MR imaging of hyperacute subarachnoid and intraventricular hemorrhage at 3T: a preliminary report of gradient echo T2*-weighted sequences

We describe MR imaging findings applying gradient echo (GRE) T2*-weighted and fluid-attenuated inversion recovery (FLAIR) MR images at 3T to three patients with hyperacute subarachnoid and intraventricular hemorrhage from ruptured aneurysms. Hyperacute subarachnoid and intraventricular hemorrhages (SAH and IVH) were more clearly visualized as an area of decreased signal intensity on GRE T2*-weighted sequences than on FLAIR sequences in all three patients. These preliminary results suggest that acute SAH and IVH with GRE T2*-weighted imaging can be reliably diagnosed at 3T.     

新生儿颅内出血的CT特征

研究新生儿颅内出血的ＣＴ特征性表现。对４８例新生儿颅内出血的ＣＴ表现进行了回顾性分析，并对１７例进行了追踪观察。蛛网膜下腔出血２９例，脑实质出血２例，脑室管膜下出血１例，脑室出血４例，混合型脑出血１２例。（１）ＳＡＨ为新生颅内出血最常见的类型约占６０％，仅表现为直窦高密度者，确定超过５ｍｍ为诊断标准，并根据其形态特征分为前窄后宽，前宽后窄和全长增宽３种类型；（２）ＳＥＨ见于早产儿，ＣＴ诊断较困难。     

Magnetic resonance imaging of subarachnoid hemorrhage

Summary Magnetic resonance (MR) imaging of subarachnoid hemorrhage (SAH) due to a ruptured aneurysm has been evaluated in relation to CT findings on 30 patients. In the acute stage, particularly less than 24 hours after the bleeding episode (25 patients), SAH appeared of high intensity relative to the surrounding brain on a T-2 weighted SE image but isointense where the corresponding CT scan showed blood clot of attenuation value over 60H. A T-2 weighted SE image was able to reveal subtle evidence of SAH not visible on the CT scan. The T-1 weighted IR image was not as sensitive. Blood clot (HU>60) appeared isointense, but mild and moderate SAH (HU<60) was indistinguishable from normal CSF. MR imaging was also sensitive to subacute and chronic SAH (5 patients). Three out of four SAH appearing normal on CT showed high intensity on T-2 weighted images. Thirteen out of 24 aneurysms (54%) larger than 5 mm in diameter on angiography were detected on T-2 weighted images. Smaller aneurysms less than 4 mm were not visualized. MR imaging was able to indicate the ruptured one in cases of multiple aneurysms by showing hemorrhagic lesions more clearly than CT. We conclude that MR imaging is very helpful for diagnosing SAH, particularly when CT is normal, and in indicating aneurysm location as well as rupture site.     

Subarachnoid hemorrhage without aneurysm

The rupture and bleeding of intracranial aneurysms is the most common cause of a spontaneous, non-traumatic subarachnoid hemorrhage (SAH). In up to 20% of these patients, no aneurysm is found, but the prognosis of these patients is known to be better than in those with aneurysms. The retrospective evaluation of the initial CT- and angiographic findings of 773 patients with spontaneous SAH, who underwent (up to three) 4-vessel DSA, brought a percentage of 12.4% with negative angiography. We found the favourable prognosis of these patients with negative angiography not only to be dependent from the distribution of the hemorrhage, with preference to perimesencephalic pattern, but the initial clinical state. 85% of our patients, who presented with perimesencephalic blood pattern and even 80% of those patients with additional intraventricular hemorrhage but the good clinical condition of Hunt-Hess I/II were discharged without neurological deficits. We recommend the obligatory 4-vessel catheter-angiography (DSA) in all patients with spontaneous SAH, independent of the blood pattern on initial CT, and one control in the presence of other than perimesencephalic subarachnoid hemorrhage, CTA might be reserved for additional controls.     

