Is There an Influence of Routine Daily Transcranial Doppler Examination on Clinical Outcome in Patients After Aneurysmal Subarachnoid Hemorrhage?

BACKGROUND: Transcranial Doppler (TCD) is widely used as a daily routine method to detect vasospasm in patients after aneurysmal subarachnoid hemorrhage (aSAH); however, there are only limited data about the real benefit of this examination. Therefore, the clinical outcome of 2 cohorts with and without daily TCD after aSAH was assessed. METHODS: All patients included in this study received a standardized diagnostic and treatment protocol. Fifty patients admitted with aSAH from January 2013 to December 2013 received daily TCD measurements; 39 patients admitted from January 2014 to September 2014 received no TCD measurements. Data on clinical grade (Hunt and Hess grade), severity of bleeding (Barrow Neurological Institute grade), localization of aneurysm, and angiographic or clinically relevant vasospasm were collected prospectively. The Glasgow Outcome Scale, modified Rankin Scale, and the National Institute of Health Stroke Scale were used as clinical outcome parameters. RESULTS: Patient baseline characteristics and clinical data were comparable; treatment modality of the aneurysm was not different between the groups (P = 0.7756). No significant difference between the Hunt and Hess grade (P = 0.818) and the Barrow Neurological Institute grade (P = 0.1551) was observed. There was also no significance concerning the incidence of angiographic or clinically relevant vasospasm between both groups (P = 0.5842 and P = 0.7933). Glasgow Outcome Scale, mRS, and National Institute of Health Stroke Scale as the primary outcome parameters showed no significant difference in morbidity and mortality between both groups (mortality P = 0.8544). CONCLUSIONS: With the limitation of an explorative cohort study, the results indicate that routine TCD studies do not improve the overall outcome of patients after aSAH.

Image Quality of 3rd Generation Spiral Cranial Dual-Source CT in Combination with an Advanced Model Iterative Reconstruction Technique: A Prospective Intra-Individual Comparison Study to Standard Sequential Cranial CT Using Identical Radiation Dose.

OBJECTIVES: To prospectively intra-individually compare image quality of a 3rd generation Dual-Source-CT (DSCT) spiral cranial CT (cCT) to a sequential 4-slice Multi-Slice-CT (MSCT) while maintaining identical intra-individual radiation dose levels. METHODS: 35 patients, who had a non-contrast enhanced sequential cCT examination on a 4-slice MDCT within the past 12 months, underwent a spiral cCT scan on a 3rd generation DSCT. CTDIvol identical to initial 4-slice MDCT was applied. Data was reconstructed using filtered backward projection (FBP) and 3rd-generation iterative reconstruction (IR) algorithm at 5 different IR strength levels. Two neuroradiologists independently evaluated subjective image quality using a 4-point Likert-scale and objective image quality was assessed in white matter and nucleus caudatus with signal-to-noise ratios (SNR) being subsequently calculated. RESULTS: Subjective image quality of all spiral cCT datasets was rated significantly higher compared to the 4-slice MDCT sequential acquisitions (p<0.05). Mean SNR was significantly higher in all spiral compared to sequential cCT datasets with mean SNR improvement of 61.65% (p*Bonferroni0.05<0.0024). Subjective image quality improved with increasing IR levels. CONCLUSION: Combination of 3rd-generation DSCT spiral cCT with an advanced model IR technique significantly improves subjective and objective image quality compared to a standard sequential cCT acquisition acquired at identical dose levels.

The spontaneous arterial blood pressure rise after aneurysmal subarachnoid hemorrhage - a biphasic phenomenon.

