Geometric versus Hemodynamic Indexes for Rupture-Destined Aneurysms: A Retrospective Cohort and a Repeated-Measures Study

Chan-Hyuk Lee; Hyo Sung Kwak; Hyun-Seung Kang; Keun-Hwa Jung; Seul-Ki Jeong

doi:10.1159/000533167

Geometric versus Hemodynamic Indexes for Rupture-Destined Aneurysms: A Retrospective Cohort and a Repeated-Measures Study

Cerebrovasc Dis. 2023 Sep 11:1-8. doi: 10.1159/000533167. Online ahead of print.

Authors

Chan-Hyuk Lee^{1

2}, Hyo Sung Kwak³, Hyun-Seung Kang⁴, Keun-Hwa Jung⁵, Seul-Ki Jeong⁶

Affiliations

¹ Department of Neurology, Asan Medical Center, Seoul, Republic of Korea.
² Department of Neurology, Ulsan University Hospital, University of Ulsan College of Medicine, Ulsan, Republic of Korea.
³ Department of Radiology and Research Institute of Clinical Medicine of Jeonbuk National University, Biomedical Research Institute of Jeonbuk National University Hospital, Jeonju, Republic of Korea.
⁴ Department of Neurosurgery, Seoul National University Hospital, Seoul National University College of Medicine, Seoul, Republic of Korea.
⁵ Department of Neurology, Seoul National University Hospital, Seoul National University College of Medicine, Seoul, Republic of Korea.
⁶ Seul-Ki Jeong Neurology Clinic, Seoul, Republic of Korea.

PMID: 37696264
DOI: 10.1159/000533167

Abstract

Introduction: A proper stratification of intracranial aneurysms is critical in identifying rupture-destined aneurysms and unruptured intracranial aneurysms. We aimed to determine the utility of geometric and hemodynamic indexes in differentiating two types of aneurysms and to examine the characteristics of natural evolutionary changes of unruptured aneurysms.

Methods: Rupture-destined aneurysm refers to an aneurysm that undergoes subsequent aneurysmal subarachnoid hemorrhage (SAH). On the other hand, an unruptured intracranial aneurysm is characterized by an aneurysm that does not experience rupture during serial time-of-flight magnetic resonance angiography (TOF-MRA). In addition to geometric indexes, signal intensity gradient (SIG), an in vivo approximated wall shear stress from TOF-MRA, was measured in aneurysms. The difference between the maximum and minimum values of SIG in an aneurysm compared to parent arterial values was designated as the delta-SIG ratio.

Results: This study analyzed 20 rupture-destined aneurysms in 20 patients and 45 unruptured intracranial aneurysms in 41 patients with follow-up TOF-MRA. While geometric indexes did not show differences between the two groups, the delta-SIG ratio was higher in the rupture-destined aneurysms (1.5 ± 0.6 vs. 1.1 ± 0.3, p = 0.032). The delta-SIG ratio showed a higher area under the receiver operating characteristic curve for SAH than the size ratio (0.72 [95% CI, 0.58-0.87] vs. 0.56 [95% CI, 0.41-0.72], p = 0.033). The longitudinal re-examination of TOF-MRA in the unruptured intracranial aneurysms revealed evidence of aneurysmal growth, while concurrently exhibiting hemodynamic stability.

Conclusion: The delta-SIG ratio showed higher discriminatory results between the two groups compared to geometric indexes. Aneurysmal rupture risk should be assessed by considering both geometric and hemodynamic information. This study was registered on <ext-link ext-link-type="uri" xlink:href="http://ClinicalTrials.gov" xmlns:xlink="http://www.w3.org/1999/xlink">ClinicalTrials.gov</ext-link> (NCT05450939).

Keywords: Delta-SIG ratio; Rupture-destined aneurysm; Signal intensity gradient; Unruptured intracranial aneurysm; Wall shear stress.

Associated data

ClinicalTrials.gov/NCT05450939