U.S. Wingspan Registry: 12-month follow-up results.

BACKGROUND AND PURPOSE: The purpose of this study is to present 12-month follow-up results for a series of patients undergoing percutaneous transluminal angioplasty and stenting with the Gateway-Wingspan stenting system (Boston Scientific) for the treatment of symptomatic intracranial atherostenosis. METHODS: Clinical and angiographic follow-up results were recorded for patients from 5 participating institutions. Primary end points were stroke or death within 30 days of the stenting procedure or ipsilateral stroke after 30 days. RESULTS: During a 21-month study period, 158 patients with 168 intracranial atherostenotic lesions (50% to 99%) were treated with the Gateway-Wingspan system. The average follow-up duration was 14.2 months with 143 patients having at least 3 months of clinical follow-up and 110 having at least 12 months. The cumulative rate of the primary end point was 15.7% for all patients and 13.9% for patients with high-grade (70% to 99%) stenosis. Of 13 ipsilateral strokes occurring after 30 days, 3 resulted in death. Of these strokes, 76.9% (10 of 13) occurred within the first 6 months of the stenting procedure and no events were recorded after 12 months. An additional 9 patients experienced ipsilateral transient ischemic attack after 30 days. Most postprocedural events (86%) could be attributed to interruption of antiplatelet medications (n=6), in-stent restenosis (n=12), or both (n=1). In 3 patients, the events were of uncertain etiology. CONCLUSIONS: After successful Wingspan percutaneous transluminal angioplasty and stenting, some patients continued to experience ipsilateral ischemic events. Most of these ischemic events occurred within 6 months of the procedure and were associated with the interruption of antiplatelet therapy or in-stent restenosis.

Symptomatic delayed reocclusion after initial successful revascularization in acute ischemic stroke.

BACKGROUND: Endovascular stroke therapy is used for patients with ischemic stroke after failed intravenous thrombolysis or in patients not eligible for thrombolytics. With increasing experience, acute reocclusion has been described and likely worsens clinical outcomes. We assessed the rates and outcomes of delayed symptomatic reocclusion after endovascular therapy for acute ischemic stroke. METHODS: Patients with acute ischemic stroke undergoing endovascular procedures at out institutions from January 2008 to August 2008 were reviewed. In all, 107 consecutive acute stroke interventions were performed. Four patients (3.5%) experienced delayed symptomatic reocclusion detectable by the National Institutes of Health Stroke Scale (NIHSS). RESULTS: The 4 patients (age 45-79 years) had baseline NIHSS score ranging from 8 to 24. Three had right middle cerebral artery occlusions and one had a left middle cerebral artery occlusion. Successful recanalization (thrombolysis in myocardial infarction score 2-3) occurred in all cases after initial treatment. All patients improved postprocedure (NIHSS score 5-10). Clinical deterioration (NIHSS score 14-22) occurred 12 to 18 hours postprocedure. Successful recanalization was achieved in each patient, with improvement in NIHSS score (range 6-13) but not to a lower level compared with after the initial intervention. CONCLUSIONS: Delayed symptomatic reocclusion after initial endovascular stroke therapy can lead to sudden clinical deterioration and impact outcomes. The entity may be missed as many patients present with large clinical deficits at presentation thus requiring careful assessments of patients treated via endovascular methods.

Spinal Dural Arteriovenous Fistula: Diagnosis, Outcomes, and Prognostic Factors.

