A multi-scanner neuroimaging data harmonization using RAVEL and ComBat.

Modern neuroimaging studies frequently combine data collected from multiple scanners and experimental conditions. Such data often contain substantial technical variability associated with image intensity scale (image intensity scales are not the same in different images) and scanner effects (images obtained from different scanners contain substantial technical biases). Here we evaluate and compare results of data analysis methods without any data transformation (RAW), with intensity normalization using RAVEL, with regional harmonization methods using ComBat, and a combination of RAVEL and ComBat. Methods are evaluated on a unique sample of 16 study participants who were scanned on both 1.5T and 3T scanners a few months apart. Neuroradiological evaluation was conducted for 7 different regions of interest (ROI's) pertinent to Alzheimer's disease (AD). Cortical measures and results indicate that: (1) RAVEL substantially improved the reproducibility of image intensities; (2) ComBat is preferred over RAVEL and the RAVEL-ComBat combination in terms of regional level harmonization due to more consistent harmonization across subjects and image-derived measures; (3) RAVEL and ComBat substantially reduced bias compared to analysis of RAW images, but RAVEL also resulted in larger variance; and (4) the larger root mean square deviation (RMSD) of RAVEL compared to ComBat is due mainly to its larger variance.

A Case Report of Spinal Arteriovenous Fistula: Vague Presentation and Successful Outcome.

Spinal arteriovenous fistula (spinal AVF) malformation is one of the rare spinal vascular diseases. Its presentation could be misleading as the patient presents with spinal cord dysfunction, including motor power loss.  Early detection is essential and requires a high suspicion by the providing physician so the patient can be rightfully directed to the proper team with vascular intervention resources. Efficient management leads to promising outcomes with patient recovery. We are presenting a case with progressing motor and sensory neurological deficits that had a vague clinical course. After a prompt diagnosis of spinal AVF, the patient was referred to the neuro-vascular specialist, who performed an embolization of the spinal AVF. The patient had an excellent outcome and was discharged to a rehabilitation facility.

Can Publicly Available Artificial Intelligence Successfully Identify Current Procedural Terminology Codes for Common Procedures in Neurosurgery?

OBJECTIVE: Coding for neurosurgical procedures is a complex process that is dynamically changing year to year, through the annual introduction and removal of codes and modifiers. The authors hoped to elucidate if publicly available artificial intelligence (AI) could offer solutions for neurosurgeons with regard to coding. METHODS: Multiple publicly available AI platforms were asked to provide Current Procedural Terminology (CPT) codes and Revenue Value Units (RVU) values for common neurosurgical procedures of the brain and spine with a given indication for the procedure. The responses of platforms were recorded and compared to the currently valid CPT codes used for the procedure and the amount of RVUs that would be gained. RESULTS: Six platforms and Google were asked for the appropriate CPT codes for 10 endovascular, spinal, and cranial procedures each. The highest performing platforms were as follows: Perplexity.AI identified 70% of endovascular, BingAI identified 55% of spinal, and ChatGPT 4.0 with Bing identified 75% of cranial CPT codes. With regard to RVUs, the top performer gained 78% of endovascular, 42% of spinal, and 70% of cranial possible RVUs. With regard to accuracy, AI platforms on average outperformed Google (45% vs. 25%, P = 0.04236). CONCLUSIONS: The ability of publicly available AIs to successfully code for neurosurgical procedures holds great promise in the future. Future development of AI should focus on improving accuracy with regard to CPT codes and providing supporting documentation for its decisions. Improvement on the existing capabilities of AI platforms can allow for increased operational efficiency and cost savings for practices.

Mildly elevated INR is associated with worse outcomes following mechanical thrombectomy for acute ischemic stroke.

