Circumferential wall enhancement in evolving intracranial aneurysms on magnetic resonance vessel wall imaging

OBJECTIVERecent MR vessel wall imaging studies have indicated intracranial aneurysms in the active state could show circumferential enhancement along the aneurysm wall (CEAW). While ruptured aneurysms frequently show CEAW, CEAW in unruptured aneurysms at the evolving state (i.e., growing or symptomatic) has not been studied in detail. The authors quantitatively assessed the degree of CEAW in evolving unruptured aneurysms by comparing it separately to that in stable unruptured and ruptured aneurysms.METHODSA quantitative analysis of CEAW was performed in 26 consecutive evolving aneurysms using MR vessel wall imaging. Three-dimensional T1-weighted fast spin echo sequences were obtained before and after contrast media injection, and the contrast ratio of the aneurysm wall against the pituitary stalk (CRstalk) was calculated as the indicator of CEAW. Aneurysm characteristics of evolving aneurysms were compared with those of 69 stable unruptured and 67 ruptured aneurysms.RESULTSThe CRstalk values in evolving aneurysms were significantly higher than those in stable aneurysms (0.54 vs 0.34, p < 0.0001), and lower than those in ruptured aneurysms (0.54 vs 0.83, p < 0.0002). In multivariable analysis, CRstalk remained significant when comparing evolving with stable aneurysms (odds ratio [OR] 12.23, 95% confidence interval [CI] 3.53–42.41), and with ruptured aneurysms (OR 0.083, 95% CI 0.022–0.310).CONCLUSIONSThe CEAW in evolving aneurysms was higher than those in stable aneurysms, and lower than those in ruptured aneurysms. The degree of CEAW may indicate the process leading to rupture of intracranial aneurysms, which can be useful additional information to determine an indication for surgical treatment of unruptured aneurysms.

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Role of magnetic resonance vessel wall imaging in detecting and managing ruptured aneurysms among multiple intracranial aneurysms

Surgical Neurology International ◽

10.25259/sni_618_2021 ◽

2021 ◽

Vol 12 ◽

pp. 460

Author(s):

Kohei Yoshikawa ◽

Junta Moroi ◽

Kohei Kokubun ◽

Nobuharu Furuya ◽

Yasuyuki Yoshida ◽

...

Keyword(s):

Magnetic Resonance ◽

Vessel Wall ◽

Intracranial Aneurysms ◽

Vessel Wall Imaging ◽

Multiple Intracranial Aneurysms ◽

Unruptured Aneurysms ◽

Multiple Aneurysms ◽

Ruptured Aneurysms ◽

Rupture Site ◽

Wall Imaging

Background: Wall enhancement of intracranial saccular aneurysms in high-resolution magnetic resonance vessel wall imaging (MR-VWI) might indicate a ruptured aneurysm. Therefore, this study aimed to determine the diagnostic ability of wall enhancement to detect the ruptured aneurysms among multiple aneurysms. Methods: Patients with subarachnoid hemorrhage (SAH) and multiple intracranial aneurysms who underwent MR-VWI before craniotomy and clipping were included in the study. Three-dimensional T1-weighted fast spin-echo sequences were obtained before and after gadolinium injection. Aneurysm rupture was estimated based on the subarachnoid clot distribution, aneurysmal contours, and MR-VWI findings. We selectively performed surgical clipping and confirmed the rupture site intraoperatively. Results: Thirteen patients with SAH with 13 ruptured and 17 unruptured aneurysms were treated at out facility. The accuracy rate of rupture site diagnosis using MR-VWI was 69.2% (9/13 cases). Each unruptured aneurysm was equally or more strongly enhanced in the other four cases than the ruptured aneurysms. In three of the four unruptured aneurysms with positive MR-VWI findings, atherosclerosis of the aneurysmal wall was observed during simultaneous or elective clipping surgery. Further, clipping surgery was performed without intraoperative rupture in two cases with the help of MR-VWI findings. Conclusion: Correct diagnosis of the rupture site using MR-VWI alone was unreliable due to false positives caused by the wall enhancement of unruptured aneurysms with atherosclerosis. Therefore, ruptured aneurysms should be detected using more information in addition to MR-VWI images. MR-VWI may be advantageous to determine surgical strategies when managing patients with SAH and multiple aneurysms.