OBJECTIVES: A spontaneous blood pressure (BP) rise is frequently observed after aneurysmal subarachnoid hemorrhage (aSAH). The current study was designed to characterize the time course of this BP rise and its relation to clinical and radiological parameters. METHODS: The diastolic (DBP), mean (MAP), and systolic (SBP) BP values were determined in 61 aSAH patients from day 0 to 9. The patient's initial status was evaluated by the world federation of neurological surgeons scale and the Hijdra scale. The clinical outcome was quantified by the modified Rankin Scale, the Glasgow Outcome Scale Extended, and the National Institute of Health Stroke Scale. The degree of proximal and global vasospasm was calculated by comparison of the baseline angiography on day 0 and the control angiography on day 8. Furthermore, the influence of propofol and norepinephrine application was analyzed. RESULTS: DBP, MAP, and SBP demonstrated an early rise in all patients from day 2 till 5 (p<0.001) and remained hypertensive until day 9. No significant correlation could be detected between this early BP rise and most clinical and radiological variables. From day 8 onwards, a divergence of the SBP courses was detected between patients with severe vs. non-severe global vasospasm. There was a secondary, norepinephrine independent SBP rise in patients with severe global vasospasm that significantly correlated with the initial Hijdra-scale and an unfavorable clinical outcome. CONCLUSIONS: The results demonstrate a biphasic BP course with a uniform early BP rise in all patients and an additional delayed SBP rise in patients with severe global vasospasm.

Dynamic Autoregulatory Response After Aneurysmal Subarachnoid Hemorrhage and Its Relation to Angiographic Vasospasm and Clinical Outcome.

BACKGROUND: Impaired cerebral autoregulation (CA) is increasingly recognized to contribute to sequelae after aneurysmal subarachnoid hemorrhage (SAH). The current study characterizes the course of the dynamic autoregulation index (ARI) during the first 8 days after SAH and its coherence with angiographic vasospasm (VS) and clinical outcome. METHODS: Fifty-one patients with SAH were prospectively included within 48 h after the ictus. The ARI was determined daily for each hemisphere with the thigh cuff test. The degree of cerebral VS was evaluated based on a baseline digital subtraction angiography (DSA) after the ictus and a follow-up DSA on day 8. The clinical outcome was determined by the Modified Rankin Scale (mRS), the Glasgow Outcome Scale Extended (GOSE), and the National Institute of Health Stroke Scale (NIHSS) at discharge from the intensive care unit. RESULTS: Impaired CA significantly correlated with unfavorable clinical outcome scores (mRS, p = 0.0021; GOSE, p = 0.0027; NIHSS, p = 0.0091). ARI-values of patients with a favorable clinical outcome (mRS 0-3) showed a significant improvement during the first 8 days (+0.1964/day; p = 0.0148) compared to a significant decrease of ARI-values in patients with an unfavorable clinical outcome (-0.2976/day; p = 0.0182). The degree of CA impairment significantly correlated with the severity of VS in the middle cerebral artery (p = 0.0184). CONCLUSIONS: Early deterioration of CA significantly correlates with unfavorable clinical outcome and severity of angiographic vasospasm. Dynamic CA measurements might represent an important tool in stratifying therapy guidelines in patients after SAH.

Missing relationship of moyamoya and persistent primitive artery in Europeans. Another distinctive feature or artifact?

PURPOSE: Previous studies found higher incidence of persistent primitive arteries in Asian moyamoya (MM) patients than in the general population, which was thought to be a characteristic trait of the MM entity in general. We analyzed incidence of persistent primitive arteries and demographics of patients with European MM treated in one single center. First, we compared our large dataset to existing literature and second, we raised the question whether European MM demonstrates similar high prevalence of persistent primitive arteries as it was previously presented within Asian MM. METHODS: All European MM on whom revascularization surgery was performed from 1999 to 2013 were included. Demographics and associated diseases were obtained by retrospective chart review. Two independent readers evaluated 122 MM angiograms to determine the occurrence of persistent primitive arteries as well as the Suzuki score. RESULTS: We identified 112 cases with MM disease, 10 with MM syndrome. Mean age at time of diagnosis was 38.2 (range 6-64 years); a peak incidence in early childhood was not observed. Ninety (73.8%) were women, associated systemic diseases were found in four patients. Seven cases (5.7%) presented with unilaterally affected vessels. The majority of patients (71; 58.2%) were graded Suzuki Score 3. One 14-year-old boy with moyamoya presented with a primitive trigeminal artery (0.89%). CONCLUSIONS: We did not find a bimodal age distribution, but only a second peak during adulthood. Unlike previous studies on Asian moyamoya patients, our collective does not exhibit a higher prevalence of persistent primitive arteries than the normal population.

MR angiography follow-up 10 years after cryptogenic nonperimesencephalic subarachnoid hemorrhage.

