动态3D CE-MRV在颅内疾病诊断及治疗中的应用初探

目的：探讨动态3D CE-MRV在颅内静脉系统疾病诊断中的成像优势及其对颅内疾病临床诊断及治疗的指导意义.方法：可疑或确诊为颅内静脉病变者36例应用3T磁共振仪及3D TRICK技术行动态CE-MRV检查,9例无颅内静脉病变者同时行2D TOF序列MRV检查.分析动态3D CE-MRV图像,观察颅内深浅静脉系统主干及其分支的显示情况,比较其相对于2D TOF序列MRV的优势;分析动态3D CE-MRV对颅内疾病如静脉窦及静脉血栓、累及静脉的血管畸形、肿瘤和外伤等的诊断价值及其对临床治疗的指导意义.结果：与2D TOF序列比较,3D CE-MRV对静脉窦属支、上下吻合静脉及海绵窦等显示更清晰（P〈0.05）.动态CE-MRV显示36例受检者大致可分为4种结果：①正常者16例,含静脉发育变异6例;②累及静脉的颅内血管畸形3例;③静脉窦或静脉血栓11例,其中3例为溶栓术后复查显示再通;④肿瘤及外伤6例：脑膜瘤或颈静脉球瘤压迫或侵犯静脉窦者3例;外伤致颅内静脉异常者3例,其中1例为颈内动脉海绵窭瘘.结论：动态3D CEMRV对颅内静脉尤其是细小静脉的观察明显优于2D TOF序列的MRV;多时相显影和多方位重组可对颅内静脉变异、静脉畸形和累及静脉的疾患能清晰显示,为临床诊断、治疗方案的确定及疗效评价提供重要的影像依据.     

颅面部动静脉畸形的CT影像学特征

目的分析颅面部动静脉畸形的CT影像表现,探讨CT增强检查对评价颅面部动静脉畸形的价值。方法回顾性分析32例经DSA确诊的颅面部动静脉畸形患者的临床及影像资料,对部位,形态,边界,血管构筑,骨和颅内侵犯等表现进行分析。结果病变部位较局限19例,病变范围广、多部位受累13例,合并颅内病灶1例,合并颅面骨病灶4例。特征性CT表现为强化的畸形血管团,粗大扭曲的引流静脉。结论 CT增强检查能准确显示动静脉畸形的畸形血管团,大部分供血动脉及引流静脉,为诊断,治疗,疗效评价随访提供重要信息。     

耳鸣与脑鸣患者三维对比增强磁共振静脉成像特征分析

目的利用三维对比增强磁共振静脉成像(3D CE-MRV)分析耳鸣与脑鸣患者头颈静脉系统的形态特征,探究3D CE-MRV技术对耳鸣及脑鸣病因诊断的应用价值。方法回顾性分析224例耳鸣或脑鸣患者的临床资料及3D CE-MRV检查。对126例耳鸣患者与98例脑鸣患者的临床特点及图像特征进行分析比较。结果耳鸣组与脑鸣组流行病学特点及头颈静脉异常表现差异均无统计学意义(P0.05);224例患者的3D CE-MRV结果显示178例(79.5%)患者均有不同类型的静脉异常表现:包括111例(49.5%)静脉引流通路局部狭窄、77例(34.3%)静脉引流通路发育不良、12例(5.3%)镰状窦开放、5例(2.2%)颅内静脉窦血栓形成。结论 3D CE-MRV对头颈静脉系统的形态学异常有良好的显示效果,为耳鸣或脑鸣患者的病因诊断和治疗提供了思路和依据。     

肝静脉流出道病变的磁共振肝脏加速容积采集成像诊断

目的 评价肝脏加速容积采集(LAVA)用于诊断肝静脉流出道病变的价值.方法 78例肝癌、布加综合征和肝移植术后随访的患者接受了LAVA检查,分析LAVA图像质量及其对各种肝静脉流出道病变和侧枝循环的显示情况.结果 78例LAVA图像均无伪影,血管显示清楚,达到诊断要求.LAVA均清楚地显示了肝静脉和下腔静脉正常解剖和各种病变,对肝静脉流出道病变的部位、程度、原因和侧枝分布均显示较好.结论 LAVA作为一种无创性检查方法,能够在显示病变的同时明确病灶与血管关系.     

