An Image-Based Workflow for Objective Vessel Wall Enhancement Quantification in Intracranial Aneurysms.

Sricharan S Veeturi,Nandor K Pinter,Vincent M Tutino,Muhammad Waqas,Hamid H Rai,Ammad A Baig,Hamidreza Rajabzadeh-Oghaz,Andre Monteiro,Adnan H Siddiqui

doi:10.3390/diagnostics11101742

Sricharan S Veeturi, Nandor K Pinter + Show 7 more

Open Access

https://doi.org/10.3390/diagnostics11101742

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Abstract

Background: VWE in contrast-enhanced magnetic resonance imaging (MRI) is a potential biomarker for the evaluation of IA. The common practice to identify IAs with VWE is mainly based on a visual inspection of MR images, which is subject to errors and inconsistencies. Here, we develop and validate a tool for the visualization, quantification and objective identification of regions with VWE. Methods: N = 41 3D T1-MRI and 3D TOF-MRA IA images from 38 patients were obtained and co-registered. A contrast-enhanced MRI was normalized by the enhancement intensity of the pituitary stalk and signal intensities were mapped onto the surface of IA models generated from segmented MRA. N = 30 IAs were used to identify the optimal signal intensity value to distinguish the enhancing and non-enhancing regions (marked by an experienced neuroradiologist). The remaining IAs (n = 11) were used to validate the threshold. We tested if the enhancement area ratio (EAR—ratio of the enhancing area to the IA surface-area) could identify high risk aneurysms as identified by the ISUIA clinical score. Results: A normalized intensity of 0.276 was the optimal threshold to delineate enhancing regions, with a validation accuracy of 81.7%. In comparing the overlap between the identified enhancement regions against those marked by the neuroradiologist, our method had a dice coefficient of 71.1%. An EAR of 23% was able to discriminate high-risk cases with an AUC of 0.7. Conclusions: We developed and validated a pipeline for the visualization and objective identification of VWE regions that could potentially help evaluation of IAs become more reliable and consistent.

Highlights

Vessel wall enhancement (VWE) has emerged as a potential image-based biomarker for the assessment of intracranial aneurysm (IA) rupture risk
VWE is a phenomenon that is observed in contrast-enhanced magnetic resonance imaging (MRI), in which the IA wall exhibits a distinctly higher intensity compared to the non-enhanced MR image
We found that the optimal EAR threshold for delineating high and low risk aneurysms was 23%, e.g., if an aneurysm had more than 23% of its area with an intensity greater than T0, it would be considered high-risk

Summary

Introduction

Vessel wall enhancement (VWE) has emerged as a potential image-based biomarker for the assessment of intracranial aneurysm (IA) rupture risk. Clinical studies have reported that unstable and rupture-prone aneurysms are more likely to demonstrate enhancement features compared to those that remain stable, indicating that VWE may be a viable biomarker to delineate high-risk lesions [1,2,3]. Identifying whether an aneurysm is demonstrating VWE can be challenging In clinical practice, this is primarily conducted via a visual inspection of non-enhanced and contrast-enhanced T1-weighted MR images, after which the type (circumferential or focal) and intensity (strong, faint or none) of the enhancement can be classified. Conclusions: We developed and validated a pipeline for the visualization and objective identification of VWE regions that could potentially help evaluation of IAs become more reliable and consistent

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