Multimodal CT Research Articles

The Los Angeles Motor Scale is independently associated with cerebral blood flow < 30% volume in large vessel occlusions.

Mechanical thrombectomy (MT) is the treatment standard for large vessel occlusion (LVO) stroke. Under current guidelines, only patients with smaller ischemic core volumes (ICV) are eligible for MT. Thus, it is of interest to quickly estimate ICV in stroke patients. The Los Angeles Motor Scale (LAMS) is a validated tool used to assess stroke severity directly in the field. This study aims to determine whether LAMS score is also associated with ICV, as defined by the CBF <30% volume on CT perfusion imaging. We performed a retrospective, multicenter cohort study of consecutive patients presenting with LVO stroke from 9/1/2017 to 10/1/2023. The inclusion criteria were patients with (1) stroke caused by large vessel occlusion confirmed on CTA and (2) diagnostically adequate, multimodal pretreatment CT imaging. Demographic, clinical, and imaging data was collected through manual chart review. Both univariate and multivariate analyses were applied to assess associations. A p-value <.05 was considered significant. A total of 283 patients (median age: 69, IQR: 61-78) were included in the study. On multivariate logistic regression analysis, we found that lower admission LAMS score (adjusted OR: 0.511, 95% CI: 0.313-0.834, p = .007) was independently associated with a CBF <30% volume of less than 50cc. Admission LAMS is an independent predictor of a CBF <30% volume of less than 50cc. This demonstrates that LAMS can be used to estimate ICV, which will aid in the early triaging of LVO patients to thrombectomy-capable centers.

Mismatch Vs No Mismatch in Large Core-AMatter of Definition.

Endovascular thrombectomy (EVT) has shown promise in randomized controlled trials (RCTs) for large ischemic core stroke patients, yet variability in core definition and onset-to-imaging time creates heterogeneity in outcomes. This study aims to clarify the prevalence and implications of core-perfusion mismatch (MM) versus no mismatch (No MM) in such patients, utilizing established imaging criteria. Aretrospective cohort study was conducted including patients from 7/29/2019 to 1/29/2023, with data extracted from acontinuously maintained database. Patients were eligible if they met criteria including multimodal CT imaging performed within 24 h from last known well (LKW), AIS-LVO diagnosis, and ischemic core size defined by specific rCBF thresholds. Mismatch was assessed based on different operational definitions from the EXTEND and DEFUSE 3trials. Fifty-two patients were included, with various time windows from LKW. Using EXTEND criteria, asignificant portion of early window patients exhibited MM; however, fewer patients met MM criteria in the late window. Defining MM using DEFUSE 3criteria yielded similar patterns, but with overall lower MM prevalence in the late window. When employing rCBF <38% as asurrogate for ischemic core, ahigher percentage of patients were classified as MM across both time windows compared to rCBF <30%. The prevalence of MM in large ischemic core patients varies significantly depending on the imaging criteria and time from LKW. Notably, MM was more prevalent in the early time window across all criteria used. Additional RCTs are needed to determine if this definition of MM identifies patients who will benefit most from EVT.

Non-invasive multimodal CT deep learning biomarker to predict pathological complete response of non-small cell lung cancer following neoadjuvant immunochemotherapy: a multicenter study

ObjectivesAlthough neoadjuvant immunochemotherapy has been widely applied in non-small cell lung cancer (NSCLC), predicting treatment response remains a challenge. We used pretreatment multimodal CT to explore deep learning-based immunochemotherapy response...

Multimodal imaging-based prediction of recurrence for unresectable HCC after downstage and resection-cohort study.

