3D Digital Subtraction Angiography Research Articles

Optimization of image shoot timing for cerebral veins 3D-digital subtraction angiography by interventional angiography systems

Abstract3D-digital subtraction angiography (3D-DSA) is essential for understanding the anatomical structure of cerebral veins, crucial in brain tumor surgery. 3D-DSA produces three-dimensional images of veins by adjusting the X-ray delay time after contrast agent injection, but the delineation of veins varies with the delay in X-ray timing. Our study aimed to refine the delay time using time-enhancement curve (TEC) analysis from 2D-DSA conducted before 3D-DSA imaging. We retrospectively reviewed 26 meningioma patients who underwent cerebral angiography from March 2020 to August 2021. Using 2D-DSA, we analyzed arterial and venous TECs to determine the contrast agent’s peak time and estimated the optimal imaging timing. Cases performed near this optimal time were in Group A, and others in Group B, with cerebral venous pixel values compared between them. TEC analysis identified peak times: internal carotid artery: 2.8 ± 0.7 s, middle cerebral artery (M4): 4.1 ± 0.9 s, superior sagittal sinus: 8.3 ± 1.1 s, sigmoid sinus: 9.5 ± 1.3 s, and venous structures near tumors: 7.3 ± 1.0 s. We observed several veins peaking immediately after arterial contrast passage, suggesting the optimal X-ray delay should incorporate the arterial contrast agent’s transit time. Statistical analysis revealed that Group A, with imaging timed to reflect the contrast agent transit time, demonstrated significantly better contrast effects than Group B. The X-ray delay time for 3D-DSA imaging of cerebral veins can be optimized in angiography systems by incorporating the contrast agent transit time, calculated from TEC analysis of cerebral 2D-DSA images.

Assessment of Interrater Reliability and Accuracy of Cerebral Aneurysm Morphometry Using 3D Virtual Reality, 2D Digital Subtraction Angiography, and 3D Reconstruction: A Randomized Comparative Study.

Detailed morphometric analysis of an aneurysm and the related vascular bifurcation are critical factors when determining rupture risk and planning treatment for unruptured intracranial aneurysms (UIAs). The standard visualization of digital subtraction angiography (DSA) and its 3D reconstruction on a 2D monitor provide precise measurements but are subject to variability based on the rater. Visualization using virtual (VR) and augmented reality platforms can overcome those limitations. It is, however, unclear whether accurate measurements of the aneurysm and adjacent arterial branches can be obtained on VR models. This study aimed to assess interrater reliability and compare measurements between 3D VR, standard 2D DSA, and 3D DSA reconstructions, evaluating the reliability and accuracy of 3D VR as a measurement tool. A pool of five neurosurgeons performed three individual analyses on each of the ten UIA cases, measuring them in completely immersed 3D VR and the standard on-screen format (2D DSA and 3D reconstruction). This resulted in three independent measurements per modality for each case. Interrater reliability of measurements and morphology characterization, comparative differences, measurement duration, and VR user experience were assessed. Interrater reliability for 3D VR measurements was significantly higher than for 3D DSA measurements (3D VR mean intraclass correlation coefficient [ICC]: 0.69 ± 0.22 vs. 3D DSA mean ICC: 0.36 ± 0.37, p = 0.042). No significant difference was observed between 3D VR and 2D DSA (3D VR mean ICC: 0.69 ± 0.22 vs. 2D DSA mean ICC: 0.43 ± 0.31, p = 0.12). A linear mixed-effects model showed no effect of 3D VR and 3D DSA (95% CI = -0.26-0.28, p = 0.96) or 3D VR and 2D DSA (95% CI = -0.02-0.53, p = 0.066) on absolute measurements of the aneurysm in the anteroposterior, mediolateral, and craniocaudal dimensions. 3D VR technology allows for reproducible, accurate, and reliable measurements comparable to measurements performed on a 2D screen. It may also potentially improve precision for measurements of non-planar aneurysm dimensions.