Coil embolization for the treatment of ruptured dissecting vertebral aneurysms

BACKGROUND AND PURPOSE: Proximal occlusion of the parent artery has been widely used for treatment of vertebral dissecting ruptured aneurysms, but this does not always completely prevent rerupture. We retrospectively studied 24 consecutive patients for clinical characteristics and/or for efficacy of occlusion with detachable coils at the site of dissection. METHODS: During a 45-month period, 24 of 242 patients with aneurysms associated with subarachnoid hemorrhage had dissecting vertebral aneurysms identified at angiography. Eighteen of the 24 patients were treated with platinum coil occlusion at the affected site as early as possible after diagnosis, two patients were treated conservatively, and four others were not eligible for treatment owing to intractable elevation of intracerebral pressure and severe brain stem dysfunction. RESULTS: The rate of aneurysmal rupture in the posterior fossa was high, at 56 (23%) of the 242 aneurysms, including 24 (10%) vertebral dissecting aneurysms. Subsequent rupture occurred in 14 (58%) of the patients, all within 24 hours after the first attack and three during transportation to the hospital. In all 18 patients, coil embolization at the affected site was successful, with no complications. Radiologic findings showed complete occlusion of the dissection site and patency of the unaffected artery (mean follow-up, 9 months). Among the six patients who did not undergo embolization, only one survived with a good outcome, the others died of repeat hemorrhage. CONCLUSION: A high rate of vertebral artery dissecting aneurysms may be expected in patients with subarachnoid hemorrhage, especially in those with early repeat hemorrhage. Detachable platinum coil embolization may be more effective than proximal occlusion for treatment of ruptured vertebral dissecting aneurysms because of immediate cessation of blood flow to the dissection site; however, in patients with bilateral dissections or hypoplastic contralateral vertebral arteries, prior bypass surgery orstent placement to preserve the artery will be needed.     

Rupture during treatment of recently ruptured aneurysms with Guglielmi electrodetachable coils.

BACKGROUND AND PURPOSEWe describe four cases of aneurysmal rupture during embolization with Guglielmi electrodetachable coils (GDCs) in an attempt to identify those aneurysms whose rupture during embolization represents a life-threatening risk; our emphasis is on emergency management, in particular, ventriculostomy.METHODSMedical records were reviewed retrospectively for 91 aneurysms treated with GDCs 0 to 21 days after subarachnoid hemorrhage. Rupture was ascertained by the presence of extravascular effusion of contrast medium.RESULTSOf the perforated aneurysms, two involved the anterior communicating artery, one the posterior inferior communicating artery, and one the basilar artery. Only two patients, whose aneurysms were located in the posterior fossa, had major complications (arterial hyperpressure, mydriasis, angiographically documented circulatory arrest or slowing). One of these patients died and the other improved after emergency ventriculostomy.CONCLUSIONAneurysmal perforation during embolization may be accompanied by severe intracranial hypertension, which causes either a decrease or arrest of cerebral perfusion, the duration of which determines clinical outcome. Emergency ventriculostomy (which should be performed in the angiographic suite) is an effective means to reduce intracranial pressure. Recognition of aneurysms associated with a high risk of mortality by rupture in the course of embolization (recently ruptured small aneurysms, posterior fossa aneurysms, associated ventricular dilatation, massive cisternal hemorrhage) and use of proper logistics should ensure the effective management of this devastating complication.     

MRI in cerebral intraventricular hemorrhage: analysis of 50 consecutive cases

MRI of intraventricular haemorrhage (IVH) has not been studied formally. We aimed to describe the degradation rate and patterns shown on 1.5 T MRI in IVH, comparing them to other coexisting brain hemorrhage. We studied 50 consecutive cases using T1-, proton-density, and T2-weighted images. IVH was seen in two forms: layered (free-flowing in ventricles) (37 cases) and/or clotted (31). Both were best shown by proton-density image. Layered IVH was seen in the dependent portions of the lateral ventricles with fluid (“blood-CSF”) levels, degrading more slowly than both clotted IVH and intraparenchymal hemorrhages (IPH) (acute blood products persisting for several more days; P < 0.05). Clotted IVH degraded at a rate comparable to IPH. IVH cleared rapidly and did not form hemosiderin. Subarachnoid hemorrhage (SAH) cleared faster and was less conspicuous than IVH. Hypertensive (22), aneurysmal (11), traumatic (2), idiopathic (9), or vascular malformation-related (6) IVH were seen. IVH coexisted with IPH (30) or SAH (12), or both (12). The high rate of layering with blood-CSF levels in IVH is most likely due to different densities of blood components and CSF and the fibrinolytic capability of the latter. Delayed degradation of layered IVH probably reflects high intra-ventricular oxygen and glucose content. Further study is necessary to determine if MRI characteristics of IVH are helpful in excluding other intraventricular diseases such as neoplasia and pyocephalus. Received: 16 September 1998 Accepted: 1 December 1998     