OBJECTIVE: Typically, the clinical presentation of a spinal dural arteriovenous fistula (SDAVF) will be insidious, with patients' symptoms regularly attributed to other conditions. Although previous studies have characterized the neurologic outcomes after treatment for SDAVFs, little is known about the pretreatment patient characteristics associated with poor and/or positive patient outcomes. We sought to characterize the pretreatment patient demographics, diagnostic history, and neurologic outcomes of patients treated for SDAVFs and to identify the patient factors predictive of these outcomes. METHODS: The medical records of patients who had been treated for SDAVFs from 2006 to 2018 across 1 healthcare system were retrospectively analyzed. Neurologic status was assessed both before and after intervention using the Aminoff-Logue scales for gait and micturition disturbances. RESULTS: Of 46 total patients, 16 (35%) had a documented misdiagnosis. Patients with a history of misdiagnosis had had a significantly longer symptom duration before treatment compared with those without a misdiagnosis (median, 2.3 vs. 0.9 years; P = 0.018). A shorter symptom duration before intervention was significantly associated with both improved motor function (median, 0.8 vs. 3.1 years; P = 0.001) and improved urinary function (median, 0.8 vs. 2.2 years; P = 0.040) after intervention. CONCLUSIONS: Misdiagnosis has been relatively common in patients with SDAVFs and contributes to delays in treatment. Delays in diagnosis and treatment of SDAVFs appear to be associated with worse clinical outcomes for patients who, ultimately, receive treatment.

Mechanical thrombectomy for acute stroke with the alligator retrieval device.

BACKGROUND AND PURPOSE: Recanalization of occluded vessels in acute ischemic stroke is associated with improved outcome. Devices that can quickly and safely remove thrombus and promote recanalization are useful in the management of these patients. The Alligator retrieval device, developed for endovascular foreign body retrieval, may also be useful for thrombus removal. METHODS: Seven patients with acute ischemic stroke (aged 31 to 88 years) who underwent intra-arterial therapy with the Alligator retrieval device at our center are presented. RESULTS: The Alligator retrieval device was able to retrieve the thrombus in 5 of 7 cases with good to excellent recanalization seen and was unsuccessful in 2 of 7 patients. Complete recanalization was obtained in one of 7 patients and near complete recanalization obtained in 4 of 7 patients. Three of the 7 patients had good outcome at 3 months and 3 of 7 patients died within 30 days of treatment. CONCLUSIONS: The Alligator retrieval device was successfully able to remove thrombus in the majority of cases. It appears to have increased success in proximal occlusions in relatively straight segments. In properly selected cases, it may be a useful device in intra-arterial stroke management.

Target lesion revascularization after wingspan: assessment of safety and durability.

BACKGROUND AND PURPOSE: In-stent restenosis (ISR) occurs in approximately one-third of patients after the percutaneous transluminal angioplasty and stenting of intracranial atherosclerotic lesions with the Wingspan system. We review our experience with target lesion revascularization (TLR) for ISR after Wingspan treatment. METHODS: Clinical and angiographic follow-up results were recorded for all patients from 5 participating institutions in our US Wingspan Registry. ISR was defined as >50% stenosis within or immediately adjacent (within 5 mm) to the implanted stent and >20% absolute luminal loss. RESULTS: To date, 36 patients in the registry have experienced ISR after percutaneous transluminal angioplasty and stenting with Wingspan. Of these patients, 29 (80.6%) have undergone TLR with either angioplasty alone (n=26) or angioplasty with restenting (n=3). Restenting was performed for in-stent dissections that occurred after the initial angioplasty. Of the 29 patients undergoing TLR, 9 required >/=1 interventions for recurrent ISR, for a total of 42 interventions. One major complication, a postprocedural reperfusion hemorrhage, was encountered in the periprocedural period (2.4% per procedure; 3.5% per patient). Angiographic follow-up is available for 22 of 29 patients after TLR. Eleven of 22 (50%) demonstrated recurrent ISR at follow-up angiography. Nine patients have undergone multiple retreatments (2 retreatments, n=6; 3 retreatments, n=2; 4 retreatments, n=1) for recurrent ISR. Nine of 11 recurrent ISR lesions were located within the anterior circulation. The mean age for patients with recurrent anterior circulation ISR was 57.9 years (vs 81 years for posterior circulation ISR). CONCLUSIONS: TLR can be performed for the treatment of intracranial Wingspan ISR with a relatively high degree of safety. However, the TLR results are not durable in approximately 50% of patients, and multiple revascularization procedures may be required in this subgroup.