Detection of hepatocellular carcinoma feeding vessels: MDCT angiography with 3D reconstruction versus digital subtraction angiography

BackgroundAccurate detection of Hepatocellular carcinoma (HCC) feeding vessels during transcatheter arterial chemoembolization (TACE) is important for an effective treatment, while limiting non-target embolization. This study aimed to investigate the feasibility and accuracy of pre-TACE three dimensional (3D) CT angiography for tumor-feeding vessels detection compared to DSA.MethodsSixty-nine consecutive patients referred for TACE from May 2022 to May 2023 were included. (3D) CT images were reconstructed from the pre-TACE diagnostic multiphasic contrast enhanced CT images and compared with non-selective digital subtraction angiography (DSA) images obtained during TACE for detection of HCC feeding vessels. A “Ground truth” made by consensus between observers after reviewing all available pre-TACE CT images, and DSA and CBCT images during TACE to detect the true feeding vessels was the gold standard. Sensitivity, specificity, negative predictive value (NPV), positive predictive value (PPV), accuracy and ROC curve with AUC were calculated for each modality and compared.ResultsA total of 136 active HCCs were detected in the 69 consecutive patients included in the study. 185 feeding arteries were detected by 3D CT and DSA and included in the analysis. 3D CT detection of feeding arteries revealed mean sensitivity, specificity, PPV, NPV and accuracy of 91%, 71%, 98%, 36%, and 90%, respectively, with mean AUC = 0.81. DSA detection of feeding arteries revealed mean sensitivity, specificity, PPV, NPV, and accuracy of 80%, 58%, 96.5%, 16.5% and 78%, respectively, with mean AUC = 0.69.ConclusionsPre-TACE 3D CT angiography has shown promise in improving the detection of HCC feeding vessels compared to DSA. However, further studies are required to confirm these findings across different clinical settings and patient populations.Trial registrationThis study was prospectively registered at Clinicaltrials.gov with ID NCT05304572; Date of registration: 2-4-2022.

The added value of 3D CT Angiography and Digital Subtraction Angiography in aneurysmal subarachnoid hemorrhage

The added value of 3D CT Angiography and Digital Subtraction Angiography in aneurysmal subarachnoid hemorrhage

Integrating PointNet-Based Model and Machine Learning Algorithms for Classification of Rupture Status of IAs.

The rupture of intracranial aneurysms (IAs) would result in subarachnoid hemorrhage with high mortality and disability. Predicting the risk of IAs rupture remains a challenge. This paper proposed an effective method for classifying IAs rupture status by integrating a PointNet-based model and machine learning algorithms. First, medical image segmentation and reconstruction algorithms were applied to 3D Digital Subtraction Angiography (DSA) imaging data to construct three-dimensional IAs geometric models. Geometrical parameters of IAs were then acquired using Geomagic, followed by the computation of hemodynamic clouds and hemodynamic parameters using Computational Fluid Dynamics (CFD). A PointNet-based model was developed to extract different dimensional hemodynamic cloud features. Finally, five types of machine learning algorithms were applied on geometrical parameters, hemodynamic parameters, and hemodynamic cloud features to classify and recognize IAs rupture status. The classification performance of different dimensional hemodynamic cloud features was also compared. The 16-, 32-, 64-, and 1024-dimensional hemodynamic cloud features were extracted with the PointNet-based model, respectively, and the four types of cloud features in combination with the geometrical parameters and hemodynamic parameters were respectively applied to classify the rupture status of IAs. The best classification outcomes were achieved in the case of 16-dimensional hemodynamic cloud features, the accuracy of XGBoost, CatBoost, SVM, LightGBM, and LR algorithms was 0.887, 0.857, 0.854, 0.857, and 0.908, respectively, and the AUCs were 0.917, 0.934, 0.946, 0.920, and 0.944. In contrast, when only utilizing geometrical parameters and hemodynamic parameters, the accuracies were 0.836, 0.816, 0.826, 0.832, and 0.885, respectively, with AUC values of 0.908, 0.922, 0.930, 0.884, and 0.921. In this paper, classification models for IAs rupture status were constructed by integrating a PointNet-based model and machine learning algorithms. Experiments demonstrated that hemodynamic cloud features had a certain contribution weight to the classification of IAs rupture status. When 16-dimensional hemodynamic cloud features were added to the morphological and hemodynamic features, the models achieved the highest classification accuracies and AUCs. Our models and algorithms would provide valuable insights for the clinical diagnosis and treatment of IAs.