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Wall Enhancement in Evolving Cerebral Aneurysms on Magnetic Resonance Vessel Wall Imaging

Neurosurgery ◽

10.1093/neuros/nyz310_300 ◽

2019 ◽

Vol 66 (Supplement_1) ◽

Cited By ~ 2

Author(s):

Shunsuke Omodaka ◽

Hidenori Endo ◽

Kuniyasu Niizuma ◽

Miki Fujimura ◽

Takashi Inoue ◽

...

Keyword(s):

Magnetic Resonance ◽

Confidence Interval ◽

Odds Ratio ◽

Vessel Wall ◽

Cerebral Aneurysms ◽

Vessel Wall Imaging ◽

Unruptured Aneurysms ◽

Ruptured Aneurysms ◽

Aneurysm Wall ◽

Wall Imaging

Abstract INTRODUCTION Recent magnetic resonance (MR) vessel wall imaging studies have indicated cerebral aneurysms in the active state could show wall enhancement along the aneurysm wall (CEAW). While ruptured aneurysms frequently show CEAW, CEAW in the unruptured aneurysms at evolving state, ie growing or symptomatic, has not been studied in detail. We assessed the degree of CEAW in evolving unruptured aneurysms by comparing separately with each of those in stable unruptured aneurysms and ruptured aneurysms. METHODS We performed quantitative analyses of CEAW in consecutive 26 evolving aneurysms using MR vessel wall imaging. Three-dimensional T1-weighted fast spin-echo sequence was obtained before and after contrast media injection, and the contrast ratio of aneurysm wall against the pituitary stalk (CRstalk) was calculated as the indicator of CEAW. We compared aneurysm characteristics of evolving aneurysms with those of 69 stable unruptured and 67 ruptured aneurysms. RESULTS The CRstalk in evolving aneurysms was significantly higher than those in stable aneurysms (0.54 vs 0.34; P < .0001), and lower than those in ruptured aneurysms (0.54 vs 0.83; P < .0002). In multivariable analysis, CRstalk remained significant in comparing evolving with stable aneurysms (odds ratio, 12.23; 95% confidence interval, 3.53-42.41), and with ruptured aneurysms (odds ratio, 0.083; 95% confidence interval, 0.022-0.310). CONCLUSION The CEAW in evolving aneurysms was higher than those in stable aneurysms, and lower than those in ruptured aneurysms.

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Vessel wall imaging in intracranial aneurysms

Journal of NeuroInterventional Surgery ◽

10.1136/neurintsurg-2019-014938 ◽

2019 ◽

Vol 11 (11) ◽

pp. 1105-1112 ◽

Cited By ~ 12

Author(s):

Edgar A Samaniego ◽

Jorge A Roa ◽

David Hasan

Keyword(s):

Vessel Wall ◽

Intracranial Aneurysms ◽

Vessel Wall Imaging ◽

Current Evidence ◽

Clinical Use ◽

Quantitative Susceptibility Mapping ◽

Aneurysm Wall ◽

Brain Aneurysms ◽

Wall Imaging

High-resolution vessel wall imaging (HR-VWI) is becoming a useful tool in the characterization and identification of unstable unruptured brain aneurysms. However, it has not been validated for clinical use. The current evidence on HR-VWI techniques for characterization of brain aneurysms is described in this review. Specific imaging approaches such as aneurysm wall contrast enhancement, MRI-quantitative susceptibility mapping, and 7T MRI are described in detail.

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Multimodal validation of focal enhancement in intracranial aneurysms as a surrogate marker for aneurysm instability

Neuroradiology ◽

10.1007/s00234-020-02498-6 ◽

2020 ◽

Vol 62 (12) ◽

pp. 1627-1635 ◽

Cited By ~ 1

Author(s):

Naomi Larsen ◽

Charlotte Flüh ◽

Sylvia Saalfeld ◽

Samuel Voß ◽

Georg Hille ◽

...

Keyword(s):

