磁敏感成像诊断脑血管畸形

目的：探讨磁敏感成像对海绵状血管瘤和静脉畸形等脑血管畸形的诊断价值。方法：回顾分析23例经手术病理证实的海绵状血管瘤和静脉畸形患者的磁敏感成像后处理图像及常规T1 WI、T2WI及增强T1WI图像。结果：23例脑血管畸形中海绵状血管瘤18例、静脉畸形5例。常规MRI和磁敏感成像均显示18例海绵状血管瘤的出血灶,磁敏感成像上14例呈“铁环”征,常规MRI仅9例见此征象,磁敏感成像显示出血范围较常规MRI大;5例静脉畸形磁敏感成像均显示引流静脉及髓静脉呈条状低信号,髓静脉呈特征性的“海蛇头”状分布,常规MRI仅2例显示此征。结论：磁敏感成像能敏感地显示出血、微出血及细小静脉,与常规MRI结合可显著提高海绵状血管瘤和静脉畸形的检出率。     

脑内出血性海绵状血管瘤的MRI诊断

目的:分析脑内出血性海绵状血管瘤(IHCA)的MRI表现特点。方法:回顾性分析25例经病理证实的脑IHCA的MRI资料。结果:25例病变均为单发,幕上18例,幕下7例,其中大脑半球11例,基底节及丘脑7例,脑干5例,小脑2例,病变形态以类圆形为主,由于反复多次出血信号不均匀,增强无或轻度强化。结论:脑IHCA的MRI表现有一定特征性,但与其它颅内病变有类似之处,认真分析其特点,可提高诊断准确性。     

Simultaneous occurrence of developmental venous anomalies and cavernous angiomas.

PURPOSETo study the clinical and radiologic findings in 15 patients presenting with both developmental venous anomalies and cavernous angiomas and to determine which lesions caused the acute clinical symptoms.METHODSLesions were infratentorial in 7 patients and supratentorial in 7 other patients. In one patient the developmental venous anomaly was infratentorial and the cavernous angioma supratentorial. In all 15 patients clinical examination and CT were performed. In 10 patients MR was performed at the time of the initial CT scan. In 5 patients only late MR is available.RESULTSAcute clinical signs were present in 9 patients (epilepsy, hemiplegia, meningeal signs, cranial nerve deficit). On CT the cavernous angioma was missed in 9 patients, in 6 patients because of acute hemorrhage. On MR the cavernous angioma was missed in 1 of 2 cases with acute hemorrhage but seen in all other patients. On repeat MR all cavernous angiomas were correctly identified. On CT, 11 developmental venous anomalies were seen. On MR all developmental venous anomalies were seen.CONCLUSIONSThe frequent association of developmental venous anomalies and cavernous angiomas is confirmed. MR is superior to CT in the detection of both cavernous angiomas and developmental venous anomalies. Furthermore our data support the hypothesis that cavernous angiomas and not the developmental venous anomalies cause the acute clinical symptoms because of hemorrhage.     

颅内海绵状血管瘤的影像诊断

目的：分析颅内海绵状血管瘤的ＣＴ和ＭＲＩ征象，以提高对其的认识。材料和方法：经病理证实的海绵状血管瘤３２例，２６例作ＣＴ检查，３０例作ＭＲＩ检查。结果：颅内海绵状血管瘤多为单发，脑内海绵状血管瘤多于脑外。ＣＴ平扫病灶呈高密度或稍高密度，增强扫描病灶呈轻至中度强化。ＭＲＩＴ２ＷＩ常显示海绵状血管瘤核心为混杂高信号，周边有一圈环状低信号。结论：ＭＲＩ对微小病灶的显示较ＣＴ优越，ＣＴ和ＭＲＩ结合是诊断海绵状血管瘤的有效方法，能全面提供诊断资料。     