Clinical experience of cone-beam computed tomography in interventional neuroradiology

Objective ‒ to analyze the experience of using cone-beam computed tomography (CBCT) angiography during diagnostic and interventional procedures in the SO «Scientific-Practical Center of Endovascular Neuroradiology NAMS of Ukraine».Materials and methods. Informed consent was obtained from each patient (parent or guardian) enrolled in the study and the study protocol conforms to the ethical guidelines of the Declaration of Helsinki as reflected in a priori approval by the Institutional Ethical Review Board (Institution's Human Research Committee). Since January 2024 in the SO «Scientific-Practical Center of Endovascular Neuroradiology NAMS of Ukraine» used in practical work a modern angio machine «Siemens Artis Q.zen» (Siemens, Erlangen, Germany), equipped with a set of various techniques and programs, in particular CBCT, syngo Aneurysm Guidance Neuro, 3D Roadmap. We analysed 36 diagnostic and interventional procedures was conducted from January 2024 to March 2024, during which CBCT was used. Among the procedures, 29 cases of brain aneurysms, 4 arteriovenous malformations and 3 cases of dural arteriovenous fistulas.Results. CBCT is useful for understanding vascular anatomy and allows for more detailed visualization of the curvilinear course of vessels in 3D space along any plane with the possibility of their correlation with bone structures compared to traditional angiography, and also has a higher resolution compared to more common 3D digital subtraction angiography. CBCT images are also a valuable source of information for further understanding of both pathological and normal neurovascular anatomy. Our center has implemented rotation 3D images with contrast of the CBCT at the stage of preparation and planning of the interventional procedure, rotation with subtraction (3D-DSA) ‒ to control implanted devices and its relationship to the vessels and long-term rotation of the CBCT without contrast ‒ to control the straightening and positioning of the stent. To control the position of the stent and its relations to the vessels, the «fusion» mode was used, providing additional information about the vascular structures imposed during conventional angiography, as well as the ability to rotate the volume at any angle regardless of the mechanical capabilities.Conclusions. CBCT is an accessible and unique function of modern angiomachines and helps to improve the understanding of anatomical features in various pathologies of cerebral vessels and helps in making clinical decisions.

A multidimensional pre-operative planning method of unruptured vertebral artery dissecting aneurysms using three-dimensional AWE mapping and hemodynamic simulation

ObjectiveHigh-resolution magnetic resonance imaging (HR-MRI) can provide valuable insights into the evaluation of vascular pathological conditions, and 3D digital subtraction angiography (3D-DSA) offers clear visualization of the vascular morphology and hemodynamics. This study aimed to investigate the potential of a multimodal method to treat unruptured vertebral artery dissection aneurysms (u-VADAs) by fusing image data from HR-MRI and 3D-DSA. MethodsThis observational study enrolled 5 patients diagnosed with u-VADAs, who were scheduled for interventional treatment. The image data of HR-MRI and 3D-DSA were merged by geometry software, resulting in a multimodal model. Quantified values of aneurysm wall enhancement (AWE), wall shear stress (WSS), neck velocity, inflow volume, intra-stent flow velocity (ISvelocity), and intra-aneurysmal velocity (IAvelocity) were calculated from the multimodal method. ResultsWe found the actual lengths of u-VADAs in the multimodal model were longer than the 3D-DSA model. We formulated surgical plannings based on the WSS, IA velocity, and neck velocity. The post-operative value of IAvelocity, neck velocity, and follow-up quantified values of AWE were decreased compared with the pre-operative condition. After that, u-VADAs were complete occlusion in four patients and near-complete occlusion in one patient during the 6th-month follow-up after surgery. ConclusionThe multidimensional method combining HR-MRI with 3D-DSA may provide more valuable information for treating VADAs, with the potential to develop effective surgical planning.

