Diagnostic Accuracy of High-Resolution 3D T2-SPACE in Detecting Cerebral Venous Sinus Thrombosis.

BACKGROUND AND PURPOSE: Assessment of cerebral venous sinus thrombosis on MR imaging can be challenging. The aim of this study was to evaluate the diagnostic accuracy of high-resolution 3D T2 sampling perfection with application-optimized contrasts by using different flip angle evolution (SPACE) in patients with cerebral venous sinus thrombosis and to compare its performance with contrast-enhanced 3D T1-MPRAGE. MATERIALS AND METHODS: We performed a blinded retrospective analysis of T2-SPACE and contrast-enhanced MPRAGE sequences from patients with cerebral venous sinus thrombosis and a control group. The results were compared with a reference standard, which was based on all available sequences and clinical history. Subanalyses were performed according to the venous segment involved and the clinical stage of the thrombus. RESULTS: Sixty-three MR imaging examinations from 35 patients with cerebral venous sinus thrombosis and 51 examinations from 40 control subjects were included. The accuracy, sensitivity, and specificity calculated from the initial MR imaging examination for each patient were 100% each for T2-SPACE and 95%, 91%, and 98%, respectively, for contrast-enhanced MPRAGE. The interrater reliability was high for both sequences. In the subanalysis, the accuracy for each venous segment involved and if subdivided according to the clinical stage of thrombus was ≥95% and ≥85% for T2-SPACE and contrast-enhanced MPRAGE, respectively. CONCLUSIONS: Both T2-SPACE and contrast-enhanced MPRAGE offer high accuracy for the detection and exclusion of cerebral venous sinus thrombosis; however, T2-SPACE showed a better overall performance and thus could be a useful tool if included in a multiparametric MR imaging protocol for the diagnosis of cerebral venous sinus thrombosis, especially in scenarios where gadolinium administration is contraindicated.

First-line surgery in prolactinomas: lessons from a long-term follow-up study in a tertiary referral center.

CONTEXT: Although consensus guidelines recommend dopamine agonists (DAs) as the first-line approach in prolactinomas, some patients may opt instead for upfront surgery, with the goal of minimizing the need for continuation of DAs over the long term. While this approach can be recommended in selected patients with a microprolactinoma, the indication for upfront surgery in macroprolactinomas remains controversial, with limited long-term data in large cohorts. We aimed at elucidating whether first-line surgery is equally safe and effective for patients with micro- or macroprolactinomas not extending beyond the median carotid line (i.e., Knosp grade ≤ 1). METHODOLOGY: Retrospective study of patients with prolactinomas Knosp grade ≤ 1 treated with upfront surgery. The primary endpoint was patients' dependence on DAs at last follow-up. The secondary endpoint was postoperative complications. Independent risk factors for long-term dependence on DAs were analyzed. RESULTS: A microadenoma was noted in 45 patients (52%) and a macroadenoma in 41 (48%), with 17 (20%) harboring a Knosp grade 1 prolactinoma. Median follow-up was 80 months. First-line surgery resulted in long-term remission in 31 patients (72%) with a microprolactinoma and in 18 patients (45%) with a macroprolactinoma (p = 0.02). DA therapy was ultimately required in 11 patients (24%) with microadenomas vs. 20 (49%) with macroadenomas (p = 0.03). As for the latter, DA was required in 13 patients (76%) with Knosp grade 1 macroadenomas vs. 7 patients (29%) with Knosp grade 0 macroadenomas (p = 0.004). There was no mortality, and morbidity was minimal. Knosp grade 1 prolactinomas (OR 7.3, 95% CI 1.4-37.7, p = 0.02) but not adenoma size (i.e., macroprolactinomas) were an independent predictor of long-term dependence on DAs. CONCLUSIONS: First-line surgery in patients with microprolactinomas or macroprolactinomas Knosp grade 0 resulted in a good chance of non-dependency on DA therapy. However, in patients with prolactinomas Knosp grade 1, first-line surgery cannot be recommended, as adjuvant DA therapy after surgery is required in the majority of them over the long term.

Cerebellar Hypoperfusion in Migraine Attack: Incidence and Significance.

