Precise Position Estimation Using Smartphone Raw GNSS Data Based on Two-Step Optimization.

This paper presents a high-precision positioning method using raw global navigation satellite system (GNSS) observations from smartphones in the Google smartphone decimeter challenge (GSDC). Compared to commercial GNSS receivers, smartphone GNSS observations are noisy owing to antenna limitations, making it difficult to apply conventional high-precision positioning methods. In addition, it is important to exclude outliers in GSDC because GSDC includes data in environments where GNSS is shielded, such as tunnels and elevated structures. Therefore, this study proposes a smartphone positioning method based on a two-step optimization method, using factor graph optimization (FGO). Here, the velocity and position optimization process are separated and the velocity is first estimated from Doppler observations. Then, the outliers of the velocity estimated by FGO are excluded, while the missing velocity is interpolated. In the next position-optimization step, the velocity estimated in the previous step is adopted as a loose state-to-state constraint and the position is estimated using the time-differenced carrier phase (TDCP), which is more accurate than Doppler, but less available. The final horizontal positioning accuracy was 1.229 m, which was the first place, thus demonstrating the effectiveness of the proposed method.

A nutritional intervention that promotes increased vegetable intake in Japanese with non-alcoholic fatty liver disease: a six-month trial.

The aim of this study was to investigate whether a nutritional intervention motivating increased vegetable consumption would be an effective treatment and diet therapy for patients with non-alcoholic fatty liver disease. We examined 15 patients with this disease (5 men and 10 women). During the 6-month intervention period, all participants received a small amount of vegetables twice a month as a nutritional education tool aimed at increasing vegetable consumption. They also received nutritional counseling and underwent ultrasound and blood biochemical examinations at baseline and 3 and 6 months after initiation of the intervention. Moreover, they were requested to submit dietary records for any 2 days. Green, white, and total vegetable intakes were significantly higher at 3 and 6 months than at baseline in 8 patients. These patients had significantly lower alanine amino-transferase and triglyceride concentrations than those whose vegetable intake did not increase. Additionally, green vegetable intake significantly negatively correlated with weight at 3 and 6 months (r = -0.617, p = 0.032 and r = -0.848, p = 0.008, respectively). These results suggest that our nutritional approach effectively increased vegetable consumption in at least some patients with non-alcoholic fatty liver disease, consequently improving their condition.

A genome-wide association study on confection consumption in a Japanese population: the Japan Multi-Institutional Collaborative Cohort Study.

Differences in individual eating habits may be influenced by genetic factors, in addition to cultural, social or environmental factors. Previous studies suggested that genetic variants within sweet taste receptor genes family were associated with sweet taste perception and the intake of sweet foods. The aim of this study was to conduct a genome-wide association study (GWAS) to find genetic variations that affect confection consumption in a Japanese population. We analysed GWAS data on confection consumption using 14 073 participants from the Japan Multi-Institutional Collaborative Cohort study. We used a semi-quantitative FFQ to estimate food intake that was validated previously. Association of the imputed variants with confection consumption was performed by linear regression analysis with adjustments for age, sex, total energy intake and principal component analysis components 1-3. Furthermore, the analysis was repeated adjusting for alcohol intake (g/d) in addition to the above-described variables. We found 418 SNP located in 12q24 that were associated with confection consumption. SNP with the ten lowest P-values were located on nine genes including at the BRAP, ACAD10 and aldehyde dehydrogenase 2 regions on 12q24.12-13. After adjustment for alcohol intake, no variant was associated with confections intake with genome-wide significance. In conclusion, we found a significant number of SNP located on 12q24 genes that were associated with confections intake before adjustment for alcohol intake. However, all of them lost statistical significance after adjustment for alcohol intake.

NLOS Multipath Classification of GNSS Signal Correlation Output Using Machine Learning.

This paper proposes a method for detecting non-line-of-sight (NLOS) multipath, which causes large positioning errors in a global navigation satellite system (GNSS). We use GNSS signal correlation output, which is the most primitive GNSS signal processing output, to detect NLOS multipath based on machine learning. The shape of the multi-correlator outputs is distorted due to the NLOS multipath. The features of the shape of the multi-correlator are used to discriminate the NLOS multipath. We implement two supervised learning methods, a support vector machine (SVM) and a neural network (NN), and compare their performance. In addition, we also propose an automated method of collecting training data for LOS and NLOS signals of machine learning. The evaluation of the proposed NLOS detection method in an urban environment confirmed that NN was better than SVM, and 97.7% of NLOS signals were correctly discriminated.