Three-dimensional fusion imaging to assess apposition of low-profile visualized intraluminal support stent for intracranial aneurysm coiling

ObjectiveTo investigate on three-dimensional (3D) fusion images the apposition of low-profile visualized intraluminal support (LVIS) stents in intracranial aneurysms after treatment and assess inter-rater reliability. Materials and methodsRecords of all patients with unruptured intracranial aneurysms who were treated with the LVIS stent were retrospectively accessed and included in this study. Two neurosurgeons evaluated the presence of malapposition between the vessel walls and the stent trunk (crescent sign) and the vessel wall and the stent edges (edge malappostion) on 3D fusion images. These images were high-resolution cone-beam computed tomography images of the LVIS stent fused with 3D-digital subtraction angiography images of the vessels. Associations between malapposition and aneurysm location were assessed by Fisher's exact test, and inter-rater agreement was estimated using Cohen's kappa statistic. ResultsForty consecutive patients were included. In all patients, 3D fusion imaging successfully visualized the tantalum helical strands and the closed-cell structure of the nitinol material of the low-profile visualized intraluminal support. A crescent sign was observed in 27.5 % and edge malapposition in 47.5 % of the patients. Malapposition was not significantly associated with location (p = 0.23 crescent sign, p = 0.07 edge malapposition). Almost perfect (κ = 0.88) and substantial (κ = 0.76) agreements between the two raters were found for the detection of crescent signs and edge appositions, respectively. Conclusions3D fusion imaging provided clear visualization of the LVIS stent and parent arteries, and could detect malapposition with excellent inter-rater reliability. This technique may provide valuable guidance for surgeons in determining postoperative management.

Evaluating the diagnostic accuracy of 3D contrast-enhanced magnetic resonance angiography versus digital subtraction angiography in spinal dural arteriovenous fistulas.

Spinal dural arteriovenous fistulas (SDAVFs) often go undiagnosed, leading to irreversible spinal cord dysfunction. Although digital subtraction angiography (DSA) is the gold standard for diagnosing SDAVF, DSA is invasive and operator dependent, with associated risks. MR angiography (MRA) is a promising alternative. This study aimed to evaluate the performance of MRA as an equal alternative to DSA in investigating, diagnosing, and localizing SDAVF. Prospectively collected data from a single neurosurgeon at a large tertiary academic center were searched for SDAVFs. Eligibility criteria included any patient with a surgically proven SDAVF in whom preoperative DSA, MRA, or both had been obtained. The eligible patients formed a consecutive series, in which they were divided into DSA and MRA groups. DSA and MRA were the index tests that were compared to the surgical SDAVF outcome, which was the reference standard. Accurate diagnosis was considered to have occurred when the imaging report matched the operative diagnosis to the correct spinal level. Comparisons used a two-sample t-test for continuous variables and Fisher-Freeman-Halton's exact test for categorical variables, with p < 0.05 specifying significance. Univariate, bivariate, and multivariate analyses were conducted to investigate group associations with DSA and MRA accuracy. Positive predictive value, sensitivity, and accuracy were calculated. A total of 27 patients with a mean age of 63 years underwent surgery for SDAVF. There were 19 male (70.4%) and 8 female (29.6%) patients, and the mean duration of symptoms at the time of surgery was 14 months (range 2-48 months). Seventeen patients (63%) presented with bowel or bladder incontinence. Bivariate analysis of the DSA and MRA groups further revealed no significant relationships between the characteristics and accuracy of SDAVF diagnosis. MRA was found to be more sensitive and accurate (100% and 73.3%) than DSA (85.7% and 69.2%), with a subanalysis of the patients with both preoperative MRA and DSA showing that MRA had a greater positive predictive value (78.6 vs 72.7), sensitivity (100 vs 72.7), and accuracy (78.6 vs 57.1) than DSA. In surgically proven cases of SDAVFs, the authors determined that MRA was more accurate than DSA for SDAVF diagnosis and localization to the corresponding vertebral level. Incomplete catheterization at each vertebral level may result in the failure of DSA to detect SDAVF.

Presurgical Simulation for Brain Arteriovenous Malformation

Surgical extirpation of brain arteriovenous malformations(AVMs)requires precise pre-surgical simulation. Utilizing image software, widely used with picture archiving and communication systems(PACS), surgeons can generate simulation images that precisely illustrate the proper feeders, passing arteries, and drainers. The crucial steps for creating informative simulation images include: (1)the free rotation of reconstructed 3D digital subtraction angiography(DSA)images; (2)removal of irrelevant arteries(the most important procedure); and(3)construction of stereo imagery of the "core images." This article presents a detailed description of these procedures.