BACKGROUND AND PURPOSE: Patients diagnosed with migraine with aura have an increased lifetime risk of ischemic stroke. It is not yet clear whether prolonged cortical hypoperfusion during an aura increases the immediate risk of cerebellar infarction because it may induce crossed cerebellar diaschisis and subsequent tissue damage. To address this question, we retrospectively analyzed potential relationships between cortical oligemia and cerebellar hypoperfusion in patients with migraine with aura and their potential relation to small infarct-like cerebellar lesions. MATERIALS AND METHODS: One hundred six migraineurs who underwent MR imaging, including DSC perfusion, were included in the study. In patients with apparent perfusion asymmetry, we used ROI analysis encompassing 18 infra- and supratentorial ROIs to account for differences in regional cerebral blood flow and volume. The presence of cerebellar hypoperfusion was calculated using an asymmetry index, with values of >10% being considered significant. RESULTS: We observed perfusion asymmetries in 23/106 patients, 22 in patients with migraine with aura (20.8%). Cerebellar hypoperfusion was observed in 12/23 patients (52.2%), and crossed cerebellar diaschisis, in 9/23 patients (39.1%) with abnormal perfusion. In none of the 106 patients were DWI restrictions observed during migraine with aura. CONCLUSIONS: Cerebellar hypoperfusion and crossed cerebellar diaschisis are common in patients with migraine with aura and cortical perfusion abnormalities. Crossed cerebellar diaschisis in migraine with aura may be considered a benign phenomenon because we observed no association with DWI restriction or manifest cerebellar infarctions, even in patients with prolonged symptom-related perfusion abnormalities persisting for up to 24 hours.

Serum neurofilament light chain in patients with acute cerebrovascular events.

BACKGROUND AND PURPOSE: Serum neurofilaments are markers of axonal injury. We addressed their diagnostic and prognostic role in acute ischemic stroke (AIS) and transient ischemic attack (TIA). METHODS: Nested within a prospective cohort study, we compared levels of serum neurofilament light chain (sNfL) drawn within 24 h from symptom onset in patients with AIS or TIA. Patients without magnetic resonance imaging on admission were excluded. We assessed whether sNfL was associated with: (i) clinical severity on admission, (ii) diagnosis of AIS vs. TIA, (iii) infarct size on admission magnetic resonance diffusion-weighted imaging (MR-DWI) and (iv) functional outcome at 3 months. RESULTS: We analyzed 504 patients with AIS and 111 patients with TIA. On admission, higher National Institutes of Health Stroke Scale (NIHSS) scores were associated with higher sNfL: NIHSS score < 7, 13.1 pg/mL [interquartile range (IQR), 5.3-27.8]; NIHSS score 7-15, 16.7 pg/mL (IQR, 7.4-34.9); and NIHSS score > 15, 21.0 pg/mL (IQR, 9.3-40.4) (P = 0.01). Compared with AIS, patients with TIA had lower sNfL levels [9.0 pg/mL (95% confidence interval, 4.0-19.0) vs. 16.0 pg/mL (95% confidence interval, 7.3-34.4), P < 0.001], also after adjusting for age and NIHSS score (P = 0.006). Among patients with AIS, infarct size on admission MR-DWI was not associated with sNfL, either in univariate analysis (P = 0.15) or after adjusting for age and NIHSS score on admission (P = 0.56). Functional outcome 3 months after stroke was not associated with sNfL after adjusting for established predictors. CONCLUSIONS: In conclusion, among patients admitted within 24 h of AIS or TIA onset, admission sNfL levels were associated with clinical severity on admission and TIA diagnosis, but not with infarct size on MR-DWI acquired on admission or functional outcome at 3 months.

Impact of intravenous thrombolysis on recanalization rates in patients with stroke treated with bridging therapy.

BACKGROUND AND PURPOSE: Randomized controlled trials have shown that bridging endovascular therapy (EVT) after intravenous thrombolysis (IVT) therapy improves outcome in patients with stroke with large-artery anterior circulation stroke compared with IVT alone. It remains unknown whether IVT adds any benefit to EVT in these patients. The aim of this study was to assess recanalization rates and thrombus dislocation before initiation of EVT in patients receiving bridging therapy. METHODS: All patients in the Bernese stroke registry (2008-2015) in whom bridging therapy was considered were included in this analysis. Relevant recanalization before EVT, thrombus dislocation and increase in thrombus load between initial and control imaging were assessed retrospectively. RESULTS: A total of 319 patients were included. Relevant recanalization before EVT occurred in 8.8% and thrombus dislocation in 7.2% of patients before EVT. Recanalization rates were significantly higher in distal compared with large and more proximal vessel occlusions of the anterior circulation (occlusion of internal carotid artery, 5.4%; middle cerebral artery segment M1, 8.1%; middle cerebral artery segment M2, 17.6%) and in drip-and-ship patients compared with mother-ship patients. In multivariable regression analysis the occlusion site was the only independent predictor of relevant recanalization before EVT (P = 0.046). CONCLUSIONS: Relevant recanalization after IVT and prior to EVT in patients receiving bridging therapy was highly dependent on the occlusion site. These findings suggest that future randomized controlled trials should consider occlusion site and treatment paradigm to specify patients who benefit most from bridging therapy in comparison to EVT or IVT alone.