Early post-Humanitarian Device Exemption experience with the Neuroform Atlas stent.

INTRODUCTION: The low-profile Neuroform Atlas stent received FDA Humanitarian Device Exemption status (HDE) in January 2018 for stent-assisted coil embolization of wide-necked saccular aneurysms. We review and report our results with the Atlas stent in our institution within the first year after its HDE approval. METHODS: Our retrospective chart review identified patients treated with the Atlas stent. We analyzed the patient demographics, aneurysm characteristics, stent parameters and configuration, complications, angiographic, and clinical outcomes at discharge. RESULTS: From January to December 2018, 76 Atlas stents were deployed in 58 patients (average 1.3 stents/patient). Median patient age was 63.5 (IQR 56-71) years. Fifty-six (96.6%) patients had elective embolization of unruptured aneurysms, while two (3.4%) patients underwent embolization of a ruptured aneurysm within 2 weeks of subarachnoid hemorrhage. Forty (69.0%) patients were treated with a single stent, 15 (25.9%) with a Y-stent, and three (5.2%) with X-stent configuration. All stent deployments were technically successful. Most stents (82.9%) were the smallest 3 mm diameter devices. Procedural complications included transient stent-associated thrombosis in three (5.2%) patients and aneurysm rupture in one (1.7%). None had distal embolization, associated cerebral infarction, or permanent neurological deficits. Immediate Raymond-Roy 1 occlusion was achieved in 41 (70.7%) patients. Median hospital length of stay for elective aneurysm embolization was 1 day. Excellent outcomes with median National Institute of Health Stroke Scale score 0 (IQR 0-0) and modified Rankin Score 0 (IQR 0-1) were seen for elective patients at discharge. CONCLUSION: The Neuroform Atlas stent provided a reliable technical and safety profile for the treatment of intracranial wide-neck aneurysms. Further experience is needed to determine long-term durability and safety of this device.

US multicenter experience with the wingspan stent system for the treatment of intracranial atheromatous disease: periprocedural results.

BACKGROUND AND PURPOSE: The current report details our initial periprocedural experience with Wingspan (Boston Scientific/Target), the first self-expanding stent system designed for the treatment of intracranial atheromatous disease. METHODS: All patients undergoing angioplasty and stenting with the Gateway balloon-Wingspan stent system were prospectively tracked. RESULTS: During a 9-month period, treatment with the stent system was attempted in 78 patients (average age, 63.6 years; 33 women) with 82 intracranial atheromatous lesions, of which 54 were > or =70% stenotic. Eighty-one of 82 lesions were successfully stented (98.8%) during the first treatment session. In 1 case, the stent could not be delivered across the lesion; the patient was treated solely with angioplasty and stented at a later date. Lesions treated involved the internal carotid (n=32; 8 petrous, 10 cavernous, 11 supraclinoid segment, 3 terminus), vertebral (n=14; V4 segment), basilar (n=14), and middle cerebral (n=22) arteries. Mean+/-SD pretreatment stenosis was 74.6+/-13.9%, improving to 43.5+/-18.1% after balloon angioplasty and to 27.2+/-16.7% after stent placement. Of the 82 lesions treated, there were 5 (6.1%) major periprocedural neurological complications, 4 of which ultimately led to patient death within 30 days of the procedure. CONCLUSIONS: Angioplasty and stenting for symptomatic intracranial atheromatous disease can be performed with the Gateway balloon-Wingspan stent system with a high rate of technical success and acceptable periprocedural morbidity. Our initial experience indicates that this procedure represents a viable treatment option for this patient population.

Long-term Follow-up of In-stent Stenosis After Pipeline Flow Diversion Treatment of Intracranial Aneurysms.

