CT angiographic study of the cerebral deep veins around the vein of Galen.

Research on the anatomy of cerebral deep veins (CDVs) around the vein of Galen (VG) is very important and has fundamental clinical significance. Large-scale anatomical studies of CDVs using computed tomography angiography (CTA) are rarely reported. A retrospective study of the CDVs around the VG was conducted in Chinese patients of Han nationality. One hundred cases were included in the final analysis. The patients were aged from 17 to 78 years (mean: 42.3 years). Also, 46% of the patients were female. The diameter of the internal cerebral vein (ICV) at its beginning and termination points ranged from 0.4 to 2.8 mm (1.49 ± 0.39 mm) and 0.4 to 3.5 mm (2.05 ± 0.47 mm), respectively. There was statistical significance regarding the diameter of the ICV at its beginning and termination points (P <0.01). The ICV length ranged from 28.5 to 47.9 mm (36.86 ± 3.74 mm). The length of the straight sinus (SS) ranged from 30.2 to 57.8 mm (43.6 ± 6.37 mm). The length of the VG ranged from 1.5 to 41.8 mm (9.30 ± 4.76 mm). The angle at the VG and SS transition area ranged from 25.4 to 110.6° (77.2 ± 18.0°). This study was a meaningful attempt to conduct anatomical research of CDVs using CTA. Preoperative familiarity with the normal venous structure and its variation around the VG would be helpful for endovascular treatment.

Fusion of subarachnoid hemorrhage data and computed tomography angiography data is helpful to identify the rupture source in patients with multiple intracranial aneurysms.

Determining the rupture source is imperative in patient with aneurysmal subarachnoid hemorrhage (SAH). About one third of SAH cases with multiple intracranial aneurysms cannot be certain of the rupture source according to the hemorrhage pattern. This study aims to identify of the rupture source in patients with multiple intracranial aneurysms by fusing SAH data and computed tomography angiography (CTA) data. This retrospective study included 52 aneurysmal SAH patients with multiple intracranial aneurysms. In the 52 patients, 36 had definitive hemorrhage patterns on computed tomography imaging. And the other 16 patients had non-definitive hemorrhage patterns, which were bewildered for us to determine the ruptured aneurysms. Fusion of SAH data and CTA data was performed to demonstrate the spatial relationship between the SAH with each aneurysm by using the 3D Slicer software. For the patients with definitive bleed patterns, all of the suspected ruptured aneurysms were confirmed to be accurate according to the surgical records. Interestingly, the suspected rupture sources were correct in 14 of 16 patients with non-definitive hemorrhage patterns. For all 52 patients with multiple intracranial aneurysms, the ruptured aneurysms were identified in 50 cases (96.2%). In conclusion, fusion of SAH data and CTA data can precisely demonstrate the spatial relationship between the SAH with each aneurysm, which is helpful to determine the ruptured aneurysm in patients with multiple intracranial aneurysms.

Changes in Neuroendovascular Procedural Volume During the COVID-19 Pandemic: An International Multicenter Study.

BACKGROUND AND PURPOSE: The effect of coronavirus disease 2019 (COVID-19) pandemic on performance of neuroendovascular procedures has not been quantified. METHODS: We performed an audit of performance of neuroendovascular procedures at 18 institutions (seven countries) for two periods; January-April 2019 and 2020, to identify changes in various core procedures. We divided the region where the hospital was located based on the median value of total number of COVID-19 cases per 100,00 population-into high and low prevalent regions. RESULTS: Between 2019 and 2020, there was a reduction in number of cerebral angiograms (30.9% reduction), mechanical thrombectomy (8% reduction), carotid artery stent placement for symptomatic (22.7% reduction) and asymptomatic (43.4% reduction) stenoses, intracranial angioplasty and/or stent placement (45% reduction), and endovascular treatment of unruptured intracranial aneurysms (44.6% reduction) and ruptured (22.9% reduction) and unruptured brain arteriovenous malformations (66.4% reduction). There was an increase in the treatment of ruptured intracranial aneurysms (10% increase) and other neuroendovascular procedures (34.9% increase). There was no relationship between procedural volume change and intuitional location in high or low COVID-19 prevalent regions. The procedural volume reduction was mainly observed in March-April 2020. CONCLUSIONS: We provided an international multicenter view of changes in neuroendovascular practices to better understand the gaps in provision of care and identify individual procedures, which are susceptible to change.

