Intraoperative DSA-guided minimal approach for craniocervical junction DAVFs obliteration.

BACKGROUND: Dural arteriovenous fistulas (DAVFs) are a group of diseases involving problematic shunts between dural arteries and venous structures such as sinuses, meningeal veins, or even cortical veins. To focus on craniocervical junction dural arteriovenous fistulas (DAVFs), we introduce a minimally invasive technique with midline incision combined with intraoperative digital subtraction angiography (DSA). This hybrid technique can minimize the incision wound to an average of 6 cm which leads to less destruction and lower risk of adverse events. METHOD: Using this minimally invasive approach, surgical obliteration was achieved in 6 patients with craniocervical junction DAVFs. A minimal midline incision was made over the C1-2 level, measuring approximately 5 to 7 cm in length. C1 hemilaminectomy was performed for DAVF obliteration followed by intraoperative DSA for confirmation of complete obliteration. RESULTS: Among these 6 patients, the radiculomedullary artery was the most common feeding artery. The mean length of the operation (including DSA performance) was 6.5 ± 1.4 h. None of these cases showed cerebrospinal fluid leakage or exacerbation of neurological symptoms after the operation. CONCLUSION: Using intraoperative DSA, the minimally invasive technique offers more precise but less destructive access than conventional far lateral suboccipital craniotomy. Most importantly, intraoperative DSA provided verification of complete closure for shunts that could not be examined for indocyanine green (ICG) dye because the microscope did not have a clear line of sight. In our experience, this technique shows encouraging results of fistula obliteration.

Acute delirium as an initial manifestation of COVID-19 patients with acute ischemic stroke: Report on two cases.

Psychiatric and neurological complications of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection are common. Psychiatric symptoms are so common that they are easily misinterpreted as an affective disorder induced by SARSCoV-2 infection. However, psychiatric symptoms, such as acute delirium, though rarely seen, can be the initial manifestations of acute ischemic stroke (AIS). These psychiatric symptoms may confuse the diagnosis of acute stroke, which needs correct and timely management. We report two hospitalized cases with SARS-CoV-2 infection and elevated serum D-dimer levels having acute delirium as the initial manifestation of AIS. The diagnostic processes were challenging and time-consuming, so reperfusion therapy could not be given in the therapeutic time window. The diagnoses of AIS were finally made by brain magnetic resonance imaging which showed diffusion restriction at the right middle cerebral artery territory in both cases. Features of psychiatric complications and stroke in coronavirus disease 2019 (COVID-19) patients are reviewed. For the hospitalized COVID-19 patients with elevated levels of serum Ddimer and acute delirium, acute stroke with neuropsychiatric manifestations should beconsidered.

CTA-guided outflow-targeted embolization of direct carotid-cavernous fistula.

This video presents a case of new-onset visual blurring, diplopia, and conjunctival injection after head injury. CTA of the brain revealed a direct carotid-cavernous fistula (dCCF) of the right side. Careful evaluation of CTA source images revealed that the fistula point was at the ventromedial aspect of the right cavernous internal carotid artery (ICA), about 3.6 × 3.6 mm2 in size, with 3 main outflow channels (2 intracranial and 1 extracranial) (CTA-guided concept). DSA of the brain also confirmed the diagnosis but was unable to locate the fistula point in a large-sized dCCF. Through a transfemoral artery approach, 3 microcatheters were navigated to each peripheral channel to initiate outflow-targeted embolization. Intracranial refluxes were blocked first to avoid cerebral hemorrhages, followed by the extracranial outflow. During embolization, accidental dislodge of one coil into the sphenoparietal vein occurred, but no attempt of coil retrieval was made. Complete obliteration of the dCCF was achieved, and the patient recovered well without new neurological deficits. 4D MRA at the 3-month follow-up showed no residual dCCF.The video can be found here: https://youtu.be/LH2lNVRZSPk.

Treating cerebrovascular diseases in hybrid operating room equipped with a robotic angiographic fluoroscopy system: level of necessity and 5-year experiences.