Vessel Wall ◽

Intracranial Aneurysms ◽

Surrogate Marker ◽

Artery Aneurysm ◽

Vessel Wall Imaging ◽

Vasa Vasorum ◽

Rupture Risk ◽

Unruptured Aneurysms ◽

Risk Of Rupture ◽

Wall Imaging

Abstract Purpose Circumferential enhancement on MR vessel wall imaging has been proposed as a biomarker of a higher risk of rupture in intracranial aneurysms. Focal enhancement is frequently encountered in unruptured aneurysms, but its implication for risk stratification and patient management remains unclear. This study investigates the association of focal wall enhancement with hemodynamic and morphological risk factors and histologic markers of wall inflammation and degeneration. Methods Patients with an unruptured middle cerebral artery aneurysm who underwent 3D rotational angiography and 3T MR vessel wall imaging showing focal wall enhancement were included. Hemodynamic parameters were calculated based on flow simulations and compared between enhanced regions and the entire aneurysm surface. Morphological parameters were semiautomatically extracted and quantitatively associated with wall enhancement. Histological analysis included detection of vasa vasorum, CD34, and myeloperoxidase staining in a subset of patients. Results Twenty-two aneurysms were analyzed. Enhanced regions were significantly associated with lower AWSS, lower maxOSI, and increased LSA. In multivariate analysis, higher ellipticity index was an independent predictor of wall enhancement. Histologic signs of inflammation and degeneration and higher PHASES score were significantly associated with focal enhancement. Conclusion Focal wall enhancement is colocalized with hemodynamic factors that have been related to a higher rupture risk. It is correlated with morphological factors linked to rupture risk, higher PHASES score, and histologic markers of wall destabilization. The results support the hypothesis that focal enhancement could serve as a surrogate marker for aneurysm instability.

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Analysis of Cerebral Aneurysm Wall Tension and Enhancement Using Finite Element Analysis and High-Resolution Vessel Wall Imaging

Frontiers in Neurology ◽

10.3389/fneur.2021.764063 ◽

2021 ◽

Vol 12 ◽

Author(s):

Adam E. Galloy ◽

Ashrita Raghuram ◽

Marco A. Nino ◽

Alberto Varon Miller ◽

Ryan Sabotin ◽

...

Keyword(s):

Finite Element Analysis ◽

Finite Element ◽

High Resolution ◽

Vessel Wall ◽

Intracranial Aneurysms ◽

Vessel Wall Imaging ◽

Wall Tension ◽

Element Analysis ◽

Aneurysm Wall ◽

Wall Imaging

Biomechanical computational simulation of intracranial aneurysms has become a promising method for predicting features of instability leading to aneurysm growth and rupture. Hemodynamic analysis of aneurysm behavior has helped investigate the complex relationship between features of aneurysm shape, morphology, flow patterns, and the proliferation or degradation of the aneurysm wall. Finite element analysis paired with high-resolution vessel wall imaging can provide more insight into how exactly aneurysm morphology relates to wall behavior, and whether wall enhancement can describe this phenomenon. In a retrospective analysis of 23 unruptured aneurysms, finite element analysis was conducted using an isotropic, homogenous third order polynomial material model. Aneurysm wall enhancement was quantified on 2D multiplanar views, with 14 aneurysms classified as enhancing (CRstalk≥0.6) and nine classified as non-enhancing. Enhancing aneurysms had a significantly higher 95th percentile wall tension (μ = 0.77 N/cm) compared to non-enhancing aneurysms (μ = 0.42 N/cm, p < 0.001). Wall enhancement remained a significant predictor of wall tension while accounting for the effects of aneurysm size (p = 0.046). In a qualitative comparison, low wall tension areas concentrated around aneurysm blebs. Aneurysms with irregular morphologies may show increased areas of low wall tension. The biological implications of finite element analysis in intracranial aneurysms are still unclear but may provide further insights into the complex process of bleb formation and aneurysm rupture.

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Circumferential Wall Enhancement on Magnetic Resonance Imaging is Useful to Identify Rupture Site in Patients with Multiple Cerebral Aneurysms

Neurosurgery ◽

10.1093/neuros/nyx267 ◽

2017 ◽

Vol 82 (5) ◽

pp. 638-644 ◽

Cited By ~ 27

Author(s):

Shunsuke Omodaka ◽

Hidenori Endo ◽

Kuniyasu Niizuma ◽

Miki Fujimura ◽

Toshiki Endo ◽

...

Keyword(s):

