Surgical Risk in Elderly Patients with Meningiomas in Japan.

Background/Objective: No guidelines indicate surgical risk factors for the elderly because of the lack of data from general neurosurgeons. To better understand the management of surgical risk in elderly patients with meningiomas based on a national database in Japan. Methods: Results of surgically treated meningiomas were explored in 8138 patients registered in the Diagnosis Procedure Combination database in Japan during 2010-2015. Age (<65, 65-74, and ≥75 years), sex, Barthel index (BI), medical history, tumor location, oral medication prescriptions on admission, and stroke complications were evaluated. Multivariate logistic regression analysis identified risk factors for stroke complications, BI deterioration between admission and discharge, and in-hospital mortality. Results: Advanced age was the prominent risk factor for BI deterioration (odds ratio: 3.26; 95% confidence interval: 2.69-3.95) but not for in-hospital mortality. Lower BI (60-80) on admission increased the risk of BI deterioration in all age groups; however, BI < 60 demonstrated a significant inverse risk (0.47; 0.32-0.69) in the elderly (≥75 years). Location (falx, parasagittal, and deep) and anticoagulants were not significant risk factors for BI deterioration in patients aged ≥ 75 years, despite being significant risk factors in patients aged <65 and/or 65-74 years. Conclusions: Although advanced age could lead to postoperative functional decline at discharge, it was not sufficiently significant enough to be associated with in-hospital mortality. Because of the possibility of recovery even in elderly patients with severe disabilities, appropriate surgical selection and optimal management may lead to favorable functional outcomes in elderly patients with meningiomas.

Magnetoencephalographic detection of synchronized epileptic activity between the hippocampus and insular cortex.

Most magnetoencephalographic signals are derived from synchronized activity in the brain surface cortex. By contrast, the contribution of synchronized activity in the deep brain to magnetoencephalography (MEG) has remained unclear. We compared stereotactic electroencephalography (sEEG) with simultaneous MEG findings in a patient with temporal lobe epilepsy to determine the conditions under which MEG could also detect sEEG findings. The synchrony and similarity of the waves were evaluated using visual inspection and wavelet coherence. A 45-year-old woman with intractable temporal lobe epilepsy underwent sEEG and MEG simultaneously to determine the laterality and precise location of the epileptic focus. When spike-and-waves were seen in the right hippocampal head alone, no distinct spike-and-waves were observed visually in the right temporal MEG. The seizure then spread to the right insula on sEEG with a rhythmic theta frequency while synchronous activity was observed in the right temporal MEG channels. When polyspikes appeared in the right hippocampus, the right temporal MEG showed electrical activity with relatively high similarity to that of the right hippocampal head and insular cortex but less similarity to that of the right lateral temporal lobe cortex. MEG might detect epileptic activity synchronized between the hippocampus and insular cortex.

Artificial intelligence for volumetric measurement of cerebral white matter hyperintensities on thick-slice fluid-attenuated inversion recovery (FLAIR) magnetic resonance images from multiple centers.

We aimed to develop a new artificial intelligence software that can automatically extract and measure the volume of white matter hyperintensities (WMHs) in head magnetic resonance imaging (MRI) using only thick-slice fluid-attenuated inversion recovery (FLAIR) sequences from multiple centers. We enrolled 1092 participants in Japan, comprising the thick-slice Private Dataset. Based on 207 randomly selected participants, neuroradiologists annotated WMHs using predefined guidelines. The annotated images of participants were divided into training (n = 138) and test (n = 69) datasets. The WMH segmentation model comprised a U-Net ensemble and was trained using the Private Dataset. Two other models were trained for validation using either both thin- and thick-slice MRI datasets or the thin-slice dataset alone. The voxel-wise Dice similarity coefficient (DSC) was used as the evaluation metric. The model trained using only thick-slice MRI showed a DSC of 0.820 for the test dataset, which is comparable to the accuracy of human readers. The model trained with the additional thin-slice dataset showed only a slightly improved DSC of 0.822. This automatic WMH segmentation model comprising a U-Net ensemble trained on a thick-slice FLAIR MRI dataset is a promising new method. Despite some limitations, this model may be applicable in clinical practice.