Association Between Adherence to Quality Indicators and 7-Day In-Hospital Mortality After Acute Ischemic Stroke.

BACKGROUND AND PURPOSE: Quality indicators (QI) are an accepted tool to measure performance of hospitals in routine care. We investigated the association between quality of acute stroke care defined by overall adherence to evidence-based QI and early outcome in German acute care hospitals. METHODS: Patients with ischemic stroke admitted to one of the hospitals cooperating within the ADSR (German Stroke Register Study Group) were analyzed. The ADSR is a voluntary network of 9 regional stroke registers monitoring quality of acute stroke care across 736 hospitals in Germany. Quality of stroke care was defined by adherence to 11 evidence-based indicators of early processes of stroke care. The correlation between overall adherence to QI with outcome was investigated by assessing the association between 7-day in-hospital mortality with the proportion of QI fulfilled from the total number of QI the individual patient was eligible for. Generalized linear mixed model analysis was performed adjusted for the variables age, sex, National Institutes of Health Stroke Scale and living will and as random effect for the variable hospital. RESULTS: Between 2015 and 2016, 388 012 patients with ischemic stroke were reported (median age 76 years, 52.4% male). Adherence to distinct QI ranged between 41.0% (thrombolysis in eligible patients) and 95.2% (early physiotherapy). Seven-day in-hospital mortality was 3.4%. The overall proportion of QI fulfilled was median 90% (interquartile range, 75%-100%). In multivariable analysis, a linear association between overall adherence to QI and 7-day in-hospital-mortality was observed (odds ratio adherence <50% versus 100%, 12.7 [95% CI, 11.8-13.7]; P<0.001). CONCLUSIONS: Higher quality of care measured by adherence to a set of evidence-based process QI for the early phase of stroke treatment was associated with lower in-hospital mortality.

Application of pigtail catheter tailing combined with long-wire swapping technique in cerebral angiography via the right radial artery.

The safety and feasibility of transradial approach for cerebral angiography has been confirmed previously. However, this approach has been limited used due to the difficulty during the procedure. This study aimed to introduce a pigtail catheter tailing and long-wire swapping technique to improve the success rate without increasing complications.From August 2015 to December 2018, 560 patients who underwent cerebral angiography via transradial approach were recruited. The data including the type of aortic arch, type of Simmon catheter were collected.The loop was successfully constructed in 553 patients using Simmon-2 or Simmon-1 catheter. Of these patients, 72 patients successfully underwent cerebral and renal angiography, while 481 patients underwent cerebral angiography. The time for angiography was 52.87 ±â€Š11.23 minutes and 47.8 ±â€Š11.8 minutes, respectively. There were 369 (66.7%), 135 (24.4%), and 49 (8.9%) patients with type I, type II, and type III aortic arches, respectively, and their success rates of looping using Simmon-2 catheter were 97.8%, 97.0%, and 89.8%, respectively. The success rates of angiography in the right internal carotid artery, right vertebral artery, left internal carotid artery, and left vertebral artery were 100%, 100%, 98.9%, and 98.9%, respectively. No serious complications were observed in all patients.The pigtail catheter tailing and long guidewire swapping is considered as a safe procedure with high success rate for loop construction using a Simmon-2 catheter through the right radial artery, subsequently improving the success rate as well as the efficiency of angiography.

Environmental sustainability in neurointerventional procedures: a waste audit.