16层螺旋CT血管造影在颅内病变中的应用

目的:探讨16层螺旋CT血管造影(CTA)对颅内疾病的应用价值。方法:应用16层螺旋CT对43例脑血管病变和颅内肿瘤患者行CTA检查,全部病例均采用多平面重建(MPR)、曲面重建(CPR)、表面遮盖显示(SSD)、最大密度投影(MIP)、三维容积重建(3D-VR)等技术显示脑血管,对脑血管显示情况进行评价,并将结果与DSA和/或手术结果比较。结果:43例患者CTA脑血管主干及1~3级分支血管显示率为100%;CTA检查未见异常4例,动脉瘤20例,血管畸形8例,缺血性脑血管病7例,脑肿瘤4例,其中21例行DSA检查,13例行手术治疗;与DSA比较,CTA对动脉瘤的敏感性为92%(12/13),CTA清晰地显示了瘤体、瘤颈、载瘤动脉及其详细关系,CTA显示的瘤体小于手术所见;CTA显示的畸形血管团大小、部位、供血动脉和引流静脉与DSA及手术所见相符;CTA显示脑血管狭窄、中断部位、形态与DSA一致;CTA显示了肿瘤与周围血管和颅骨间的三维关系。结论:16层螺旋CT血管造影对颅内各种血管性病变的诊断及显示血管与其他颅内病变的三维空间关系具有重要价值,是诊断颅内病变的重要而有效的检查方法。     

旋转DSA及三维重组技术在颅内动脉海绵窦瘘诊断中的应用价值

目的 评价旋转DSA及血管三维重组技术在颅内动脉海绵窦瘘诊断中的价值. 资料与方法 20例单侧眼球突出患者(除外非动脉海绵窦瘘疾病)应用传统DSA,旋转DSA及血管三维重组进行检查,对比不同方法对动脉海绵窦瘘病变的显示情况.结果 20例患者均确诊为动脉海绵窦瘘,常规DSA不同体位均能显示病变部位及范围,但对于瘘口的位置、数目以及与病变动静脉之间的关系均不能显示.旋转DSA显示动脉海绵窦瘘结构的能力较常规DSA明显提高.所有血管三维重组的图像都清晰显示了瘘口的位置、数目以及与病变动静脉之间的关系.结论旋转DSA及血管三维重组技术对颅内动脉海绵窦瘘病变结构显示极佳,尤其是三维重组技术,明显有助于对颅内动脉海绵窦瘘的诊断和介入治疗.     

320排动态容积CT扫描技术在脑血管疾病中的应用

目的 探讨320排动态容积CT在脑血管疾病检查中的优势及临床应用价值.方法 对196例急慢性脑血管病变或术后复查患者行320排头颅动态容积CT检查,1次注射对比剂同时得到脑实质、脑血管及脑灌注图像.评价图像质量及诊断效果,计算放射剂量.结果 196例患者中,急慢性脑血管闭塞或狭窄46例,动静脉分流性疾病及血管畸形29例,动脉瘤82例,脑血管病变术后复查39例.动态CTA能清晰显示血管病变解剖细节,CTP(CT Perfusion)图能提供受累血管供血区血流动力学变化.动静脉分流患者能清晰显示供血动脉、血管巢及引流静脉,并能显示静脉引流模式,对于血管畸形及动脉瘤术后患者能评价治疗效果及了解有无并发症.结论 320排动态容积CT可以动态观察颅内血管的解剖细节及动态血流信息、评价全脑灌注情况并进行量化,实现对脑血管病变的全面评估.     

Budd-Chiari综合征:肝静脉CT、MRI对比分析

目的比较CT和MRI在Budd-Chiari综合征诊断中对肝静脉病变及肝外侧支血管的显示能力。资料与方法对30例Budd-Chiari综合征患者均前瞻性进行CT和MRI检查,将获取的影像资料进行对比、统计、分析,探讨CT、MRI在Budd-Chiari综合征时对肝静脉血管病变全面显示的优缺点。结果 MSCT显示单支肝静脉6例阻塞,两支肝静脉阻塞12例,三支肝静脉阻塞5例;单支副肝静脉阻塞6例;肝外侧支血管显示30例。MRI显示单支肝静脉阻塞6例,两支肝静脉阻塞15例,三支肝静脉阻塞8例;单支副肝静脉阻塞3例;肝外侧支血管显示30例。结论 CT、MRI均能较好地显示肝外侧支血管情况,MRI较CT更能显示出肝内静脉病变情况。     