Fully automated stroke tissue estimation using random forest classifiers (FASTER).

Several clinical trials have recently proven the efficacy of mechanical thrombectomy for treating ischemic stroke, within a six-hour window for therapy. To move beyond treatment windows and toward personalized risk assessment, it is essential to accurately identify the extent of tissue-at-risk ("penumbra"). We introduce a fully automated method to estimate the penumbra volume using multimodal MRI (diffusion-weighted imaging, a T2w- and T1w contrast-enhanced sequence, and dynamic susceptibility contrast perfusion MRI). The method estimates tissue-at-risk by predicting tissue damage in the case of both persistent occlusion and of complete recanalization. When applied to 19 test cases with a thrombolysis in cerebral infarction grading of 1-2a, mean overestimation of final lesion volume was 30 ml, compared with 121 ml for manually corrected thresholding. Predicted tissue-at-risk volume was positively correlated with final lesion volume ( p < 0.05). We conclude that prediction of tissue damage in the event of either persistent occlusion or immediate and complete recanalization, from spatial features derived from MRI, provides a substantial improvement beyond predefined thresholds. It may serve as an alternative method for identifying tissue-at-risk that may aid in treatment selection in ischemic stroke.

Whole-Brain Susceptibility-Weighted Thrombus Imaging in Stroke: Fragmented Thrombi Predict Worse Outcome.

BACKGROUND AND PURPOSE: The prevalence and clinical importance of primarily fragmented thrombi in patients with acute ischemic stroke remains elusive. Whole-brain SWI was used to detect multiple thrombus fragments, and their clinical significance was analyzed. MATERIALS AND METHODS: Pretreatment SWI was analyzed for the presence of a single intracranial thrombus or multiple intracranial thrombi. Associations with baseline clinical characteristics, complications, and clinical outcome were studied. RESULTS: Single intracranial thrombi were detected in 300 (92.6%), and multiple thrombi, in 24 of 324 patients (7.4%). In 23 patients with multiple thrombi, all thrombus fragments were located in the vascular territory distal to the primary occluding thrombus; in 1 patient, thrombi were found both in the anterior and posterior circulation. Only a minority of thrombus fragments were detected on TOF-MRA, first-pass gadolinium-enhanced MRA, or DSA. Patients with multiple intracranial thrombi presented with more severe symptoms (median NIHSS scores, 15 versus 11; P = .014) and larger ischemic areas (median DWI ASPECTS, 5 versus 7; P = .006); good collaterals, rated on DSA, were fewer than those in patients with a single thrombus (21.1% versus 44.2%, P = .051). The presence of multiple thrombi was a predictor of unfavorable outcome at 3 months (P = .040; OR, 0.251; 95% CI, 0.067-0.939). CONCLUSIONS: Patients with multiple intracranial thrombus fragments constitute a small subgroup of patients with stroke with a worse outcome than patients with single thrombi.

Thrombolysis in patients with prior stroke within the last 3 months.

BACKGROUND AND PURPOSE: Patients with prior stroke within 3 months have been mostly excluded from randomized thrombolysis trials mainly because of the fear of an increased rate of symptomatic intracerebral hemorrhage (sICH). The aim of this study was to compare baseline characteristics and clinical outcome of thrombolyzed patients who had a previous stroke within the last 3 months with those not fulfilling this criterion (comparison group). METHODS: In all, 1217 patients were included in our analysis (42.2% women, mean age 68.8 ± 14.4 years). RESULTS: Patients with previous stroke within the last 3 months (17/1.4%) had more often a basilar artery occlusion (41.2% vs. 10.8%) and less frequently a modified Rankin scale (mRS) score 0-1 prior to index stroke (88.2% vs. 97.3%) and a higher mean time lapse from symptom onset to thrombolysis (321 min vs. 262 min) than those in the comparison group. Stroke severity was not different between the two groups. Rates of sICH were 11.8% vs. 6%. None of the sICHs and only one asymptomatic intracerebral hemorrhage occurred in the region of the former infarct. At 3 months, favorable outcome (mRS ≤ 2) in patients with previous stroke within 3 months was 29.4% (vs. 48.9%) and mortality 41.2% (vs. 22.7%). CONCLUSIONS: In patients with prior stroke within the last 3 months, none of the sICHs and only one asymptomatic intracerebral hemorrhage occurred in the region of the former infarct. The high mortality was influenced by four patients, who died until discharge due to acute major index stroke. It is reasonable to include these patients in randomized clinical trials and registries to assess further their thrombolysis benefit-risk ratio.