OBJECTIVES: Long-term magnetic resonance angiography (MRA) follow-up studies regarding cryptogenic nonperimesencephalic subarachnoid hemorrhage (nSAH) are scarce. This single-centre study identified all patients with angiographically verified cryptogenic nSAH from 1998 to 2007: The two main objectives were to prospectively assess the incidence of de novo aneurysm with 3.0-MRI years after cryptogenic nSAH in patients without evidence for further hemorrhage, and retrospectively assess patient demographics and outcome. METHODS: From prospectively maintained report databases all patients with angiographically verified cryptogenic nSAH were identified. 21 of 29 patients received high-resolution 3T-MRI including time-of-flight and contrast-enhanced angiography, 10.2 ± 2.8 years after cryptogenic nSAH. MRA follow-up imaging was compared with initial digital subtraction angiography (DSA) and CT/MRA. Post-hemorrhage images were related to current MRI with reference to persistent lesions resulting from delayed cerebral ischemia (DCI) and post-hemorrhagic siderosis. Patient-based objectives were retrospectively abstracted from clinical databases. RESULTS: 29 patients were identified with cryptogenic nSAH, 17 (59%) were male. Mean age at time of hemorrhage was 52.9 ± 14.4 years (range 4 - 74 years). 21 persons were available for long-term follow-up. In these, there were 213.5 person years of MRI-follow-up. No de novo aneurysm was detected. Mean modified Rankin Scale (mRS) during discharge was 1.28. Post-hemorrhage radiographic vasospasm was found in three patients (10.3%); DCI-related lesions occurred in one patient (3.4%). Five patients (17.2%) needed temporary external ventricular drainage; long-term CSF shunt dependency was necessary only in one patient (3.4%). Initial DSA retrospectively showed a 2 x 2 mm aneurysm of the right distal ICA in one patient, which remained stable. Post-hemorrhage siderosis was detected 8.1 years after the initial bleeding in one patient (4.8%). CONCLUSION: Patients with cryptogenic nSAH have favourable outcomes and do not exhibit higher risks for de novo aneurysms. Therefore the need for long-term follow up after cryptogenic nSAH is questionable.

Influence of cervical bone mineral density on cage subsidence in patients following stand-alone anterior cervical discectomy and fusion.

PURPOSE: Anterior cervical discectomy and fusion (ACDF) is a common procedure for the treatment of cervical degenerative diseases. However, cage subsidence remains a frequent problem. We therefore investigated if cage design and site-specific bone mineral density (BMD) contribute to the rate and direction of subsidence following ACDF. METHODS: Patients were prospectively included and received two different cages (groups 1 and 2) using minimization randomization. The degree and direction of cage subsidence were determined using plain radiographs. Neck pain intensity on the visual analogue scale (VAS), the neck disability index (NDI), and the patient satisfaction index were recorded up to 12 months after surgery. RESULTS: 88 patients were analysed with a mean age of 53.7 ± 11.8 years. BMD values decreased in craniocaudal direction from 302.0 ± 62.2 to 235.5 ± 38.9 mg/cm(3). Both groups showed significant height gain after the operation (both p < 0.001), followed by height loss at 3 months (both p < 0.05) and at 3-12 months after the operation (both p > 0.05). Both groups showed improvement of VAS neck pain intensity (both p < 0.05) and NDI (both p < 0.05). The direction of cage subsidence was similar, no correlations were found between cage subsidence and BMD or various clinical parameters. CONCLUSIONS: Implant geometry of both cages and variations of the operative procedure promoted a relatively high degree of cage subsidence. Further studies are necessary to identify a relation of BMD and subsidence using optimized implant geometry and by controlling additional intraoperative variables.

Collateralization and ischemia in hemodynamic cerebrovascular insufficiency.