磁敏感成像序列对颅内海绵状血管瘤的诊断价值

目的探讨磁敏感成像序列对颅内海绵状血管瘤的检出率与诊断价值。资料与方法回顾性分析25例在SET1WI和SET2WI序列上无阳性或表现不典型、加作磁敏感成像序列扫描后诊断为海绵状血管瘤的46个病灶,所有病例均经临床或手术病理证实。结果25例中,单发病灶22例,多发病灶3例,其中1例同时发现12个病灶。46个病灶在SET1WI和SET2WI上呈等、低、高或混杂信号,未显示“铁环征”26个（56．5％）,较明显“铁环征”7个（15．2％）,不明显“铁环征”13个（28．3％）;在磁敏感成像序列上,21个（45．7％）表现为完全低信号,25个（54．3％）在低信号中伴有点状、条状、桑葚状高信号,并出现明显的“铁环征”,MR诊断为海绵状血管瘤,手术病理证实诊断正确率为100％。结论磁敏感成像序列对颅内海绵状血管瘤的诊断有重要价值。     

Cerebral vascular malformations: applications of magentic resonance imaging to differential diagnosis

Summary Twelve patients with cerebral vascular malformations (5 cavernous angiomas, 1 thrombosed arteriovenous malformation, and 6 venous angiomas) were studied with magnetic resonance (MR) imaging. All lesions were clearly depicted. Characteristic MR findings were obtained mainly on T2-weighted images: a markedly low intensity area was always seen. The margins of arteriovenous malformation (AVM) and venous angioma were irregular while those of cavernous angioma were smooth in all planes on T2-weighted images. Gradient-echo (GrE) pulse sequences were more sensitive than T2-weighted spin echo (SE) in lesion detection. MR imaging could play an important role in the differential diagnosis of cerebral vascular malformations.     

Venous angiomas: plain and contrast-enhanced MRI and MR angiography

We studied 17 patients with venous angiomas, 4 of whom had associated cavernous angiomas. All underwent MRI with spin-echo T1- and T2-weighted images and T1-weighted images after Gd-DTPA; MR angiography (MRA) was also performed with 3D and 2D time-of-flight technique; 5 patients underwent conventional angiography. Contrast-enhanced MRI demonstrated all the lesions, showing the peripheral medullary veins, the collector and the type of drainage. Both 3D and 2D MRA provided diagnostic information identical to that obtained after infusion of Gd-DTPA. Contrast-enhanced were T1-weighted images and MRA superior in all the cases to images without gadolinium. The possible association with cavernous angiomas (24% in our study) indicates T2-weighted imaging.     

Dural cavernous angioma: MR features.

The imaging features of a cavernous angioma, which originated from the meninges, are presented. The patient harbored a second cavernous angioma within the brain parenchyma. Cavernous angioma should be included in the differential diagnosis of dural lesions, especially when other cavernous angiomas are present.     

Intracranial cavernous angioma.

Cavernous angiomas are a rare but important clinical entity because of their potential curability. Three patients who had intracranial cavernous angiomas confirmed at surgery are presented. Preoperative recognition is greatly aided by a tendency to calcify, as identified both by skull films and more sensitively by computed tomography. A well demarcated collection of rounded densities of CT scanning, showing mild contrast enhancement and no significant mass effect, should suggest the possibility of cavernous angioma. Conventional angiography characteristically reveals a hypovascular appearance without abnormal arterial feeding vessels. On films of high technical quality, a subtle vascular stain, possibly associated with a few large draining veins, may be detected. There is usually no mass effect unless there has been a previous episode of hemorrhage. Cavernous angiomas may manifest a pronounced increase in activity on radionuclide brain scanning.     