直接法CE-MRV在下肢深静脉血栓中的应用初探

目的探讨直接法对比增强磁共振静脉血管成像(CE-MRV)在诊断下肢深静脉血栓中的应用价值。资料与方法对临床高度怀疑下肢静脉血栓疾病的27例患者进行直接法减影CE-MRV,将采集的原始数据减影后导入后处理工作站行最大密度投影(MIP),多平面重组(MPR)及表面遮盖(SSD)法重组,分析下肢深静脉血栓形成的影像学表现。结果 27例患者双侧下肢深静脉重组图像显示清晰,重组血管对比度良好,背景抑制满意,6例正常,表现为静脉显影完整,走行自然,原始轴位显示管壁光滑。21例显示不同部位、不同程度的血栓形成,CE-MRV原始轴位图像呈偏心性的充盈缺损,重组图像上显示管腔狭窄、节段性中断或变细、浅静脉代偿扩张、深浅静脉交通支明显增多,侧支循环开放,直接造影法引起的边流效应一般表现为较长节段的中心性充盈缺损,连续断层或MPR图像显示无基底附着于管壁。结果直接法减影CE-MRV检查技术可准确地显示下肢静脉血栓性病变情况,有效避免动脉伪影及周围组织的干扰,图像清晰度及可靠性高,可明确病灶的范围和程度及侧支循环的建立与否,有重要临床应用价值。     

透视触发三维快速梯度回波技术在颅内静脉成像的应用

目的探讨透视触发血管成像技术在脑静脉系统疾病诊断中的价值。方法使用三维快速梯度回波技术（Flash 3D）序列透视触发血管成像,通过调节扫描参数、薄层、高像素,并减少造影剂量等方法,对50例临床怀疑脑内静脉系统病变的患者进行对比增强静脉成像,并评价所获影像中血管主干及分支解剖显示情况。结果50例临床怀疑脑内静脉系统病变患者均成功完成了透视触发Flash 3D序列扫描血管成像,均能满意地显示血管影像,12例未见异常,脑静脉血栓4例,静脉型血管瘤19例,动脉静脉畸形6例,血液病浸润2例,肿瘤压迫及侵犯7例。结论Flash 3D对比增强血管成像能清楚地显示脑部静脉系统及其与病变的关系,为临床对疾病的诊断和治疗提供依据。     

Partially recanalized chronic dural sinus thrombosis: findings on MR imaging, time-of-flight MR venography, and contrast-enhanced MR venography

BACKGROUND AND PURPOSE: The imaging appearance of chronic, partially recanalized dural sinus thrombosis has been incompletely described. We sought to more fully characterize the imaging findings of this entity on MR imaging, time-of-flight MR venography (TOF-MRV), and elliptic centric-ordered contrast-enhanced MR venography (CE-MRV). Materials and METHODS: From a data base of patients with cerebral venous thrombosis, 10 patients were identified with imaging and clinical findings consistent with the diagnosis of chronic, partially recanalized, dural sinus thrombosis. All patients had MR imaging of the brain without and with contrast. Nine patients underwent MRV, and 6 had both CE-MRV and TOF-MRV. Thirty-four venous segments were thrombosed and were assessed in detail for multiple imaging features. RESULTS: Most thrombosed segments were isointense to gray matter on T1-weighted images (85%), and hyperintense to gray matter on T2-weighted images (97%). Visible serpiginous intrathrombus flow voids were visible in 23 segments (8/10 patients) corresponding with areas of flow signal intensity on TOF-MRV and enhancing channels on contrast MRV. Eighty-four percent of thrombosed segments enhanced equal to or greater than venographically normal venous sinuses. TOF-MRV and CE-MRV were abnormal in all patients, and CE-MRV more completely characterized the thrombosed segments. The imaging appearance did not change in those patients with follow-up imaging (average 13.6 months). CONCLUSION: Chronic, partially recanalized, venous thrombosis has a characteristic appearance on MR and MRV. CE-MRV was abnormal in all cases, despite the intense enhancement of the thrombosed segments. Because of the highly selected nature of the cases reported, further study is required to determine whether these findings are present in all cases of this condition.     