The Anatomical Variation of the Distal Anterior Cerebral Artery: An Angiographic Study in a Greek Population Sample.

Objective The current retrospective angiographic study establishes the rates of variants in the distal anterior cerebral artery (DACA) in a sample of the Greek population. Methods Data were collected from 456 patients who underwent two-dimensional (2D) or three-dimensional (3D) digital subtraction angiography (DSA) of the carotid and vertebral arteriesbilaterally. The study focused on patients with good visualization of the anterior and posterior circulations and employed magnetic resonance (MR) or computed tomography (CT) angiography for 3D reconstruction. The anterior cerebral artery (ACA) was classified into one of its two basic configurations, that is, with or without the callosomarginal artery (CMA). The bihemispheric, median, and azygos ACA patterns were also identified. Results The majority (373/456, 81.8%) exhibited a typical DACA pattern. The bihemispheric, median, and azygos patterns were identified in 66/456 (14.5%), 10/456 (2.2%), and 7/456 (1.5%), respectively. The CMA was present in 824/912 (90.4%) of the hemispheres, with a trend towardmale predominance for bilateral presence (males: 167/192, 86.98%; females: 210/264, 79.55%; p = 0.05). In particular, the CMA was present significantly more frequently (p = 0.002) in the left hemispheres of male patients. Gender differences in CMA presence persisted in the analysis of the patients with a typical DACA pattern. Conclusion This study provides insights into the variations of the DACA in the Greek population. The observed gender differences in CMA rates suggest potential morphological variations in cerebral vasculature between males and females and contribute to a better understanding of vascular anatomy for clinical and surgical applications.

Abstract TP151: Usefulness of 3D I-Flow Application in Predicting the Outcome of Flow Diverter Stenting for Large or Giant Carotid Aneurysms

Background and Purpose: The flow diverter (FD) has dramatically improved the treatment outcome of large / giant internal carotid artery (IC) aneurysms. However, it is difficult to predict the treatment outcome of FD just after the treatment. 3D iFlow is a novel application of 4D-digital subtraction angiography (4D-DSA) that can evaluate the arrival time of contrast media in 3D images, but its usefulness for neurointervention is unclear. Therefore, the aim of this study was to elucidate the utility of 3D iFlow in predicting the outcome of FD treatment for large / giant IC aneurysms. Methods: A total of 8 cases of large / giant aneurysms at IC cavernous portion treated with FD and were enrolled in this study. 3D iFlow images before and after placement of FD were acquired in all cases. Treatment outcome was evaluated by O’Kelly-Marotta(OKM) Grading Scale with DSA 6 months after treatment. The regions of interests (ROI) were set in IC bifurcation and petrous segment with 3D iFlow application, and the 3D iFlow transit time was measured by comparing the peak contrast intensities in 2 ROIs. We investigated the rate of changes in 3D iFlow transit time before and after the placement of FD. Results: FD was deployed successfully in all cases without coils. The number of OKM grade B, C and D with DSA 6 months after treatment were 2, 3 and 3 cases, respectively. The rate of changes in 3D iFlow transit time was significantly shorter in OKM grade D cases compared with grade B and C (52.5% vs 84.7%, p=0.03). Conclusion: 3D iFlow application may be effective to predict the treatment outcome of FD.

Updates on Neuronavigation: Emerging tools for tumor resection.

Multiple studies have been conducted to properly elucidate the various tools available to help enhance the resection of tumor tissue, aneurysms, and arteriovenous malformations (AVM). Diffusion tensor imaging (DTI) tractography is useful in providing a map of the tumor borders, allowing the optimal preservation of function and structure of specific regions of the brain. During neurosurgery, especially craniotomies, the possibility of the brain shifting due to swelling or gravity is high. Thus, tools for intraoperative imaging such as high-frequency linear array ultrasound transducers and doppler ultrasonography are utilized for high resolution images and detecting frequency shifts. 4D-digital subtraction angiography (DSA) is another technique used to create spatial resolutions and 3D maps for aneurysms. These similar techniques can also be utilized to assess the integrity of white matter in AVM. By implementing effective evaluation strategies, healthcare professionals can make informed decisions regarding treatment options, preventive measures, and long-term care plans tailored to individual patients.