BACKGROUND: A hybrid operating room (OR) equipped with robotic angiographic fluoroscopy system has become prevalent in neurosurgery. The level of necessity of the hybrid OR in treating cerebrovascular diseases (CVD) is rarely discussed. OBJECTIVE: The authors proposed a scoring and classification system to evaluate the cerebrovascular procedures according to the level of treatment necessity for CVD in a hybrid OR and shared our 5-year experiences. METHODS: From December 2009 to January 2016, the registry of cerebrovascular procedures performed in the hybrid OR was retrieved. A scoring system was used to evaluate the importance of the surgical and interventional components of a cerebrovascular procedure performed in the hybrid OR. The score of either component ranged from 1, 1.5, to 2 (1 = no role, 1.5 = supplementary or informative, 2 = important or therapeutic). The total score of a procedure was by multiplying two individual scores. Levels of necessity were classified into level A (important), level B (beneficial), and level C (replaceable). RESULTS: A total of 1027 cerebrovascular procedures were performed during this period: diagnostic angiography in 328, carotid artery stenting in 286, aneurysm coiling in 128, intra-operative DSA in 101, aspiration of ICH under image guidance in 79, intra-arterial thrombolysis/thrombectomy in 51, intracranial angioplasty/stenting in 30, hybrid surgery/serial procedures in 19, and rescue surgery during embolization in 5. According to the scoring system, hybrid surgery and serial procedures scored the highest points (2 × 2). The percentages distributed at each level: levels A (2.3%), B (17.5%), and C (80.2%). CONCLUSION: This study conveys a concept of what a hybrid OR equipped with robotic angiographic fluoroscopy system is capable of and its potential. For cerebrovascular diseases, hybrid OR exerts its value via hybrid surgery or avoiding patient transportation in serial procedures (level A), via providing real-time high-quality angiography and image guidance (level B), which constituted about 20% of the cases. The subspecialty of the group using the hybrid OR directly reflects on the number of procedures categorized in each level. In a hybrid OR, innovative treatment strategies for difficult-to-treat CVD can be developed.

Angiographic doughnut-shaped aneurysm of intracranial internal carotid artery.

Morphologic characteristics of angiographic doughnut-shaped aneurysms of the intracranial internal carotid artery (ICA) have been rarely reported in the literature and were discussed only radiologically. In this case, surgical clipping was performed, and the specimen from the aneurysm was examined to correlate the pathologic findings and morphologic characteristics. A 59-year-old male presented with diffuse subarachnoid hemorrhage secondary to a ruptured vascular lesion originating from the intracranial portion of the right ICA. Digital subtraction angiography showed a 1.5-cm doughnut-shaped aneurysm at the junction of the ICA and the posterior communicating artery. The aneurysm was successfully clipped in a neurosurgical hybrid operating room. The pathologic findings of the content inside the aneurysm revealed only fibrinoid exudates, materials from thrombosis. This is the first report to prove that the mechanism of a doughnut-shaped aneurysm formation is central thrombosis inside the aneurysm, possibly related to its complex hemodynamic flow.

Preoperative Computed Tomography Angiography for Evaluation of Feasibility of Free Flaps in Difficult Reconstruction of Head and Neck.