Role of contrast-enhanced MR venography in the preoperative evaluation of parasagittal meningiomas

Parasagittal meningiomas (PSM) may pose a difficult surgical challenge since venous patency and collateral anastomoses have to be clearly defined for correct surgical planning. The aim of this study was to assess the diagnostic value of contrast-enhanced (CE) magnetic resonance venography (MRV) in the preoperative evaluation of venous infiltration and collateral venous anastomoses in patients with PSM. CE-MRV was compared with phase-contrast (PC) magnetic resonance (MR) angiography, conventional angiography (when available), and surgery as a reference. Twenty-three patients undergoing surgery for meningiomas located adjacent to the superior sagittal sinus were prospectively evaluated. All the patients underwent both conventional MR examination and MRV. This was performed by means of PC and CE techniques. Both sets of angiograms (CE and PC) were evaluated by two expert neuroradiologists to assess (1) patency of the sinus (patent/occluded), (2) the extent of occlusion (in centimeters), and (3) the number of collateral anastomoses close to the insertion of the meningioma. Eight patients underwent digital subtraction angiography (DSA). All patients were operated on, and intraoperative findings were taken as the gold standard to evaluate the diagnostic value of MRA techniques. PC-MRV showed a flow void inside the sinus compatible with its occlusion in 15 cases, whereas CE-MRV showed the sinus to be occluded in five cases. CE-MRV data were confirmed by surgery, showing five patients to have an occlusion of the superior sagittal sinus. The PC-MRV sensitivity was thus 100% with a specificity of 50%. In those cases in which both MRV techniques documented occlusion of the sinus, the extent of occlusion was overestimated by PC compared with CE and surgery. CE-MRV depicted 87% of collateral venous anastomoses close to the meningioma as subsequently confirmed by surgery, while PC showed 58%. In the preoperative planning for patients with meningiomas located close to a venous sinus, CE-MRV provides additional and more reliable information concerning venous infiltration and the presence of collateral anastomoses compared with PC sequences.     

The dural venous sinuses: normal intraluminal architecture defined on contrast-enhanced MR venography

Introduction Our objective was to define the appearance and distribution of normally occurring intraluminal structures within the dural venous sinuses on contrast-enhanced MR venography (CE-MRV). Methods Informed consent was obtained from all subjects participating in the study, and the study protocol was approved by the institutional review board of the University Health Network. A group of 56 patients underwent CE-MRV. Intraluminal structures were categorized as an arachnoid granulation (AG) or trabeculation (Willis cord). Willis cords within the transverse and sigmoid sinuses as well as AGs 4 mm or more in size were recorded. Results In 20 of the 56 patients (36%), 29 AGs measuring 4 mm or more were identified within the dural sinuses. All AGs were spherical or ovoid and occurred at sites where a cortical vein joined a dural sinus. Nearly all AGs (28 of 29, 97%) displayed an eccentric internal vein. Willis cords were seen within the superior sagittal sinus in all patients. Willis cords were less prevalent in the remaining dural sinuses. A minimum of one Willis cord was seen in 58 of the 112 transverse sinuses (52%). These cords were 1–2 mm in maximal thickness, uniformly smooth, and commonly partitioned the sinus. Willis cords and AGs (of any size) were not encountered within the sigmoid sinuses or jugular veins. Conclusion CE-MRV elucidates structures normally found within the dural sinuses. These consist of AGs and Willis cords. This report confirms and establishes new criteria for identification of these normally occurring intraluminal structures providing a basis for their differentiation from pathologic entities.     

High-resolution three-dimensional contrast-enhanced blood oxygenation level-dependent magnetic resonance venography of brain tumors at 3 Tesla: first clinical experience and comparison with 1.5 Tesla