Magnetic Resonance ◽

Aspect Ratio ◽

Vessel Wall ◽

Vessel Wall Imaging ◽

Irregular Shape ◽

Fast Spin Echo ◽

Multiple Aneurysms ◽

Aneurysm Size ◽

Aneurysm Wall ◽

Wall Imaging

Abstract BACKGROUND Identification of rupture sites in patients with multiple intracranial aneurysms is largely based on aneurysm size, location, and shape. Finding circumferential enhancement along the aneurysm wall (CEAW) on magnetic resonance (MR) vessel wall imaging was recently shown to be indicative of ruptured aneurysm. OBJECTIVE To investigate the hypothesis that a higher degree of CEAW would identify the site of rupture in patients with multiple aneurysms. METHODS We prospectively performed quantitative analysis of CEAW in consecutive patients with both aneurysmal subarachnoid hemorrhage and multiple aneurysms (26 patients with a total of 62 aneurysms), using MR vessel wall imaging. Three-dimensional T1-weighted fast spin-echo sequences were obtained before and after injection of contrast media, and the wall enhancement index (WEI) was calculated. Aneurysm characteristics (size, location, irregular shape, aspect ratio [neck-to-dome length/neck width], and WEI) were compared between ruptured and unruptured aneurysms. Odds ratios with 95% confidence intervals for ruptures were calculated with conditional univariable logistic regression analysis. Analyses were repeated after adjustment for aneurysm size. RESULTS Large aneurysm size, high aspect ratio, WEI (above the median values), and irregular shape were significantly associated with aneurysm rupture. After adjustment for aneurysm size, WEI (adjusted odds ratio: 8.8; 95% confidence interval, 1.1-72.6) as well as irregular shape and aspect ratio showed a strong association with rupture. CONCLUSION CEAW is associated with rupture of intracranial aneurysm independent of aneurysm size and patient characteristics. Contrast-enhanced MR vessel wall imaging helps to identify the site of rupture in patients with multiple aneurysms.

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Vessel wall enhancement of intracranial aneurysms: fact or artifact?

Neurosurgical FOCUS ◽

10.3171/2019.4.focus19236 ◽

2019 ◽

Vol 47 (1) ◽

pp. E18 ◽

Cited By ~ 5

Author(s):

Bart M. W. Cornelissen ◽

Eva L. Leemans ◽

Cornelis H. Slump ◽

Henk A. Marquering ◽

Charles B. L. M. Majoie ◽

...

Keyword(s):

Vessel Wall ◽

Intracranial Aneurysms ◽

Ruptured Aneurysm ◽

Acquisition Time ◽

Imaging Data ◽

Luminal Diameter ◽

Unruptured Aneurysms ◽

Ruptured Aneurysms ◽

Aneurysm Wall ◽

Contrast Enhanced

OBJECTIVEFor patients with subarachnoid hemorrhage (SAH) and multiple intracranial aneurysms, it is often challenging to identify the ruptured aneurysm. Some investigators have asserted that vessel wall imaging (VWI) can be used to identify the ruptured aneurysm since wall enhancement after contrast agent injection is presumably related to inflammation in unstable and ruptured aneurysms. The aim of this study was to determine whether additional factors contribute to aneurysm wall enhancement by assessing imaging data in a series of patients.METHODSPatients with symptoms of SAH who subsequently underwent VWI in the period between January 2017 and September 2018 were eligible for study inclusion. Three-dimensional turbo spin-echo sequences with motion-sensitized driven-equilibrium preparation pulses were acquired using a 3-T MRI scanner to visualize the aneurysm wall. Identification of the ruptured aneurysm was based on aneurysm characteristics and hemorrhage distributions on MRI. Complementary imaging data (CT, DSA, MRI) were used to assess potential underlying enhancement mechanisms. Additionally, aneurysm luminal diameter measurements on MRA were compared with those on contrast-enhanced VWI to assess the intraluminal contribution to aneurysm enhancement.RESULTSSix patients with 14 aneurysms were included in this series. The mean aneurysm size was 5.8 mm (range 1.1–16.9 mm). A total of 10 aneurysms showed enhancement on VWI; 5 ruptured aneurysms showed enhancement, and 1 unruptured but symptomatic aneurysm showed enhancement on VWI and ruptured 1 day later. Four unruptured aneurysms showed enhancement. In 6 (60%) of the 10 enhanced aneurysms, intraluminal diameters appeared notably smaller (≥ 0.8 mm smaller) on contrast-enhanced VWI compared to their appearance on multiple overlapping thin slab acquisition time of flight (MOTSA-TOF) MRA and/or precontrast VWI, suggesting that enhancement was at least partially in the aneurysm lumen itself.CONCLUSIONSSeveral factors other than the hypothesized inflammatory response contribute to aneurysm wall enhancement. In 60% of the cases in this study, enhancement was at least partially caused by slow intraaneurysmal flow, leading to pseudo-enhancement of the aneurysm wall. Notwithstanding, there seems to be clinical value in differentiating ruptured from unruptured aneurysms using VWI, but the hypothesis that we image the inflammatory cell infiltration in the aneurysm wall is not yet confirmed.

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