An Intraosseous Pterygopalatine Fossa Dural Arteriovenous Fistula

Intraosseous dural arteriovenous fistulas (DAVFs) are distinct in that the fistula is located within the bone rather than the dura through which the dural vessels pass. It has been stated that only fistulas within marrow should be considered as intraosseous DAVFs rather than DAVFs with traditional angioarchitecture that erode into bone or are located within a bony foramen. The ambiguity in the definition may have contributed to the oversight and scarcity of relevant cases reported in the literature. Three- or four-dimensional digital subtraction angiography is useful for determining the location of the fistula and developing treatment plans. We present an intraosseous DAVF around the pterygopalatine fossa using a transvenous approach.

CROSS SECTIONAL RETROSPECTIVE ANALYTICAL STUDY OF MORPHOMETRY OF INTERNAL CAROTID ARTERY

Background: The internal carotid artery (ICA) is essential for diagnosing and treating cerebrovascular diseases and plays a significant role in the human head and neck circulatory system. Traditional techniques of ICA research have their limitations, but more recent developments in medical imaging—particularly retrospective angiography—offer more thorough evaluation options. Objective: This study aimed to investigate variations and morphometry of the ICA using 2D digital subtraction angiography (DSA) images, with a focus on age and gender-related differences. Methods: The 149 individuals with subarachnoid hemorrhage who had cerebral angiography were included in the research. Analysis was done on 2D ICA pictures without any obvious pathology. PACS imaging techniques were used to measure morphometric characteristics such as the length, angle, and diameter of the ICA segments. Results: According to the study, ICA length and direction were not substantially affected by age, but segment diameters were highly associated with age, indicating that segment diameters decreased with age. However, gender indicated statistically significant variations in several segment sizes, with males typically having greater diameters than females. Gender had little effect on length and orientation. Conclusion: This study sheds light on ICA changes and morphometry, emphasizing age-related diameter decreases and gender-related variations in segment diameters. These findings highlight the need to take age and gender into account when conducting clinical evaluations and cerebrovascular disease therapies.

Spatiotemporal frequency domain analysis for blood velocity measurement during embolization procedures.

Currently, determining procedural endpoints and treatment efficacy of vascular interventions is largely qualitative and relies on subjective visual assessment of digital subtraction angiography (DSA) images leading to large interobserver variabilities and poor reproducibility. Quantitative metrics such as the residual blood velocity in embolized vessel branches could help establish objective and reproducible endpoints. Recently, velocity quantification techniques based on a contrast enhanced X-ray sequence such as qDSA and 4D DSA have been proposed. These techniques must be robust, and, to avoid radiation dose concerns, they should be compatible with low dose per frame imageacquisition. To develop and evaluate a technique for robust blood velocity quantification from low dose contrast enhanced X-ray image sequences that leverages the oscillating signal created by pulsatile bloodflow. The proposed spatiotemporal frequency domain (STF) approach quantifies velocities from time attenuation maps (TAMs) representing the oscillating signal over time for all points along a vessel centerline. Due to the time it takes a contrast bolus to travel along the vessel centerline, the resulting TAM resembles a sheared sine wave. The shear angle is related to the velocity and can be determined in the spatiotemporal frequency domain after applying the 2D Fourier transform to the TAM. The approach was evaluated in a straight tube phantom using three different radiation dose levels and compared to ultrasound transit-time-based measurements. The STF velocity results were also compared to previously published approaches for the measurement of blood velocity from contrast enhanced X-ray sequences including shifted least squared (SLS) and phase shift (PHS). Additionally, an in vivo porcine study (n = 8) was performed where increasing amounts of embolic particles were injected into a hepatic or splenic artery with intermittent velocity measurements after each injection to monitor the resulting reduction invelocity. At the lowest evaluated dose level (average air kerma rate 1.3 mGy/s at the interventional reference point), the Pearson correlation between ultrasound and STF velocity measurements was . This was significantly higher ( ) than corresponding correlation results between ultrasound and the previously published SLS and PHS approaches ( and , respectively). In the in vivo study, a reduction in velocity was observed in of cases after injection of 1 mL, after 3 mL, and after 4 mL of embolicparticles. The results show good agreement of the spatiotemporal frequency domain approach with ultrasound even in low dose per frame image sequences. Additionally, the in vivo study demonstrates the ability to monitor the physiological changes due to embolization. This could provide quantitative metrics during vascular procedures to establish objective and reproducibleendpoints.

