Get 20M+ Full-Text Papers For Less Than $1.50/day. Start a 14-Day Trial for You or Your Team.

Learn More →

Quantifying Intracranial Aneurysm Wall Permeability for Risk Assessment Using Dynamic Contrast-Enhanced MRI: A Pilot Study

Quantifying Intracranial Aneurysm Wall Permeability for Risk Assessment Using Dynamic... BACKGROUND AND PURPOSE: Pathological changes in the intracranial aneurysm wall may lead to increases in its permeability; however the clinical significance of such changes has not been explored. The purpose of this pilot study was to quantify intracranial aneurysm wall permeability ( K trans , V L ) to contrast agent as a measure of aneurysm rupture risk and compare these parameters against other established measures of rupture risk. We hypothesized K trans would be associated with intracranial aneurysm rupture risk as defined by various anatomic, imaging, and clinical risk factors. MATERIALS AND METHODS: Twenty-seven unruptured intracranial aneurysms in 23 patients were imaged with dynamic contrast-enhanced MR imaging, and wall permeability parameters ( K trans , V L ) were measured in regions adjacent to the aneurysm wall and along the paired control MCA by 2 blinded observers. K trans and V L were evaluated as markers of rupture risk by comparing them against established clinical (symptomatic lesions) and anatomic (size, location, morphology, multiplicity) risk metrics. RESULTS: Interobserver agreement was strong as shown in regression analysis ( R 2 > 0.84) and intraclass correlation (intraclass correlation coefficient >0.92), indicating that the K trans can be reliably assessed clinically. All intracranial aneurysms had a pronounced increase in wall permeability compared with the paired healthy MCA ( P < .001). Regression analysis demonstrated a significant trend toward an increased K trans with increasing aneurysm size ( P < .001). Logistic regression showed that K trans also predicted risk in anatomic ( P = .02) and combined anatomic/clinical ( P = .03) groups independent of size. CONCLUSIONS: We report the first evidence of dynamic contrast-enhanced MR imaging–modeled contrast permeability in intracranial aneurysms. We found that contrast agent permeability across the aneurysm wall correlated significantly with both aneurysm size and size-independent anatomic risk factors. In addition, K trans was a significant and size-independent predictor of morphologically and clinically defined high-risk aneurysms. ABBREVIATIONS: DCE dynamic contrast-enhanced IA intracranial aneurysm ISUIA International Study of Unruptured Intracranial Aneurysms K trans contrast-transfer coefficient V L fractional volume of extravascular extracellular space per unit tissue http://www.deepdyve.com/assets/images/DeepDyve-Logo-lg.png American Journal of Neuroradiology American Journal of Neuroradiology

Quantifying Intracranial Aneurysm Wall Permeability for Risk Assessment Using Dynamic Contrast-Enhanced MRI: A Pilot Study

Loading next page...
 
/lp/american-journal-of-neuroradiology/quantifying-intracranial-aneurysm-wall-permeability-for-risk-jsHNycXPHJ

References (27)

Publisher
American Journal of Neuroradiology
Copyright
Copyright © 2015 by the American Society of Neuroradiology.
ISSN
0195-6108
eISSN
1936-959X
DOI
10.3174/ajnr.A4225
pmid
25655875
Publisher site
See Article on Publisher Site

Abstract

BACKGROUND AND PURPOSE: Pathological changes in the intracranial aneurysm wall may lead to increases in its permeability; however the clinical significance of such changes has not been explored. The purpose of this pilot study was to quantify intracranial aneurysm wall permeability ( K trans , V L ) to contrast agent as a measure of aneurysm rupture risk and compare these parameters against other established measures of rupture risk. We hypothesized K trans would be associated with intracranial aneurysm rupture risk as defined by various anatomic, imaging, and clinical risk factors. MATERIALS AND METHODS: Twenty-seven unruptured intracranial aneurysms in 23 patients were imaged with dynamic contrast-enhanced MR imaging, and wall permeability parameters ( K trans , V L ) were measured in regions adjacent to the aneurysm wall and along the paired control MCA by 2 blinded observers. K trans and V L were evaluated as markers of rupture risk by comparing them against established clinical (symptomatic lesions) and anatomic (size, location, morphology, multiplicity) risk metrics. RESULTS: Interobserver agreement was strong as shown in regression analysis ( R 2 > 0.84) and intraclass correlation (intraclass correlation coefficient >0.92), indicating that the K trans can be reliably assessed clinically. All intracranial aneurysms had a pronounced increase in wall permeability compared with the paired healthy MCA ( P < .001). Regression analysis demonstrated a significant trend toward an increased K trans with increasing aneurysm size ( P < .001). Logistic regression showed that K trans also predicted risk in anatomic ( P = .02) and combined anatomic/clinical ( P = .03) groups independent of size. CONCLUSIONS: We report the first evidence of dynamic contrast-enhanced MR imaging–modeled contrast permeability in intracranial aneurysms. We found that contrast agent permeability across the aneurysm wall correlated significantly with both aneurysm size and size-independent anatomic risk factors. In addition, K trans was a significant and size-independent predictor of morphologically and clinically defined high-risk aneurysms. ABBREVIATIONS: DCE dynamic contrast-enhanced IA intracranial aneurysm ISUIA International Study of Unruptured Intracranial Aneurysms K trans contrast-transfer coefficient V L fractional volume of extravascular extracellular space per unit tissue

Journal

American Journal of NeuroradiologyAmerican Journal of Neuroradiology

Published: May 1, 2015

There are no references for this article.