BACKGROUND: Free tissue transfer has been advocated for anatomic and functional reconstruction of soft tissue defects after surgical removal of an extensive recurrent tumor and/or arising from previous irradiation in the head and neck. We report a case series of difficult reconstruction in the head and neck in which preoperative computed tomography (CT) angiography was utilized to evaluate the feasibility of free flap reconstruction. The preoperative radiological evaluation was performed to determine the availability of reliable vessels for anastomosis in free flap reconstruction. If none was found, regional pedicle flap or palliative treatment was applied instead. The use of CT angiography allows the clinical surgeon to perform precise surgical planning with greater confidence. This may improve surgical results, thereby potentially reducing perioperative morbidity. METHODS: Twenty CT angiograms were obtained from 20 patients. All patients were men with a mean age of 57.2 years (range, 42-72 years) and were scheduled to undergo difficult reconstruction in the head and neck. All patients (20/20 [100%]) suffered from oral squamous cell carcinoma. They had all received extensive operations and radiation therapy. Eighteen patients (18/20 [90%]) had completed a course of perioperative irradiation. The CT angiography reports were used to perform detailed preoperative surgical planning accordingly. The findings of CT angiography were classified into 3 groups: group I: normal CT angiography (patent recipient arteries) (Fig. 3); group II: abnormal CT angiography (recipient vessels were present but stenosis or atherosclerotic lesions were noted) (Fig. 4); group III: abnormal CT angiography with no patent recipient arteries in bilateral sides of the neck (Fig. 5); CT angiography results were correlated to the operative findings. RESULTS: The patients were classified into 3 groups based on the angiographic findings. Six patients (6/20 [30%]) were assigned to group I, 8 patients (8/20 [40%]) to group II, and 6 patients (6/20 [30%]) to group III. In groups I and III, all patients (12/12 [100%]) underwent the treatment according to the original preoperative detailed planning. No flap failure was noted in these 2 groups. In group II, 4 patients' recipient vessels (4/8 [50%]) possessed adequate blood flow intraoperatively; hence, microvascular free flaps were transplanted. Venous congestion in 1 case (1/4 [25%]) was noted. The remaining patients in this group (4/8 [50%]) underwent reconstruction with pedicle flaps rather than free flaps because of the lack of suitable target vessels intraoperatively. All flaps (4/4 [100%]) survived. Among the patients who were treated surgically, intraoperative findings were in accordance with those predicted by CT angiography. The total abnormality rate of CT angiography was 70%. Vascular abnormalities detected as a result of preoperative CT angiography led to changes in the operative plan in 50% (10/20) of the patients. CONCLUSIONS: The use of CT angiography should be considered for difficult microsurgical reconstructions in the head and neck. When an abnormality in vascular anatomy is detected by CT angiography, the surgeon is advised to consider altering the operative plan accordingly. This allows precise operation, thereby maximizing the possibility of an optimal outcome. Changing the operative plan based on results of CT angiography may also help to avoid the difficult situation in which the surgeon finds that there are no suitable recipient vessels for free flap reconstruction during the operation. In addition, CT angiography enables surgeons to conduct the preoperative surgical planning with greater confidence, thereby potentially enhancing the success rate of difficult reconstructions in the head and neck, which in turn would tend to improve the perioperative course for the patient and consequently to improve results by decreasing vascular complication rates.

Time-Resolved Magnetic Resonance Angiography in the Evaluation of Intracranial Vascular Lesions and Tumors: A Pictorial Essay of Our Experience.

Time-resolved magnetic resonance angiography (TR MRA) is a promising less invasive technique for the diagnosis of intracranial vascular lesions and hypervascular tumors. Similar to 4-dimensional computed tomographic angiography obtaining high frame rate images, TR MRA utilizes acceleration techniques to acquire sequential arterial and venous phase images for identifying, localizing, and classifying vascular lesions. Because of the good agreement with digital subtraction angiography for grading brain arteriovenous malformations with the Spetzler-Martin classification and the good sensitivity for visualizing arteriovenous fistulas, studies have suggested that TR MRA could serve as a screening or routine follow-up tool for diagnosing intracranial vascular disorders. In this pictorial essay, we report on the use of TR MRA at 3.0 T to diagnose intracranial vascular lesions and hypervascular tumors, employing DSA as the reference technique.

Risk factors for subsidence in anterior cervical fusion with stand-alone polyetheretherketone (PEEK) cages: a review of 82 cases and 182 levels.