BACKGROUND: There is scant information on in-stent stenosis after flow diversion treatment of intracranial aneurysms with the Pipeline Embolization Device (PED). OBJECTIVE: To assess the incidence, severity, nature, and clinical consequences of in-stent stenosis on angiographic follow-up after treatment with the PED. METHODS: A retrospective study of patients who underwent aneurysm treatment with the PED was conducted. In-stent stenosis was assessed on subsequent follow-up angiography. Intimal hyperplasia was defined as a uniform growth process beyond the limits of the metallic mesh at <25%. In-stent stenosis represented an area of parent vessel narrowing, most often focal, graded as mild (25%-50%), moderate (50%-75%), or severe (>75%). RESULTS: Between June 2011 and April 2015, 80 patients were treated with the PED. Angiographic follow-up was available for 51 patients (representing 76% of available or 64% of all patients). Mean follow-up was 12.5 months. In-stent stenosis was detected in 5 patients (9.8%) at a median of 6 months. Stenosis was mild in 4 of 5 (80%) and moderate in 1 of 5 (20%) patients. There were no cases of severe stenosis. No stenosis caused flow limitation, clinical symptoms, or required re-treatment. Additional follow-up angiography was available in 2 of 5 stenosis patients showing marked improvement. Sixteen patients (31%) had intimal hyperplasia, and 28 patients (55%) had no stenosis. Asymptomatic stent occlusion occurred in 2 patients (4%) related to medication noncompliance. CONCLUSION: Treatment with the PED was associated with a 9.8% rate of in-stent stenosis, detected on first angiographic follow-up, at a median of 6 months. None were symptomatic or required re-treatment, and they showed significant improvement on follow-up. ABBREVIATION: FD, flow diverter.

Stent-assisted angioplasty of intracranial vertebrobasilar atherosclerosis: midterm analysis of clinical and radiologic predictors of neurological morbidity and mortality.

BACKGROUND AND PURPOSE: Initial reports of stent-assisted angioplasty for intracranial vertebrobasilar atherosclerosis suggest this is a feasible treatment, but there have been little data regarding predictors of success or failure. We analyzed a series of patients for independent predictors of neurologic morbidity and mortality. METHODS: Patient charts and angiograms from 39 patients who underwent intracranial angioplasty and stent placement of vertebrobasilar stenoses were retrospectively reviewed to obtain clinical and detailed angiographic data on potential predictors of neurologic morbidity and mortality. Univariate analyses of these predictors were performed with either Fisher's exact test or simple logistic regression. Multivariate analysis was subsequently performed on the statistically significant predictors. RESULTS: Complete clinical data were obtained for 39 patients, and angiographic review was possible for 35 of them. Angiography revealed severe intracranial vertebral (n = 18), basilar (n = 15), or basilar and vertebral (n = 2) stenoses. Two patients (5.1%) died in the periprocedural period, nine patients (23.1%) had neurologic complications, and one patient (2.6%) had transient neurologic symptoms. Univariate analysis revealed female sex, diabetes, and failure of coumadin or heparin therapy were associated with neurologic morbidity, whereas female sex, Mori B lesion, and length-to-stenosis ratio were associated with mortality. The presence of diabetes was the only independent predictor of neurologic morbidity and mortality. CONCLUSION: Because of the limited number of patients available for analysis, the only independent predictor of neurologic morbidity and mortality was diabetes, but several other predictors showed trends that deserve further review in future series.

Optical coherence tomography: a new method to assess aneurysm healing.