A T1 hyperintense perilesional signal aids in the differentiation of a cavernous angioma from other hemorrhagic masses

BACKGROUND AND PURPOSE: A cavernous angioma is a developmental vascular malformation with a high risk of hemorrhage. The purpose of this work was to retrospectively determine whether an MR sign of T1 hyperintense perilesional signal intensity is useful for the differentiation of cavernous angioma from other hemorrhagic cerebral masses.MATERIALS AND METHODS: The institutional review board approved this study. We retrospectively evaluated the MR images of 72 patients with acute or subacute cerebral hemorrhagic lesions with perilesional edema (29 cavernous angiomas, 13 glioblastomas, 1 oligodendroglioma, 16 metastatic tumors, and 13 intracerebral hemorrhages) for the presence of T1 hyperintense perilesional signal intensity. In addition, T1 signal intensities of a perilesional edema were quantitatively analyzed. In cavernous angiomas, volumes of hemorrhagic lesions and perilesional edemas, lesion locations, presence of contrast enhancement, and time intervals between symptom onset and MR imaging were also assessed. Data were analyzed using unpaired t test or Fisher exact test.RESULTS: T1 hyperintense perilesional signal intensity sign was found in 18 (62.1%) of 29 cavernous angiomas, in 1 (6.3%) of 16 metastases, and in 0 primary brain tumors or intracerebral hemorrhages. Sensitivity, specificity, and positive predictive value of this sign for cavernous angioma were 62%, 98%, and 95%, respectively. The perilesional T1 hyperintensity was significantly higher in cavernous angiomas (P = .045) than in normal white matter. Perilesional edema volumes were larger in cavernous angiomas with the MR sign than in cavernous angiomas without the sign (P = .009).CONCLUSION: When the MR sign of T1 hyperintense perilesional signal intensity is present, there is a high probability of cavernous angioma being present in the brain, and this MR sign may be helpful for differentiating cavernous angioma from hemorrhagic tumors and intracerebral hemorrhages.

A cavernous angioma, also known as a cavernous malformation or cavernoma, is a developmental vascular malformation that is typically a discrete multilobulated, berrylike lesion containing hemorrhage in various stages of evolution. Hemorrhage is a common complication of a cavernous angioma and is the cause of the first presentation in 30% of cases.^1,2 The reported annual risk of hemorrhage in a cavernous angioma varies widely (1%–6.8%).^3–5MR imaging is the most important diagnostic technique for the detection of cavernous angiomas and frequently produces highly characteristic images. Typically, cavernous angiomas show a mixed signal intensity core, a reticulated “popcorn ball” appearance, and a “T2 blooming sign,” which is due to a low signal intensity hemosiderin rim that completely surrounds the lesion.^6,7 Susceptibility-weighted imaging, such as a T2* gradient-echo image, is more useful for the detection of the hemosiderin deposit and the diagnosis of a cavernous angioma. The typical MR signs of “popcorn ball” appearance and “T2 blooming sign” on T2-weighted images have been reported to be found in approximately 50%–67% of cavernous angiomas.^2,8Based on these MR findings, although diagnosis is usually straightforward in typical cases of a cavernous angioma, lesions with unusual MR features may be misdiagnosed as primary or metastatic brain tumors.^9–18 The atypical MR features of cavernous angiomas include variable or strong enhancement,^2,9,10,19 a large perilesional vasogenic edema and mass effect,^2,10,19,20 the cystic form of a cavernous angioma,^9,20,21 and the manifestations of a recent hematoma.^22,23 Cavernous angiomas that present with recent hemorrhage and with a surrounding edema may mimic a primary or secondary brain tumor with hemorrhage; these lesions may be frequently underestimated as a sole hematoma.Recently, we encountered some cases that showed T1 hyperintensity in a perilesional edema around the acute or subacute hemorrhagic masses. As far as we know, the MR feature of T1 hyperintensity in a perilesional edema around a hemorrhagic mass has not yet been documented. The aim of this study was to determine in a retrospective study whether the MR sign of a T1 hyperintense perilesional signal intensity is useful for differentiating a cavernous angioma from other hemorrhagic cerebral masses.     