INTRODUCTION: To determine risk factors for subsidence in patients treated with anterior cervical discectomy and fusion (ACDF) and stand-alone polyetheretherketone (PEEK) cages. MATERIALS AND METHODS: Records of patients with degenerative spondylosis or traumatic disc herniation resulting in radiculopathy or myelopathy between C2 and C7 who underwent ACDF with stand-alone PEEK cages were retrospectively reviewed. Cages were filled with autogenous cancellous bone harvested from iliac crest or hydroxyapatite. Subsidence was defined as a decrease of 3 mm or more of anterior or posterior disc height from that measured on the postoperative radiograph. Eighty-two patients (32 males, 50 females; 182 treatment levels) were included in the analysis. RESULTS: Most patients had 1-2 treatment levels (62.2 %), and 37.8 % had 3-4 treatment levels. Treatment levels were from C2-7. Of the 82 patients, cage subsidence occurred in 31 patients, and at 39 treatment levels. Multivariable analysis showed that subsidence was more likely to occur in patients with more than two treatment levels, and more likely to occur at treatment levels C5-7 than at levels C2-5. Subsidence was not associated with postoperative alignment change but associated with more disc height change (relatively oversized cage). CONCLUSION: Subsidence is associated with a greater number of treatment levels, treatment at C5-7 and relatively oversized cage use.

A Retrospective Observational Study to Evaluate Adjacent Segmental Degenerative Change with the Dynesys-Transition-Optima Instrumentation System.

BACKGROUND: This study evaluates the impact of hybrid dynamic stabilization using the Dynesys-Transition-Optima (DTO) system on adjacent segment disease (ASD) in lumbar spinal stenosis patients with spondylolisthesis. METHODS: From 2012 to 2020, 115 patients underwent DTO stabilization at a single center by a single neurosurgeon. After exclusions for lack of specific stabilization and incomplete data, 31 patients were analyzed. Follow-up was conducted at 6, 12, and 24 months postoperatively, assessing disc height, listhesis distance, and angular motion changes at L2-L3, L3-L4, and L5-S1. RESULTS: L3-L4 segment (the index level), demonstrated a delayed increase in listhesis distance, contrasting with earlier changes in other segments. At two years, L3-L4 exhibited less increase in listhesis distance and less disc height reduction compared to L2-L3 and L5-S1. Notably, the L3-L4 segment showed a significant reduction in angular motion change over two years. CONCLUSIONS: In conclusion, while ASD was not significantly prevented, the study indicates minor and delayed degeneration at the index level. The L3-L4 segment experienced reduced angular change in motion, suggesting a potential benefit of DTO in stabilizing this specific segment.

Incidence and risk factors of heterotopic ossification after cervical Baguera C disc arthroplasty.

OBJECTIVE: This retrospective study was designed to evaluate the incidence and predisposing factors of heterotopic ossification (HO) after cervical disc arthroplasty (CDA) with a specific implant at 1 and 2 levels, and to investigate the biomechanical effects related to HO. The study goal was to identify ways to reduce the likelihood of HO formation after surgery. METHODS: The study included patients who underwent only 1- or 2-level CDA with the Baguera C disc between November 2014 and December 2021 at a single medical center. All patients were operated on by the same neurosurgeon. The surgical indication included 1-level or 2-level disc herniation between C3 and C7 with radiculopathy, myelopathy, or both, with minimal spondylosis. The various factors were assessed by evaluating plain radiographs and cervical CT scans. The presence of HO was evaluated at different intervals postsurgery, and HO severity was graded using the McAfee classification. RESULTS: Of 107 patients who underwent CDA, 47 (43.9%) had HO at 63 of 171 levels (36.8%). Most cases with HO were grade 1, and no grade 4 was observed. Statistically significant risk factors for HO were the length of endplate coverage ratio and inferior anterior residual exposed endplate (AREE); sex, age, implant height and width, shell angle, and pre- and postoperative functional spinal unit (FSU) angle were not significant. More AREE and greater kyphotic postoperative FSU angle in the flexion position were significant factors differentiating HO grades 0 and 1 from grades 2 and 3. Furthermore, the non-HO group showed a trend of higher range of motion at any postoperative time compared to the HO group, especially at 1 month after surgery. CONCLUSIONS: The HO incidence after CDA was correlated with the residual length of endplate coverage and inferior AREE. Additionally, the AREE and kyphotic postoperative FSU angle in the flexion position were associated with HO grade progression. Patients with HO also showed a trend of lower range of motion at 1 month after surgery. Using an adequately sized implant and encouraging neck motion may help prevent HO development and progression.