BACKGROUND: Operating rooms contribute between 20% to 70% of hospital waste. This study aimed to evaluate the waste burden of neurointerventional procedures performed in a radiology department, identify areas for waste reduction, and motivate new greening initiatives. METHODS: We performed a waste audit of 17 neurointerventional procedures at a tertiary-referral center over a 3-month period. Waste was categorized into five streams: general waste, clinical waste, recyclable plastic, recyclable paper, and sharps. Our radiology department started recycling soft plastics from 13 December 2019. Hence, an additional recyclable soft plastic waste stream was added from this time point. The weight of each waste stream was measured using a digital weighing scale. RESULTS: We measured the waste from seven cerebral digital subtraction angiograms (DSA), six mechanical thrombectomies (MT), two aneurysm-coiling procedures, one coiling with tumour embolization, and one dural arteriovenous fistula embolization procedure. In total, the 17 procedures generated 135.3 kg of waste: 85.5 kg (63.2%) clinical waste, 28.0 kg (20.7%) general waste, 14.7 kg (10.9%) recyclable paper, 3.5 kg (2.6%) recyclable plastic, 2.2 kg (1.6%) recyclable soft plastic, and 1.4 kg (1.0%) of sharps. An average of 8 kg of waste was generated per case. Coiling cases produced the greatest waste burden (13.1 kg), followed by embolization (10.3 kg), MT (8.8 kg), and DSA procedures (5.1 kg). CONCLUSION: Neurointerventional procedures generate a substantial amount of waste, an average of 8 kg per case. Targeted initiatives such as engaging with suppliers to revise procedure packs and reduce packaging, digitizing paper instructions, opening devices only when necessary, implementing additional recycling programs, and appropriate waste segregation have the potential to reduce the environmental impact of our specialty.

Radiological classification of azygos anterior cerebral artery and evaluation of the accompanying vascular anomalies.

PURPOSE: There is not a classification of azygos anterior cerebral artery (ACA) based on anatomical branching levels in the literature. In the present study, a classification of azygos ACA was made based on radiological imaging for a common terminology, and frequency, accompanying vascular anomalies and malformations were investigated. METHODS: A total of 4913 cases who had brain CTA, MRA, contrast-enhanced MRI and DSA in January 2010-January 2020 period were screened for the study. Based on anatomical branching level, azygos ACAs were classified into four groups. Aneurysms, anomalies and malformations accompanying azygos ACA were identified. The associations of azygos ACA types with the presence of aneurysm or ACA A1 segment anomalies were investigated. RESULTS: Azygos ACA was observed in 57 cases (29 male and 28 female) and frequency of azygos ACA was 1.16%. Average age of the cases with ACA was 56.19 ± 19.65 years. Forty-eight of the cases had type C azygos ACA, four cases type B, four cases type D and one case type A azygos ACA. A total of nine intracranial aneurysms were identified in seven of the cases (12.28%). Five of the aneurysms were located in MCA and four in distal ACA. Most common vascular anomalies accompanying azygos ACA were unilateral vertebral artery hypoplasia and ACA A1 segment hypoplasia. Azygos types did not have significant correlations with the presence of aneurysms or ACA A1 segmental anomalies (p = 0.683 and p = 0.949, respectively). CONCLUSION: Azygos ACA is a rare variation, but it could be accompanied by aneurysms or other vascular anomalies.

Evaluation of Cerebral Blood Flow Dynamics in Transient Ischemic Attacks Patients with Fast Cine Phase Contrast Magnetic Resonance Angiography.

Fast cine phase contrast magnetic resonance angiography (PC-MRA) has the potential to provide a quantitative measurement method for the diagnosis and treatment of cerebrovascular disease. To evaluation the changes of cerebral blood flow and the characteristics of artery lesion distribution in the patients of transient ischemic attacks (TIA). In all, 98 normal subjects and 106 TIA patients who underwent MRI examination within 72 h after the last symptom onset including the DWI sequence to exclude acute cerebral infarction were enrolled. The blood flow of the cranial total, the area of the internal carotid artery and vertebral artery, the average velocity, and the average blood flow were obtained and compared in normal subjects and TIA group. Analysis of Variance (ANOVA), t-test, and Kruskal-Wallis test were used for statistical assessments. The total cerebral blood flow of the TIA group and normal control group was no significant statistical difference (P > 0.05). The total blood flow decreased with increasing age, and the TIA group was much lower than the control group. The blood flow of the right internal carotid artery in the TIA group had a significant difference compared with controls (P < 0.05). However, the same situation did not happen in both of the left internal carotid artery and vertebral artery. Phase contrast magnetic resonance imaging has the potential to evaluate the change of cerebral blood flow in TIA patients. The decrease in the total blood flow and the symptom onset of TIA is consistent. Phase contrast magnetic resonance imaging could provide guidance to the diagnosis of TIA.