The role of Oryza sativa L. 'Milyang 44' husks on the resistance to two rice stink bugs.

To elucidate the resistance mechanisms of the rice (Oryza sativa L.) cultivar 'Milyang 44' against rice stink bugs, we compared the number of stylet sheaths, husk perforations, and feeding marks on the surface of the grains caused by Leptocorisa chinensis and Cletus punctiger on Milyang 44 and the control cultivar, i.e., 'Aichinokaori SBL'. We also examined the cross-sectional structure of the rice husks. We found that the number of stylet sheaths per panicle was higher in Milyang 44 than in Aichinokaori SBL for both rice stink bug species, except in one test involving C. punctiger. However, Milyang 44 had significantly less damage per number of stylet sheaths than Aichinokaori SBL, resulting in a lower percentage rates of pecky rice grains in Milyang 44. Interestingly, there was no difference in the percentage rates of pecky rice between the two cultivars after removing one third of the husks. Histological analysis showed that the sclerenchymatous cell wall containing lignin of husk was thicker in Milyang 44 than in Aichinokaori SBL, suggesting that the husk of Milyang 44 plays an important role in its resistance to these two rice stink bug species.

[The nutritional and dietary intake among community-dwelling elderly female users of mobile vendor vehicles].

AIM: We compared the nutritional and dietary intakes of users of mobile vendor vehicles and users of stores to clarify the problems in the nutritional intake of users of mobile vendor vehicles. METHODS: We conducted a questionnaire about the food accessibility among 257 elderly women (age: ≥65 years) who used mobile vendor vehicles and/or stores to shop. The nutritional intake was assessed using the 24-hour recall method. We used an analysis of covariance (ANCOVA) to calculate the age-adjusted mean values for the total nutritional intake. RESULTS: The nutritional intake among users of mobile vendor vehicles included significantly lower intakes of energy (168 kcal), green vegetables, other vegetables, and meats. Furthermore, those who only shopped at mobile vendor vehicles consumed less energy and fewer nutrients than those who shopped at places other than mobile vendor vehicles. The comparison of the shopping frequency and nutritional intake of the subjects who used mobile vendor vehicles alone revealed that the energy and protein intakes of those who shopped once per week was significantly lower in comparison to those who shopped twice per week. CONCLUSIONS: Users of mobile vendor vehicles had lower intakes of macronutrients and various minerals and vitamins. Among the food groups, intakes of vegetables, meat, and dairy products were low. These findings suggest that the lack of means of shopping other than mobile vendor vehicles and shopping once per week may be associated with an inadequate dietary intake among users of mobile vendor vehicles. It would be desirable to develop the shopping environment is desirable.

A Case of Rheumatoid Meningitis Diagnosed with FLAIR Images and Anti-cyclic Citrullinated Peptide Antibodies Levels.

Rheumatoid meningitis (RM) is a rare but serious extra-articular manifestation of rheumatoid arthritis. Due to the absence of specific biomarkers, imaging findings, or guidelines for its detection, the diagnosis of RM is difficult. This report describes a patient of RM diagnosed with an open biopsy and discusses the utility of anticyclic citrullinated peptide antibodies (ACPA) levels in the serum and cerebrospinal fluid (CSF), and contrast-enhanced (CE) fluid-attenuated inversion recovery (FLAIR) images for screening and monitoring RM. A 65-year-old woman presented with a 2-month history of headaches. Imaging studies showed asymmetric meningeal and leptomeningeal involvement seen on brain magnetic resonance imaging (MRI). An open biopsy of the meninges and leptomeninges depicted palisaded and necrotizing granulomatous inflammation, which suggests rheumatoid nodules. Treatment with prednisolone and tocilizumab led to symptom improvement and reduced lesion intensity on follow-up MRI. Throughout the treatment, the ACPA index in her serum and CSF, and the findings of CE-FLAIR images, rather than the CE T1WI, reflected disease activity. For 6 months, the patient has been stable without symptom recurrence. The ACPA index and the CE-FLAIR images were useful for the diagnosis and monitoring of RM. To validate these findings, further studies are necessary.