Disc Height and Angle Changes on Radiographs and Magnetic Resonance Imaging after Anterior or Posterior Percutaneous Endoscopic Cervical Discectomy.

Objectives: Cervical disc herniation (CDH) leads to pain, numbness, and potential disability. Percutaneous endoscopic cervical discectomy (PECD) offers an anterior or posterior approach. This study aims to compare postoperative disc height and angle changes one year after PECD, considering both approaches. Methods: We retrospectively reviewed the data from patients with CDH who underwent PECD from October 2017 to July 2022. Cervical disc height was measured using the preoperative and one-year postoperative magnetic resonance imaging (MRI) examinations. Lordotic angle (LA), global alignment angle (GAA), segmental alignment angle (SAA), and slippage distance (SD) at the surgical level were measured on radiographs in the neutral, flexion, and extension positions. Results: Thirty-eight patients who underwent posterior PECD (PPECD) and five patients who underwent anterior PECD (APECD) were included in the evaluation. The mean age of the patients was 47.4 years (range: 29-69 years). There was a significant difference in the preoperative and one-year postoperative GAA and SAA in extension in the PPECD group (p = 0.003 and 0.031, respectively). The mean decreased disc height one-year postoperative was 1.30 mm in the APECD group and 0.3 mm in the PPECD group by MRI. A significant disc height decrease was observed in the APECD group (p < 0.001). Conclusions: Treating CDH with PPECD or APECD is feasible, as it can relieve symptoms and reduce disability. Stability remained unaffected during the first year after surgery, even though there was an increase in angulation during extension. Despite a significant decrease in disc space following APECD, patients reported significant symptom improvement and no new symptoms.

Risk Factors for Cervical Disc Arthroplasty Subsidence with Bryan Disc-A Retrospective Observational Analysis.

Background: Cervical disc arthroplasty (CDA) is currently used instead of fusion to preserve cervical spine motion. Cervical implant subsidence is a potential complication after CDA. Methods: Radiological measurements were recorded via patient anteroposterior and lateral radiographs in the neutral position. Subsidence was defined as a decrease of 3 mm or more in functional spinal unit height (FSUH) from which was measured on a post-operative (OP) radiograph. Results: This study included 104 patients who underwent 153 CDA levels with the Bryan Disc. Approximately one-quarter of the implants (22.9%) showed subsidence. Binary logistic regression analysis indicated that pre-OP mean disc height (DH) was identified as an independent risk factor for subsidence in multivariate analysis (0.151, 95% Confidence Interval 0-0.073, p = 0.018). Receiver operating characteristic curve analysis (area under the curve = 0.852, sensitivity 84.7%, specificity 77.1%) revealed a cut-off value of 4.48 mm for pre-OP Mean-DH in the risk for implant subsidence. Conclusions: In this study, the subsidence rate significantly increased when the implants were oversized beyond a pre-OP Mean-DH of approximately >4 mm. Moreover, the implant subsidence incidence was higher than that reported in previous studies. This is possibly due to endplate over-preparation or disc space over-distraction during placement at the same height as the Bryan Disc (8.5 mm).

The residual exposed endplate ratio is predictive of posterior heterotopic ossification after cervical Bryan disc arthroplasty.

OBJECTIVES: Heterotopic ossification (HO), a major cause of dysfunction after disc arthroplasty (CDA). The aim of this study was to determine the cut value of the residual exposed endplate (REE) ratio and to predict the development of posterior HO after Bryan CDA. METHODS: This retrospective study investigated the relationship between the REE ratio and posterior HO formation after Bryan CDA. Consecutive adult patients who underwent 1- or 2-level Bryan CDA by a single neurosurgeon between 2006 and 2016 with at least two years follow-up were included. Postoperative radiographic analysis and measurement were performed to obtain the REE ratio and the HO grade. RESULTS: Of 249 patients with 384 surgical levels who underwent Bryan CDA during the study period, 114 (45.8 %) received 1-level CDA and 135 (54.2 %) received 2-level CDA. Lateral radiographs showed that 169 implants (44 %) had posterior HOs in all grades after two years or more of follow up and 14 implants (3.64 %) had severe HO (McAfee grades 3 and 4). In 329 implants (85.7 %), a comparison of radiographs to CT examination of HO grading showed a substantial relationship. Using area under the curve (AUC) analysis, a REE ratio >9 %, with 65.1 % sensitivity and 86.5 % specificity, was the cut point for posterior HO formation. CONCLUSIONS: REE is highly correlated with the development of postoperative posterior HO after Bryan CDA, regardless of the level of implantation. An undersized implant causing a REE ratio >9 % is a predictor of postoperative posterior HO formation after cervical Bryan CDA.