Relevance of the Foramen of Vesalius for Preoperative Tumor Embolization in Skull Base Meningioma.

OBJECTIVE: The objective of this study was to investigate the role of the foramen of Vesalius (FV) in the pathogenesis of skull base meningioma by analyzing data from various multi-image modalities. METHODS: For this single-center retrospective study, 39 consecutive patients with skull base meningioma who underwent tumor resection between January 2020 and March 2023 were enrolled. The anatomical and pathological characteristics of the FV were evaluated using computed tomography and 3-dimensional digital subtraction angiography. The clinical significance of the FV in tumor hemodynamics and treatment, such as preoperative tumor embolization, was investigated using the 3-dimensional digital subtraction angiography/computed tomography fusion images. RESULTS: We identified FV in 52% (17/27) of the finally included patients. In 10 (30%) patients, the FV was found bilaterally with no significant variation in appearance between the healthy and tumor-affected sides (P = 0.786). The mean FV diameter was significantly larger on the tumor-affected side (P = 0.010). No significant anatomical differences, like duplication and partial assimilation with the foramen ovale, were observed between the 2 sides. The FV was involved in venous skull base perfusion around the tumor in 9 cases. In 4 cases where it was the pathway for tumor feeders, preoperative tumor embolization via the FV resulted in disappearance of the tumor stain. No complications associated with endovascular treatment were observed. CONCLUSIONS: This study elucidated the anatomical asymmetry of the FV and its role in the hemodynamics of skull base meningioma. Our findings highlight the significance of performing anatomical and pathological evaluations of the FV in determining treatment strategies, including preoperative embolization, for skull base lesions.

Usefulness of combined bypass surgery for moyamoya disease in infants under 1 year of age: A technical case report.

Background: Among pediatric cases of moyamoya disease (MMD), cerebral ischemic symptoms often progress and worsen rapidly in infants under one year of age; therefore, it is important to treat them as early as possible. However, direct bypass surgery is often technically difficult for infants due to their small blood vessels. Here, we describe our technique to resolve the technical challenges encountered during superficial temporal artery-to-middle cerebral artery (STA-MCA) bypass surgery in infants aged <1 year with MMD, focusing on specific procedures. Case Description: We performed bilateral STA-MCA and indirect bypass in a 1-year-old girl with MMD and cerebral infarction. Before treatment, a peripherally inserted central venous catheter (PICC) was placed to avoid ischemic attacks associated with crying, dehydration, and malnutrition. All examinations and procedures that would be stressful to the patient, such as blood examinations, were performed using PICC or under sedation. The STA-MCA diameters were 0.8 and 1.2 mm, respectively. After suturing the planned anastomosis with one stitch using an 11-0 monofilament nylon thread, the thread was lifted upward, and the arterial wall was incised. Anastomosis was performed using an 11-0 monofilament nylon thread with 2-4 stitches on each side. The operation was completed without patency problems. Postoperative blood flow improved, and the patient had a good treatment course. Conclusion: Direct bypass for MMD patients aged <1 year is technically challenging; however, the vessels can be connected if the procedure is carefully performed with consideration of the characteristics of the infant's vessels.

Compatibility of the semijailing technique with extremely soft i-ED coils for ruptured blood blister-like and dissecting aneurysms: patient series.

BACKGROUND: Optimal treatment options for ruptured blood blister-like aneurysms (BBAs) and dissecting aneurysms (DAs) have not yet been established. Endovascular treatment may achieve vessel reconstruction with the preservation of antegrade blood flow; however, securing curative hemostasis at the fragile rupture point remains a major concern. OBSERVATIONS: Two ruptured BBAs and two ruptured DAs treated by stent-assisted coiling with the semijailing technique in the last 2 years are described herein. The devices used were braided stents and i-ED coils, which are new low-memory shape and extremely soft coils. Neither rebleeding nor ischemic complications were observed. All patients had a favorable outcome and showed no recurrence after treatment. LESSONS: All aneurysms were treated without ischemic complications or rebleeding. The good compatibility of braided stents and the new concept coils in stent-assisted coiling by the semijailing technique provides insight into these intractable hemorrhagic vascular pathologies.

