Analysis of quantitative angiography in intracranial aneurysm using projection foreshortening correction and injection bias removal.

Background: In neurovascular disease applications, 2D quantitative angiography (QA) based on digital subtraction angiography (DSA), is an intraoperative methodology used to assess disease severity and guide treatment. However, despite DSA's ability to produce detailed 2D projection images, the inherent dynamic 3D nature of blood flow and its temporal aspects can distort key hemodynamic parameters when reduced to 2D. This distortion is primarily due to biases such as projection-induced foreshortening and variability from manual contrast injection.

Minimizing human-induced variability in quantitative angiography for a robust and explainable AI-based occlusion prediction in flow diverter-treated aneurysms.

Background: Bias from contrast injection variability is a significant obstacle to accurate intracranial aneurysm (IA) occlusion prediction using quantitative angiography (QA) and deep neural networks (DNNs). This study explores bias removal and explainable AI (XAI) for outcome prediction.

Objective: To implement an injection bias removal algorithm for reducing QA variability and examine the impact of XAI on the reliability and interpretability of deep learning models for occlusion prediction in flow diverter-treated aneurysms.

Minimizing Human-Induced Variability in Quantitative Angiography for Robust and Explainable AI-Based Occlusion Prediction.

Background: Bias from contrast injection variability is a significant obstacle to accurate intracranial aneurysm (IA) occlusion prediction using quantitative angiography (QA) and deep neural networks (DNNs). This study explores bias removal and explainable AI (XAI) for outcome prediction.

Objective: Implement injection bias removal algorithm for reducing QA variability and examine XAI's impact on the reliability and interpretability of deep learning models for occlusion prediction in flow diverter-treated aneurysms.

A novel swine model of selective middle meningeal artery catheterization and embolization.

Background: Middle meningeal artery (MMA) embolization is a promising intervention as a stand-alone or adjunct treatment to surgery in patients with chronic subdural hematomas. There are currently no large animal models for selective access and embolization of the MMA for preclinical evaluation of this endovascular modality. Our objective was to introduce a novel in vivo model of selective MMA embolization in swine.

Enhancing cerebral vasculature analysis with pathlength-corrected 2D angiographic parametric imaging: A feasibility study.

Background: 2D angiographic parametric imaging (API) quantitatively extracts imaging biomarkers related to contrast flow and is conventionally applied to 2D digitally subtracted angiograms (DSA's). In the interventional suite, API is typically performed using 1-2 projection views and is limited by vessel overlap, foreshortening, and depth-integration of contrast motion.

Purpose: This work explores the use of a pathlength-correction metric to overcome the limitations of 2D-API: the primary objective was to study the effect of converting 3D contrast flow to projected contrast flow using a simulated angiographic framework created with computational fluid dynamics (CFD) simulations, thereby removing acquisition variability.

Angiographic velocimetry analysis using contrast dilution gradient method with a 1000 frames per second photon-counting detector.

Purpose: Contrast dilution gradient (CDG) analysis is a quantitative method allowing blood velocity estimation using angiographic acquisitions. Currently, CDG is restricted to peripheral vasculature due to the suboptimal temporal resolution of current imaging systems. We investigate extension of CDG methods to the flow conditions of proximal vasculature using 1000 frames per second (fps) high-speed angiographic (HSA) imaging.

Design and Physical Properties of 3-Dimensional Printed Models Used for Neurointervention: A Systematic Review of the Literature.

Background: Three-dimensional (3D) printing has revolutionized training, education, and device testing. Understanding the design and physical properties of 3D-printed models is important.

Objective: To systematically review the design, physical properties, accuracy, and experimental outcomes of 3D-printed vascular models used in neurointervention.

Use of a neck-bridging device for endovascular coiling of a wide-necked middle cerebral artery aneurysm.

Endovascular treatment of wide-necked bifurcation intracranial aneurysms is technically challenging, often requiring adjunctive devices such as stents or balloons to maintain coil mass within the aneurysm sac. Comaneci is a radiopaque embolization-assist device that can be temporarily deployed in the parent artery across the aneurysm neck without arresting blood flow for remodeling of coil mass. It is removed once coiling without luminal coil protrusion is achieved.

Single-center experience of using high definition (Hi-Def) imaging during neurointervention treatment of intracranial aneurysms using flow diverters.

Background: A new dual resolution imaging x-ray detector system (Canon Medical Systems Corporation, Tochigi, Japan) has a standard resolution 194 µm pixel conventional flat-panel detector (FPD) mode and a high-resolution 76 µm high-definition (Hi-Def) mode in a single unit. The Hi-Def mode enhances the visualization of the intravascular devices.

Objective: We report the clinical experience and physician evaluation of this new detector system with Hi-Def mode for the treatment of intracranial aneurysms using a Pipeline embolization device (PED).

High-Definition Zoom Mode: A High Resolution X-ray Microscope for Neurointerventional Treatment Procedures.

Background And Purpose: Visualization of structural details of treatment devices during neurointerventional procedures can be challenging. A new true two-resolution imaging X-ray detector system features a 194 µm pixel conventional flat-panel detector (FPD) mode and a 76 µm pixel high-resolution high-definition (Hi-Def) zoom mode in one detector panel. The Hi-Def zoom mode was developed for use in interventional procedures requiring superior image quality over a small field of view (FOV).

Deployment of distal posterior cerebral artery flow diverter in tortuous anatomy.

Progressive deconstruction with flow diversion using a Pipeline embolization device (PED; Medtronic) can be utilized to promote thrombosis of broad-based fusiform aneurysms. Current flow diverters require a 0.027-inch microcatheter for deployment.

Assessment of distal access catheter performance during neuroendovascular procedures: measuring force in three-dimensional patient specific phantoms.

Background: The amount of force applied on a device is an important measure to evaluate the endovascular and surgical device manipulations. The measure has not been evaluated for neuroenodvascular procedures.

Purpose: We aimed to study the use of force measure as a novel approach to test distal access catheter (DAC) performance during catheterization of cervical and intracranial vessels using patient specific 3-dimentional (3D) phantoms.

Stent retriever thrombectomy with the Cover accessory device versus proximal protection with a balloon guide catheter: in vitro stroke model comparison.

Background: Recently, an in vitro cerebrovascular occlusion model of the intracranial circulation was developed for testing thrombectomy devices. The Cover accessory (Lazarus Effect; Campbell, California, USA) is a novel nitinol braided mesh device that surrounds the stent retrieval device and thrombus during the retrieval process to help prevent clot fragmentation and embolization.

Methods: Using the in vitro model, after introducing fresh clot into the middle cerebral artery, we compared rates of target vessel recanalization and embolization in new territories (areas in which clot had not been introduced) achieved with the Solitaire Flow Restoration (FR) stent retriever (Covidien, Irvine, California) in conjunction with the use of a conventional guide catheter (control group), a balloon guide catheter (BGC group), and the Cover device (Cover group).

Primary stentriever versus combined stentriever plus aspiration thrombectomy approaches: in vitro stroke model comparison.

Background: Artificial stroke models can be used for testing various thrombectomy devices.

Objective: To determine the value of combined stentriever-aspiration thrombectomy compared with the stentriever-alone approach.

Methods: We designed an in vitro model of the intracranial circulation with a focus on the middle cerebral artery (MCA) that closely resembles the human intracranial circulation.