Regional Aneurysm Wall Enhancement is Affected by Local Hemodynamics: A 7T MRI Study

Hadad, Sara; Mut, Fernando; Chung, Bong Jae; Roa, Jorge A; Robertson, Anne M.; Hasan, David; Samaniego, Edgar A; Cebral, Juan R.

doi:10.3174/ajnr.a6927

Cited by 22 publications

(26 citation statements)

References 30 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…However, there is no consensus on how to determine thresholds of AWE or what part of the aneurysm should be sampled to analyze enhancement. 3D maps may also provide further information about the aneurysm biology as it has been shown that aneurysm compartments have different patterns of enhancement directly influenced by local flow conditions 10 . 7T MRI studies have demonstrated a linear correlation between wall thickness and SI.…”

Section: Discussionmentioning

confidence: 99%

“…Detailed analysis of focal AWE (FAWE) has determined that the colocalization of these areas with low wall shear stress, such as blebs (Fig. 1 ) is associated with a higher risk of rupture 10 , 11 . Other groups determined a higher risk of rupture when circumferential wall enhancement (CAWE) is present, instead of FAWE 1 , 12 , 13 .…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Semiautomated 3D mapping of aneurysmal wall enhancement with 7T-MRI

Raghuram

Varón

Roa

et al. 2021

Sci Rep

View full text Add to dashboard Cite

Aneurysm wall enhancement (AWE) after the administration of contrast gadolinium is a potential biomarker of unstable intracranial aneurysms. While most studies determine AWE subjectively, this study comprehensively quantified AWE in 3D imaging using a semi-automated method. Thirty patients with 33 unruptured intracranial aneurysms prospectively underwent high-resolution imaging with 7T-MRI. The signal intensity (SI) of the aneurysm wall was mapped and normalized to the pituitary stalk (PS) and corpus callosum (CC). The CC proved to be a more reliable normalizing structure in detecting contrast enhancement (p < 0.0001). 3D-heatmaps and histogram analysis of AWE were used to generate the following metrics: specific aneurysm wall enhancement (SAWE), general aneurysm wall enhancement (GAWE) and focal aneurysm wall enhancement (FAWE). GAWE was more accurate in detecting known morphological determinants of aneurysm instability such as size ≥ 7 mm (p = 0.049), size ratio (p = 0.01) and aspect ratio (p = 0.002). SAWE and FAWE were aneurysm specific metrics used to characterize enhancement patterns within the aneurysm wall and the distribution of enhancement along the aneurysm. Blebs were easily identified on 3D-heatmaps and were more enhancing than aneurysm sacs (p = 0.0017). 3D-AWE mapping may be a powerful objective tool in characterizing different biological processes of the aneurysm wall.

show abstract

Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Semiautomated 3D mapping of aneurysmal wall enhancement with 7T-MRI

Raghuram

Varón

Roa

et al. 2021

Sci Rep

View full text Add to dashboard Cite

show abstract

“…Thus, commonly used isotropic voxel sizes range between 0.5 – 0.8 mm 3 . MR imaging at higher magnetic fields (7T or more) can improve the SNR ( 30 ). The development of new acceleration techniques can reduce the examination time ( 31 ) while maintaining or increasing the spatial resolution.…”

Section: Mrimentioning

confidence: 99%

Imaging Inflammation – From Whole Body Imaging to Cellular Resolution

et al. 2021

View full text Add to dashboard Cite

Imaging techniques have evolved impressively lately, allowing whole new concepts like multimodal imaging, personal medicine, theranostic therapies, and molecular imaging to increase general awareness of possiblities of imaging to medicine field. Here, we have collected the selected (3D) imaging modalities and evaluated the recent findings on preclinical and clinical inflammation imaging. The focus has been on the feasibility of imaging to aid in inflammation precision medicine, and the key challenges and opportunities of the imaging modalities are presented. Some examples of the current usage in clinics/close to clinics have been brought out as an example. This review evaluates the future prospects of the imaging technologies for clinical applications in precision medicine from the pre-clinical development point of view.

show abstract

“…However, several studies have suggested using wall enhancement in contrast-enhanced vessel wall magnetic resonance imaging (VW-MRI) as an indirect marker for wall inflammation [18][19][20]. Exemplarily, different flow conditions (e.g., at the neck, aneurysm body or dome) were associated with a varying degree of local enhancement [21]. Furthermore, VW-MRI in combination with flow MRI was used to correlate morphology and haemodynamics in IAs [22].…”

Section: Introductionmentioning

confidence: 99%

Luminal enhancement in intracranial aneurysms: fact or feature?—A quantitative multimodal flow analysis

et al. 2021

View full text Add to dashboard Cite

Purpose Intracranial aneurysm (IA) wall enhancement on post-contrast vessel wall magnetic resonance imaging (VW-MRI) is assumed to be a biomarker for vessel wall inflammation and aneurysm instability. However, the exact factors contributing to enhancement are not yet clarified. This study investigates the relationship between luminal enhancement and intra-aneurysmal flow behaviour to assess the suitability of VW-MRI as a surrogate method for determining quantitative and qualitative flow behaviour in the aneurysm sac. Methods VW-MRI signal is measured in the lumen of three patient-specific IA flow models and compared with the intra-aneurysmal flow fields obtained using phase-contrast magnetic resonance imaging (PC-MRI) and computational fluid dynamics (CFD). The IA flow models were supplied with two different time-varying flow regimes. Results Overall, the velocity fields acquired using PC-MRI or CFD were in good agreement with the VW-MRI enhancement patterns. Generally, the regions with slow-flowing blood show higher VW-MRI signal intensities, whereas high flow leads to a suppression of the signal. For all aneurysm models, a signal value above three was associated with velocity values below three cm/s. Conclusion Regions with lower enhancements have been correlated with the slow and high flow at the same time. Thus, further factors like flow complexity and stability can contribute to flow suppression in addition to the flow magnitude. Nevertheless, VW-MRI can qualitatively assess intra-aneurysmal flow phenomena and estimate the velocity range present in the corresponding region.

show abstract

Regional Aneurysm Wall Enhancement is Affected by Local Hemodynamics: A 7T MRI Study

Cited by 22 publications

References 30 publications

Semiautomated 3D mapping of aneurysmal wall enhancement with 7T-MRI

Semiautomated 3D mapping of aneurysmal wall enhancement with 7T-MRI

Imaging Inflammation – From Whole Body Imaging to Cellular Resolution

Luminal enhancement in intracranial aneurysms: fact or feature?—A quantitative multimodal flow analysis

Contact Info

Product

Resources

About