Treatment of unruptured aneurysms with GDCs: clinical experience with 247 aneurysms

BACKGROUND AND PURPOSE: The GDC system is a valuable therapeutic alternative to surgical treatment of intracranial aneurysms. We present our clinical experience with the GDC technique used to treat unruptured cerebral aneurysms. METHODS: This is a retrospective review of 217 patients with 247 unruptured intracranial aneurysms who underwent embolization with GDCs between August 1991 and June 2000. One hundred sixty-seven of the 217 were female patients. Patient age ranged from 13 to 83 years. In 118 patients, the aneurysms were found when unrelated non-neurologic conditions indicated angiography, CT angiography, or MR angiography (group 1). Fifty-one patients with mass effect symptoms comprised group 2, 12 patients with aneurysms associated with arteriovenous malformations or tumors of the brain comprised group 3, 17 patients with unruptured aneurysms treated during the chronic phase of subarachnoid hemorrhage (SAH) comprised group 4, and 19 patients treated during the acute phase of SAH due to another ruptured aneurysm comprised group 5. RESULTS: Angiographic results revealed complete occlusion in 138 of 247 aneurysms (55.9%), neck remnants in 92 (37.2%), and incomplete occlusion in three (1.2%). GDC embolization was attempted unsuccessfully in 14 aneurysms (5.7%). Of the 198 patients without acute SAH (groups 1-4), 186 (93.9%) of 198 remained neurologically unchanged. Eleven of the 217 patients (5.1%) experienced neurologic deterioration caused by immediate procedural complications. One patient died (0.5%) as a result of aneurysmal rupture during embolization. For asymptomatic patients and those treated after the chronic period of SAH, the mean hospitalization stay was 2.9 days. CONCLUSION: GDC technology constitutes safe treatment for unruptured aneurysms, with successful anatomic and clinical results and low complication rates achieved.     

Pseudoaneurysm of the anterior spinal artery in a patient with Moyamoya: an unusual cause of subarachnoid hemorrhage

Subarachnoid hemorrhage (SAH) is a recognized presentation of Moyamoya disease in adults. Because there are extensive collateral networks and potential complications that develop, a thorough investigation of the intracranial and extracranial circulation is necessary to exclude a treatable cause when these patients present with SAH. We present a case of SAH due to a ruptured pseudoaneurysm of the anterior spinal artery arising from the supreme intercostal artery, which was the sole source of blood supply to the intracranial circulation.     

Solitary spinal artery aneurysms as a rare source of spinal subarachnoid hemorrhage: potential etiology and treatment strategy

Solitary aneurysms of spinal arteries lacking associated vascular malformations are rare. We report three patients with spinal subarachnoid hemorrhage (SAH) due to rupture of such aneurysms, which regressed spontaneously, as confirmed on conventional angiography. One patient had spinal SAH with presumed spontaneous dissection of a segmental artery. In the other two, SAH resulted from ruptured fusiform aneurysms of the artery of Adamkiewicz immediately proximal to the anterior spinal artery. Solitary aneurysms of the spinal arteries appear to be etiopathologic entities completely different from intracranial aneurysms. Spontaneous occlusion seems to be common, justifying a wait-and-see strategy rather than urgent treatment.     

Primary treatment of ruptured blood blister-like aneurysms with stent-assisted coil embolization: report of two cases

Blood blister-like aneurysms (BBAs) are among the most hazardous cerebrovascular aneurysms to treat; microsurgical treatment of these small, wide-necked, and exceptionally fragile aneurysms place patients at significant risk of morbidity or mortality. We report two cases of ruptured BBAs attempted to be treated for the first time with stent-assisted coil embolization solely and review the current literature on treatment options. Our patients underwent stent-assisted coil embolization of the aneurysms in the acute stage of subarachnoid hemorrhage (SAH). One patient was successfully treated without procedure-related complications. The other patient died after surgical internal carotid artery (ICA) occlusion, carried out after intraoperative rerupture of the aneurysm during the endovascular treatment. In the successful case, 8-month and 19-month follow-up angiograms demonstrated incomplete (>90%) occlusion with residual filling of the aneurysm neck, which did not need additional coil embolization. Even though stent-assisted coil embolization of ruptured BBAs in the acute stage appears to be a technically feasible treatment option, the present stent-related endovascular technology has potentially hazardous drawbacks.     