Anterior Bone Loss after Cervical Baguera C Disc versus Bryan Disc Arthroplasty.

Objectives: The objectives of this study were to identify the risk factors and incidence of anterior bone loss (ABL) after Baguera C cervical disc arthroplasty (CDA) and identify whether design differences in artificial discs affect ABL. Methods: In this retrospective radiological review of patients who underwent single-level Baguera C CDA in a medical center, the extent of ABL and the following radiological parameters were recorded: global and segmental alignment angle, lordotic angle (or functional spinal unit angle), shell angle, global range of motion (ROM), and ROM of the index level. ABL at the index level was grade 0-2. Grade 0 was defined as no remodeling, grade 1 as spur disappearance or mild change in body contour, and grade 2 as obvious bone regression with Baguera C Disc exposure. Results: Combining grade 1 and grade 2, ABL was found in 56 upper adjacent vertebrae and 52 lower adjacent vertebrae of the 77 patients. Only 18 patients (23.4%) had no ABL. Shell angle differed significantly between ABL grades of both the upper and lower adjacent level: 0.0° in grade 0 and 1 ABL vs. 2.0° in grade 2 ABL of the upper adjacent level (p < 0.05); and 0.0° in grade 0 and 1 ABL vs. 3.5° in grade 2 ABL of the lower adjacent level (p < 0.05). A female predominance of ABL was found. Hybrid surgery and artificial disc size were also related to ABL. Conclusions: ABL is more common in Baguera C Disc arthroplasty than Bryan Disc arthroplasty. Larger shell angle was related to ABL after CDA with Baguera C Discs, which may indicate that shell angle is pivotal in determining the incidence of ABL after CDA. Females had more ABL with Baguera C Disc arthroplasty; this might be related to shorter endplate lengths as well as a smaller endplate-implant mismatch.

Improving Patient Safety in the X-ray Inspection Process with EfficientNet-Based Medical Assistance System.

Patient safety is a paramount concern in the medical field, and advancements in deep learning and Artificial Intelligence (AI) have opened up new possibilities for improving healthcare practices. While AI has shown promise in assisting doctors with early symptom detection from medical images, there is a critical need to prioritize patient safety by enhancing existing processes. To enhance patient safety, this study focuses on improving the medical operation process during X-ray examinations. In this study, we utilize EfficientNet for classifying the 49 categories of pre-X-ray images. To enhance the accuracy even further, we introduce two novel Neural Network architectures. The classification results are then compared with the doctor's order to ensure consistency and minimize discrepancies. To evaluate the effectiveness of the proposed models, a comprehensive dataset comprising 49 different categories and over 12,000 training and testing sheets was collected from Taichung Veterans General Hospital. The research demonstrates a significant improvement in accuracy, surpassing a 4% enhancement compared to previous studies.

Compressive optic neuropathy caused by a flow-diverter-occluded-but-still-growing supraclinoid internal carotid aneurysm: illustrative case.