BACKGROUND: Moyamoya disease and atherosclerotic cerebrovascular occlusive disease lead to hemodynamic impairment of cerebral blood flow. One major differentiation between both disease entities lies in the collateralization pathways. The clinical implications of the collateralization pathways for the development of hemodynamic ischemia remain unknown. The aim was to characterize collateralization and ischemia patterns in patients with chronic hemodynamic compromise. METHODS: Hemodynamic compromise was verified using acetazolamide-stimulated xenon-CT or SPECT in 54 patients [30 moyamoya and 24 atherosclerotic cerebrovascular disease (ACVD)]. All patients received MRI to differentiate hemodynamic ischemia into anterior/posterior cortical border zone infarction (CBI), inferior border zone infarction (IBI) or territorial infarction (TI). Digital subtraction angiography was applied to evaluate collateralization. Collateralization was compared and correlated with the localization of ischemia and number of vascular territories with impaired cerebrovascular reserve capacity (CVRC). RESULTS: MM patients showed collateralization significantly more often via pericallosal anastomosis and the posterior communicating artery (flow in the anterior-posterior direction; MM: 95%/95% vs. ACVD: 23%/12%, p < 0.05). ACVD patients demonstrated collateralization via the anterior and posterior communicating arteries (flow in the posterior-anterior direction, MM: 6%/5% vs. ACVD: 62%/88%, p < 0.05). Patterns of infarction were comparable (aCBI: MM: 36% vs. ACVD: 35%; pCBI: MM: 10% vs. ACVD: 20%; IBI: MM: 35% vs. ACVD: 41%; TI: MM: 13% vs. ACVD: 18%). The number and localization of vascular territories with impaired CVRC were comparable. CONCLUSIONS: Despite significant differences in collateralization, the infarct patterns and severity of CVRC impairment do not differ between MMV and ACVD patients. Cerebral collateralization does not allow reaching conclusions about the localization of cerebral ischemia or severity of impaired CVRC in chronic hemodynamic impairment.

MRI verification of ultrasound-guided infiltrations of local anesthetics into the piriformis muscle.

OBJECTIVE: Patients presenting with buttock pain syndromes are common. Up to 8% of these conditions may be attributed to piriformis syndrome. Included in several therapeutic and diagnostic approaches, injections directly into the piriformis muscle may be performed. Because the muscle lies very close to neurovascular structures, electromyographic, fluoroscopic, computed tomographic, and magnetic resonance imaging (MRI) guidance have been employed. In few studies, an ultrasound-guided technique was used to inject a local anesthetic into the piriformis muscle without impairing adjacent neuronal structures. DESIGN: Feasibility study in healthy human subjects. Confirmation of ultrasound-guided injections by MRI. SUBJECTS: In 10 male human subjects, ultrasound-guided injections of 3 mL of a local anesthetic into the piriformis muscle were performed. METHODS: Directly after the injection, the subjects were placed in an MRI scanner, and the placement of the liquid depot was confirmed by MRI imaging. Somatosensory deficits were evaluated after the injection. RESULTS: The MRI showed that 9 of 10 of the injections were correctly placed within the piriformis muscle. The distance of the depot to the sciatic nerve decreased over time due to dispersion, but the nerve itself was not reached in the MRI. Only one subject experienced slight, short-term sensorimotor deficits. CONCLUSIONS: MRI confirmed the correct placement of the local anesthetic within the muscle. The dispersion of the fluid 30 minutes after the injection could be visualized. Moreover, only one subject experienced slight motor deficits without anatomical correlate. This ultrasound-guided method will be further employed in ongoing clinical studies.

Short-term experience with a new absorbable composite cage (ß-tricalcium phosphate-polylactic acid) in patients after stand-alone anterior cervical discectomy and fusion.