Retained Intracerebral Depth Electrode after Stereotactic Electroencephalography Monitoring: A Case Report.

Stereotactic electroencephalography (SEEG) is an increasingly popular surgical modality for localizing the epileptogenic zone. Robot-guided stereotactic electrode placement has been covered in Japan by National Health Insurance since 2020. However, several surgical devices, such as the anchor bolt (a thin, hollow, metal shaft that serves as a guide screw or fixing for each electrode), have not been approved. A 14-year-old female who underwent SEEG for intractable epilepsy and required additional surgery to remove a retained depth electrode from the skull after the SEEG monitoring was finished. She had uncontrolled focal seizures consisting of nausea and laryngeal constriction at the onset. After a comprehensive presurgical evaluation, robot-guided stereotactic electrode implantation was performed to evaluate her seizures by SEEG. Nine depth electrodes were implanted through the twist drill hole. The electrodes were sutured to her skin for fixation without anchor bolts. When we attempted to remove the electrodes after 8 days of SEEG monitoring, one of the electrodes was retained. The retained electrode was removed through an additional skin incision and a small craniectomy under general anesthesia. We confirmed narrowing of the twist drill hole pathway in the internal table of the skull due to osteogenesis, which locked the electrode. This complication might be avoided if an anchor bolt had been used. This case report prompts the approval of the anchor bolts to avoid difficulty in electrode removal. Moreover, approval of a depth electrode with a thinner diameter and more consistent hardness is needed.

[Thrombectomy].

Endovascular procedures have become the standard treatment for acute stroke caused by large vessel occlusion. Various strategies are available, including stent retrieval, aspiration catheter placement, and combined techniques. However, the first-pass effect can be maximized using the technique most familiar to each surgeon and institution. Therefore, it is necessary to understand the characteristics of each device and develop case-specific treatment strategies.

[Preoperative Simulation in Epilepsy Surgery].

In patients with intractable epilepsy, seizure focus resection can yield favorable seizure outcomes. First, the localization of the seizure focus is estimated by noninvasive methods such as magnetic resonance imaging(MRI), video-electroencephalography(EEG)monitoring, nuclear medicine examinations, magnetoencephalography, and neuropsychological tests. A subgroup of patients may require additional information obtained from the intracranial EEG. There are two major methods for intracranial EEG: intracranial EEG with subdural grid electrodes(SDG)and stereotactic electroencephalography. If the estimated seizure focus overlaps with the eloquent area in noninvasive studies, the margin and extent of the resection are determined by the results of intracranial EEG and functional mapping by electrical cortical stimulation. Herein, we present a case of lobe epilepsy with subtle MRI lesions in the superior temporal sulcus of the language-dominant hemisphere. The results of the SDG and functional mapping showed that the seizure onset zone overlapped with the language area. Resection of the middle and inferior temporal gyri and multiple transections of the language area resulted in Engel IIB seizure outcomes. In such cases, a thorough preoperative simulation is required to determine the best resection margin for seizure control and functional preservation.

[Carotid Artery Stenting].

Currently, stricter indications for carotid artery stenosis are required owing to improvements in multifaceted medical treatment, including the intensive management of risk factors for atherosclerosis and lifestyle changes. High-risk factors for carotid artery stenting, such as vulnerable plaques, severe calcification, pseudo-occlusion, and difficult access, should be evaluated before endovascular intervention. Therefore, we need to understand the characteristics of each device to achieve maximum risk reduction for carotid artery stenting.

Characteristics of MicroRNA Expression Depending on the Presence or Absence of Meningioma in Patients with Neurofibromatosis Type 2: A Secondary Analysis.