Computed tomographic diagnosis of intraventricular hemorrhage. Etiology and prognosis

Sixty-eight patients with intraventricular hemorrhage (IVH) diagnosed by computed tomography (CT) were reviewed retrospectively to determine the etiology and prognosis, relationship to delayed hydrocephalus, and effect on neurological outcome. The most common causes were a ruptured aneurysm, trauma, and hypertensive hemorrhage. Ruptured aneurysms of the anterior communicating artery can often be predicted from the nonenhanced CT scan. The total mortality rate was 50%; however, 21% of patients returned to normal or had only mild disability. Patients in whom no cause was identified had a better prognosis. Delayed hydrocephalus was related to the effects of subarachnoid hemorrhage rather than obstruction of the ventricular system by blood. IVH per se is seldom a major factor in the neurological outcome.     

Posterior fossa hemorrhage after supratentorial surgery.

PURPOSETo evaluate the imaging findings, possible pathogenesis, and frequency of hemorrhage near the tentorial surface of the cerebellum after supratentorial surgery.METHODSOver a 5-year period, 13 patients with posterior fossa hemorrhage after supratentorial surgery were identified with postoperative CT studies, which were obtained in all patients after craniotomy. Four of the 13 patients also had postoperative MR examinations. Preoperative and postoperative radiologic studies and medical records were reviewed.RESULTSAll hemorrhages were located along the superior aspect of the cerebellum transversely oriented along the cerebellar fossa and fissures. None of the patients had coagulopathy or radiologic evidence of posterior fossa tumor or vascular malformation. None of the hemorrhages had an appearance typical of hypertensive hemorrhage. Ten patients (77%) had lumbar drains placed before surgery and all had epidural drains placed at the conclusion of surgery. One patient had surgery for a meningioma, and 12 had surgery for aneurysms. The frequency of hemorrhage after aneurysmal surgery was 3.5%. No neurologic deficits developed referable to the cerebellum.CONCLUSIONSHemorrhage should be viewed as a potentially benign sequela of surgery rather than as an indication of hypertension, aneurysm, or previously unrecognized vascular malformation or neoplasm.     

Neuroform支架辅助弹簧圈填塞治疗颅内宽颈动脉瘤

目的 探讨 Neuroform支架辅助弹簧圈填塞治疗颅内宽颈动脉瘤的技术,并评价临床疗效和并发症.方法 采用Neuroform支架辅助技术对31例颅内宽颈动脉瘤进行了弹簧圈填塞治疗.31例患者共有颅内动脉瘤43枚,均为破裂动脉瘤,其中39枚为宽颈动脉瘤,21枚颈:体≥1,18枚颈:体<1;4枚为宽颈动脉瘤患者合并的非宽颈动脉瘤.结果 31例患者共置入支架35枚,其中3例患者两侧颈内动脉各置入1枚支架,1例两侧大脑中动脉各置入1枚.43枚动脉瘤中41枚进行了不同程度的填塞,2枚末行填塞.2例宽颈动脉瘤患者置入支架后出现非动脉瘤破裂性出血,均可能由于输送导丝损伤大脑中动脉分支引起;1例后交通动脉瘤患者,弹簧圈飘至大脑中动脉M2段,引起相应脑缺血症状.获随访的29例中无死亡病例和再次出血病例,28例生存良好,1例留有明显神经功能障碍.结论 支架辅助技术进行弹簧圈填塞治疗颅内宽颈动脉瘤是安全、有效的临床技术,可以拓宽颅内动脉瘤治疗的适应证.     