RATIONALE AND OBJECTIVES: To evaluate the clinical potential of high-resolution 3D contrast-enhanced blood oxygenation level-dependent MR-Venography (CE-MRV) for primary brain tumors and metastases at 3 Tesla (T) in comparison to 1.5 T. METHODS: Eighteen patients with brain tumors were examined using CE-MRV after application of a standard dose of MRI contrast agent (0.1 mmol/kg gadodiamide). CE-MRV is based on a high-resolution 3D flow-compensated gradient-echo sequence with long echo times that uses the contrast-enhanced blood oxygenation level-dependent effect. This technique was performed using the same volume coverage and acquisition time at both field strengths after performing standard imaging sequences. RESULTS: The higher spatial resolution of CE-MRV at 3 T showed more details within and around tumors than at 1.5 T. Visibility was enhanced by stronger susceptibility weighting and higher intrinsic signal-to-noise at 3 T. Compared with standard imaging protocols, additional information characterized as tubular and nontubular hypointense structures were found within or around lesions on CE-MRV images. CONCLUSIONS: Acquisition of CE-MRV data at 3 T enables spatial resolution to be increased within the same measurement time and with the same volume coverage compared with 1.5 T, thus providing more detailed information. The method may also show the potential to estimate oxygen supply of tumors, especially at high field strengths.     

Fast contrast-enhanced MR whole-brain venography

Our aim was to assess the value of a new fast contrast-enhanced MR venography (CE-MRV) sequence in the investigation of normal and diseased cerebral veins. Conventional time-of-flight (TOF) MRV is time consuming, with imaging for a single sequence taking many minutes. MRI was performed with a clinical 1.5-T scanner; conventional TOF MRV followed by CE-MRV was performed using a modified 3D first-pass MR angiography sequence. Ten control subjects without cerebral pathology were studied as well as ten patients with cerebral venous thrombosis for a total of 20 studies with both sequences. CE-MRV was able to provide a set of complete MRV images in a significantly shorter time than conventional MRV sequencing could. The field of view also provided greater coverage of the vessels of the head and neck. CE-MRV also provided more extensive small vein detail and provided a better demonstration of intraluminal defects, despite a slightly lower resolution. Both methods were equally suited for the demonstration of venous thrombosis and demonstrated all cases equally well; however, CE-MRV provided more detailed information by showing partially obstructed sinuses and by showing better the presence of cortical collateral venous drainage.     

The value of paramagnetic contrast agent gadolinium-DTPA in the diagnosis of pituitary adenomas

Summary The purpose of this study was to assess the role of MR imaging and the paramagnetic contrast agent Gadolinium-DTPA(Gd-DTPA) in the diagnosis of pituitary macroadenomas. 44 macroadenomas were examined with MRI before and after intravenous application of Gd-DTPA. Gd-DTPA produced excellent enhancement of solid adenoma. The best contrast between adenoma and surrounding structures could be gained on post-Gd T1-weighted images. Post-Gd images were equivalent to pre-Gd images in the evaluation of supra-and infrasellar extensions of macroadenomas. Post-Gd images had advantages in the evaluation of cavernous sinus invasion by adenoma. The difference in degree of contrast enhancement between adenoma and cavernous sinus facilitated the exact evaluation of lateral extension by adenoma in 18 cases. Almost equal degree of enhancement of both structures impaired tumor-sinus contrast in 2 cases. In the other 24 cases the tumor filled the cavernous sinus completely. It is our opinion that Gd-DTPA can be used on a widespread basis because of its excellent capability to highlight and delineate pituitary adenomas.     

Lymphoma of nasal and sinus cavities

Seven cases of non-Hodgkin lymphoma of the nasal cavities and paranasal sinuses are reported. All but one were primary lesions. Five of the 7 cases involved only the facial structures. Sites of involvement were the maxillary sinus (4 cases), the nasal fossae (2 cases), and one case in which lesions of both the ethmoid and sphenoid sinuses were associated with intracranial extension. CT studies showed sinus opacification and invasion of adjacent structures, but bone destruction was inconstant. Follow-up studies during treatment revealed rapid tumor regression with non specific images of mucosal hypertrophy.     