Surgical resection (SR) following transarterial chemoembolization (TACE)-based downstaging is a promising treatment for unresectable hepatocellular carcinoma (uHCC), and identification of patients at high-risk of postoperative recurrence may assist individualized treatment. To develop and externally validate preoperative and postoperative prognostic models integrating multimodal CT and digital subtraction angiography features as well as clinico-therapeutic-pathological features for predicting disease-free survival (DFS) after TACE-based downstaging therapy. From March 2008 to August 2022, 488 consecutive patients with Barcelona Clinic Liver Cancer (BCLC) A/B uHCC receiving TACE-based downstaging therapy and subsequent SR were included from four tertiary-care hospitals. All CT and digital subtraction angiography images were independently evaluated by two blinded radiologists. In the derivation cohort ( n =390), the XGBoost algorithm was used for feature selection, and Cox regression analysis for developing nomograms for DFS (time from downstaging to postoperative recurrence or death). In the external testing cohort ( n =98), model performances were compared with five major staging systems. The preoperative nomogram included over three tumors [hazard ratio (HR), 1.42; P =0.003], intratumoral artery (HR, 1.38; P =0.006), TACE combined with tyrosine kinase inhibitor (HR, 0.46; P <0.001) and objective response to downstaging therapy (HR, 1.60; P <0.001); while the postoperative nomogram included over three tumors (HR, 1.43; P =0.013), intratumoral artery (HR, 1.38; P =0.020), TACE combined with tyrosine kinase inhibitor (HR, 0.48; P <0.001), objective response to downstaging therapy (HR, 1.69; P <0.001) and microvascular invasion (HR, 2.20; P <0.001). The testing dataset C-indexes of the preoperative (0.651) and postoperative (0.687) nomograms were higher than all five staging systems (0.472-0.542; all P <0.001). Two prognostically distinct risk strata were identified according to these nomograms (all P <0.001). Based on 488 patients receiving TACE-based downstaging therapy and subsequent SR for BCLC A/B uHCCs, the authors developed and externally validated two nomograms for predicting DFS, with superior performances than five major staging systems and effective survival stratification.

IV Thrombolysis for Acute Ischemic Stroke with Unknown Onset in Patients on Oral Anticoagulation

Introduction: IV thrombolysis (IVT) is established in the unknown or extended time window based on multimodal imaging. Further, increasing evidence exists regarding IVT in patients on oral anticoagulation including direct oral anticoagulants (DOACs). However, data on IVT in ischemic stroke patients on oral anticoagulation with unknown time of stroke onset are sparse. Methods: This study bases on the longitudinal cohort study Stroke Research Consortium in Northern Bavaria (STAMINA; ClinicalTrials.gov Identifier: NCT04357899). Acute ischemic stroke patients treated with IVT in the unknown or extended time window from January 2015 to December 2019 were included. Patient selection was based on multimodal CT or MRI. Patients on oral anticoagulation (vitamin-K antagonist [VKA] or DOAC within 48 h) were eligible for IVT based on INR measurement (VKA) or plasma levels (DOAC) according to an institutional protocol. Primary outcomes were the incidence of any and symptomatic intracranial hemorrhage. Results: Of 170 ischemic stroke patients treated with IVT in the unknown or extended time window, 151 had no oral anticoagulation at stroke onset and 19 were on oral anticoagulation (6 on VKA and 13 on DOAC). The risk of symptomatic ICH according to ECASS II criteria was similar between the patients with and without oral anticoagulation (1 [5.3%] vs. 4 [2.7%], p = 0.453). After adjustment for confounding factors, pre-medication with oral anticoagulation was not associated with symptomatic ICH (aOR 1.02 [0.09–11.02], p = 0.988). Conclusion: IVT for ischemic stroke with unknown onset appeared safe in selected patients on oral anticoagulation with both DOAC and VKA.

Effectiveness of computed tomography perfusion imaging in stroke management.