Endovascular treatment of posterior cerebral artery aneurysms

BACKGROUND AND PURPOSE: The purpose of this study was to report the incidence, clinical presentation, endovascular treatment, and outcome of aneurysms of the posterior cerebral artery (PCA). PATIENTS AND METHODS: Among 1880 aneurysms treated between January 1995 and January 2005, 22 aneurysms (1.2%) in 22 patients were located on the PCA. Ten patients presented with subarachnoid hemorrhage (SAH) from the PCA aneurysm: 2 of these patients had additional visual field deficits and 2 had additional occulomotor palsy. One patient presented with acute occulomotor palsy only. Eleven PCA aneurysms were unruptured: 9 were additional to another ruptured aneurysm and 2 were incidentally discovered. Three aneurysms were >15 mm and the other 19 aneurysms were < or = 8 mm. Eighteen aneurysms were saccular, 2 were fusiform, one was dissecting, and one was mycotic. RESULTS: All aneurysms were successfully treated, 17 with selective occlusion of the aneurysm with coils and 5 with simultaneous occlusion of the aneurysm and parent PCA with coils. There were no complications of treatment. Two patients died of sequelae of SAH shortly after treatment. One patient died 2 months after coiling of an unruptured P1 aneurysm with intramural thrombus of SAH from the same aneurysm. One patient had persistent hemianopsia. In 2 patients with intact visual field in which the parent PCA was occluded, no hemianopsia developed due to sufficient leptomeningeal collateral circulation. CONCLUSION: Aneurysms of the PCA are rare with an incidence in our practice of 1.2% of all types of aneurysms. Clinical presentation is variable with SAH, occulomotor palsy, visual field deficit or a combination. Endovascular treatment with either selective occlusion of the aneurysm or occlusion of the aneurysm together with the parent artery with coils is safe and effective with good clinical results.     

Zerebrales Aneurysma bei einem 10-jährigen Mädchen

Subarachnoid hemorrhages are usually caused by congenital or degenerative aneurysms of the circulus arteriosus cerebri. Subarachnoid hemorrhaging reaches a peak at the age of 50 so that an unexpected subarachnoid hemorrhage in childhood can cause diagnostic problems. The case of a 10-year-old girl who died after a medical examination for severe headache and vomiting without signs of irritation of the meninges (meningism) is reported. The forensic autopsy revealed a giant aneurysm of the posterior cerebral artery with intracerebral haemorrhaging and infiltration of the ventricular system. The lacking signs of meningism could be explained by the weakly expressed subarachnoid haemorrhage. Only 1–2% of all symptomatic intracerebral aneurysms occur in patients under 18 years and the posterior cerebral artery is commonly affected (48%).     

Fatal subarachnoid hemorrhage caused by rupture of variant anterior communicating artery: a case report and literature review

Fatal subarachnoid hemorrhage (SAH) caused by anterior communicating artery (ACoA) rupture is a rare event in medicolegal practice. Anatomical variations of the ACoA tend to make its anatomical structure, and as a result, blood flow through it, more complicated, which may increase hemodynamic stress and cause weak spots in the affected blood vessels. Variant ACoAs are prone to rupture in the event of a blunt-force trauma. Here, we report a fatal case of SAH caused by the rupture of a variant ACoA when the victim’s head was struck from behind, causing the head to rotate and the victim to fall forward onto the ground. A medicolegal autopsy revealed diffuse basal SAH and ACoA duplication. The smaller of the two variant ACoA branches had ruptured near its junction with the right anterior cerebral artery. No basal aneurysms or other fatal diseases or injuries were found. This case highlights the significance of anatomical variation in forensic pathology.     

Fluid-attenuated inversion-recovery MR imaging in acute and subacute cerebral intraventricular hemorrhage.

BACKGROUND AND PURPOSE: Fluid-attenuated inversion-recovery (FLAIR) MR imaging may show subarachnoid hemorrhage (SAH) with high sensitivity. We hypothesized that the FLAIR technique is effective and reliable in the diagnosis of cerebral intraventricular hemorrhage (IVH). METHODS: Two observers evaluated the 1.5-T MR fast spin-echo FLAIR images, T1- and T2-weighted MR images, and CT scans of 13 patients with IVH and the FLAIR images of 40 control subjects. RESULTS: IVH appeared bright on the FLAIR images obtained during the first 48 hours and was of variable appearance at later stages. FLAIR MR imaging detected 12 of 13 cases of IVH; no control subjects were falsely thought to have IVH (92% sensitivity, 100% specificity). However, IVH could not be fully excluded in the third ventricle (20%, n = 8) or in the fourth ventricle (28%, n = 11) on some control images because of CSF pulsation artifacts. Two cases had CT-negative IVH seen on FLAIR images. One case had FLAIR-negative IVH seen by CT. Although the sensitivities of conventional MR imaging (92%) and CT (85%) were also high, FLAIR imaging showed IVH more conspicuously than did standard MR imaging and CT in 62% of the cases (n = 8). FLAIR was as good as or better than CT in showing IVH in 10 cases (77%). FLAIR images showed all coexisting SAH. CONCLUSION: FLAIR MR imaging identifies acute and subacute IVH in the lateral ventricles with high sensitivity and specificity. In cases of subacute IVH, conventional MR imaging complements FLAIR in detecting IVH. The usefulness of the FLAIR technique for detecting third and fourth ventricular IVH may be compromised by artifacts. Blood hemoglobin degradation most likely causes the variable FLAIR appearance of IVH after the first 48 hours.     