STUDY DESIGN: Prospective clinical single center series with 50 patients to include, with planned follow-up intervals at 3 and 12 months postoperative. OBJECTIVE: Absorbable cages were developed with the purpose to enhance fusion rates and to reduce the rate of cage subsidence. The gradual increase of load transfer during cage degradation facilitates new bone formation, which possibly leads to higher arthrodesis rates. SUMMARY OF BACKGROUND DATA: Absorbable cages consisting of a mixture of polylactic and polyglycolic acid (PLLA-PGLA) or poly (L-lactide-co-D, L-lactide) experimentally showed disappointing results with formation of cartilage and fibrous tissue components, which was much less pronounced using composite cages consisting of a polymer and calciumphosphate. METHODS: Patients showing degenerative cervical mono- or bi-level pathology were prospectively included. Using anteroposterior and lateral radiographs, segmental height of the treated segments was determined quantitatively. Cage characteristics were described qualitatively. Clinical data such as the Neck Disability Index, pain severity on the visual analogue scale were collected at all time points separately for neck and arm. RESULTS: A total of 33 patients were included, with a mean age of 51.9 ± 9 years. As cage dislocations occurred in 4 out of 33 patients (12.1%), the study was prematurely discontinued. All patients with cage dislocations were surgically revised. Clinical outcome of the remaining patients showed significant improvement of visual analogue scale neck pain from 6.0 ± 2.5 to 2.8 ± 2.3 (P < 0.005), visual analogue scale arm pain from 5.3 ± 2.7 to 1.6 ± 1.6 (P < 0.005), and Neck Disability Index from 21.2 ± 8.6 to 12.5 ± 9.6 (P < 0.005) after surgery. CONCLUSION: Because of the high rate of cage dislocations, the use of the present composite cage cannot be recommended as a stand-alone device unless implant fixation will not be improved significantly. Evaluation of clinical and radiological long-term effects is essential to estimate the potential benefit of composite cages. LEVEL OF EVIDENCE: 2.

High prevalence of heterotopic ossification after cervical disc arthroplasty: outcome and intraoperative findings following explantation of 22 cervical disc prostheses.

OBJECT: Cervical disc arthroplasty (CDA) has been increasingly used for the treatment of cervical disc herniations. However, the impact of CDA on adjacent-segment degeneration and the degree of heterotopic ossification (HO) of the treated segment remain a subject of controversy. Due to a product failure of the Galileo-type disc prosthesis, 22 of these devices were explanted. The radiological and clinical course in each case was investigated in detail with an emphasis on the incidence of HO and facet joint degeneration 18 months following the operation. Intraoperative findings regarding ossification and implant fixation were documented. Thus, the authors were able to describe the true rate of adjacent-segment degeneration and HO following CDA and the clinical relevance thereof. METHODS: In all 22 patients, functional radiographic imaging was performed prior to surgery, 3 and 12 months after surgery, and prior to disc prosthesis explantation. At all time points, the range of motion (ROM) in the operated and adjacent segments was determined. A motion index was calculated using the preoperative and all postoperative ROMs (preoperative ROM/postoperative ROM). Computed tomography was used preoperatively to measure the height of the index segment, extent of HO, and the degree of the progression of facet arthrosis, and was used postoperatively prior to prosthesis explantation. Patients completed clinical questionnaires that included a visual analog scale and the Neck Disability Index. RESULTS: The motion index of the index segment declined gradually from 1.4 at 3 months postoperative to 1.2 prior to explantation, while the motion index of the adjacent upper segment increased from 0.9 to 1.3. The mean ROM of the index segment was 10.4° ± 6.7°, and fusion was observed in 2 (9%) of the 22 patients. Prosthesis migration was present in 3 patients (13.6%). Severe HO (Grades 3 and 4) was present in 17.4%. Computed tomography showed a significant increase of segmental height of the index segment (1.6 ± 1.1 mm, p = 0.035), and a significant increase of left-sided lateral osteophytes (1.7 ± 2.1 mm, p = 0.009). The incidence of severe osteophyte formation (> 2 mm) occurred in 40%. Intraoperative findings reflected the results from CT, with primary lateral proliferation of osteophytes found in approximately 25% of patients. The mean visual analog scale scores were 3.8 ± 2.7 (neck) and 2.4 ± 2.5 (arms), and the mean Neck Disability Index score was 30 ± 22. No correlation was found between radiological and clinical parameters. CONCLUSIONS: In this study, a higher incidence of HO after CDA could be demonstrated using CT, compared with studies using fluoroscopy only. However, patient selection and/or the operative technique might have contributed to the high prevalence of osteophyte formation. Thus, the exact indication for CDA has to be reconsidered. Because implant migration was detected, using fixation in the present CDA model appears suboptimal.

Correlation of clinical outcome and angiographic vasospasm with the dynamic autoregulatory response after aneurysmal subarachnoid hemorrhage.