Current guidelines do not support the use of computed tomography perfusion (CTP) in stroke, except when identifying the penumbra during an extended treatment window. Therefore, this study aimed to define the yield of CTP in diagnosing a stroke diagnosis beyond the imaging of the penumbra in the hyperacute phase (0-6 h) and an extended time window (6-24 h). All consecutive patients with acute onset of symptoms within a 24-h window underwent CTP imaging. The diagnostic value of CTP was calculated against the clinical and radiological diagnoses of stroke. A positive CTP result was determined by the presence of either a core or penumbra on the RAPID summary. Clinical diagnoses corresponded to discharge diagnoses of stroke. A radiological diagnosis was established if early ischemic changes [Alberta Stroke Program Early CT Score (ASPECTS) <10] were observed on the baseline CT scan, acute infarction was confirmed on follow-up imaging, or symptomatic occlusion was evident on baseline CTA. Between November 2018 and November 2019, 585 consecutive patients with an acute neurological deficit underwent multimodal CT imaging. A total of 500 patients (85%) were included, where 274 (55%) were within the hyperacute phase, 153 (31%) had a radiological diagnosis of stroke, and 122 (24%) had a clinical diagnosis of stroke. CTP yielded positive results only in patients with a confirmed stroke (positive predictive value and specificity of 100%). When CTP results were negative, 43% of the cases turned out to stroke mimics. Patients with stroke mimics were younger (66 ± 17 vs. 73 ± 13) and had lower scores on the National Institutes of Health Stroke Scale [median 0; interquartile range (IQR) 0-2 vs. median 4; IQR 2-6] compared to patients with CTP-negative strokes. In our study, CTP consistently indicated brain ischemia; therefore, in stroke management, CTP is most beneficial when it yields a positive result. A positive CTP result should prompt adequate stroke management actions without any delay. Conversely, a negative CTP result necessitates the consideration of both stroke and non-stroke diagnoses.

The importance of MDCT in the evaluation of risk factors before the TAVI procedure and its complications after implantation

Transcatheter aortic valve implantation (TAVI) is the alternative to surgical valve replacement, expanding its indications in the latest guidelines. Multimodal CT (MDCT) is essential in patient selection and detection of complications. Vascular complications are frequent, so it is important to analyse the anatomy of the vessels before the procedure. Regarding annular ruptures and ventricular perforations, the volume and distribution of calcium and the ventricular diameter play an important role. Finally, valve migration is a rare complication that can occur both during and after TAVI. Proper planning of the MDCT procedure reduces the risk of complications and gives the interventional cardiologist security both before and during the procedure.

Overestimation of the Ischemic Core Is Associated With Higher Core Lesion Volume and Degree of Reperfusion After Thrombectomy.

Background CT perfusion (CTP)-derived baseline ischemic core volume (ICV) can overestimate the true extent of infarction, which may result in exclusion of patients with ischemic stroke from endovascular treatment (EVT). Purpose To determine whether ischemic core overestimation is associated with larger ICV and degree of recanalization. Materials and Methods This retrospective multicenter cohort study included patients with acute ischemic stroke triaged at multimodal CT who underwent EVT between January 2015 and January 2022. The primary outcome was ischemic core overestimation, which was assumed when baseline CTP-derived ICV was larger than the final infarct volume at follow-up imaging. The secondary outcome was functional independence defined as modified Rankin Scale scores of 0-2 90 days after EVT. Successful vessel recanalization was defined as extended Thrombolysis in Cerebral Infarction score of 2b or higher. Categorical variables were compared between patients with ICV of 50 mL or less versus large ICV greater than 50 mL with use of the χ2 test. Adjusted multivariable logistic regression analyses were used to assess the primary and secondary outcomes. Results In total, 721 patients (median age, 76 years [IQR, 64-83 years]; 371 female) were included, of which 162 (22%) demonstrated ischemic core overestimation. Core overestimation occurred more often in patients with ICV greater than 50 mL versus 50 mL or less (48% vs 16%; P < .001) and those with successful versus unsuccessful vessel recanalization (26% vs 13%; P < .001). In an adjusted model, successful recanalization after EVT (odds ratio [OR], 3.14 [95% CI: 1.65, 5.95]; P < .001) and larger ICV (OR, 1.03 [95% CI: 1.02, 1.04]; P < .001) were independently associated with core overestimation, while the time from symptom onset to imaging showed no association (OR, 0.99; P = .96). Core overestimation was independently associated with functional independence (adjusted OR, 2.83 [95% CI: 1.66, 4.81]; P < .001) after successful recanalization. Conclusion Ischemic core overestimation occurred more frequently in patients presenting with large CTP-derived ICV and successful vessel recanalization compared with those with unsuccessful recanalization. © RSNA, 2024 Supplemental material is available for this article.

CT Perfusion Derived rCBV < 42% Lesion Volume Is Independently Associated with Followup FLAIR Infarct Volume in Anterior Circulation Large Vessel Occlusion.