16层螺旋CT血管造影在颅内动脉瘤破裂中的临床应用

目的通过与DSA和手术对照,探讨16层螺旋CT血管造影（CTA）在颅内动脉瘤破裂的临床应用价值。资料与方法对33例动脉瘤性蛛网膜下腔出血（SAH）、脑出血患者进行回顾性分析,33例均使用16层螺旋CT进行了CTA检查,其中18例行DSA检查;6例DSA下介入治疗,27例开颅行动脉瘤颈夹闭术;将CTA与DSA和术中所见对照。结果33例中,CTA共发现动脉瘤36个,其中18例行DSA检查者中,CTA发现动脉瘤20个,DSA发现动脉瘤21个;CTA能够清晰显示动脉瘤瘤体（形态、指向、轮廓）、瘤颈的宽度、载瘤动脉及与颅骨之间的关系;与DSA和手术对照,CTA对动脉瘤的检出率为95．2％,对破裂动脉瘤的诊断敏感性和特异性均为100％。结论16层螺旋CT脑血管造影重组图像质量高,安全、快速、无创,可以作为颅内动脉瘤破裂首选的筛检方法。     

Clearing of red blood cells in lumbar puncture does not rule out ruptured aneurysm in patients with suspected subarachnoid hemorrhage but negative head CT findings

BACKGROUND AND PURPOSE: In evaluating the results of lumbar puncture (LP), a decrease in the number of red blood cells (RBCs)/mm3 between the first and fourth tubes collected (clearing) has often been assumed to indicate a traumatic puncture rather than the presence of subarachnoid hemorrhage (SAH). We tested the hypothesis that, in the setting of severe headache, CSF clearing coupled with an unremarkable unenhanced CT scan was negatively predictive of the presence of aneurysm and could be used to reduce the need for conventional arteriography. METHODS: Cerebral angiography was performed to evaluate suspected SAH in 123 consecutive patients over 2 years at a university teaching hospital. Records of these patients were reviewed. Among the subset without SAH on CT scan, LP results were evaluated for clearing. Clearing was arbitrarily defined as a 25% reduction in RBCs between the first and fourth tubes. This subset's records were also reviewed for the presence of aneurysm at cerebral angiography or at follow-up 6 weeks later. Data were analyzed for correlation between clearing and aneurysm. RESULTS: Of the 123 patients whose records were reviewed, 22 did not show an SAH on CT scan. Of those 22 patients, eight had aneurysm at angiography and 14 did not. Clinical diagnoses in the other 14 included trauma, herpes meningitis, sickle cell disease, and cocaine use. CSF clearing was noted in 25% of those with an aneurysm (two of 8) and 21% of those without an aneurysm (three of 14). In the two cases with aneurysms, RBCs cleared from 3550 to 2550 (-28%) and from 24,686 to 17,842 (-28%), respectively. In the remaining six cases with aneurysms, RBCs increased a mean of 1370% between the first and fourth tubes (range, -22% to 7700%). Two of these six had a reduction that did not meet our criteria for clearing (-22% and -5.3%, respectively). In the 14 cases without aneurysms, RBCs increased a mean of 70% between the first and fourth tubes (range, -99% to 895%). In addition to the three of these 14 that met our criteria for clearing (-99%, -99%, and -43%), four cases had a reduction that did not (range, -0.7% to -14%). CONCLUSION: A 25% reduction in RBC concentration between the first and fourth tubes of CSF in patients with suspected SAH but negative CT findings occurs even in cases of ruptured aneurysms. Formal evaluation for the presence of an aneurysm is still necessary in this scenario.