StrokeNet: An automated approach for segmentation and rupture risk prediction of intracranial aneurysm.

Intracranial Aneurysms (IA) present a complex challenge for neurosurgeons as the risks associated with surgical intervention, such as Subarachnoid Hemorrhage (SAH) mortality and morbidity, may outweigh the benefits of aneurysmal occlusion in some cases. Hence, there is a critical need for developing techniques that assist physicians in assessing the risk of aneurysm rupture to determine which aneurysms require treatment. However, a reliable IA rupture risk prediction technique is currently unavailable. To address this issue, this study proposes a novel approach for aneurysm segmentation and multidisciplinary rupture prediction using 2D Digital Subtraction Angiography (DSA) images. The proposed method involves training a fully connected convolutional neural network (CNN) to segment aneurysm regions in DSA images, followed by extracting and fusing different features using a multidisciplinary approach, including deep features, geometrical features, Fourier descriptor, and shear pressure on the aneurysm wall. The proposed method also adopts a fast correlation-based filter approach to drop highly correlated features from the set of fused features. Finally, the selected fused features are passed through a Decision Tree classifier to predict the rupture severity of the associated aneurysm into four classes: Mild, Moderate, Severe, and Critical. The proposed method is evaluated on a newly developed DSA image dataset and on public datasets to assess its generalizability. The system's performance is also evaluated on DSA images annotated by expert neurosurgeons for the rupture risk assessment of the segmented aneurysm. The proposed system outperforms existing state-of-the-art segmentation methods, achieving an 85 % accuracy against annotated DSA images for the risk assessment of aneurysmal rupture.

Percutaneous microwave ablation for lung tumors: a retrospective case-control study of conventional CT and C-arm CT guidance.

Although conventional computed tomography (cCT) is the mainstream guidance equipment for lung microwave ablation (MWA), C-arm CT can provide 3-dimensional (3D) CT-like images reconstructed from 2-dimensional (2D) digital subtraction angiography (DSA) information within 8 seconds, highlighting its utility as a new guidance tool. This retrospective case-control study was performed to evaluate the clinical performance of percutaneous MWA for lung tumors using cCT and C-arm CT guidance. From April 2015 to April 2020, 101 consecutive patients with solitary lung tumors who underwent percutaneous MWA at our single center (Zhengzhou, China) were divided into 2 groups: the cCT group (n=56), with unarmed puncture, and the C-arm CT group (n=45), with iGuide navigation-assisted puncture. The primary endpoints were technical success, technical efficacy, puncture scoring (PS), and complete ablation (CA) rate. The secondary endpoints were complications, median progression-free survival (mPFS), and median overall survival (mOS). The technical success rates were 100% in both the C-arm CT group and cCT group. The technical efficacies were 93.3% and 91.1% in the C-arm CT group and cCT group, respectively, with no statistical difference (P=0.67). The PS (2.9 vs. 2.5, P=0.02), total procedure time (TPT; 39.3 vs. 50.0 min, P<0.001), puncture time (PT; 12.6 vs. 15.7 min, P=0.001), and irradiation effective dose (ED; 15.2 vs. 20.9 mSV, P<0.001) showed significances between patients in the C-arm CT and those in the cCT group. The ablation time (AT; 9.1 vs. 9.6 min, P=0.36), CA rate (93.3% vs. 92.9%, P=0.93), local tumor progression (LTP) rate (11.1% vs. 8.9%, P=0.98), complications, mPFS (9.5 vs. 10.1 months, P=0.52), and mOS (37.9 vs. 38.8 months, P=0.67) showed no statistically significant difference between the 2 groups. C-arm CT guidance is as feasible and effective as cCT for lung tumor MWA, which can increase PS and decrease TPT.