Pretreatment CT Perfusion (CTP) parameter rCBV < 42% lesion volume has recently been shown to predict 90-day mRS. In this study, we aim to assess the relationship between rCBV < 42% and a radiographic follow-up infarct volume delineated on FLAIR images. In this retrospective evaluation of our prospectively collected database, we included acute stroke patients triaged by multimodal CT imaging, including CT angiography and perfusion imaging, with confirmed anterior circulation large vessel occlusion between 9 January 2017 and 10 January 2023. Follow-up FLAIR imaging was used to determine the final infarct volume. Student t, Mann-Whitney-U, and Chi-Square tests were used to assess differences. Spearman's rank correlation and linear regression analysis were used to assess associations between rCBV < 42% and follow-up infarct volume on FLAIR. In total, 158 patients (median age: 68 years, 52.5% female) met our inclusion criteria. rCBV < 42% (ρ = 0.56, p < 0.001) significantly correlated with follow-up-FLAIR infarct volume. On multivariable linear regression analysis, rCBV < 42% lesion volume (beta = 0.60, p < 0.001), ASPECTS (beta = -0.214, p < 0.01), mTICI (beta = -0.277, p < 0.001), and diabetes (beta = 0.16, p < 0.05) were independently associated with follow-up infarct volume. The rCBV < 42% lesion volume is independently associated with FLAIR follow-up infarct volume.

The Relative Cerebral Blood Volume (rCBV) < 42% Is Independently Associated with Collateral Status in Anterior Circulation Large Vessel Occlusion.

Background: The pretreatment CT perfusion (CTP) marker the relative cerebral blood volume (rCBV) < 42% lesion volume has recently been shown to predict 90-day functional outcomes; however, studies assessing correlations of the rCBV < 42% lesion volume with other outcomes remain sparse. Here, we aim to assess the relationship between the rCBV < 42% lesion volume and the reference standard digital subtraction angiography (DSA)-derived American Society of Interventional and Therapeutic Neuroradiology/Society of Interventional Radiology (ASITN) collateral score, hereby referred as the DSA CS. Methods: In this retrospective evaluation of our prospectively collected database, we included acute stroke patients triaged by multimodal CT imaging, including CT angiography and perfusion imaging, with confirmed anterior circulation large vessel occlusion between 1 September 2017 and 1 October 2023. Group differences were assessed using the Student's t test, Mann-Whitney U test and Chi-Square test. Spearman's rank correlation and logistic regression analyses were used to assess associations between rCBV < 42% and DSA CS. Results: In total, 222 patients (median age: 69 years, 56.3% female) met our inclusion criteria. In the multivariable logistic regression analysis, taking into account age, sex, race, hypertension, hyperlipidemia, diabetes, atrial fibrillation, prior stroke or transient ischemic attack, the admission National Institute of Health stroke scale, the premorbid modified Rankin score, the Alberta stroke program early CT score (ASPECTS), and segment occlusion, the rCBV < 42% lesion volume (adjusted OR: 0.98, p < 0.05) was independently associated with the DSA CS. Conclusion: The rCBV < 42% lesion volume is independently associated with the DSA CS.

Abstract TP170: An Explainable Deep Learning Method to Quantitatively Predict Hematoma Progression After Intracerebral Hemorrhage

In patients with intracerebral hemorrhage (ICH), it is important to quickly and accurately individualize the treatment decision by quantitatively predicting the hematoma progression using medical information collected on admission. Current approaches only qualitatively predict ICH progression trends leveraging anatomical features extracted from non-contrast computed tomography (NCCT) images. However, these approaches do not consider the hemodynamics of the cerebral circulation system, cannot quantitatively predict ICH progression, and lack the needed explainability. To address these technical challenges, in this work, we developed an explainable deep learning method to quantitatively predict hematoma progression after ICH, which quantitatively predicts ICH progression leveraging (i) deep anatomical features (baseline ICH lesion volume) derived from NCCT images, and (ii) deep hemodynamic features focusing veins-of-interest derived from time-resolved CT images collected on admission. A total of 73 patients categorized into the training data set (containing 58 patients) and the test data set (containing 15 patients), with 216 sets of images, were used in the development and validation of the model. For the ICH lesion volume predicted by this model, the mean difference with respect to the reference volume is -0.96 mL, and the agreement limits are [-9.64 mL, +7.71 mL] (Figure 1). In conclusions, by simultaneously leveraging deep anatomical and hemodynamic features, our model can quantitatively predict ICH progression using multimodal CT images collected on admission and hence help individualize the treatment decision during hospitalization.