Large arachnoid granulations involving the dorsal superior sagittal sinus: findings on MR imaging and MR venography

BACKGROUND AND PURPOSE: Large arachnoid granulations (AG) within the dorsal superior sagittal sinus (SSS) have been incompletely characterized and can be confused with pathology. This report reviews the characteristics of these anatomic structures to establish common imaging features that allow differentiation from pathology.MATERIALS AND METHODS: Twelve cases of large AG in the dorsal SSS are presented, identified by MR imaging. Signal intensity characteristics, size, location, venographic appearance, and association with adjacent venous and osseous structures were documented.RESULTS: A defect in the dura of the SSS was seen in all of the cases communicating with the subjacent subarachnoid space. The average size of the AG was 8.1 × 9.4 × 10.0 mm (range, 4–19 mm). Ten produced calvarial remodeling, and 11 were in the direct vicinity of the lambda. On T2-weighted images, all were hyperintense to the brain. On T1-weighted images, 8 were hypointense and 4 were hypointense with mixed areas of isointense signal intensity. All of the AGs were associated with cortical venous structures entering the sinus. On MR venography, AGs appeared as focal protrusions into the sinus, displacing, distorting, and narrowing the sinus lumen. Seven patients had headache without other visible cause on MR imaging, and 4 were initially interpreted as thrombosis or tumor.CONCLUSION: Large AGs can occur in the dorsal SSS. They are well-defined projections of the subarachnoid space into the sinus, can cause luminal narrowing and calvarial remodeling, and have typical signal intensity characteristics, position, and morphology differentiating them from other pathology. Association with patient symptoms is uncertain.

Arachnoid granulations (AGs) are normal structures that can be demonstrated on CT and MR imaging.¹ They typically are identified as CSF attenuation or signal intensity protuberances projecting into the lumen of the dural sinuses.¹ Although most commonly identified on standard imaging studies in the midlateral transverse sinuses (TSs),^2,3 when more detailed high-resolution MR imaging examinations with contrast are used, they can be identified throughout the dural sinuses.⁴ Rarely, large AGs have been described in the dorsal (posterior inferior) superior sagittal sinus (SSS) on imaging^1,5 and on anatomic assessment.⁶ Because of their infrequency and large size, they can be misdiagnosed as a thrombus or tumor in this location.⁵ We have identified 12 cases of large AGs in the dorsal SSS on MR imaging (1.5T and 3T), and describe their appearance on standard MR pulse sequences, time-of-flight MR venography (MRV; TOF-MRV) and contrast-enhanced MRV (CE-MRV). We compared these cases with the few cases reported previously in the literature and established common imaging features that allow differentiation from pathology.     

Magnetic resonance imaging characteristics with pathological correlation of cavernous malformation in cavernous sinus

OBJECTIVE: To analyze extracerebral cavernous malformation located in the cavernous sinus and correlate their magnetic resonance imaging (MRI) features to pathological findings. MATERIALS AND METHODS: Nineteen patients (5 men and 14 women; mean age, 50.6 years; range, 32-71 years) with surgically verified cavernous malformations in the cavernous sinus were reviewed. MRI including T1-weighted, T2-weighted, and postcontrasted T1-weighted imaging was carried out in all instances with a 1.5-T superconductive system (Signa; General Electric Medical Systems, Milwaukee, WI). RESULTS: All these lesions measured from 2.5 cm to 6 cm (average, 4.3 cm) with 13 lesions located to the right side and 6 to the left side. Magnetic resonance images showed that 18 cases were hypointense to white matter on T1-weighted images with only one case showed mixed hypointensity and hyperintensity. On T2-weighted images, 17 cases showed marked homogeneous hyperintensity, 1 case showed marked hyperintensity with some signal void structures and 1 with mixed intensity. Marked homogeneous enhancement after contrast material administration was found in 7 cases, and the remaining 12 showed marked heterogeneous enhancement. Pathologically, these lesions can be classified as type A, type B, and type C. Type A was sponge-like with intact pseudocapsule; type B was mulberry-like with the pseudocapsule incomplete or absent; and type C was composed of both mulberry-like composition and sponge-like composition. Lesions with homogeneous contrast enhancement on MRI correlated with type A pathological findings, whereas those with heterogeneous enhancement correlated with type B and type C pathological findings. Asymmetrical dumbbell-shaped masses of 13 cases involving the sellar and round masses of 6 cases with 2 protruding into the sellar were found. All of the cavernous malformations displaced the adjacent temporal lobe without adjacent brain edema. The internal carotid arteries were displaced or encased in all cases. CONCLUSIONS: If a well-demarcated, homogeneous high signal intensity lesion on T2-weighted images with a dumbbell configuration involving both parasellar and sellar regions with marked heterogeneous or homogeneous enhancement is found, the diagnosis of cavernous sinus cavernous malformation should be entertained.     

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。