Subarachnoid Hemorrhage Confirmed by Magnetic Resonance Imaging in a Patient with Brain Death owing to Hypoxic Encephalopathy Following Suicide by Hanging.

Although true subarachnoid hemorrhage (SAH) is an atypical complication owing to suicide by hanging, pseudo-SAH can often develop because of hypoxic encephalopathy. Therefore, differentiating pseudo-SAH from true SAH using brain computed tomography (CT) is often challenging. In Japan, an individual's cause of brain death must be determined to be eligible for organ donation, regardless of whether true SAH is involved or not. Herein, we report a case of SAH confirmed by magnetic resonance imaging (MRI) in a patient with brain death owing to hypoxic encephalopathy following suicide by hanging. A 48-year-old man attempted suicide by hanging. Upon arrival at the hospital, he developed pulseless electrical activity with apnea. Although spontaneous circulation returned within a few minutes of his arrival, spontaneous breathing did not recover. The patient was in deep comatose state without response to pain stimulation, brainstem reflexes, or electrical activities on an electroencephalogram. Consequently, the patient met diagnostic criteria for clinical brain death based on the Japanese organ transplantation law. Brain CT revealed global hypoxic injury and high density in the basal cisterns and subarachnoid space. Brain MR T2*-weighted imaging revealed low intensity at the left Sylvian fissure underlying the hematoma. These findings indicated brain death owing to hypoxic encephalopathy following hanging, and incidental true SAH was confirmed by MRI. Donor surgery and organ transplantation were performed. Spontaneous SAH can often develop secondary to hanging, and brain MRI can effectively determine whether the cause of brain death involves true SAH.

Evaluation of L6 augmentation signal reception characteristics and positioning accuracy of compact and lightweight GNSS antennas.

Applications requiring outdoor position estimation, such as unmanned construction and delivery automation, focus on receiving global navigation satellite system (GNSS) correction information from satellites for high-precision positioning. In particular, the delivery of correction information for the Galileo high-accuracy service (HAS) and quasi-zenith satellite system (QZSS) centimeter-level augmentation service (CLAS) is based on a new frequency band called L6. The L6 signal is a new type of GNSS signal, and a GNSS antenna corresponding to the frequency of the L6 signal (1275.46 MHz) is required to receive and decode the correction messages. The reception characteristics of the L6 signal are important for receiving correction information. However, the reception performance of antennas supporting the new L6 signal has not been evaluated. Therefore, in this study, we evaluate the reception characteristics of the L6 signal of a compact and lightweight L6-compatible antenna, and the multipath characteristics, which are the fundamental performance of the antenna that affects high-precision positioning. In a 24-hour static test, each antenna's signal reception performance and multipath characteristics were evaluated, and significant differences were found in performance among the antennas capable of receiving the L6 signal. Furthermore, in a kinematic test, we evaluated high-accuracy positioning using QZSS CLAS with multiple antennas and showed that centimeter-level positioning using L6 augmentation signals is possible even with compact and lightweight GNSS antennas. These evaluations provide guidelines for antenna selection when high-precision positioning using L6 signals is employed in various applications.

Moyamoya Syndrome Presenting with Ischemic Stroke Caused by Rapid Worsening of Vessel Stenosis Associated with Triple-seropositive Antiphospholipid Syndrome.

Several case reports of patients with both moyamoya syndrome (MMS) and antiphospholipid syndrome (APS) have been published. However, the relationship between MMS and APS has not been clarified. We herein report a patient with MMS who had an ischemic stroke with rapid worsening of stenosis of the middle cerebral artery associated with APS. The patient was triple-positive for antiphospholipid antibodies. Patients with MMS complicated by APS should be closely followed up with vascular imaging.

Effect of combination therapy with the angiotensin receptor blocker losartan plus hydrochlorothiazide on brain perfusion in patients with both hypertension and cerebral hemodynamic impairment due to symptomatic chronic major cerebral artery steno-occlusive disease: a SPECT study.