Endovascular therapy in 201 patients with acute symptomatic occlusion of the internal carotid artery.

BACKGROUND AND PURPOSE: Endovascular therapy is used increasingly for treatment of acute symptomatic internal carotid artery (ICA) occlusion, although randomized trials are lacking. Predictors of outcome are therefore of special interest. METHODS: From 1992 to 2010 we treated 201 patients with acute ICA occlusion with intra-arterial pharmacological thrombolysis (32), endovascular mechanical therapy (78) or a combination of both (91). All data were assessed prospectively. RESULTS: There were 76/38% patients with tandem occlusions [ICA plus middle (MCA) or anterior cerebral arteries (ACA)], 18/9% without concomitant occlusions of major intracranial arteries (ICA plus branch occlusion) and 107/53% with functional ICA-T occlusions (ICA plus MCA and ACA). Median baseline National Institute of Health Stroke Scale (NIHSS) score was 17. Good recanalization (Thrombolysis in Myocardial Infarction 2-3) was achieved in (157/201) 78% patients and good reperfusion (Thrombolysis in Cerebral Infarction 2-3) in (151/182) 83%. Better recanalization rates were obtained with mechanical approaches, with/without thrombolytics (78/91 = 86% and 64/78 = 82%) compared with pharmacological thrombolysis only (15/32 = 47%; P < 0.001). Twelve patients (6%) suffered symptomatic intracranial haemorrhages. The 3-month outcome was favourable [modified Rankin score (mRS) 0-2] in 54/28% patients and moderate (mRS 0-3) in 90/46%; 60/31% patients died. Only 17/16% patients with functional ICA-T occlusions had favourable outcomes compared with 32/44% with tandem occlusions and 5/31% with ICA plus cerebral branch occlusions (P = 0.001). In multivariate analysis age [odds ratio (OR) = 0.96, 95% confidence interval (CI) = 0.93-0.98], NIHSS on admission (OR = 0.9, 95% CI = 0.83-0.98) and functional ICA-T occlusion (OR = 0.35, 95% CI = 0.16-0.77) were non-modifiable predictors, and vessel recanalization was the only modifiable predictor of outcome (OR = 9.30, 95% CI = 2.03-42.63). CONCLUSIONS: The outcome of acute symptomatic ICA occlusion is poor. However, recanalization is associated with better outcome, and recanalization rates with mechanical techniques were superior to merely pharmacological recanalization attempts.

Safety of endovascular treatment beyond the 6-h time window in 205 patients.

BACKGROUND AND PURPOSE: Intra-arterial treatment (IAT) is effective when performed within 6 h of symptom onset in selected stroke patients ('T < 6H'). Its safety and efficacy is unclear when the patient has had symptoms for more than 6 h ('T > 6H') or for an unknown time (unclear-onset stroke, UOS), or woke up with a stroke (wake-up stroke, WUS). In this study we compared the safety of IAT in these four patient groups. METHODS: Eight-hundred and fifty-nine patients treated with IAT were enrolled. The main outcome parameters were clinical outcome [excellent: modified Rankin Scale (mRS) 0 or 1; or favorable: mRS 0-2] or mortality 3 months after treatment. Further outcome parameters were the rates of vessel recanalization, and cerebral and systemic hemorrhage. RESULTS: Six-hundred and fifty-four patients were treated before (T < 6H) and 205 after 6 h or an unknown time (128 T > 6H, 55 WUS and 22 UOS). NIHSS scores were higher in UOS patients than in T < 6H patients, vertebrobasilar occlusion was more common in T > 6H and UOS patients, and middle cerebral artery occlusions less common in T > 6H than in T < 6H patients. Other baseline characteristics were similar. There was no significant difference in clinical outcome and the rate of hemorrhage in multivariable regression analysis. CONCLUSIONS: Clinical outcome of our four groups of patients was similar with no increase of hemorrhage rates in patients treated after awakening, after an unknown time or more than 6 h. Our preliminary data suggest that treatment of such patients may be performed safely. If confirmed in randomized trials, this would have major clinical implications.