BACKGROUND: Elevated International Normalized Ratio (INR) is a marker of coagulopathy, but its impact on outcomes following mechanical thrombectomy (MT) in patients with stroke is unclear. This study investigates the impact of mild INR elevations on clinical outcomes following MT. METHODS: In this retrospective cohort study, consecutive patients with stroke treated with MT were identified from 2015 to 2020 at a Comprehensive Stroke Center. Demographic information, past medical history, INR, National Institutes of Health Stroke Scale score, use of tissue plasminogen activator, and last known normal to arteriotomy time were recorded. Outcome measures included modified Thrombolysis in Cerebral Infarction (mTICI) score, modified Rankin Scale (mRS) score at 90 days, and intracerebral hemorrhage (ICH). Patients were divided into two groups: normal INR (0.8-1.1) and mildly elevated INR (1.2-1.7). RESULTS: A total of 489 patients were included for analysis, of which 349 had normal INR and 140 had mildly elevated INR. After multivariable adjustments, mildly elevated INR was associated with lower odds of excellent outcomes (mRS 0-1, OR 0.24, p=0.009), lower odds of functional independence (mRS 0-2, OR 0.38, p=0.038), and higher odds of 90-day mortality (OR 3.45, p=0.018). Elevated INR was not associated with a higher likelihood of ICH, and there were no differences in rates of HI1, HI2, PH1, or PH2 hemorrhagic transformations; however, elevated INR was associated with significantly higher odds of 90-day mortality in patients with ICH (OR 6.22, p=0.024). This effect size was larger than in patients without ICH (OR 3.38, p<0.001). CONCLUSION: In patients with stroke treated with MT, mildly elevated INR is associated with worse clinical outcomes after recanalization and may worsen the mortality risk of hemorrhagic transformations.

Peri-procedural decrease in hemoglobin following mechanical thrombectomy for ischemic stroke.

BACKGROUND: Peri-procedural blood loss and hemodilution occur in patients undergoing mechanical thrombectomy (MT) for ischemic stroke; however, its relationships with thrombectomy passes, procedure times, and clinical outcomes are unknown. METHODS: Consecutive patients undergoing MT for anterior circulation large-vessel occlusion ischemic strokes were identified at a Comprehensive Stroke Center. Clinical information, modified treatment in cerebral ischemia (mTICI) scores, and modified Rankin Scores (mRS) at 90 days were prospectively collected from 2012 to 2021. Hemoglobin measurements before and after MTs were collected retrospectively via chart review, and changes were quantified. Patients with new-onset severe anemia (defined as post-MT hemoglobin less than 10g/dL) were identified. Modified Rankin scale (mRS) at 90 days was used to measure clinical outcomes. RESULTS: Four-hundred and forty-five patients were identified. Hemoglobin decreased 1.27 ± 1.05 g/dL after MT on average. Greater number of thrombectomy passes and longer procedure times were associated with larger decreases in hemoglobin (p < 0.001 and p = 0.002, respectively). 11.5% (51 of 445) of patients had new-onset severe anemia, and this incidence was significantly higher with more thrombectomy passes (6.4% for one pass, 11.9% for two passes, and 17.4% for three or more passes; p = 0.010). In multivariable analyses, new-onset severe anemia was associated with significantly higher odds of 90-day poor outcomes (mRS 3-6, OR 2.70 [95%CI 1.12-6.51], p = 0.027) and death (OR 2.73 [95%CI 1.06-7.04], p = 0.037) compared to mild post-MT anemia. CONCLUSIONS: More thrombectomy passes and longer procedure times were significantly associated with larger peri-procedural decreases in hemoglobin. Patients with new-onset hemoglobin less than 10 g/dL are at risk of poor outcomes.

Iodine-based dual-energy CT predicts early neurological decline from cerebral edema after large hemispheric infarction.