BACKGROUND: A certain correlation between unfavorable clinical outcome, incidence of vasospasm, and impaired pressure autoregulation in patients following aneurysmal subarachnoid hemorrhage (aSAH) has been suggested. However, determination of vasospasm is inaccurate and the measurement technique of cerebral vasoreactivity seems not to have been sufficiently validated. Therefore, a correlation of clinical outcome and the extent of angiographic VS was performed using an established autoregulation test. MATERIAL AND METHODS: Proximal and global angiographic vasospasm (pVS, gVS) were determined in bilateral M1 segments. Dynamic tests of pressure autoregulation were performed 1 day before and after, and on the day of angiography using Aaslid's thigh leg cuff test. Patient outcome was assessed using the Extended Glasgow Outcome Scale (GOSE). KEY RESULTS: Complete datasets were available for 22 patients. Mean autoregulatory indices (ARI) around the day of angiography were 3.9 ± 2.3. Proximal mean reduction of vessel diameter was -23.3% ± 9.1%. Global vasospasm was not present in 10 hemispheres, mild in 15, moderate in 15, and severe in 4. Hemispheric ARI values and angiographic data showed a significant correlation (pVS -0.382, p = 0.015; gVS -0.477, p = 0.002). The degree of angiographic vasospasm and low ARI values correlated significantly with an unfavorable outcome (0.677, p = 0.001). CONCLUSION: Incidence of angiographic vasospasm and impaired clinical outcome seems to be related to impaired pressure autoregulation following aSAH.

Variations of the superior sagittal sinus and bridging veins in human dissections and computed tomography venography.

OBJECTIVES: The aim of the present study was to examine the superior sagittal sinus (SSS) and bridging veins (BVs) from an anatomical, neurosurgical and radiological perspective. METHODS: Computed tomography venographies (CTVs) of 30 patients and 9 cadaveric dissections of human SSS were analyzed. RESULTS: CTV and cadavers showed most BVs emptying into the SSS close by (±3 cm) and distal to the coronary suture (74% in CTV, 62% in cadavers). CONCLUSIONS: Important anatomical information can be drawn from cerebral CTV for neurosurgical preoperative planning.

Noise reduction and image quality improvement of low dose and ultra low dose brain perfusion CT by HYPR-LR processing.

PURPOSE: To evaluate image quality and signal characteristics of brain perfusion CT (BPCT) obtained by low-dose (LD) and ultra-low-dose (ULD) protocols with and without post-processing by highly constrained back-projection (HYPR)-local reconstruction (LR) technique. METHODS AND MATERIALS: Simultaneous BPCTs were acquired in 8 patients on a dual-source-CT by applying LD (80 kV, 200 mAs, 14×1.2 mm) on tube A and ULD (80 kV, 30 mAs, 14×1.2 mm) on tube B. Image data from both tubes was reconstructed with identical parameters and post-processed using the HYPR-LR. Correlation coefficients between mean and maximum (MAX) attenuation values within corresponding ROIs, area under attenuation curve (AUC), and signal to noise ratio (SNR) of brain parenchyma were assessed. Subjective image quality was assessed on a 5-point scale by two blinded observers (1: excellent, 5: non-diagnostic). RESULTS: Radiation dose of ULD was more than six times lower compared to LD. SNR was improved by HYPR: ULD vs. ULD+HYPR: 1.9±0.3 vs. 8.4±1.7, LD vs. LD+HYPR: 5.0±0.7 vs. 13.4±2.4 (both p<0.0001). There was a good correlation between the original datasets and the HYPR-LR post-processed datasets: r = 0.848 for ULD and ULD+HYPR and r = 0.933 for LD and LD+HYPR (p<0.0001 for both). The mean values of the HYPR-LR post-processed ULD dataset correlated better with the standard LD dataset (r = 0.672) than unprocessed ULD (r = 0.542), but both correlations were significant (p<0.0001). There was no significant difference in AUC or MAX. Image quality was rated excellent (1.3) in LD+HYPR and non-diagnostic (5.0) in ULD. LD and ULD+HYPR images had moderate image quality (3.3 and 2.7). CONCLUSION: SNR and image quality of ULD-BPCT can be improved to a level similar to LD-BPCT when using HYPR-LR without distorting attenuation measurements. This can be used to substantially reduce radiation dose. Alternatively, LD images can be improved by HYPR-LR to higher diagnostic quality.

Abciximab does not prevent ischemic lesions related to cerebral angiography: a randomized placebo-controlled trial.