Meningioma is the second most frequent tumor in patients with neurofibromatosis type 2 (NF2). The presence of meningioma is believed to be a negative prognostic marker in these patients. However, the molecular mechanisms involved in the tumorigenesis of NF2-associated meningioma are not well characterized. Epigenetic regulation, including microRNAs (miRNAs), may be involved in the development of different tumor types in patients with NF2. The objective of this study is to explore the different characteristics of serum miRNA expression depending on the presence or absence of meningioma in patients with NF2. Nine patients with NF2 who were treated at the Department of Neurosurgery, Hiroshima University Hospital, were included. Total RNA (including small RNAs) was extracted from serum samples for the preparation of a small RNA library for next-generation sequencing analysis. Differentially expressed miRNAs (DEMs) were analyzed using the DESeq2 package to compare the characteristic miRNA expression profiles of patients with and without meningioma. In small RNA sequencing analysis, out of a total of 1,879 miRNAs registered in the database, the expressions of 657 miRNAs were observed. In DEM analysis, the expressions of four miRNAs, namely, hsa-miR-664b, hsa-miR-7706, hsa-miR-590, and hsa-miR-6513, were downregulated in patients with NF2 with meningioma compared with patients with NF2 without meningioma. Hsa-miR-193a was identified as the only upregulated miRNA in patients with NF2 with meningioma. In conclusion, we identified different circulating miRNA expression characteristics depending on the presence or absence of meningioma in patients with NF2.

Endovascular Treatment for Ruptured Intracranial Aneurysms with Intracerebral Hematoma-Clinical Propriety of Less Invasive Treatment.

BACKGROUND: Endovascular treatment of ruptured intracranial aneurysms (rIAs) accompanied by intracerebral hematoma (ICH) can be challenging because the ICH can be enlarged due to intraoperative anticoagulation during the endovascular procedure. This retrospective study aimed to compare the outcomes of aneurysmal subarachnoid hemorrhage with and without ICH treated by endovascular procedures. METHODS: We reviewed 62 patients who underwent endovascular treatment of rIAs between January 2015 and April 2023. The patients were divided into 2 groups: those with ICH (group H; n = 13) and those without ICH (group N; n = 49). The patient demographics, aneurysm characteristics, World Federation of Neurosurgical Societies (WFNS) grade, complications (e.g., symptomatic vasospasm, hydrocephalus), and outcomes were assessed stratified by the presence of ICH. In group H, age, sex, complications, WFNS grade, and hematoma volume were also analyzed in relation to the outcomes at discharge. RESULTS: None of these patients required removal of ICH after endovascular treatment of the rIA. We found no significant differences in patient characteristics, aneurysm morphologies, WFNS grade, or overall outcomes between the 2 groups. In contrast, only a poor WFNS grade was significantly associated with poor outcomes (modified Rankin scale score ≥3) in group H (P = 0.04), and the ICH volume was not significantly different between those with good (6.2 ± 5.8 mL) and poor (14.6 ± 10.4 mL) outcomes in group H (P = 0.20). CONCLUSIONS: Endovascular treatment without hematoma evacuation did not adversely affect the outcomes of rIAs with ICH when the clinical condition and aneurysm morphology permitted. Surgical invasion might be avoidable with this less-invasive strategy without worsening the outcomes.

High signal intensity of the intraaneurysmal sac on T1 CUBE imaging as a predictor of aneurysm stability after coil embolization.

OBJECTIVE: Histopathological studies of aneurysms after coil embolization showed that thrombus formation during the first month after endovascular treatment (EVT) played an important role in the healing process. The authors hypothesized that dedicated T1-weighted imaging may be used to predict stable aneurysms by visualizing the thrombus status within coil-treated aneurysms. Therefore, this study investigated the relationship between the signal intensity (SI) of the intraaneurysmal sac after coil embolization and aneurysm stability. METHODS: The study population included 82 patients with 86 aneurysms who underwent T1-weighted 3D black-blood fast spin-echo (T1 CUBE) imaging within 1 month after coil embolization between 2019 and 2022. The relative SI of a coil-treated aneurysm (RSIcoiled) was calculated as follows: the mean SI of the intraaneurysmal sac/the mean SI of the genu of the corpus callosum. Aneurysms with enlarged remnants on MR angiography (MRA) within 6 months after EVT were defined as recurrence, while a decrease of intraaneurysmal flow on MRA was defined as improved embolization status. Stable aneurysms were defined as improvement or no change in embolization status 6 months after coil embolization. The volume embolization ratio (VER) was calculated as the ratio of the packed coil volume to the aneurysm volume. Differences between stable and recurrent aneurysms were examined. All aneurysms were divided into high and low RSIcoiled groups based on the cutoff value of RSIcoiled, and differences between the two groups were also evaluated. RESULTS: Recurrence was confirmed for 26 of 86 aneurysms. A univariable analysis showed that small aneurysms, high VER, and high RSIcoiled were associated with aneurysm stability. In the receiver operating characteristic curve analysis, the optimal cutoff value for RSIcoiled to differentiate stable from recurrent aneurysms was 0.54. The cutoff value for RSIcoiled was selected as 0.50 (sensitivity 0.77, specificity 0.70) because it was half the value of the SI of the corpus callosum and close to the optimal cutoff value. In a multivariable analysis, RSIcoiled > 0.50 (OR 8.1, 95% CI 2.5-27) remained a significant factor for aneurysm stability. The high RSIcoiled group showed a higher rate of an improved embolization status (26% vs 6.1%, p = 0.022) and stable aneurysms (85% vs 15%, p = 0.0002). CONCLUSIONS: RSIcoiled was associated with postcoiling aneurysm stability. High RSIcoiled might imply intraaneurysmal thrombus formation associated with the healing process of coil-treated aneurysms.