BACKGROUND: While the combination of an angiotensin receptor blocker with thiazide diuretics produces a clinically beneficial reduction in blood pressure in patients who otherwise only partially respond to monotherapy with an angiotensin receptor blocker, blood pressure-lowering therapy with combination antihypertensive drug regimens in patients with cerebral hemodynamic impairment may adversely affect cerebral hemodynamics. The purpose of the present exploratory study was to determine whether blood pressure-lowering therapy with the combination of the angiotensin receptor blocker losartan plus hydrochlorothiazide (LPH) worsens brain perfusion in patients with both hypertension and cerebral hemodynamic impairment due to symptomatic chronic major cerebral artery steno-occlusive disease. METHODS: Patients with losartan-resistant hypertension and reduced cerebrovascular reactivity (CVR) to acetazolamide due to symptomatic chronic internal carotid artery (ICA) or middle cerebral artery (MCA) steno-occlusive disease were prospectively entered into the present study and received 50 mg/day of losartan plus 12.5 mg/day of hydrochlorothiazideat 14 weeks after the last ischemic event. Cerebral blood flow (CBF) and CVR were measured before and 12 weeks after initiating LPH using N-isopropyl-p-[(123)I]-iodoamphetamine single-photon emission computed tomography (SPECT). A region of interest (ROI) was automatically placed in the MCA territory on each SPECT image using a three-dimensional stereotactic ROI template. RESULTS: None of the 18 patients who participated in the study experienced any new neurological symptoms or adverse effects related to antihypertensive drugs. Systolic (p < 0.001) and diastolic (p < 0.001) blood pressures were significantly reduced after the administration of LPH, with average reductions of 11 mm Hg in systolic blood pressure and 10 mm Hg in diastolic blood pressure. While in the affected hemisphere CBF did not differ between measurements taken before and after the administration of LPH, CVR was significantly higher after the administration of LPH than before (p = 0.007) and was significantly improved in 5 of 18 patients. In the contralateral hemisphere, CBF and CVR did not differ between measurements taken before and after the administration of LPH. There were no patients who experienced a significant deterioration in CBF or CVR in the affected or contralateral hemisphere after the administration of LPH. CONCLUSIONS: Although the present study was exploratory and its results were preliminary due to the small sample size, the current data suggest that blood pressure-lowering therapy with LPH apparently does not result in worsening of cerebral hemodynamics in patients with both hypertension and cerebral hemodynamic impairment due to symptomatic chronic ICA or MCA steno-occlusive disease.

Postoperative cerebral white matter damage associated with cerebral hyperperfusion and cognitive impairment after carotid endarterectomy: a diffusion tensor magnetic resonance imaging study.

BACKGROUND: Cerebral hyperperfusion after carotid endarterectomy (CEA), even when asymptomatic, often impairs cognitive function. However, conventional magnetic resonance (MR) imaging rarely demonstrates structural brain damage associated with postoperative cognitive impairment. MR diffusion tensor imaging (DTI) is potentially more sensitive for detection of white matter damage. Among the common parameters derived by DTI, fractional anisotropy (FA) is a marker of tract integrity, and mechanical disruption of axonal cylinders and loss of continuity of myelin sheaths may be responsible for reduced FA in white matter. The purpose of the present study was to determine whether postoperative cerebral white matter damage that can be detected by FA derived by DTI is associated with cerebral hyperperfusion after CEA and correlates with postoperative cognitive impairment. METHODS: In 70 patients undergoing CEA for ipsilateral internal carotid artery stenosis (≥70%), cerebral blood flow (CBF) was measured using single-photon emission computed tomography (SPECT) before and immediately after CEA and on postoperative day 3. FA values in cerebral white matter were assessed using DTI before and 1 month after surgery. These values were normalized and analyzed using statistical parametric mapping 5. In each corresponding voxel in the pre- and postoperative normalized FA maps of each patient, a postoperative FA value minus a preoperative FA value was calculated, and a voxel with postoperatively reduced FA was defined based on data obtained from healthy volunteers. The number of voxels with postoperatively reduced FA was calculated and defined as the volume with postoperatively reduced FA. Neuropsychological testing, consisting of the Wechsler Adult Intelligence Scale Revised, the Wechsler Memory Scale and the Rey-Osterreith Complex Figure test, was also performed preoperatively and after the first postoperative month. Postoperative cognitive impairment on neuropsychological testing in each patient was defined based on data obtained from patients with asymptomatic unruptured cerebral aneurysms. RESULTS: Post-CEA hyperperfusion on brain perfusion SPECT (CBF increase ≥100% compared with preoperative values) and postoperative cognitive impairment on neuropsychological testing were observed in 11 (16%) and 9 patients (13%), respectively. The volume with postoperatively reduced FA in cerebral white matter ipsilateral to surgery was significantly greater in patients with post-CEA hyperperfusion than in those without (p < 0.0001). This volume in cerebral white matter ipsilateral to surgery was also significantly associated with postoperative cognitive impairment (95% confidence interval, 1.559-8.853; p = 0.0085). CONCLUSIONS: Cerebral hyperperfusion after CEA results in postoperative cerebral white matter damage that correlates with postoperative cognitive impairment.