OBJECT: Aneurysmal subarachnoid hemorrhage affects approximately 10/100,000 people per year. Endovascular coil embolization is used increasingly to treat cerebral aneurysms and its safety and durability is rapidly developing. The long-term durability of coil embolization of cerebral aneurysms remains in question; patients treated using this modality require multiple follow-up angiography studies and occasional repeated treatments. METHODS: Optical coherence tomography (OCT) is an emerging imaging modality that uses backscattered light to produce high-resolution tomography of optically accessible biological tissues such as the eye, luminal surface of blood vessels, and gastrointestinal tract. Vascular OCT probes in the form of imaging microwires are presently available--although not Food and Drug Administration-approved--and may be adapted for use in the cerebral circulation. In this study the authors describe the initial use of OCT to make visible the neck of aneurysms created in a canine model and treated with coil embolization. Optical coherence tomography images demonstrate changes that correlate with the histological findings of healing at the aneurysm neck and thus may be capable of demonstrating human cerebral aneurysm healing. CONCLUSIONS: Optical coherence tomography may obviate the need for subsequent follow-up angiography studies as well as aid in the understanding of endovascular tissue healing. Data in this study demonstrate that further investigation of in vivo imaging with such probes is warranted.

Neurovascular rescue.

Neurovascular complications of carotid artery stenting (CAS) include intracranial embolism and hemorrhage, carotid dissection, in-stent thrombosis and vasospasm. Management of these crises requires knowledge of the intracranial vascular anatomy and collateral circulation, correct identification of the complication and its clinical implications, and a response plan that is appropriate to the complication and to the skill set of the operator. In this chapter the authors discuss techniques for the avoidance and management of CAS procedural complications.

Imaging in acute brain infarction.

Imaging in a patient suspected of having suffered an acute stroke is used primarily to clear the patient for thrombolytic therapy, by excluding intracranial hemorrhage and nonstroke causes of the patient's symptoms, within a critical 3-hour window. Noncontrast CT of the brain is the imaging test of choice for the initial evaluation of a patient with suspected acute ischemic stroke. It is rapid and readily available and has a high sensitivity for intracranial hemorrhage. Contrast-enhanced CT angiography and perfusion imaging may provide additional information with only a minimal increase in scanning time. Finally, diffusion-weighted magnetic resonance sequences have a high sensitivity for acute stroke and, with magnetic resonance perfusion imaging, may play an increasing role in the future treatment of stroke.

The location of pretreatment hyperdense middle cerebral artery sign predicts the outcome of intraarterial thrombectomy for acute stroke.

BACKGROUND AND PURPOSE: Intraarterial (IA) mechanical thrombectomy has an excellent recanalization rate but does not always correlate with good clinical outcomes. We aimed to investigate whether hyperdense middle cerebral artery sign (HMCAS) on preintervention nonenhanced CT (NECT) predicts IA therapy outcome for acute stroke. METHODS: Data were abstracted from our Hyperacute Ischemic Stroke database. Patients with occlusion in ICA, MCA, or MCA M2 branches who underwent IA therapy were included. RESULTS: Among 126 patients who underwent IA treatment, 64 (51%) had hyperdense M1 MCA sign (M1 HMCAS), 11 (9%) had hyperdense M2, and 51 (40%) had No HMCAS (NHMCAS).M1 HMCAS and NHMCAS group has comparable baseline stroke severity and infarct volume (P > .05); and the differences of favorable outcome (modified Rankin Score 0-2) at 30 days were not significant (21% vs. 30%, P = .259). For those with HMCAS, favorable 30-day outcome was most frequent in Distal HMCAS (39%), followed by hyperdense M2 (27%), HMCAS proximal (11%), and HMCAS full length (0%). CONCLUSIONS: For acute ischemic stroke due to large vessel occlusion, the lack of HMCAS on NECT does not predict favorable outcome after IA therapy. Among those with HMCAS, proximal and longer HMCAS predicts unfavorable outcome.

Aneurysm clips: evaluation of magnetic field interactions and translational attraction by use of "long-bore" and "short-bore" 3.0-T MR imaging systems.