Differences in invasiveness and recurrence rate among nonfunctioning pituitary neuroendocrine tumors depending on tumor subtype.

PURPOSE: To clarify the invasiveness to surrounding structures and recurrence rate of each subtype of nonfunctioning pituitary neuroendocrine tumor (Pit-NETs) according to the WHO 2022 classification. METHODS: This retrospective study utilized data from 292 patients with nonfunctioning Pit-NETs treated with initial transsphenoidal surgery. Recurrence was evaluated on 113 patients who were available for a magnetic resonance imaging follow-up ≥ 60 months. All tumors were assessed by immunohistochemical staining for Pit-1, T-PIT, and GATA3. Invasiveness to surrounding structures was evaluated based on intraoperative findings. RESULTS: Cavernous sinus invasion was found in 47.5% of null cell tumors, 50.0% of Pit-1 lineage tumors, 31.8% of corticotroph tumors, and 18.3% of gonadotroph tumors. Dura mater defects in the floor of sellar turcica, indicating dural invasion, were found in 44.3% of null cell tumors, 36.4% of corticotroph tumors, 16.7% of Pit-1 lineage tumors, and 17.3% of gonadotroph tumors. In logistic regression analysis, Pit-1 (OR 5.90, 95% CI 1.71-20.4, P = 0.0050) and null tumors (OR 4.14, 95% CI 1.86-9.23, P = 0.0005) were associated with cavernous sinus invasion. Recurrence was found in 8 (4.9%) patients, but without significant differences between tumor subtypes. The presence of cavernous sinus invasion was correlated with recurrence (HR = 1.95, 95% CI 1.10-3.46, P = 0.0227). CONCLUSION: Among nonfunctioning Pit-NETs, Pit-1 lineage tumors tend to invade the cavernous sinus, corticotroph tumors may produce dura mater defects, and null cell tumors tend to cause both. Pit-NETs with cavernous sinus invasion require a careful attention to recurrence.

Arterial Spin Labeling-Based MR Angiography for Cerebrovascular Diseases: Principles and Clinical Applications.

Arterial spin labeling (ASL) is a noninvasive imaging technique that labels the proton spins in arterial blood and uses them as endogenous tracers. Brain perfusion imaging with ASL is becoming increasingly common in clinical practice, and clinical applications of ASL for intracranial magnetic resonance angiography (MRA) have also been demonstrated. Unlike computed tomography (CT) angiography and cerebral angiography, ASL-based MRA does not require contrast agents. ASL-based MRA overcomes most of the disadvantages of time-of-flight (TOF) MRA. Several schemes have been developed for ASL-based MRA; the most common method has been pulsed ASL, but more recently pseudo-continuous ASL, which provides a higher signal-to-noise ratio (SNR), has been used more frequently. New methods that have been developed include direct intracranial labeling methods such as velocity-selective ASL and acceleration-selective ASL. MRA using an extremely short echo time (eg, silent MRA) or ultrashort echo-time (TE) MRA can suppress metal susceptibility artifacts and is ideal for patients with a metallic device implanted in a cerebral vessel. Vessel-selective 4D ASL MRA can provide digital subtraction angiography (DSA)-like images. This review highlights the principles, clinical applications, and characteristics of various ASL-based MRA techniques. LEVEL OF EVIDENCE: 5 TECHNICAL EFFICACY: Stage 2.