New ischemic lesions on brain magnetic resonance imaging in patients with blunt traumatic cerebrovascular injury.

BACKGROUND: Patients with blunt cerebrovascular injuries are at risk of thromboembolic stroke. Although primary prevention with antithrombotic therapy is widely used in this setting, its effectiveness is not well defined and requires further investigation. The aim of this study was to evaluate the utility of magnetic resonance imaging (MRI)-detected ischemic brain lesions as a possible future outcome for randomized clinical trials in this patient population. METHODS: This prospective observational study included 20 adult blunt trauma patients admitted to a level I trauma center with a screening neck CTA showing extracranial carotid or vertebral artery injury. All subjects lacked initial evidence of an ischemic stroke and were managed with antithrombotic therapy and observation and then underwent brain MRI within 30 days of the injury to assess for ischemic lesions. The MRI scans included diffusion, susceptibility, and Fluid-attenuated Inversion Recovery (FLAIR) sequences, and were reviewed by two neuroradiologists blinded to the computed tomography angiography (CTA) findings. RESULTS: Eleven CTAs were done in the emergency department upon admission. There were 12 carotid artery dissections and 11 unilateral or bilateral vertebral artery injuries. Median interval between injury and MRI scan was 4 days (range, 0.1-14; interquartile range, 3-7 days). Diffusion-weighted imaging evidence of new ischemic lesions was present in 10 (43%) of 23 of the injured artery territories. In those injuries with ischemic lesions, the median number was 8 (range, 2-25; interquartile range, 5-8). None of the lesions were symptomatic. Blunt cerebrovascular injury was associated with a higher mean ischemic lesion count (mean count of 3.17 vs. 0.14, p < 0.0001), with the association remaining after adjusting for injury severity score (p < 0.0001). CONCLUSION: In asymptomatic blunt trauma patients with CTA evidence of extracranial cerebrovascular injury and treated with antithrombotic therapy, nearly half of arterial injuries are associated with ischemic lesions on MRI. LEVEL OF EVIDENCE: Therapeutic/care management, level IV.

Factors determining the best surgical exposure and safe clip positioning in surgical treatment of anterior communicating artery (AComA) aneurysms - particular significance of AComA complex rotation in the axial plane.

INTRODUCTION: The aim of this study was to evaluate whether Anterior Communicating Artery (AComA) complex rotation in axial plane may influence the ease of surgical exploration in this region and safety of clip positioning when left vs right-sided approach is compared. MATERIALS AND METHODS: This is a retrospective study based on analysis of patients operated due to AComA aneurysm, both ruptured and unruptured. AComA complex position in relation to coronal plane was evaluated using 3D-CTA VR reconstructions. Next, comparison between surgical approach from the side where A1-A2 junction (angle) was located anterior and posterior to coronal plane was performed in relation to surgical difficulties and intra- and postoperative complications. RESULTS: Subgroup statistical analysis revealed that there is a strong and statistically significant correlation between AComA complex rotation and surgical difficulties expressed by the need of repeated temporary clip application and brain transgression. When anterior vs posterior angle side approach was compared in relation to surgical difficulties and complications, there was a statistically significant difference with strong correlation (p < 0.05) in favour of posterior angle side approach. Interestingly, in 72.7% and 45.5% of patients that were operated from the side where A1-A2 junction was located posterior to coronal plane, the approach was performed form the side of a non-dominant A1 and aneurysm dome projection side, respectively. CONCLUSIONS: Despite its limitations, our results suggest that microsurgical clipping strategy of AComA aneurysms should at least include AComA complex rotation in axial plane, besides well acknowledged factors, when deciding from which side these lesions will be approached.