Applicability of tableside flat panel detector CT parenchymal cerebral blood volume measurement in neurovascular interventions: preliminary clinical experience.

BACKGROUND AND PURPOSE: CBV is a vital perfusion parameter in estimating the viability of brain parenchyma (eg, in cases of ischemic stroke or after interventional vessel occlusion). Recent technologic advances allow parenchymal CBV imaging tableside in the angiography suite just before, during, or after an interventional procedure. The aim of this work was to analyze our preliminary clinical experience with this new imaging tool in different neurovascular interventions. MATERIALS AND METHODS: FPD-CBV measurement was performed on a biplane FPD angiographic system. Eighteen patients (11 women, 7 men) were examined (age range, 18-86 years; median, 58.7 years). In the 10 patients with stroke, the extent of intracranial hypoperfusion was evaluated. The remaining 8 patients had an intracranial hemorrhage; periprocedural CBV was evaluated during the course of interventional treatment. RESULTS: In the 18 cases studied, 23 CBV measurements were performed. Twenty acquisitions were of sufficient diagnostic quality. The remaining 3 acquisitions failed technically, 1 due to motion artifacts and 2 due to injection technique and/or hardware failure. CONCLUSIONS: FPD-CBV measurement in the angiography suite provides a feasible and helpful tool for peri-interventional neuroimaging. It extends the intraprocedural imaging modalities to the level of tissue perfusion. However, the technique has technical limitations and shows room for improvement in the future.

Susceptibility-weighted MR imaging for diagnosis of capillary telangiectasia of the brain.

BACKGROUND AND PURPOSE: BCT is a benign entity, whose appearance on conventional MR imaging makes its differentiation from neoplastic, inflammatory, or subacute ischemic disease challenging. SWI is sensitive to susceptibility effects from deoxyhemoglobin with excellent spatial resolution. Only scarce case reports have described the utility of SWI in cases of BCT. Our aim was to show the diagnostic value of SWI applied to a larger series of cases. MATERIALS AND METHODS: This was an observational retrospective study of 33 BCTs in 27 consecutive patients examined from August 2009 to January 2011 with MR imaging, including SWI. Morphology, signal intensity characteristics, and additional vascular malformations were analyzed. Preceding or follow-up examinations were available in 18 patients with a median time interval of 14.5 months (range, 2-115 months). RESULTS: Twenty-five pontine and 8 supratentorial BCTs demonstrated distinct signal-intensity loss on SWI in combination with postcontrast enhancement. Mean lesion diameter was 4.9 mm (range, 1.5-17 mm). Thirty-nine percent showed slight signal-intensity changes on T1 and/or T2; the remainder were isointense to normal brain. In 30%, a prominent draining vessel was observed. Additional cerebral vascular malformations were found in 5 patients. CONCLUSIONS: SWI represents a valuable tool for confirmation of presumed BCT. Demonstration of signal-intensity loss on SWI in an enhancing focal brain lesion, otherwise unremarkable on conventional MR images, is highly specific for BCT, thus excluding serious pathology and reassuring the patient and referring physician. This is particularly helpful for BCT in less typical locations.

Passing the thrombus in endovascular treatment of acute ischemic stroke: do we penetrate the thrombus?