Intracranial aneurysms treated with stent-assisted coil embolization: evaluation with four-dimensional ultrashort-TE MR angiography.

As a novel follow-up method for intracranial aneurysms treated with stent-assisted coil embolization (SACE), we developed four-dimensional magnetic resonance angiography (MRA) with minimized acoustic noise utilizing ultrashort-echo time (4D mUTE-MRA). We aimed to assess whether 4D mUTE-MRA is useful for the evaluation of intracranial aneurysms treated with SACE. This study included 31 consecutive patients with intracranial aneurysm treated with SACE who underwent 4D mUTE-MRA at 3T and digital subtraction angiography (DSA). For 4D mUTE-MRA, five dynamic MRA images with a spatial resolution of 0.5 × 0.5 × 0.5 mm3 were obtained every 200ms. Two readers independently reviewed the 4D mUTE-MRA images to evaluate the aneurysm occlusion status (total occlusion, residual neck, and residual aneurysm) and the flow in the stent using a 4-point scale (from 1 [not visible] to 4 [excellent]). The interobserver and intermodality agreement was assessed using κ statistics. On DSA images, 10 aneurysms were classified as total occlusion, 14 as residual neck, and 7 as residual aneurysm. In terms of aneurysm occlusion status, the intermodality and interobserver agreement was excellent (κ = 0.92 and κ = 0.96, respectively). For the flow in the stents on 4D mUTE-MRA, the mean score was significantly higher for single stents than multiple stents (p < .001) and for open-cell type stents than closed-cell type (p < .01). 4D mUTE-MRA is a useful tool with a high spatial and temporal resolution for the evaluation of intracranial aneurysms treated with SACE. • In the evaluation of intracranial aneurysms treated with SACE on 4D mUTE-MRA and DSA, the intermodality and interobserver agreement in aneurysm occlusion status was excellent. • 4D mUTE-MRA shows good to excellent visualization of flow in the stents, especially for cases treated with a single or open-cell stent. • 4D mUTE-MRA can provide hemodynamic information related to embolized aneurysms and the distal arteries to stented parent arteries.

Accuracy of uncalibrated 2D digital subtraction angiography measurements on a novel biplane system compared to computed tomography angiography.

2D digital subtraction angiography (DSA) images are the gold standard for neuroradiological vascular assessment and the basis of interventional procedures such as mechanical thrombectomy and cerebral aneurysm coiling. However, length measurements in projected DSA images are affected by the distance between the x-ray source, the object, and the detector. Precise coordination between all integrated parts of a novel biplane system makes it possible to accurately measure DSA distances without manual calibration. The aim of this study was to compare vascular diameter measurements in uncalibrated DSA images with computed tomography angiography (CTA). Consecutive patients undergoing interventional neuroradiological procedures were retrospectively included. Vascular diameter measurements in the image isocenter and periphery were performed. These measurements were repeated in picture archiving and communication system (PACS) on DSA images and maximum intensity pixel (MIP) CTA images. Forty-two (42) consecutive patients with adequate DSA and CTA images were included in the final analysis. The correlation between vessel diameter measurements in the image isocenter (R2 = 0.81/0.85, p < 0.0001/p < 0.0001 [Reader1/Reader2]), periphery (R2 = 0.85/0.82, p < 0.0001/p < 0.0001 [Reader1/Reader2]), and all measurements combined (R2 = 0.87/0.87, p < 0.0001/p < 0.0001 [Reader1/Reader2]) on DSA and CTA were strong and statistically significant. The interclass correlation coefficient for measurements performed by two independent reviewers was strong (ICC = 0.96, 95% CI 0.92-0.98). The correlations between uncalibrated DSA measurements and CTA for vessel diameter were strong. In addition, there were strong correlations between these image types for repeated measurements in the image isocenter as well as image periphery for vessel diameter. Consequently, endovascular devices can be sized correctly without the need for pre-operative non-invasive imaging.