Preoperative diagnostic value of multimodal spectral CT for patients with atrial fibrillation undergoing radiofrequency ablation.

Delayed enhancement cardiac computed tomography (CT) empowers the diagnosis of left atrial appendage thrombus while limited to scanning heterogeneity. We optimized the spectral CT scan and post-process protocols, incorporating delayed enhancement and spectral iodine analysis to discriminate left atrial appendage (LAA) thrombus with better morphological relationships between the left atrium, pulmonary vein, and esophagus. A total of 278 consecutive patients were retrieved from January 2019 to June 2023. All patients underwent transesophageal echocardiography (TEE) and spectral CT scan of the left atrial and pulmonary vein, with a complete period including the pulmonary venous phase and three delay phases. TEE diagnosis was used as the standard reference. For patients exhibiting LAA filling defects during the pulmonary venous phase, a delayed scan of 30 s (phase I) was performed. If the filling defects persisted, a further delayed scan of 1 min (phase II) was conducted. In cases where the filling defects persisted, an additional delayed scan of 2 min (phase III) was carried out. Iodine concentration in the filled defect area of LAA and the left atrium was measured in phase III. Moreover, 30 patients were randomly selected for water-swallowing and the other 30 for calm breathing. The image quality and esophageal dilation of the two groups were assessed by two experienced surgeons specializing in radiofrequency ablation. In total, 14 patients were diagnosed with thrombi by TEE. The sensitivity, specificity, positive predictive values, negative predictive values, and AUC of phase III delayed combined with iodine quantification for thrombi diagnosis were all 100%. The water-swallowing group exhibited significantly greater esophageal filling and expansion than the calm-breathing group, contributing to a better morphology assessment with no significant difference in image quality. Combined with iodine quantification, delayed enhancement of spectral CT imaging presents a promising diagnostic potency for LAA thrombus. Incorporating water swallowing into the CT scan process further enables anatomical visualization of the esophagus, left atrium, and pulmonary vein, thereby providing more objective and authentic imaging evidence to assess the esophageal morphology and positional relationships.

Preoperative 3D Microvascular Decompression Simulation

Preoperative surgical simulation via three-dimensional fusion computer graphics models have been widely accepted as a legitimate means of securing the diagnosis and treatment effectiveness of neurovascular compression. The authors discussed three factors of surgical simulation as being 1. Knowing the anatomical relationship, 2. Knowing the desirable end result of surgical intervention, and 3. Knowing how to design surgical interventions to achieve such desirable end results. Satisfying each factor requires distinct functionality from the software used in the surgical simulation. As per the imaging study used to construct the multimodal computer graphic models, CT scan and MR are usually sufficient, although renal function-permitting contrast enhancement can be a feasible option for depicting minute vessels in particular. There are three major steps in building three-dimensional fusion computer graphics models:1. Image interpretation, 2. co-registration, and 3. Segmentation. Each step comprises an essential part that must be handled with care. The segmentation step is where rigorous technological advancement takes place, although classical techniques, such as the seeded region growing method or the multi-threshold method, are still practically important. Regarding surgical simulation after three-dimensional model construction, technical challenges concerning large deformations should be recognized to ensure non-nonsense surgical simulation.

Volumetric feature points integration with bio-structure-informed guidance for deformable multi-modal CT image registration

Objective. Medical image registration represents a fundamental challenge in medical image processing. Specifically, CT-CBCT registration has significant implications in the context of image-guided radiation therapy (IGRT). However, traditional iterative methods often require considerable computational time. Deep learning based methods, especially when dealing with low contrast organs, are frequently entangled in local optimal solutions. Approach. To address these limitations, we introduce a registration method based on volumetric feature points integration with bio-structure-informed guidance. Surface point cloud is generated from segmentation labels during the training stage, with both the surface-registered point pairs and voxel feature point pairs co-guiding the training process, thereby achieving higher registration accuracy. Main results. Our findings have been validated on paired CT-CBCT datasets. In comparison with other deep learning registration methods, our approach has improved the precision by 6%, reaching a state-of-the-art status. Significance. The integration of voxel feature points and bio-structure feature points to guide the training of the medical image registration network has achieved promising results. This provides a meaningful direction for further research in medical image registration and IGRT.