Mechanical thrombectomy is increasingly applied during the treatment of acute stroke. Various devices have been advocated with different sites of force effect at the thrombus. The purpose of this study was to evaluate the angiographic route of passing systematically and therefore to assess the site of deployment of mechanical devices in correlation to the thrombus in interventional stroke treatment. Twenty-one consecutive patients with endovascular treatment for acute ischemic stroke with 26 passing procedures were evaluated prospectively. Occlusion site was the M1-segment in 17 cases (65.4%), ICA termination in five cases (19.2%), M2-segment in two cases (7.7%), the A2-segment in one case (3.8%) and basilar artery in one case (3.8%). On angiographic images the microwire and microcatheter passage was evaluated by illustrating the entry point and course across the occlusion site in relation to the thrombus in different projections and in correlation to the recanalisation result. Results were correlated to the origin of the thrombi according to the TOAST criteria. In all cases the point of entry to the occlusion site was delineated laterally to the thrombus in at least one projection. The course of the wire across the occluded segment in relation to the thrombus was found to be laterally in 22 procedures (84.6%). In the majority of M1-occlusions (12/17, 70.6%) the passage was found in the cranial aspect of the thrombus. In four procedures (15.4%) angiograms in different projections did not unequivocally confirm a passage laterally to the thrombus. The route of passing the thrombus was independent of thrombus origin according to the TOAST criteria. In the majority of cases the complete route of passing the occlusion site was visualized angiographically. Entrance of the microwire and microcatheter at proximal surface of the thrombus takes place laterally to the thrombus and accordingly the passage takes place between the thrombus and the vessel wall independent of thrombus origin. A penetration of the thrombus was not observed. This route of passing has implications on deployment and transmission of force in relation to the thrombus in mechanical approaches and consequently on the development of retrieval devices.

Impact of retrievable stents on acute ischemic stroke treatment.

BACKGROUND AND PURPOSE: Retrievable stents combine the high recanalization rate of stents and the capability of removing the thrombus offered by mechanical thrombectomy devices. We hypothesized that retrievable stents shorten time to recanalization in the multimodal approach for endovascular stroke treatment. MATERIALS AND METHODS: Forty consecutive patients with acute ischemic stroke and undergoing endovascular therapy were included. Treatment included thromboaspiration, thrombus disruption, thrombolysis, PTA, and stent placement. In 17 patients, a retrievable stent was used (group A) in addition to multimodal therapy. The remaining 23 patients constituted group B. Baseline characteristics, occlusion sites, urokinase dose, recanalization rate, and time to recanalization were compared between the groups. RESULTS: Median NIHSS scores were higher in group A compared with group B on admission (19 versus 12.5; P = .018) but were not significantly different at day 1 (14 versus 10; P = .6). Intra-arterial thrombolysis was used in significantly fewer patients of group A than group B (53% versus 87%, respectively; P = .017), and median urokinase dose was lower in group A than in group B (250,000 IU versus 700,000 IU; P = .006). Time to recanalization was significantly shorter in group A compared with group B (median time to recanalization 52.5 minutes versus 90 minutes, respectively; P = .001). Recanalization rate was higher in group A than group B (94% versus 78%; P = .17). CONCLUSIONS: Addition of retrievable stents to the multimodal endovascular approach for acute ischemic stroke treatment significantly reduces time to recanalization and further increases the recanalization rate.

Percutaneous transluminal angioplasty and stent placement in acute vessel occlusion: evaluation of new methods for interventional stroke treatment.

BACKGROUND AND PURPOSE: The major goal of acute ischemic stroke treatment is fast and sufficient recanalization. Percutaneous transluminal balloon angioplasty (PTA) and/or placement of a stent might achieve both by compressing the thrombus at the occlusion site. This study assesses the feasibility, recanalization rate, and complications of the 2 techniques in an animal model. MATERIALS AND METHODS: Thirty cranial vessels of 7 swine were occluded by injection of radiopaque thrombi. Fifteen vessel occlusions were treated by PTA alone and 15, by placement of a stent and postdilation. Recanalization was documented immediately after treatment and after 1, 2, and 3 hours. Thromboembolic events and dissections were documented. RESULTS: PTA was significantly faster to perform (mean, 16.6 minutes versus 33.0 minutes for stent placement; P < .001), but the mean recanalization rate after 1 hour was significantly better after stent placement compared with PTA alone (67.5% versus 14.6%, P < .001). Due to the self-expanding force of the stent, vessel diameter further increased with time, whereas the recanalization result after PTA was prone to reocclusion. Besides thromboembolic events related to the passing maneuvers at the occlusion site, no thrombus fragmentation and embolization occurred during balloon inflation or stent deployment. Flow to side branches could also be restored at the occlusion site because it was possible to direct thrombus compression. CONCLUSIONS: Stent placement and postdilation proved to be much more efficient in terms of acute and short-term vessel recanalization compared with PTA alone.

[Thrombolysis of the middle cerebral artery]. / Thrombolyse der Arteria cerebri media.