Giant cavernous angioma of the temporal lobe: a case report and review of the literature

Cavernous angiomas of the central nervous system are angiographically occult vascular lesions and are easily diagnosed by magnetic resonance imaging (MRI). Giant cavernous angiomas (GCA) are rare, with only 11 cases reported in the literature. Imaging appearance of GCAs has not been reviewed previously. We report a GCA of the temporal lobe, and discuss its computed tomography and MRI findings in the view of the literature. Imaging appearance of GCAs is variable. Some GCAs have features that are similar to those of typical cavernous angiomas, whereas some lesions may be purely cystic; and some present with significant contrast enhancement and mass effect, mimicking neoplasms. While the presence of hemosiderin, blood degradation products, and calcification may be helpful in the diagnosis of some cases, the correct diagnosis is not apparent until histopathological evaluation of the specimen is made in many instances.     

3D-TOF MRA及SWI对脑血管畸形的对照研究

目的:通过分析脑动静脉畸形和海绵状血管瘤的的3D-TOF MRA及SWI磁共振表现,探讨3D-TOF MRA及SWI对脑血管畸形的诊断价值。方法:对我院收治的44例血管畸形进行高场磁共振成像,并加扫3D-TOF MRA及SWI序列,其中26例海绵状血管瘤、18例动静脉畸形。通过分析SW I和3D-TOF-MRA技术对脑血管畸形的显示情况,比较二者对脑血管畸形的检出率以及细微特征的鉴别能力等。结果:3D-TOF MRA可以清晰显示动静脉畸形的部位、大小、输入动脉的来源、输出静脉的去向等;海绵状血管瘤MRA检查均未见异常供血动脉,病灶内无异常流空信号。SWI可清晰显示海绵状血管瘤,病灶的数目及范围较常规序列增大;SWI只能显示动静脉畸形迂曲的小静脉,但不能直观显示畸形血管团的全貌及输入动脉等粗大血管的情况。结论:3D-TOF MRA技术对于AVM之类高流速低阻力的血管畸形的显示具有独特的价值,而SWI技术则对于海绵状血管瘤等小血管或低流速的血管畸形的显示具有明显的优势。     

椎管内硬膜外海绵状血管瘤的MRI特征分析

目的研究椎管内硬膜外海绵状血管瘤的MRI表现特征,提高对本病的认识及诊断水平。方法回顾分析经手术病理证实的9例椎管内硬膜外海绵状血管瘤病例的临床资料,总结其MRI影像学特征。结果 9例椎管内硬膜外海绵状血管瘤病例病灶均位于胸段椎管,其中3例位于上胸段,6例位于下胸段,病灶均沿脊柱长轴生长;T1WI呈高低混杂信号,T2WI呈明显高信号,与脑脊液信号相仿。矢状位显示病灶呈梭形或卵圆形附于椎管侧后壁,相应硬膜外间隙增宽,在病灶两端形成T1WI及T2WI均为高信号的脂肪帽,呈＂笔套样＂改变,增强后病灶显著均匀强化,强化后的瘤体与高信号的脂肪帽分界不清,共同形成＂双尾样＂改变。冠状位及轴位显示病灶沿相邻椎间孔＂伪足样＂向外生长,相应椎间孔轻度增宽,骨质轻度压迫吸收。结论椎管内硬膜外海绵状血管瘤的MRI表现具有一定的特征性,多平面全方位观察有助于术前准确定位及诊断。     

Intracranial vascular malformations in children: computed tomographic and angiographic evaluation

Thirty-nine cases of intracranial vascular malformations in children were reviewed. All patients underwent preoperative computed tomography (CT) and 35 had complete preoperative angiographic work-ups. The CT features of intracranial vascular malformations in children are described. Among the 39 patients, there were 30 parenchymal arteriovenous malformations, four dural arteriovenous malformations, three cavernous angiomas, and two venous angiomas. Combined CT and angiography allowed a highly specific diagnosis in 77% of the cases.     