Clinical Policy: Critical Issues in the Evaluation and Management of Adult Patients Presenting to the Emergency Department With Acute Headache

This clinical policy from the American College of Emergency Physicians addressed key issues in the evaluation and management of adult patients presenting to the emergency department with acute headache. A writing subcommittee conducted a systematic review of the literature to derive evidence-based recommendations to answer the following clinical questions: (1) In the adult emergency department patient presenting with acute headache, are there risk-stratification strategies that reliably identify the need for emergent neuroimaging? (2) In the adult emergency department patient treated for acute primary headache, are nonopioids preferred to opioid medications? (3) In the adult emergency department patient presenting with acute headache, does a normal noncontrast head computed tomography scan performed within 6 hours of headache onset preclude the need for further diagnostic workup for subarachnoid hemorrhage? (4) In the adult emergency department patient who is still considered to be at risk for subarachnoid hemorrhage after a negative noncontrast head computed tomography, is computed tomography angiography of the head as effective as lumbar puncture to safely rule out subarachnoid hemorrhage? Evidence was graded and recommendations were made based on the strength of the available data.

Practice Variation in the Diagnosis of Aneurysmal Subarachnoid Hemorrhage: A Survey of US and Canadian Emergency Medicine Physicians.

BACKGROUND AND AIMS: Spontaneous subarachnoid hemorrhage (SAH) from a brain aneurysm, if untreated in the acute phase, leads to loss of functional independence in about 30% of patients and death in 27-44%. To evaluate for SAH, the American College of Emergency Physicians (ACEP) Clinical Policy recommends obtaining a non-contrast brain computed tomography (CT) scan followed by a lumbar puncture (LP) if the CT is negative. On the other hand, current evidence from prospectively collected data suggests that CT alone may be sufficient to rule out SAH in patients who present within 6 h of symptom onset while anecdotal evidence suggests that CT angiogram (CTA) may be used to detect aneurysms, which are the probable cause of SAH. Since many different options are available to emergency physicians, we examined their practice pattern variation by observing their diagnostic approaches and their adherence to the ACEP Clinical Policy. METHODS: We developed, validated, and distributed a survey to emergency physicians at three practice sites: (1) Stanford Healthcare, California, (2) Intermountain Healthcare (five emergency departments), Utah, and (3) Ottawa General Hospital, Toronto. The survey questions examined physician knowledge on CT and LP's test performance and used case-based scenarios to assess diagnostic approaches, variation in practice, and adherence to guidelines. Results were presented as proportions with 95% CIs. RESULTS: Of the 216 physicians surveyed, we received 168 responses (77.8%). The responses by site were: (1) (n = 38, 23.2%), (2) (n = 70, 42.7%), (3) (n = 56, 34.1%). To the CT and LP test performance question, most physicians indicated that CT alone detects > 90% of SAH in those with a confirmed SAH [n = 150 (89.3%, 95% CI 83.6-93.5]. To the case-based questions, most physicians indicated that they would perform a CTA along with a CT [n = 110 (65.5%, 95% CI 57.8-72.6)], some indicated a LP along with a CT [n = 57, 33.9% 95% CI 26.8-41.6)], and a few indicated both a CTA and a LP [n = 16, 9.5%, 95% CI 5.5-15.0]. We also observed practice site variation in the proportion of physicians who indicated that they would use CTA: (1) (n = 25, 65.8%), (2) (n = 54, 77.1%), and (3) (n = 28, 50.0%) (p = 0.006). CONCLUSIONS: Survey responses indicate that physicians use some or all of the imaging tests, with or without LP to diagnose SAH. We observed variation in the use of CTA by site and academic setting and divergence from ACEP Clinical Policy.

Endovascular Neurosurgery in the Northern Macro-Region of Rio Grande do Sul: Part I

Introduction The city of Passo Fundo, in the north of the Rio Grande do Sul state, has been standing out in the health care field for many years. The state has become a reference in endovascular interventional neuroradiology. We will cover 10 years of experience in this area and divide our observations in 3 parts: cerebral angiograms (part I), carotid angioplasties (part II) and intracranial aneurysms (part III). The goal of part I is to statistically assess the cerebral angiograms, their indications, risks and complications, as well as to do a technical review. Materials and Methods A retrospective study from 2005 to 2015 with a total of 5,567 interventional neuroradiology procedures performed. A total of 4,114 angiograms, 639 embolizations of intracranial aneurysms, 414 carotid angioplasties, 143 embolizations of cerebral arteriovenous malformations, 32 embolizations of dural arteriovenous fistulas, 102 cerebral vasospasm treatments, 21 treatments of epistaxis, 36 embolizations of craniocervical tumor, 25 thrombolysis of ischemic stroke, 18 vertebroplasties and 13 embolizations of arteriovenous malformations of the face. Results A total of 4,084 procedures performed, 21,811 vessels studied, average vase 7.62/2.82 vessel and patient/procedure. Of these, 2,536 were diagnostic procedures and 1,548 angiographic controls. Of the total, 1,188 patients received only an angiogram, 27.14% of which were therapeutic procedures. We obtained a total of 3.89% complications: 2.33% reflection vasovagal, 0.56% allergic skin reaction, anaphylactic shock 0.07%, 0.27% femoral hematoma, 0.26% transient neurological deficit, 0.12% permanent neurological deficit and no case of death. Conclusion Cerebral angiography in adults, children and infants is a safe procedure with low risk of permanent neurological complications.