Key CT markers for predicting haemorrhagic transformation after ischaemic stroke: a prospective cohort study in China

ObjectivesLimited studies have systematically addressed the CT markers of predicting haemorrhagic transformation (HT). We aimed to (1) investigate the predictive ability of the imaging factors on multimodal CT for HT...

Net water uptake within the ischemic penumbra predicts the presence of the midline shift in patients with acute ischemic stroke.

The study aimed to explore the association between midline shift (MLS) and net water uptake (NWU) within the ischemic penumbra in acute ischemic stroke patients. This was a retrospective cohort study that examined patients with anterior circulation stroke. Net water uptake within the acute ischemic core and penumbra was calculated using data from admission multimodal CT scans. The primary outcome was severe cerebral edema measured by the presence of MLS on 24 to 48 h follow-up CT scans. The presence of a significant MLS was defined by a deviation of the septum pellucidum from the midline on follow-up CT scans of at least 3 mm or greater due to the mass effect of ischemic edema. The net water uptake was compared between patients with and without MLS, followed by logistic regression analyses and receiver operating characteristics (ROCs) to assess the predictive power of net water uptake in MLS. A total of 133 patients were analyzed: 50 patients (37.6%) with MLS and 83 patients (62.4%) without. Compared to patients without MLS, patients with MLS had higher net water uptake within the core [6.8 (3.2-10.4) vs. 4.9 (2.2-8.1), P = 0.048] and higher net water uptake within the ischemic penumbra [2.9 (1.8-4.3) vs. 0.2 (-2.5-2.7), P < 0.001]. Penumbral net water uptake had higher predictive performance than net water uptake of the core in MLS [area under the curve: 0.708 vs. 0.603, p < 0.001]. Moreover, the penumbral net water uptake predicted MLS in the multivariate regression model, adjusting for age, sex, admission National Institutes of Health Stroke Scale (NIHSS), diabetes mellitus, atrial fibrillation, ischemic core volume, and poor collateral vessel status (OR = 1.165; 95% CI = 1.002-1.356; P = 0.047). No significant prediction was found for the net water uptake of the core in the multivariate regression model. Net water uptake measured acutely within the ischemic penumbra could predict severe cerebral edema at 24-48 h.

Automatic statistical diagnosis of COVID-19 based on multi-modal CT feature extraction

Background and purposeComputed tomography (CT) is highly sensitive to lung-related abnormalities as a non-invasive method and has become an essential tool for screening and diagnosing Coronavirus disease 2019 (COVID-19). To reduce the stress of work for physicians and speed up diagnosis, we propose a novel automatic diagnosis pipeline for COVID-19 based on high-dimensional radiomic features extracted from multimodal CT scans (multi-geometric and multiscale). Materials and methodsThere are 746 CT scans involved in this study, where 349 CT scans are COVID-19 positive and 397 CT scans are COVID-19 negative. All of them are from the public dataset. We first construct a transfer learning-based auto-segmentation model with a morphological post-processing block to improve the lung region segmentation. Then the radiomics feature extraction is guided by the proposed multi-modal CT scans strategy. In addition, our automatic diagnosis pipeline is driven by a well-designed loss function. We also explain the diagnosis capability from the related theory of linear subspace spanned by multi-modal radiomics features. ResultsUnder the 10-fold cross-validation strategy, our approach can achieve an improvement in diagnostic performance of 5. 77%, 7. 78%, 7. 74%, 7. 78%, 7. 45% compared to the radiomic features extracted from the original CT scans, and diagnosis performance is promoted to 91.53%, 86.46%, 86.47%, 86.46%, 86.95% in terms of AUC, Acc, F1, Recall and Precision in public datasets. ConclusionsWe demonstrate a statistically significant improvement of the proposed statistical learning method compared to the state-of-the-art machine learning-based diagnosis approaches. Thanks to theoretical support and excellent diagnostic performance, our method can be deployed in clinical auxiliary diagnosis, releasing the overstretched medical resources.