BACKGROUND: Flow diverter stenting is an effective treatment for large proximal internal carotid artery (ICA) aneurysms. Cranial neuropathy caused by the mass effect of the aneurysm usually subsides over time. However, a new onset of compressive optic neuropathy after successful flow diverter stenting of a large proximal ICA aneurysm is seldom reported. OBSERVATIONS: A 57-year-old woman had a right supraclinoid ICA aneurysm (approximately 17 mm) on magnetic resonance angiography (MRA) in a health checkup. She received intervention with the Pipeline embolization device. Six months later, she started to experience progressive hemianopia in the left half of the visual field. Nine months after stenting, MRA showed that the aneurysm was growing and causing mass effect, but digital subtraction angiography confirmed that the aneurysm was completely excluded from the circulation. She received a craniotomy for microsurgical decompression of the optic nerve and coagulation shrinkage of the aneurysm. Clipping and thrombectomy were not attempted. Her visual fields recovered gradually. Follow-up MRA showed that the aneurysm also diminished in size. LESSONS: Whether the coagulation technique of the flow-diverter-occluded aneurysm alone is enough to cause satisfactory shrinkage and interaction between the flow diverter and the aneurysmal vasa vasorum/neointima formation should be further examined.

Accuracy of MRI derived cerebral aqueduct flow parameters in the diagnosis of idiopathic normal pressure hydrocephalus.

Idiopathic normal pressure hydrocephalus (iNPH) is a potentially reversible cause of dementia-like symptoms among the elderly. Current diagnostic guidelines for iNPH rely on clinical manifestations and ventricular morphology, which often lack accuracy. While magnetic resonance imaging (MRI) CSF flowmetry of the cerebral aqueduct provides a noninvasive aid to differential diagnosis, previous studies suffered from small sample sizes. This study compares the accuracy of different CSF flow parameters for iNPH diagnosis in a general patient population. From 2016 to 2018, a total of 216 subjects over 60 years of age were retrospectively enrolled, including 38 patients with iNPH and 178 patients with non-iNPH neurological conditions. All participants received phase-contrast MRI (PC-MRI) CSF flowmetry, with measurements performed independently by two radiologists. Flow parameters of iNPH and non-iNPH groups were compared along with their diagnostic accuracy. Absolute stroke volume (ABSV), forward flow, backward flow, mean flux and peak velocity were significantly higher in iNPH patients (P < 0.001, P < 0.001, P < 0.001, P = 0.008, P = 0.038, respectively). Backward flow had the highest diagnostic accuracy, followed by ABSV and forward flow. Net caudocranial aqueductal flow was observed in both groups, but with greater volume in the iNPH group. PC-MRI provides a non-invasive method of CSF flowmetry across the cerebral aqueduct and may aid in iNPH diagnosis. ABSV and its component flow values may provide better accuracy in identifying iNPH than other parameters.

Using deep learning convolutional neural networks to automatically perform cerebral aqueduct CSF flow analysis.

Since the development of phase-contrast magnetic resonance imaging (PC-MRI), quantification of cerebrospinal fluid (CSF) flow across the cerebral aqueduct has been utilized for diagnosis of conditions such as normal pressure hydrocephalus (NPH). This study aims to develop an automated method of aqueduct CSF flow analysis using convolution neural networks (CNNs), which can replace the current standard involving manual segmentation of aqueduct region of interest (ROI). Retrospective analysis was performed on 333 patients who underwent PC-MRI, totaling 353 imaging studies. Aqueduct flow measurements using manual ROI placement was performed independently by two radiologists. Two types of CNNs, MultiResUNet and UNet, were trained using ROI data from the senior radiologist, with PC-MRI studies being randomly divided into training (80%) and validation (20%) datasets. Segmentation performance was assessed using Dice similarity coefficient (DSC), and CSF flow parameters were calculated from both manual and CNN-derived ROIs. MultiResUNet, UNet and second radiologist (Rater 2) had DSCs of 0.933, 0.928, and 0.867, respectively, with p < 0.001 between CNNs and Rater 2. Comparison of CSF flow parameters showed excellent intraclass correlation coefficients (ICCs) for MultiResUNet, with lowest correlation being 0.67. For UNet, lower ICCs of -0.01 to 0.56 were observed. Only 3/353 (0.8%) studies failed to have appropriate ROIs placed by MultiResUNet, compared to 12/353 (3.4%) failed cases for UNet. In conclusion, CNNs were able to measure aqueductal CSF flow with similar performance to a senior neuroradiologist. MultiResUNet demonstrated fewer cases of segmentation failure and more consistent flow measurements compared to the widely adopted UNet.