Small Intracranial Aneurysms: Diagnostic Accuracy of CT Angiography.

Purpose To assess the accuracy of computed tomographic (CT) angiography for diagnosis of cerebral aneurysms 5 mm or smaller, with digital subtraction angiography (DSA) as the reference standard, in a large patient cohort Materials and Methods This retrospective study was approved by the local institutional review board with a waiver of written informed consent. A total of 1366 patients who underwent cerebral CT angiography followed by DSA were included. The performance of CT angiography for depiction of aneurysms was evaluated by two readers on a per-patient and per-aneurysm basis and based on size of aneurysm, location, and status of rupture. The performance of CT angiography for diagnosis of aneurysms of different size, location, and rupture status was compared by using χ2 test. κ statistic was used to assess interreader agreement for diagnosis of aneurysms. Results Of 1366 patients, 579 patients had 711 small aneurysms at DSA. By using DSA as the reference standard, the respective sensitivity, specificity, and accuracy of CT angiography for readers 1 and 2 for detection of small aneurysms on a per-patient basis were 97.1% (562 of 579) and 97.4% (564 of 579), 98.5% (451 of 458) and 99.1% (454 of 458), and 97.7% (1013 of 1037) and 98.2% (1018 of 1037) and those on a per-aneurysm basis were 95.2% (677 of 711) and 95.4% (678 of 711), 96.6% (451 of 467) and 97.0% (454 of 468), and 95.8% (1128 of 1178) and 96.0% (1132 of 1179). The sensitivities of CT angiography were lower for detection of aneurysms smaller than 3 mm and unruptured compared with aneurysms that were 3-5 mm and ruptured (P < .001). No difference existed for the sensitivities of CT angiography for diagnosis of aneurysms in the anterior versus posterior circulation (P > .0167). Excellent or good interreader agreement was found for detection of intracranial aneurysms on a per-patient (κ = 0.982) and per-aneurysm (κ = 0.748) basis. Conclusion This large cohort study demonstrated that CT angiography had high accuracy for detection of small cerebral aneurysms, including those smaller than 3 mm. © RSNA, 2017 Online supplemental material is available for this article.

Interfacility Transfer Directly to the Neuroangiography Suite in Acute Ischemic Stroke Patients Undergoing Thrombectomy.

BACKGROUND AND PURPOSE: In patients identified at referring facilities with acute ischemic stroke caused by a large vessel occlusion, bypassing the emergency department (ED) with direct transport to the neuroangiography suite may safely shorten reperfusion times. METHODS: We conducted a single-center retrospective review of consecutive patients transferred to our facility for consideration of endovascular therapy. Patients were identified as admitted directly to the neuroangiography suite (DAN), transferred to the ED before intra-arterial therapy (ED-IA), and transferred to the ED but did not receive IA therapy (ED-IV). RESULTS: A retrospective review of a prospectively maintained database of transfer patients between January 2013 and October 2016 with large vessel occlusions identified 108 ED-IV patients and 261 patients who underwent mechanical thrombectomy (DAN=111 patients and ED-IA=150 patients). There were no differences in baseline characteristics among the 3 groups. The median computed tomography ASPECTS (Alberta Stroke Program Early CT Score) was lower in the ED-IV group versus the ED-IA and DAN groups (8 versus 9; P=0.001). In the DAN versus ED-IA cohort, there were comparable rates of TICI2b/3 recanalization and access to recanalization time. There was significantly faster hospital arrival to groin access time in the DAN cohort (81 minutes versus 22 minutes; P=0.001). Functional independence at 90 days was comparable in the DAN versus ED-IA cohorts but worse in the ED-IV group (43% versus 44% versus 22%; P=0.001). CONCLUSIONS: DAN is safe, feasible, and associated with faster times of hospital arrival to recanalization. The clinical benefit of this approach should be assessed in a prospective randomized trial.