Flow volume mismatch dramatically affects transient neurologic symptoms after direct bypass in Moyamoya disease.

Transient neurological events (TNEs) occur after bypass surgery in Moyamoya disease (MMD); however, their pathology remains unknown. To elucidate the pathophysiology of TNEs, we investigated their relationship with perioperative superficial temporal artery (STA) blood flow volume, which was evaluated using ultrasonography. Forty-nine patients with MMD, who underwent direct bypass surgery, were included and stratified into TNE and non-TNE groups, respectively. The STA blood flow volume was evaluated at four time points (preoperatively and 2-4, 7, and 10-14 days postoperatively), and a change in volume during the postoperative period was defined as a flow volume mismatch. We investigated the association between ultrasonographic findings of flow volume mismatch and TNEs and magnetic resonance imaging findings, such as the cortical hyperintensity belt (CHB) sign, using univariate and path analyses. The STA blood flow volume increased immediately postoperatively, gradually decreasing over time, in both groups. The TNE group showed a significant increase in blood flow volume 2-4 days postoperatively (P = 0.042). Flow volume mismatch was significantly larger in the TNE group than in the non-TNE group (P = 0.020). In the path analysis, STA flow volume mismatch showed a positive association with the CHB sign (P = 0.023) and TNEs (P = 0.000). Additionally, the CHB sign partially mediated the association between STA flow volume mismatch and TNEs. These results suggest that significantly high STA blood flow volume changes occurring during the acute postoperative period after direct bypass surgery in MMD are correlated with TNEs and the CHB sign, suggesting involvement in the pathophysiology of TNEs.

Residual diffusion-weighted imaging hyperintense signal in primary central nervous system lymphoma can predict early recurrence.

BACKGROUND: The treatment response of primary central nervous system lymphomas (PCNSLs) is mainly evaluated using postcontrast T1-weighted imaging (T1WI). Because poorly enhanced lesions may contain residual tumors, the combination of evaluation methods will potentially improve the accuracy of determining treatment effectiveness. In this study, we evaluated the usefulness of diffusion-weighted imaging (DWI) in predicting recurrence among patients with PCNSL who achieved complete response (CR)/unconfirmed CR (CRu). METHODS: Fifty-four patients newly diagnosed with PCNSL who were treated at our institution and achieved CR/CRu at the end of treatment were included in this study. The patients were divided into two groups according to the presence or absence of residual DWI hyperintense signal at the tumor site at the end of treatment. Kaplan-Meier analysis was performed to analyze the median overall survival (OS) and progression-free survival (PFS). RESULTS: The mean age of the 54 patients was 66.4 ± 13.3 years. The induction therapies were HD-MTX in 20 patients, R-MPV in 29 patients, and other chemotherapies in five patients. Radiotherapy was performed in 35 patients, high-dose cytarabine therapy in 14 patients, and autologous hematopoietic stem cell transplantation in one patient, and of the 54 patients, 10 had no consolidation therapy. The residual DWI hyperintense signal sign was observed in 18 patients. The R-MPV regimen was statistically associated with a lower rate of residual DWI hyperintense signal (p = 0.0453). The median PFS was statistically shorter in the residual DWI hyperintense signal group than in the non-residual DWI hyperintense signal group (14.0 months vs. 85.1 months) (p < 0.0001, log-rank test). CONCLUSION: A residual DWI hyperintense signal at the end of treatment was statistically associated with shorter PFS. Among patients who achieved CR/CRu evaluated based on postcontrast T1WI, DWI could be a valuable additional sequence to predict the early recurrence of PCNSL.

Effectiveness of tuning an artificial intelligence algorithm for cerebral aneurysm diagnosis: a study of 10,000 consecutive cases.