Intracranial aneurysm rupture within three days after receiving mRNA anti-COVID-19 vaccination: Three case reports.

Background: Although neurological adverse events have been reported after receiving coronavirus disease 2019 (COVID-19) vaccines, associations between COVID-19 vaccination and aneurysmal subarachnoid hemorrhage (SAH) have rarely been discussed. We report here the incidence and details of three patients who presented with intracranial aneurysm rupture shortly after receiving messenger ribonucleic acid (mRNA) COVID-19 vaccines. Case Description: We retrospectively reviewed the medical records of individuals who received a first and/ or second dose of mRNA COVID-19 vaccine between March 6, 2021, and June 14, 2021, in a rural district in Japan, and identified the occurrences of aneurysmal SAH within 3 days after mRNA vaccination. We assessed incidence rates (IRs) for aneurysmal SAH within 3 days after vaccination and spontaneous SAH for March 6-June 14, 2021, and for the March 6-June 14 intervals of a 5-year reference period of 2013-2017. We assessed the incidence rate ratio (IRR) of aneurysmal SAH within 3 days after vaccination and spontaneous SAH compared to the crude incidence in the reference period (2013-2017). Among 34,475 individuals vaccinated during the study period, three women presented with aneurysmal SAH (IR: 1058.7/100,000 person-years), compared with 83 SAHs during the reference period (IR: 20.7/100,000 persons-years). IRR was 0.026 (95% confidence interval [CI] 0.0087-0.12; P < 0.001). A total of 28 spontaneous SAHs were verified from the Iwate Stroke Registry database during the same period in 2021 (IR: 34.9/100,000 person-years), and comparison with the reference period showed an IRR of 0.78 (95%CI 0.53-1.18; P = 0.204). All three cases developed SAH within 3 days (range, 0-3 days) of the first or second dose of BNT162b2 mRNA COVID-19 vaccine by Pfizer/BioNTech. The median age at the time of SAH onset was 63.7 years (range, 44- 75 years). Observed locations of ruptured aneurysms in patients were the bifurcations of the middle cerebral artery, internal carotid-posterior communicating artery, and anterior communicating artery, respectively. Favorable outcomes (modified Rankin scale scores, 0-2) were obtained following microsurgical clipping or intra-aneurysm coiling. Conclusion: Although the advantages of COVID-19 vaccination appear to outweigh the risks, pharmacovigilance must be maintained to monitor potentially fatal adverse events and identify possible associations.

Longitudinal Study on Relationships among Snack Energy Intake, Body Mass Index, and Nutrient Intake in Japanese Children Aged 6-7 Years.

A longitudinal study was conducted to assess associations between snack energy intake and either body mass index (BMI) or nutrient intake in Japanese children. A baseline survey was conducted with 243 children aged 6-7 y, and follow-up was performed 4 y later. Finally, 189 subjects were selected for the analysis. Snack intakes were obtained from self-administered records by guardians. The daily habitual whole dietary intake and exercise/sleep hours were obtained by questionnaires during the follow-up. Subjects were grouped into three, as per snack energy intake tertiles at baseline. Differences and linear trends between the three groups were tested for the mean values of snack energy intake, BMI, and nutrient density, 4 y after the baseline survey. In follow-up, the snack energy intake (kcal) in females was significantly higher in the intermediate (335±35, p<0.01) and high (318±32, p<0.05) groups than in low group (196±25). There was no significant difference in follow-up BMI in the three groups. However, after adjustment of the baseline BMI, a significantly positive linear trend (p<0.05) was observed in the follow-up BMI in females. There was no significant difference in total energy intake per day. In contrast, a significantly negative linear trend (p<0.05) was observed among the three groups in dietary nutrient density of calcium and vitamin A in females. These results suggest that, in females, a higher intake of snacks may affect the daily dietary balance, resulting in a higher BMI and lower mineral and vitamin intakes.