BACKGROUND: To assess the efficiency of IIb/IIIa platelet receptor inhibition by abciximab in the prevention of silent embolism during digital subtraction angiography. METHODS: In this randomized, double-blind, prospective study, pre- and postangiographic diffusion-weighted magnetic resonance imaging (DWI) of 184 participants was evaluated for the occurrence of silent embolism. RESULTS: No significant relationship was found between the patients receiving abciximab before digital subtraction angiography (15 of 90; 16.7%) and patients in the placebo group (16 of 94; 17.0%) regarding postangiographic appearance of silent emboli (p = 0.9). CONCLUSIONS: IIb/IIIa receptor inhibition by abciximab does not diminish the occurrence of silent embolism during digital subtraction angiography. Our findings indicate that solid blood clots are not the origin of hyperintense lesions observed on DWI and enhance the role of alternative mechanisms.

Comparison of selective arterial spin labeling using 1D and 2D tagging RF pulses.

Generic arterial spin labeling (ASL) techniques label all brain feeding arteries. In this work, we used two different selective ASL (SASL) methods to show the perfusion of one single artery. A slice selective inversion of an area including the desired vessel was compared to a multidimensional RF pulse with Gaussian profile to label only the artery of interest. Perfusion images with a resolution of 2 x 2 x 5 mm(3) are shown that were acquired after tagging only the internal carotid artery of healthy volunteers. In addition, both techniques were applied to a patient with an extra-intracranial bypass to illustrate its perfusion territory. These perfusion images are consistent with a standard angiography. SASL imaging with a resolution of 2 x 2 x 5 mm(3) is possible in a total scan time of 5 min. The presented MR techniques may in part replace the assessment of revascularization success by conventional angiography.

Computed tomographic angiography of the superior sagittal sinus and bridging veins.

PURPOSE: The primary aim of our paper was to describe typical anatomical patterns of the superior sagittal sinus (SSS) and bridging veins (BV) using cerebral venous computed tomographic angiography (CTA) with a focus on the direction of the BV entering the SSS. METHODS: We retrospectively analyzed venous CTA of 30 patients to estimate the total number and direction of the BV entering the SSS. Maximum intensive projections were analyzed for length, diameter and cross-sectional area of the SSS. RESULTS: Thee hundred and fifty-four BV were assessed. The mean total length of the SSS was 25.6 ± 1.6 cm (mean ± 1 SD). The mean horizontal diameter at the level of the coronary suture was 6.7 ± 2.0 mm, and the mean vertical diameter at the coronary suture measured 5.3 ± 1.8 mm. Most BV emptied into the SSS, at the level of or distal to the coronary suture (74%). The BV draining into the SSS at the level of the coronary suture typically joined into a lacunar formation (43%). Veins draining into the sinus more than 3 cm distal from the coronary suture presented a predominantly retrograde inflow direction (77%). CONCLUSIONS: Despite large variations in the location and course of BV, typical anatomical patterns were noted especially in relation to the direction of BV entering the SSS. The present anatomical analysis of the cerebral convexity veins by cerebral venous CTA provides an overview of the configuration of these veins which is useful information in neurosurgical preoperative planning.

TrueFISP imaging of the pineal gland: more cysts and more abnormalities.

INTRODUCTION: Although pineal cysts are found with a frequency of over one third in autopsy series, prevalences reported in standard magnetic resonance imaging (MRI) studies only range between 0.14% and 4.9%. With the advances in scanner technology and more sensitive high-resolution 3D-sequences, pineal cysts with atypical appearance are more frequently encountered as an incidental finding. In order to help the radiologist and the clinician to correctly interpret these incidental findings and to avoid follow-up MRI or even surgical intervention, we analysed the frequency of typical and atypical pineal cysts using standard MRI-sequences and a high-resolution 3D-trueFISP-sequence (true-Fast-Imaging-with-Steady-State-Precession). METHODS: In 111 patients undergoing MRI we analysed the prevalence of pineal cysts in relation to gender and age, as well as the frequency of atypical cysts defined by thickened rim, trabeculations, or asymmetric form using three standard MRI-sequences (T1-SE (T1 weighted spin echo), T2-TSE (T2 weighted turbo spin echo), FLAIR (fluid attenuated inversion recovery)) and compared the diagnostic certainty of these standard sequences with the sensitivity of a high-resolution trueFISP MRI sequence. RESULTS: Using trueFISP pineal cysts were detected more frequently than in the standard sequences (35.1% vs. 9.0% (T1-SE), 4.5% (T2-TSE) and 9.0% (FLAIR)). Diagnostic uncertainty was least frequent in trueFISP. In trueFISP, 41.0% of the detected cysts showed one or more features of atypical cysts (standard sequences: 21.4%). Highest prevalence of cysts was detected in the group of 20-30-year-old patients and decreased with increasing age. CONCLUSION: High-resolution 3D-sequences like trueFISP increase the detection rate of pineal cysts to levels reported in autoptic series while decreasing the diagnostic uncertainty. Atypically configurated pineal cysts are frequently detected as an incidental finding.