BACKGROUND AND PURPOSE: The use of 3.0-T MR systems is increasing worldwide. We evaluated magnetic field interactions and translational attraction for 32 aneurysm clips in association with exposure to "long-bore" and "short-bore" 3.0-T MR imaging systems. METHODS: Thirty-two different aneurysm clips were evaluated in this investigation. Each aneurysm clip was qualitatively evaluated for magnetic field interactions and quantitatively assessed for translational attraction by using the deflection angle test. The deflection angle tests were performed at the points of the highest spatial gradients for long-bore and short-bore 3.0-T MR imaging systems. RESULTS: Seventeen of the 32 aneurysm clips showed positive magnetic field interactions. Deflection angles for the aneurysm clips were significantly (P <.001) higher on the short-bore (range, 0-18 degrees) compared with those recorded on the long-bore (range, 0-16 degrees) 3.0-T MR imaging system. Aneurysm clips made from commercially pure titanium and titanium alloy displayed no translational attraction (n = 15), whereas those made from stainless steel alloy, Phynox, and Elgiloy displayed positive deflection angles (n = 17). CONCLUSION: The 32 different aneurysm clips passed (angle <45 degrees) the deflection angle test by using the long- and short-bore 3.0-T MR imaging systems, indicating that they are safe for patients and other persons in these MR environments (ie, immediate area of MR imaging systems). However, only clips made from the titanium and titanium alloy are entirely safe for patients undergoing MR imaging procedures because of the total lack of magnetic field interactions. The remaining clips require characterization of magnetic field-induced torque. Because of possible differences in the points of the highest spatial gradients for different 3.0-T MR imaging systems, the results are specific to the imaging units and bore designs used in this investigation.

A novel endovascular treatment of a wide-necked basilar apex aneurysm by using a Y-configuration, double-stent technique.

Wide-necked bifurcation aneurysms remain a formidable challenge to the neuroendovascular surgeon. A 36-year-old woman with a wide-necked basilar bifurcation aneurysm was unsuccessfully treated by endovascular methods, despite the use of the balloon-remodeling technique. Successful coiling was ultimately achieved by use of a Y-configuration double stent-assisted technique. This novel method of using self-expanding stents may represent a significant advance in the management of basilar apex and other bifurcation aneurysms.

Outcome after the treatment of spinal dural arteriovenous fistulae: a contemporary single-institution series and meta-analysis.

OBJECTIVE: Spinal dural arteriovenous fistulae (Type I spinal AVMs) are the most common type of spinal vascular malformations. The optimal treatment strategy has yet to be defined, and endovascular embolization is being offered with increasing frequency. A 7-year single-institution retrospective review of outcome with surgical management of Type I spinal AVMs is presented along with a meta-analysis of existing literature. METHODS: For the institutional analysis, a retrospective review of all patients who underwent treatment at our institution for Type I spinal AVMs was performed. Between 1995 and the present (the time frame during which endovascular treatments were available), 19 consecutive patients were treated. Follow-up was performed by clinical examination or telephone interview, and functional status was measured by use of the Aminoff-Logue score. For the meta-analysis, a MEDLINE search between 1966 and the present was performed for surgical, endovascular, or combined treatment of spinal dural arteriovenous fistula. These series were included in a meta-analysis to evaluate success and failure rates, complications, and functional outcome. Specifically, embolization and microsurgery were compared. RESULTS: For the institutional analysis, 18 of 19 patients were available for long-term follow-up after surgery. There were no surgical failures, but one complication was seen. Patients demonstrated a statistically significant improvement in gait and bladder function after surgery. For the meta-analysis, 98% of those patients treated with microsurgery had their dural arteriovenous fistulae successfully obliterated after the initial treatment, compared with only 46% with embolization, as judged by radiographic or clinical follow-up. 89% percent of patients demonstrated improvement or stabilization in neurological symptoms after surgical treatment. Few complications were demonstrated with either surgery or embolization. CONCLUSION: At this point, surgery seems to be superior to embolization for the management of spinal dural arteriovenous fistula. The fistula is usually obliterated after the initial treatment, with few clinical or radiographic recurrences. The majority of patients either improve or stabilize after treatment. Few worsen, and the morbidity is minimal. It is reasonable to attempt initial embolization, especially at the time of the initial diagnostic spinal angiogram. The treating physicians and patients should be aware of the high chance of recurrence, and patients may ultimately require surgery or repeat embolization. After endovascular therapy, patients are committed to repeat angiography and probably embolization. For these reasons, it is the authors' opinion that surgery should be used as the first-line therapy for spinal dural arteriovenous fistulae.