Association of Protein and Magnesium Intake with Prevalence of Prefrailty and Frailty in Community-Dwelling Older Japanese Women.

We examined the association between nutrient intake and prefrailty. Data from 815 older people (63% women) who participated in a community-based health check survey (Tarumizu Study) were analyzed. Prefrailty were defined using five parameters (exhaustion, slowness, weakness, low physical activity, and weight loss). Participants with one or more components were considered to belong to the prefrailty group. Nutrition intake was estimated from a validated brief-type self-administered diet history questionnaire. Among the participants, 154 men (52%) and 278 women (54%) were found to be in a status of prefrailty. In men, there were no significant associations between nutrient intake and prefrailty. In women, carbohydrate intake was slightly higher in prefrailty group. Vitamins K, B1, B2, folic acid, pantothenic acid, phosphorus, potassium, calcium, magnesium, iron, zinc, and copper intake was significantly lower in the prefrailty group. Among the nutrients, magnesium was identified as a significant covariate of prefrailty using a stepwise regression method. In women adjusted ORs (95%CI, p value) for prefrailty in the first, second, third, and fourth quartiles of magnesium intake were 1.00 (reference), 0.52 (0.29-0.92, 0.024), 0.51 (0.28-0.95, 0.033), and 0.38 (0.19-0.74, 0.005), respectively, by multivariate logistic regression analysis (variates: age, body mass index, energy intake, supplement use, osteoporosis, magnesium, and protein intake). Protein intake did not related to prefrailty. Protein intake might be sufficient to prevent prefrailty in the present study. We propose magnesium to be an important micronutrient that prevents prefrailty in community-dwelling older Japanese women.

A genome-wide association study on fish consumption in a Japanese population-the Japan Multi-Institutional Collaborative Cohort study.

BACKGROUND/OBJECTIVE: Although benefits of fish consumption for health are well known, a significant percentage of individuals dislike eating fish. Fish consumption may be influenced by genetic factors in addition to environmental factors. We conducted a genome-wide association study (GWAS) to find genetic variations that affect fish consumption in a Japanese population. METHODS: We performed a two-stage GWAS on fish consumption using 13,739 discovery samples from the Japan Multi-Institutional Collaborative Cohort study, and 2845 replication samples from the other population. We used a semi-quantitative food frequency questionnaire to estimate food intake. Association of the imputed variants with fish consumption was analyzed by separate linear regression models per variant, with adjustments for age, sex, energy intake, principal component analysis components 1-10, and alcohol intake (g/day). We also performed conditional analysis. RESULTS: We found 27 single nucleotide polymorphisms (SNPs) located in 12q24 and 14q32.12 that were associated with fish consumption. The 19 SNPs were located at 11 genes including six lead SNPs at the BRAP, ACAD10, ALDH2, NAA25, and HECTD4 regions on 12q24.12-13, and CCDC197 region on 14q32.12. In replication samples, all five SNPs located on chromosome 12 were replicated successfully, but the one on chromosome 14 was not. Conditional analyses revealed that the five lead variants in chromosome 12 were in fact the same signal. CONCLUSION: We found that new SNPs in the 12q24 locus were related to fish intake in two Japanese populations. The associations between SNPs on chromosome 12 and fish intake were strongly confounded by drinking status.

Negative Association in Reported Dietary Energy Intake and Physique in Japanese Schoolchildren.

Appropriate dietary assessment and health education are necessary for children to achieve a healthy physique. To explore the relationship between habitual reported dietary energy intake (EI) and physique in elementary schoolchildren by sex and age, we conducted a longitudinal study, in the fiscal year 2011, that included all elementary schools in Omihachiman City, Shiga Prefecture, Japan. The study lasted for four consecutive years, ending in fiscal year 2014, and included 545 7-y-old schoolchildren in the target city. The subjects completed a brief self-administered diet history questionnaire with their guardians. The results of the study demonstrated a negative relationship between energy intake and the estimated energy requirement ratio and body mass index percentile values for both 7-, 9-, and 10-y-old boys and 7- to 10-y-old girls. These results suggest that there is a need to keep in consideration the under-reporting of obese children and over-reporting of lean children for dietary energy evaluation.

Preoperative single-slab 3D time-of-flight magnetic resonance angiography predicts development of new cerebral ischemic events after carotid endarterectomy. Clinical article.

