动态增强MR血管成像(3D DCE MRA)对显示门静脉高压症患者侧支循环的作用。方法30例门静脉高压症患者进行3D DCE MRA,其中12例采用75～90 mm的三维采集厚度,扫描时相以呼吸次数粗略估计,采集3-5次,18例采用150～180 mm三维采集厚度,扫描时相以秒表计时确定,分别于0、20、40、60、90 s采集5次。比较减影前后的最大强度投影(MIP)重组图像对门静脉系统血管主干及侧支的显示能力(以4级法评价),并统计患者显示的所有侧支血管及其显示的最佳时间。结果减影技术会降低门静脉主干的显示效果[减影前(2．74±0．31)级,减影后(2．53±0．49)级],差异有统计学意义(t=2．65,P<0．05),而提高食管胃底曲张静脉的显示[减影前(1．63±0．50)级,减影后(2．58±0．30)级],差异有统计学意义(t=-12．56,P<0．01)。门静脉主干与多数侧支循环为20 s左右显示最佳,个别侧支血管显影延迟。结论采用减影后处理技术能提高对门静脉高压症患者侧支血管的显示,规范的扫描时相不会遗漏显影较晚的侧支循环,增大采集厚度能保证前后腹壁侧支循环的显示。     

导航技术三维对比剂增强磁共振冠状动脉成像

目的评价导航技术三维对比剂增强磁共振冠状动脉成像的应用价值。方法应用导航技术三维对比剂增强磁共振血管成像方法,对20例受检者分别进行左、右冠状动脉成像,经后处理获得左、右冠状动脉血管图像。应用信噪比和对比噪声比评价增强前后的冠状动脉图像,并对冠状动脉主干及其主要分支的显示情况进行评价。结果(1)对获得成功的18例冠状动脉图像进行评价,增强前冠状动脉图像的信噪比为26.37±7.02,对比噪声比为14.76±6.97;增强后冠状动脉图像的信噪比为38.87±11.62,对比噪声比为33.72±10.80,经统计学比较,信噪比和对比噪声比增强前后的差异有统计学意义(t=2.91,4.62;P<0.05)。(2)对比剂增强后左、右及左回旋支冠状动脉近中段的显示率为100%,远侧段的显示率分别为94.4%、88.8%、77.8%。结论导航技术三维对比剂增强磁共振冠状动脉成像有较高的信噪比和对比噪声比,应用于临床尚需进一步的对照研究。     

颅内静脉窦磁共振2DPC与3DPC MRA的对比研究

目的：比较2DPC、3DPC MRA不同扫描方位对颅内静脉窦的成像价值。方法：通过对20例志愿者3种流速下2DPC、3DPC MRA信号强度的测量。选出最佳流速。为30例健康志愿者另行2DPC、3DPC轴、矢、冠三个平面的血管成像，评价6个序列颅内静脉窦的显示情况，并进行统计学分析。结果：轴位3DPC、2DPC MRA显示颅内静脉窦无明显差异（P＞0．05），矢状、冠状位3DPC MRA优于2DPC MRA（P＜0．05）。结论：2DPC MRA及3DPC MRA对较粗大的静脉窦均能清晰显示，但对于细小静脉窦的显示3DPC MRA优于2DPC MRA。