Analysis of Radiation Doses and Dose Reduction Strategies During Cerebral Digital Subtraction Angiography.

OBJECTIVE: Adverse effects of increased use of cerebral digital subtraction angiography (DSA) include radiation-induced skin reactions and increased risk of malignancy. This study aimed to identify a method for reducing radiation exposure during routine cerebral DSA. METHODS: A retrospective review of 138 consecutive adult patients who underwent DSA with a biplane angiography system (Artis Zee, Siemens, Germany) from September 2015 to February 2016 was performed. In January 2016, the dose parameter was reset by the manufacturer from 2.4 µGy to 1.2 µGy. Predose (group 1) and postdose parameter reduction (group 2) groups were established. Angiograms and procedure examination protocols were reviewed according to patient age, gender, and diagnosis and angiography techniques were reviewed on the basis of the following radiation dose parameters: fluoroscopy time, reference point air kerma (Ka,r; in mGy), and kerma-area product (PKA; in µGym2). RESULTS: The mean Ka,r values in groups 1 and 2 were 1841.5 mGy and 1274.8 mGy, respectively. The mean PKA values in groups 1 and 2 were 23212.5 µGym2 and 14854.0 µGym2, respectively. Ka,r and PKA values were significantly lower in group 2 compared with group 1 (P < 0.001). Among individual factors, young age was a determining factor for reduced fluoroscopy time (P < 0.001), Ka,r (P = 0.047), and PKA (P = 0.022). CONCLUSIONS: Increased awareness of radiation risks, as well as the establishment of strategies to reduce radiation dose, led to lower radiation doses for DSA. The use of appropriate examinations and low-dose parameters in fluoroscopy contributed significantly to the radiation dose reductions.

Complications of in-patient Cerebral Angiography: Comparison between patients with and without sub arachnoid haemorrhage.

OBJECTIVE: To compare complications of cerebral angiography among patients with and without subarachnoid haemorrhage. METHODS: This retrospective study was conducted at the Aga Khan University Hospital, Karachi, and comprised records of patients undergoing inpatient therapeutic and diagnostic cerebral angiographies from 2001 to 2010. The patients were divided into subarachnoid and non-subarachnoid haemorrhage groups. During the study period no modifications were made to the operational protocol and all patients were subjected to the same procedure and prophylactic care. RESULTS: Of the 93 patients, 42(45.2%) were women and 51(54.8%) were men. The overall mean age was 45.27±16.15 years (range: 4-80 years). The comparison between the two groups regarding new onset of neurological deficit was statistically significant (p=0.001). However, the same comparison regarding drop in Glasgow Coma Scale was statistically not significant (p=0.073). CONCLUSIONS: The rate of neurological complications was higher in patients with subarachnoid haemorrhage.

Interrater variability for CT angiography evaluation between neurologists and neuroradiologist in acute stroke patients.