Implementation and Comparative Study of Pyramid-based Image Fusion Techniques for Lumbar Spine Images

Image fusion is a method of combining the necessary and relevant information from the set of source images into a single (fused) image which can be deemed to be more informative than the source. This paper discusses the implementation of various pyramid-based image fusion algorithms, such as the Laplacian pyramid, the ratio of the low-pass pyramid, the contrast pyramid, and the filter subtract decimate pyramid on multimodal CT and MR images of the lumbar spine. The fused images were evaluated using various objective evaluation quality metrics. The experimental results demonstrated that the ratio of the low pass pyramid achieved better performance compared to the other pyramids implemented, indicating that the fused image can also be used for further image fusion application or analysis purposes.

Clinical outcomes after endovascular thrombectomy in different triage methods

ObjectiveThe purpose of this study was to evaluate the effectiveness and safety of drip and ship (DS) for acute ischemic stroke (AIS) by comparing three treatment strategies: 1) patients seen at a primary stroke center, started on emergency intravenous thrombolysis and then transported to a comprehensive stroke center (drip and ship, DS); 2) patients immediately transferred to comprehensive stroke center without starting intravenous thrombolysis, for mechanical thrombectomy (non-drip and ship, non-DS); and 3) patients admitted directly to the comprehensive stroke center for assessment and subsequent bridging thrombolysis (mothership, MS). MethodsWe retrospectively reviewed the data of patients that underwent mechanical thrombectomy for AIS from November 2020 to May 2022 at our institution. Patients were divided into three groups: DS, non-DS, and MS. Time course, multimodal CT features and clinical results were compared among the three groups. ResultsThe study included 62 patients, with 19, 18, and 25 patients in DS, non-DS, and MS groups, respectively. Baseline characteristics did not differ among the three groups. The DS group had a significantly longer median onset to groin time than the MS group (395 min vs 244 min; P < 0.001), a significantly shorter onset to primary stroke center time than the non-DS group (90 min vs 463 min; P < 0.001), and a longer primary stroke center to groin puncture time than the non-DS group (277 min vs 162 min; P = 0.002). The onset to needle time was longer in the MS group than the DS group (151.2 min vs 111.8 min; P = 0.041). The intravenous thrombolysis to puncture time was shorter in the MS group compared with DS (56 min vs 278 min; P < 0.001). No significant differences were present among groups in post-operative variables measured. ConclusionsDS is a safe and effective method, with no increased risk of postoperative complications or death compared to non-DS and MS methods. The study provides a reference for the selection of transport modes for AIS patients.

P.001 Application of low-intensity transcranial focused unltrasound to the hippocampus in Alzheimer’s Disease

Background: The purpose of this study was to evaluate the safety and efficacy of low-intensity tFUS under the threshold for BBB disruption in patients with AD. In addition, we assessed changes in the regional cerebral metabolic rate of glucose (rCMRglu) using F-18 fluoro-2-deoxyglucose positron emission tomography (FDG-PET) and cognitive function after tFUS. Methods: Eight AD patients were recruited. We applied low-intensity tFUS to the right hippocampus for 3 minutes using an image-guided tFUS system. For multi-modal neuroimaging guidance, MRI and CT data were spatially co-registered using the maximization of normalized mutual information. The subjectspecific coordinates of the hippocampus in the right hemisphere were identified as the tFUS target location. Results: Radiological evidence of contrast enhancement associated with BBB opening was not found in neither the visual inspection nor the ICA of the DCE-MRI data. No adverse events were observed during the hospitalization and follow-up outpatient visits for 5 to 24 months. The immediate recall and recognition memory on the SVLT were significantly improved after the sonication. The PET analysis showed the increased level of rCMRglu in the right hippocampus. Conclusions: Application of low-intensity tFUS to the hippocampus with MB did not open blood brain barrier but increased hippocampal glucose metabolism and memory function.