Brown-Séquard syndrome secondary to spontaneous bleed from postradiation cavernous angiomas

SUMMARY: The spontaneous occurrence of acute Brown-Séquard syndrome is an extremely rare event, with most reported cases being secondary to spontaneous epidural hematomas and spinal cord ischemia. We report a rare case of Brown-Séquard syndrome from spontaneous intraspinal hemorrhage in a patient with multiple cavernous angiomas in the spinal cord secondary to craniospinal radiation in childhood. Postulated mechanisms leading to the condition include postradiation molecular changes and venous occlusion.     

Bleeding from a cavernous angioma mimicking rupture of a middle cerebral artery aneurysm

Cavernous angiomas and aneurysms may both present with acute cerebral haemorrhage. We present a case in which the coexistence of an unruptured aneurysm obscured the diagnosis of cerebral haemorrhage from a cavernous angioma. Although this association was presumably coincidental, this case demonstrates that obvious pathology (an angiographically proven aneurysm at the site of haemorrhage) may reduce awareness of other, possibly more common, causes of cerebral haemorrhage. Received: 25 January 2001/Accepted: 20 March 2001     

SWI对脑静脉性血管畸形的诊断价值

目的：探讨磁敏感加权成像（SWI）技术在脑静脉性血管畸形中的诊断价值。方法：对18例静脉性血管畸形患者的影像资料进行回顾性分析。18例患者均进行了常规MRI平扫及SWI检查．其中6例同时行MRGd—DTPA增强扫描,5例行CT平扫。结果：MRI平扫部分（14／18例）可显示扩张的引流静脉及髓静脉;而SWI可显示全部的引流静脉及扩张的髓静脉,呈典型“水母头”样改变．4例同时显示了静脉畸形同一部位伴发的海绵状血管瘤。结论：SWI无需注射对比剂,能够清晰地显示静脉畸形以及伴发的隐匿性血管畸形,可以作为脑静脉性血管畸形首选的检查方法。     

不典型颅内海绵状血管瘤的CT、MRI诊断初探

目的 探讨颅内海绵状血管瘤(ICA)的CT和MRI不典型表现.资料与方法 回顾性分析经手术病理证实的不典型ICA9例,男5例,女4例,年龄11～72岁,平均35岁.所有病例均行MRI平扫及增强检查,其中4例行CT扫描.结果 9例均位于脑内.病灶最大径平均值5.5cm.行CT检查的4例中,2例表现为等、高密度,2例表现为等、低密度;3例病灶内可见钙化.9例T1WI和T2WI呈混杂信号,周围低信号环4例,囊实性病灶5例,囊内见液平面3例,其中囊变伴附壁结节4例,6例出现明显灶周水肿.增强扫描8例呈明显不均匀强化,1例无明显强化.结论 发现瘤体巨大伴有囊性变、瘤体占位效应、病变多种形式的强化等ICA不典型的CT和MRI征象时,应考虑ICA的诊断.     

High-resolution blood oxygen-level dependent MR venography (HRBV): a new technique

Our purpose of this study was to demonstrate the clinical potential and spatial resolution of a new MRI technique: high-resolution blood oxygen-level dependent venography (HRBV), in well- known intracranial vascular lesions, such as cavernous and venous angiomas, and venous sinus thrombosis. HRBV provides unique high-resolution information on veins without administration of contrast medium. The data are independent of conventional findings on MRI and potentially useful in characterising and demonstrating the architecture of vascular lesions of the brain. Received: 12 March 2000 Accepted: 3 May 2000     

Hepatic angiosarcoma. CT and MRI aspects. A case report and review of the literature

The authors report a case of hepatic angiosarcoma revealed by massive haemoperitoneum. They analyse the CT and MRI features of this rare tumour and recall the difficult diagnostic problems raised by cavernous angiomas. The new MRI diagnostic criteria must be recognized, but do not constitute formal proof of the diagnosis.