Intravenous thrombolysis (IVT) is the evidence-based treatment of acute ischemic stroke in the first 3 h after symptom onset (IVT 3-4.5 h: off-label use with informed consent of the patient). However, intra-arterial thrombolysis (IAT) results in higher recanalization rates of the middle cerebral artery compared to IVT. Therefore it seems reasonable to apply IAT in addition or instead of IVT up to 6 h after symptom onset.

Clinical validation of an automated vessel-segmentation software of the extracranial-carotid arteries based on 3D-MRA: a prospective study.

OBJECTIVES: To determine the accuracy of automated vessel-segmentation software for vessel-diameter measurements based on three-dimensional contrast-enhanced magnetic resonance angiography (3D-MRA). METHOD: In 10 patients with high-grade carotid stenosis, automated measurements of both carotid arteries were obtained with 3D-MRA by two independent investigators and compared with manual measurements obtained by digital subtraction angiography (DSA) and 2D maximum-intensity projection (2D-MIP) based on MRA and duplex ultrasonography (US). In 42 patients undergoing carotid endarterectomy (CEA), intraoperative measurements (IOP) were compared with postoperative 3D-MRA and US. RESULTS: Mean interoperator variability was 8% for measurements by DSA and 11% by 2D-MIP, but there was no interoperator variability with the automated 3D-MRA analysis. Good correlations were found between DSA (standard of reference), manual 2D-MIP (rP=0.6) and automated 3D-MRA (rP=0.8). Excellent correlations were found between IOP, 3D-MRA (rP=0.93) and US (rP=0.83). CONCLUSION: Automated 3D-MRA-based vessel segmentation and quantification result in accurate measurements of extracerebral-vessel dimensions.

Contribution of the apparent diffusion coefficient in perilesional edema for the assessment of brain tumors.

OBJECTIVES: Diffusion-weighted MRI is sensitive to molecular motion and has been applied to the diagnosis of stroke. Our intention was to investigate its usefulness in patients with brain tumor and, in particular, in the perilesional edema. METHODS: We performed MRI of the brain, including diffusion-weighted imaging and mapping of the apparent diffusion coefficient (ADC), in 16 patients with brain tumors (glioblastomas, low-grade gliomas and metastases). ADC values were determined by the use of regions of interest positioned in areas of high signal intensities as seen on T2-weighted images and ADC maps. Measurements were taken in the tumor itself, in the area of perilesional edema and in the healthy contralateral brain. RESULTS: ADC mapping showed higher values of peritumoral edema in patients with glioblastoma (1.75 x 10(-3)mm(2)/s) and metastatic lesions (1.61 x 10(-3)mm(2)/s) compared with those who had low-grade glioma (1.40 x10(-3)mm(2)/s). The higher ADC values in the peritumoral zone were associated with lower ADC values in the tumor itself. CONCLUSIONS: The higher ADC values in the more malignant tumors probably reflect vasogenic edema, thereby allowing their differentiation from other lesions.

Neuro-imaging of cerebral ischemic stroke.

Major progress has recently been made in the neuro-imaging of stroke as a result of improvements in imaging hardware and software. Imaging may be based on either magnetic resonance imaging (MRI) or computed tomography (CT) techniques. Imaging should provide information on the entire vascular cervical and intracranial network, from the aortic arch to the circle of Willis. Equally, it should also give information on the viability of brain tissue and brain hemodynamics. CT has the advantage in the detection of acute hemorrhage whereas MRI offers more accurate pathophysiological information in the follow-up of patients.

Identification of brain structures involved in micturition with functional magnetic resonance imaging (fMRI).

OBJECTIVE: The voluntary control of micturition is believed to be integrated by complex interactions among the brainstem, subcortical areas and cortical areas. Several brain imaging studies using positron emission tomography (PET) have demonstrated that frontal brain areas, the limbic system, the pons and the premotor cortical areas were involved. However, the cortical and subcortical brain areas have not yet been precisely identified and their exact function is not yet completely understood. MATERIALS AND METHODS: This study used functional magnetic resonance imaging (fMRI) to compare brain activity during passive filling and emptying of the bladder. A cathetherism of the bladder was performed in seven healthy subjects (one man and six right-handed women). During scanning, the bladder was alternatively filled and emptied at a constant rate with bladder rincing solution. RESULTS: Comparison between passive filling of the bladder and emptying of the bladder showed an increased brain activity in the right inferior frontal gyrus, cerebellum, symmetrically in the operculum and mesial frontal. Subcortical areas were not evaluated. CONCLUSIONS: Our results suggest that several cortical brain areas are involved in the regulation of micturition.