In vitro labeling of glioma cells with gadofluorine M enhances T1 visibility without affecting glioma cell growth or motility.

Gadofluorine is a novel macrocyclic, amphiphilic gadolinium-based contrast agent. We found that malignant glioma cells could be labeled in vitro using Gadofluorine without the need for transfection agents or any other additional means. Labeling with Gadofluorine enhanced the visualization of glioma cells in T(1)-weighted sequences, even if the cells had been cultured in medium without Gadofluorine over several days. The intracellular uptake of Gadofluorine was measured and the loss of relevant amounts of Gadofluorine into the cell culture medium was ruled out by MRI. Confocal laser fluorescence microscopy revealed Cy-5-labeled Gadofluorine in the perinuclear cytoplasmic region, but neither within the nucleus nor bound to the cell membrane. Adverse effects of cellular Gadofluorine uptake were ruled out by proliferation and migration assays. Finally, in vivo analyses provided good visibility of labeled glioma cells in T(1)-weighted sequences after intracerebral injection in mice for more than 2 weeks. We thus conclude that Gadofluorine can easily be used to label glioma cells in vitro without affecting glioma cell biology. Gadofluorine provides an interesting alternative for cellular labeling if iron oxide particles are incorporated insufficiently by target cells or if the vicinity of susceptibility artifacts prohibits the use of signal-decreasing contrast agents.

Risk of intraoperative ischemia due to temporary vessel occlusion during standard extracranial-intracranial arterial bypass surgery.

OBJECT: Standard extracranial-intracranial (EC-IC) arterial bypass surgery represents a well-recognized procedure in which the aim is to augment distal cerebral circulation. The creation of the bypass requires temporary occlusion of the recipient vessel. Thus, there exists controversy about the risk of standard EC-IC arterial bypass surgery causing ischemic complications due to temporary vessel occlusion. In this prospective study, the incidence of intraoperative ischemia was investigated in symptomatic patients with steno-occlusive cerebrovascular disease and existing hemodynamic insufficiency. METHODS: Twenty consecutive patients (14 women and 6 men; mean age 46 +/- 11 years) suffering from recurrent transient ischemic attacks due to occlusive cerebrovascular disease and proven hemodynamic compromise in functional blood flow studies were enrolled in this study. The underlying pathological condition was internal carotid artery (ICA) or middle cerebral artery (MCA) occlusion in 6 cases and ICA or MCA stenosis in 3 cases, whereas 11 patients presented with moyamoya syndrome or moyamoya disease. The surgical procedure consisted of the establishment of a standard superficial temporal artery (STA)-MCA bypass, and was performed while a strict intraoperative management protocol was applied. Patients underwent clinical examination and magnetic resonance (MR) imaging within 48 hours before and after surgery. RESULTS: The incidence of reversible clinical signs of ischemia was 2 (10%) of 20 patients. Postoperative MR imaging revealed signs of diffusion disturbances in 2 (10%) of 20 cases. The observed diffusion-weighted imaging changes, however, were situated within the dependent vascular territory at risk for ischemia in 1 patient only. No permanent neurological deficit occurred. The temporary vessel occlusion time ranged between 25 and 42 minutes (mean 33 +/- 7 minutes). All means are expressed +/- the standard deviation. CONCLUSIONS: Temporary vessel occlusion during standard STA-MCA arterial bypass surgery carries a low risk of intraoperative ischemia when a strict perioperative management protocol is applied.