OBJECT: Preoperative impairment of cerebral hemodynamics predicts the development of new cerebral ischemic events after carotid endarterectomy (CEA), including neurological deficits and cerebral ischemic lesions on diffusion weighted MR imaging. Furthermore, the signal intensity of the middle cerebral artery (MCA) on single-slab 3D time-of-flight MR angiography (MRA) can assess hemodynamic impairment in the cerebral hemisphere. The purpose of the present study was to determine whether, on preoperative MR angiography, the signal intensity of the MCA can be used to identify patients at risk for development of cerebral ischemic events after CEA. METHODS: The signal intensity of the MCA ipsilateral to CEA on preoperative MR angiography was graded according to the ability to visualize the MCA in 106 patients with unilateral internal carotid artery stenosis (>or=70%). Diffusion weighted MR imaging was performed within 3 days of and 24 hours after surgery. The presence or absence of new postoperative neurological deficits was also evaluated. RESULTS: Cerebral ischemic events after CEA were observed in 16 patients. Reduced signal intensity of the MCA on preoperative MR angiography was the only significant independent predictor of postoperative cerebral ischemic events. When the reduced MCA signal intensity on preoperative MR angiography was defined as an impairment in cerebral hemodynamics, MR angiography grading resulted in an 88% sensitivity and 63% specificity, with a 30% positive- and a 97% negative-predictive value for the development of postoperative cerebral ischemic events. CONCLUSIONS: Signal intensity of the MCA on preoperative single-slab 3D time-of-flight MR angiography is useful for identifying patients at risk for cerebral ischemic events after CEA.

Microsurgical Management for Aneurysm Arising from a Low-Lying Internal Carotid Artery-Posterior Communicating Artery Bifurcation through the Anterior Temporal Approach.

A low-lying internal carotid artery (ICA) running closer to the skull base than in usual cases prevents use of the standard transsylvian approach (TSA) to view an aneurysm through the retrocarotid space. A 75-year-old male had a 10-day history of headache and left eyelid ptosis. Initial computed tomography (CT) showed no evidence of subarachnoid hemorrhage. Emergency three-dimensional CT angiography showed a saccular aneurysm with bleb arising from the left horizontally projecting ICA. The aneurysm was approached through the TSA but could not be visualized well. We used the anterior temporal approach (ATA) followed by the TSA, offering a more lateral line of vision and allowing the surgeon to visualize the aneurysmal neck. The aneurysm was successfully obliterated. The ATA provided a better lateral view than the standard TSA for the ICA aneurysm. We emphasize the effectiveness of ATA for aneurysm arising from a low-lying IC-posterior communicating artery bifurcation.

Utility of Single Fenestrated Miniclip in Management of Small Cerebral Aneurysm: Technical Report of 2 Cases.

BACKGROUND: Fenestrated miniclips were developed as an effective tool for dog-ear-shaped remnants of aneurysms. However, the special property of these clips may have other applications. Here, we report 2 cases of ruptured small aneurysm and suggest the alternative utility of a single application of a fenestrated miniclip. CASE DESCRIPTION: A 77-year-old woman was admitted to our hospital with subarachnoid hemorrhage due to an anterior communicating aneurysm. The aneurysm was treated with surgical clipping via a right pterional approach. Because dissection of tight adhesion between the aneurysm and ipsilateral A2 might cause intraoperative bleeding, the angled fenestrated miniclip was applied across the ipsilateral A2 without dissection of adhesion and obliterated the aneurysm without complications. In another case, a 60-year-old man presented with subarachnoid hemorrhage due to ruptured vertebral artery-posterior inferior cerebellar artery (PICA) aneurysm and was treated with surgical clipping via a far-lateral approach. Because aneurysm visualization was impeded by PICA even after mobilization of the PICA and vertebral artery, a fenestrated standard-clip was applied across the PICA. However, this clip impeded visualization of the aneurysm and could not be opened in the tight surgical field. In contrast, subsequent application of a fenestrated miniclip allowed better visualization of the aneurysm, even in a tight field, and resulted in successful obliteration of the aneurysm. CONCLUSION: Single application of fenestrated mini-clips may be suitable in cases of small aneurysms with thin walls adhering to branch vessels or where visualization of the aneurysm is impeded by the parent artery.