OBJECTIVE: The diagnosis of arterial occlusion has a considerable impact on the indication of mechanical thrombectomy, and CT angiography (CTA) is recommended in the management of acute stroke. The goal of the present study is to assess the interrater agreement in the diagnosis of occlusion of intracranial arteries on CTA between a neuroradiologist and neurologists. METHODS: CTA images of 75 acute stroke patients were evaluated for occlusion of intracranial arteries by an experienced interventional neuroradiologist, and stroke and general neurologists. RESULTS: 75 patients who were treated by intravenous thrombolysis were enrolled in the study. CTA images were available for all 75 patients (34 females; mean age ± SD, 72 ± 14 years; National Institutes of Health Stroke Scale 10; median 8-14; and Alberta Stroke Program Early CT mean 9.7). The agreement between the neuroradiologist and neurologists in evaluation of intracranial artery occlusion was as follows: occlusion of the middle cerebral artery segment M1: observer agreement 77%, kappa (κ) = 0.61 and middle cerebral artery M2: observer agreement 77%, κ 0.48; internal carotid artery: observer agreement 92%, κ 0.84; T occlusion: observer agreement 90.0%, κ 0.33; posterior cerebral artery segments P1 and P2: observer agreement 98%, κ 0.97; basilar artery: observer agreement 96%, κ 0.92; and vertebral artery segment V4: observer agreement 88%, κ 0.48. CONCLUSION: Interrater agreement of CTA evaluation of occlusion between the neurologists and the neuroradiologist was very strong. The ability of the trained neurologists to read an intracranial large vessel occlusion correctly may improve the door-to-needle times in acute stroke. Advances in knowledge: In this study, the neurologists were able to recognize occlusion of intracranial arteries. This could accelerate the management of acute stroke care.

Timing of Mean Transit Time Maximization is Associated with Neurological Outcome After Subarachnoid Hemorrhage.

PURPOSE: Computed tomography perfusion (CTP) has gained significant relevance for the radiological screening of patients at risk of developing delayed cerebral ischemia (DCI) after aneurysmal subarachnoid hemorrhage (aSAH). Particularly, the impact of MTTPEAK, i.e., the maximal mean transit time value in a series of CTP measurements, for the prediction of long-term outcome has recently been demonstrated by our group. Complementing this recent work, the present study investigated how the timing of MTTPEAK affected the long-term outcome after aneurysmal subarachnoid hemorrhage. METHODS: CTP examinations from 103 patients with clinical deterioration attributed to DCI after aSAH were retrospectively analyzed for time interval between SAH ictus and onset of MTTPEAK in association with modified Rankin Scale (mRS) 23.1 months after SAH. RESULTS: Patients with unfavorable outcome (mRS > = 2) suffered significant earlier MTTPEAK onsets than patients with favorable outcome (mRS = 0 and 1). MTTPEAK within the first week was associated with significantly higher mRS scores compared to later MTTPEAK. Timing of MTTPEAK together with the value of MTTPEAK and initial World Federation of Neurosurgical Societies (WFNS) grade was a significant predictor for an unfavorable outcome (mRS > = 2). CONCLUSIONS: The current findings suggest a presumably higher vulnerability of the brain to early microcirculatory impairments after aSAH and highlight that timing of MTT elevations could be considered for the identification of patients at increased risk for poor neurological outcome due to DCI.

Bacterial Contamination During Diagnostic and Interventional Neuroangiography is a Frequent Finding: But Does It Matter? An Observational Study.

INTRODUCTION: Bacterial contamination during angiographic procedures is a potential source of bacteremia. It is largely unknown whether it is clinically relevant. Our aim was to evaluate the incidence of contamination of liquids during catheter-based neuroangiographic examinations, the spectrum of microorganisms, a comparison of two different trolley-settings, and a follow-up of all patients with regard to clinical and lab signs of infection. METHODS: A total of 170 patients underwent either diagnostic angiography (n = 111) or arterial neuroendovascular procedures (n = 59). To study the impact of airborne contamination of sterile liquids, we randomly assigned equal numbers of procedures to two distinct setups. Group A with standard open-surface bowls and group B with repetitive coverage of liquids throughout the procedure. Patient preparation was performed with utmost care. After each procedure, samples of the liquids were sent for microbiological evaluation. Patients were followed for signs of infection (fever, white blood cell count, C-reactive-protein). RESULTS: Of all samples, 25.3 % were contaminated. Contamination consisted of resident skin microbiota only and was more common with procedures (28.8 %) than with diagnostic angiography (23.4 %) and less common in uncovered (23.5 %) than in covered bowls (27.1 %). However, these differences were insignificant. None of the patients developed clinical or lab signs of infection. CONCLUSION: Contamination during diagnostic and interventional angiography does occur and cannot be avoided by intermittent coverage. Despite a surprisingly high incidence, our findings support the common strategy that antibiotic coverage is unnecessary in most patients undergoing arterial angiography as it lacks clinical impact. Airborne contamination does not appear to play a role.