Comparison of Multispectral Image-Processing Methods for Brain Tissue Classification in BrainWeb Synthetic Data and Real MR Images.

Accurate quantification of brain tissue is a fundamental and challenging task in neuroimaging. Over the past two decades, statistical parametric mapping (SPM) and FMRIB's Automated Segmentation Tool (FAST) have been widely used to estimate gray matter (GM) and white matter (WM) volumes. However, they cannot reliably estimate cerebrospinal fluid (CSF) volumes. To address this problem, we developed the TRIO algorithm (TRIOA), a new magnetic resonance (MR) multispectral classification method. SPM8, SPM12, FAST, and the TRIOA were evaluated using the BrainWeb database and real magnetic resonance imaging (MRI) data. In this paper, the MR brain images of 140 healthy volunteers (51.5 ± 15.8 y/o) were obtained using a whole-body 1.5 T MRI system (Aera, Siemens, Erlangen, Germany). Before classification, several preprocessing steps were performed, including skull stripping and motion and inhomogeneity correction. After extensive experimentation, the TRIOA was shown to be more effective than SPM and FAST. For real data, all test methods revealed that the participants aged 20-83 years exhibited an age-associated decline in GM and WM volume fractions. However, for CSF volume estimation, SPM8-s and SPM12-m both produced different results, which were also different compared with those obtained by FAST and the TRIOA. Furthermore, the TRIOA performed consistently better than both SPM and FAST for GM, WM, and CSF volume estimation. Compared with SPM and FAST, the proposed TRIOA showed more advantages by providing more accurate MR brain tissue classification and volume measurements, specifically in CSF volume estimation.

Endovascular Mechanical Thrombectomy and On-Site Chemical Thrombolysis for Severe Cerebral Venous Sinus Thrombosis.

Cerebral venous sinus thrombosis (CVST) is a rare cause of cerebral infarction. Once patients survive the acute phase, long-term prognosis is generally satisfactory. CVST patients who harbored risk factors known for poor prognosis (e.g., deterioration of consciousness/neurological functions and seizures) were oftentimes unresponsive to systemic heparin treatment. The advantage of combined endovascular mechanical thrombectomy (EMT) and on-site chemical thrombolysis (OCT) plus systemic heparin for CVST over the heparin treatment alone has not been proved. A retrospective study was conducted to analyze consecutive patients with CVST from 2005 to 2015. Patients having clinical improvement or stable disease after heparin treatment were in I/S group; patients having continuous deterioration of consciousness/neurological functions and refractory seizures (despite the use of multiple anti-epileptic drugs) after heparin treatment were in D group. EMT and OCT were indicated for patients in D group. Imaging studies and medical records were reviewed for statistical analysis. Safety issues included new-onset/progression of symptomatic intracerebral hemorrhages (ICH) or procedure-related complications. Total thirty patients were included (I/S group = 16; D group = 14). In D group, the mean time frame from the start of heparin treatment to the endovascular treatment was 3.2 days. Compared with I/S group, all patients in D group had complete stenosis of the sinuses, with higher initial mRS, lower initial GCS, and more seizures (p = 0.006, 0.007, and 0.031, respectively), but no significant differences in the mRS at discharge (p = 0.504). Shorter length of thrombosis and lower initial mRS were associated with better outcomes (p = 0.009 and 0.003, respectively). Thrombosis involving the superior sagittal sinus (SSS) was associated with bad outcomes (p = 0.026). There were two patients (6.7%) with worsening symptomatic ICH, one in each group, managed surgically. The overall mortality of the study was 6.7% (2/30). Combined EMT and OCT after heparin treatment for severe CVST were reasonably safe, which might be considered as a salvage treatment in severe CVST patients who are unresponsive to heparin with heavy clot burden involving SSS in the acute phase. However, further studies are needed to confirm its efficacy and validity.