Background & Purpose: Ischemia affecting two thirds of the MCA territory predicts development of malignant cerebral edema. However, early infarcts are hard to diagnose on conventional head CT. We hypothesize that high-energy (190keV) virtual monochromatic images (VMI) from dual-energy CT (DECT) imaging enables earlier detection of secondary injury from malignant cerebral edema (MCE). Methods: Consecutive LHI patients with NIHSS ≥ 15 and DECT within 10 hours of reperfusion from May 2020 to March 2022 were included. We excluded patients with parenchymal hematoma-type 2 transformation. Retrospective analysis of clinical and novel variables included VMI Alberta Stroke Program Early CT Score (ASPECTS), total iodine content, and VMI infarct volume. Primary outcome was early neurological decline (END). Secondary outcomes included hemorrhagic transformation, decompressive craniectomy (DC), and medical treatment of MCE. Fisher's exact test and Wilcoxon test were used for univariate analysis. Logistic regression was used to develop prediction models for categorical outcomes. Results: Eighty-four LHI patients with a median age of 67.5 [IQR 57,78] years and NIHSS 22 [IQR 18,25] were included. Twenty-nine patients had END. VMI ASPECTS, total iodine content, and VMI infarct volume were associated with END. VMI ASPECTS, VMI infarct volume, and total iodine content were predictors of END after adjusting for age, sex, initial NIHSS, and tPA administration, with a AUROC of 0.691 [0.572,0.810], 0.877 [0.800, 0.954], and 0.845 [0.750, 0.940]. By including all three predictors, the model achieved AUROC of 0.903 [0.84,0.97] and was cross validated by leave one out method with AUROC of 0.827. Conclusion: DECT with high-energy VMI and iodine quantification is superior to conventional CT ASPECTS and is a novel predictor for early neurological decline due to malignant cerebral edema after large hemispheric infarction.

Presence of a left common pulmonary vein and pulmonary vein anatomical characteristics as predictors of outcome following cryoballoon ablation for paroxysmal atrial fibrillation.

PURPOSE: Pulmonary vein (PV) isolation using cryoballoon ablation (CBA) is a common therapy for patients with drug-refractory paroxysmal atrial fibrillation (PAF). However, initial CBA is successful in only 70-80% of patients. The role of an atypical left common PV (LCPV) and PV anatomical indices on CBA outcomes remains unclear. METHODS: We followed 80 patients (age 60.7 ± 9.7, 31 % women) with PAF undergoing CBA for 1-year post-procedure for the development of recurrent atrial arrhythmias (AA). Recurrence was assessed by documented AA on EKG or any form of long-term cardiac rhythm monitoring. The presence of an LCPV and individual PV diameters were evaluated using cardiac CT. Based on the maximum and minimum PV ostial diameters, the eccentricity index (EI), ovality index (OI), and PV ostial area (PVA) were calculated for all the veins. A multivariable Cox-proportional hazard model assessed whether the presence of an LCPV or PV anatomic indices (EI, OI, and PVA) predicted recurrence of AA following CBA. RESULTS: After 1-year follow-up, 19 (23.7%) participants developed recurrence of AA. On multivariable regression, the presence of an LCPV did not predict the recurrence of AA (p = 0.38). Among the PV anatomical indices, on univariate analysis, only the area of the left inferior PV showed a trend towards predicting recurrence, though this result was not significant on multivariate analysis (p = 0.09). CONCLUSIONS: In patients with PAF, neither the presence of an LCPV nor individual PV anatomical indices predicted recurrence of AA following CBA.

Outcomes in patients with acute ischemic stroke from proximal intracranial vessel occlusion and NIHSS score below 8.

OBJECTIVE: Acute ischemic stroke due to proximal intracranial vessel occlusion is associated with poor prognosis and neurologic outcomes. Outcomes specifically in patients with stroke due to these occlusions and lower National Institutes of Health Stroke Scale (NIHSS) scores (0-7 range) have not been described previously. METHODS: We retrospectively reviewed discharge outcomes (reported in our 'Get With the Guidelines-Stroke' database) in patients with an admission NIHSS score of 0-7 due to proximal intracranial large vessel occlusion (based on CT angiography results) who were excluded from receiving intravenous (IV) thrombolysis with recombinant tissue plasminogen activator and endovascular intra-arterial (IA) stroke interventions. RESULTS: Among the 204 patients included in our analysis, younger age and lower admission NIHSS score (0-4 range) were strong predictors of good outcome (defined as ability to ambulate independently) at discharge whereas female sex was a predictor of poor outcome. There was no significant difference between cerebrovascular risk factors, specific sites of occlusion, or presenting symptoms and outcomes at discharge. There was great variability in functional outcomes at discharge and discharge disposition (home versus acute or subacute facility or nursing home versus death/hospice) with a trend toward worse outcomes in patients with higher (5-7 range) NIHSS scores on admission. CONCLUSIONS: Patients with acute stroke due to large vessel occlusion and low admission NIHSS scores (0-7 range) may have poor functional outcomes at discharge. These patients, if not eligible for IV thrombolysis, might benefit from IA revascularization therapies.