A transcranial approach for direct mechanical thrombectomy of dural sinus thrombosis. Report of two cases.

Cerebral venous sinus thrombosis is often difficult to manage. Treatment options include systemically delivered anticoagulation therapy or chemical thrombolysis. Targeted endovascular delivery of thrombolytic agents is currently a popular option, but it carries an increased risk of hemorrhage. These strategies require significant time to produce thrombolysis, often in a patient with a rapidly deteriorating neurological condition. Rapid mechanical recanalization with thrombectomy is therefore very attractive; this procedure provides rapid recanalization with no increased risk of hemorrhage from use of thrombolytic agents. Nevertheless, the rheolytic catheter is large and stiff and may not be able to navigate tortuous intracranial vascular anatomy. The authors present their experience with direct dural sinus mechanical thrombectomy performed using the rheolytic catheter via a transcranial route. Two patients with dural sinus thrombosis and rapidly deteriorating levels of consciousness underwent unsuccessful attempts at mechanical thrombolysis via the usual transfemoral route. Through a burr hole over the dural sinus, mechanical thrombectomy was subsequently performed using the thrombectomy catheter. Sinus patency was restored following treatment and both patients demonstrated neurological recovery. Hemorrhage or a rapidly deteriorating neurological condition may preclude the use of systemic or locally delivered thrombolytic agents for the treatment of cerebral venous sinus thrombosis. Mechanical thrombectomy may be the treatment of choice in these circumstances. In patients with limited transfemoral access, a transcranial approach may be used to access the cerebral dural sinuses and thrombectomy may be safely and effectively performed. Further evaluation of this therapy is warranted.

Imaging of acute stroke: state of the art.

The high incidence of stroke, plus its fatal or debilitating outcome, has prompted tremendous advances over the last two decades on both diagnostic and therapeutic fronts. Multiple randomized trials have proven the utility of thrombolytic agents with rejuvenation of the role of diagnostic imaging. State of the art imaging (mainly computed tomography and magnetic resonance imaging) is crucial for patient selection (eg, excluding intracranial hemorrhage), diagnosis of stroke and prediction of prognosis. Here, we discuss the anatomic and physiologic changes due to an ischemic insult as manifested by modern imaging techniques, including diffusion and perfusion imaging, as well as demonstration of vascular disease by cross sectional angiography supplemented by three dimensional postprocessing. The main target of management is "Penumbra", or salvageable tissue, which is primarily dependent upon the expediency of the whole process, better expressed by the phrase "Time is Brain".

Diagnostic imaging for intracerebral hemorrhage.

Magnetic resonance imaging (MRI) is an excellent tool for the diagnosis and evaluation of intracerebral hemorrhage with its unique specificity to hemoglobin degradation products in different stages. Computed tomography (CT) remains the diagnostic test of choice in the setting of acute intracerebral hemorrhage because of its exquisite sensitivity and specificity for small amounts of intracerebral hemorrhage (although there is emerging evidence that MRI may be as sensitive as CT). The effects of the biochemical evolution of intracerebral hemorrhage on the temporal MRI signal changes are described. This article discusses imaging features of the common causes of intracerebral hemorrhage.

Optic nerve edema: complication of peripheral hemodialysis shunt.

Peripheral arteriovenous fistulas for hemodialysis can be complicated by infection, limb edema, venous thrombosis and stenosis, aneurysm, venous hypertension, and rarely, ophthalmic manifestations. We report an unusual case of unilateral optic nerve edema secondary to a contralateral peripheral hemodialysis shunt.