Diagnostic image analysis for unruptured cerebral aneurysms using artificial intelligence has a very high sensitivity. However, further improvement is needed because of a relatively high number of false positives. This study aimed to confirm the clinical utility of tuning an artificial intelligence algorithm for cerebral aneurysm diagnosis. We extracted 10,000 magnetic resonance imaging scans of participants who underwent brain screening using the "Brain Dock" system. The sensitivity and false positives/case for aneurysm detection were compared before and after tuning the algorithm. The initial diagnosis included only cases for which feedback to the algorithm was provided. In the primary analysis, the sensitivity of aneurysm diagnosis decreased from 96.5 to 90% and the false positives/case improved from 2.06 to 0.99 after tuning the algorithm (P < 0.001). In the secondary analysis, the sensitivity of aneurysm diagnosis decreased from 98.8 to 94.6% and the false positives/case improved from 1.99 to 1.03 after tuning the algorithm (P < 0.001). The false positives/case reduced without a significant decrease in sensitivity. Using large clinical datasets, we demonstrated that by tuning the algorithm, we could significantly reduce false positives with a minimal decline in sensitivity.

Pulsatility index of superficial temporal artery was associated with cerebral infarction after direct bypass surgery for moyamoya disease.

OBJECTIVE: Direct bypass surgery by superficial temporal artery (STA) - middle cerebral artery anastomosis is an established procedure for moyamoya disease (MMD). However, some patients may develop cerebral infarction (CI) due to the watershed shift phenomenon after the surgery. This study sought to investigate the correlation between the postoperative changes of STA flow as well as cerebral blood flow (CBF) and the incidence of CI after direct bypass surgery for MMD. METHODS: We conducted a retrospective study of 62 hemispheres in 50 subjects who underwent direct bypass surgery for MMD. All subjects underwent pre- and post-operative MR imaging, ultrasound evaluation of STA, and single-photon emission computed tomography. The presence of CI was correlated with preoperative CBF, the delta difference of each value of the STA between before and after the surgery, and the postoperative increase ratio of CBF. RESULTS: All bypass procedures were patent, and CI was observed in 4 cases (6.4%). There was no significant association between the incidence of CI and both pre- and post-operative CBF. However, there was a significant difference in delta pulsatility index (PI) of the STA between cases with or without CI (-0.38±0.22 and -0.87±0.63, respectively, p=0.03). Whereas, other factors did not show any significant differences between those with or without CI. CONCLUSIONS: A relatively high postoperative PI of the STA was significantly associated with the incidence of CI after direct bypass surgery for MMD. A larger study is needed to confirm these findings.

T1-T2 Mismatch Sign as a Predictor of Ipsilateral Ischemic Change After Carotid Artery Stenting.

BACKGROUND: Magnetic resonance (MR)-plaque imaging reflects the characteristics of carotid plaque. We evaluated the relationship between MR-plaque images and ischemic change after carotid artery stenting (CAS). METHODS: MR-plaque images were acquired from patients with carotid artery stenosis before CAS treatment. We calculated the relative signal intensity of plaque components compared with that of the sternocleidomastoid muscle and evaluated the presence/absence of T1-T2 mismatch and match sign. We then assessed the appearance of new ischemic lesions after CAS on diffusion-weighted imaging (DWI). Factors associated with the appearance of a high-intensity lesion on DWI were retrospectively analyzed. RESULTS: A total of 64 patients with carotid artery stenoses treated with CAS were included in this study. In univariate analysis, T1-T2 mismatch sign was associated with the appearance of high-intensity lesions on DWI after CAS (odds ratio [OR], 12.00; 95% confidence interval [CI], 3.593-40.072; P < 0.0001), whereas T1-T2 match sign and high intensity on T2-weighted imaging were negatively associated (OR, 0.061, 95% CI, 0.007-0.502, P = 0.009 and OR, 0.085; 95% CI, 0.022-0.334, P = 0.0004, respectively). In multivariate logistic regression analysis, T1-T2 mismatch sign was independently associated with the appearance of a high-intensity lesion on DWI after CAS (OR, 16.695; 95% CI, 1.324-210.52; P = 0.0295). CONCLUSIONS: T1-T2 mismatch sign on MR-plaque imaging is significantly associated with the appearance of new ischemic lesions after CAS. T1-T2 mismatch sign may be useful in considering treatment strategies for carotid artery stenosis.