Circumferential wall enhancement with contrast ratio measurement in unruptured intracranial aneurysm for aneurysm instability

Abstract

Background Aneurysm wall enhancement on high‐resolution vessel wall imaging (HR‐VWI) may represent vessel wall inflammation for unruptured intracranial aneurysms (UIAs). Further evidence for the role of circumferential aneurysm wall enhancement (CAWE) in evaluating the instability of UIAs is required, especially in small aneurysms (<7 mm). Methods We analyzed patients with saccular UIAs who prospectively underwent HR‐VWI on a 3.0 T MRI scanner in our center from September 2017 to August 2021. The presence of AWE was identified and quantitatively measured using the aneurysm‐to‐pituitary stalk contrast ratio (CRstalk) with maximal signal intensity value. The PHASES and ELAPSS scores were used to assess the risk of aneurysm rupture and growth. We evaluated the association of CAWE and CRstalk value with intracranial aneurysm instability. Results One hundred patients with 109 saccular UIAs were included in this study. Eighty‐three UIAs (76.1%) had a size smaller than 7 mm. PHASES and ELAPSS scores were significantly higher in UIAs with CAWE than in UIAs without CAWE (p < .01). The association of CAWE with PHASES and ELAPSS scores remained in small UIAs (<7 mm). The optimal cutoff value of CRstalk for CAWE was 0.5. PHASES and ELAPSS scores were significantly higher in UIAs with CRstalk ≥0.5 than in UIAs with CRstalk <0.5 (p < .01). Conclusions CAWE on HR‐VWI is a valuable imaging marker for aneurysm instability in UIAs. CRstalk value ≥0.5 may be associated with a higher risk of intracranial aneurysm rupture and growth.

Neutrophil-to-Lymphocyte Ratio Is Associated With Circumferential Wall Enhancement of Unruptured Intracranial Aneurysm

“…In a study of 19 patients harboring 22 unruptured IAs, there was a significant association of CRstalk ≥0.5 with decreased plasma concentration of the anti-inflammatory cytokine IL-10 in the aneurysm sac ( 19 ). In our previous study, the optimal cutoff value of CRstalk for circumferential AWE was 0.5 ( 24 ). We found that the level of NLR at admission and aneurysm size was associated with CRstalk ≥0.5 in 57 patients with 60 unruptured IAs in the current study.…”

“…Recently, quantitative measurement of AWE on HR-VWI has been used to avoid the subjectivity of the readers ( 19 , 24 , 26 ). CRstalk using maximal SI may be a new tool to predict the instability of unruptured IA.…”

“…Patients with unruptured IAs underwent brain MR for HR-VWI on a 3.0T MRI scanner with a 32-channel head coil (Achieva TX, Philips Healthcare, Best, the Netherlands). We used our previously published HR-VWI protocol in this study ( 24 ).The 2D T1-weighted black-blood vessel wall sequence was performed between September 2017 and September 2018. Since October 2018, the 3D T1-weighted VISTA sequence was performed.…”

“…We divided the patten of AWE of saccular unruptured IAs as none AWE, focal AWE, and circumferential AWE according to the precontrast and postcontrast HR-VWI T1-weighted sequences ( 6 – 8 ).We measured signal intensity (SI) of the aneurysm wall (SIwall) and the pituitary stalk (SIstalk) on the 3D postcontrast HR-VWI T1-weighted sequence. The aneurysm-to-pituitary stalk contrast ratio (CRstalk) was calculated using the maximal SI value of SIwall and SIstalk as CRstalk = SIwall/SIstalk, which was an optimal quantitative analysis of AWE in unruptured IA ( 24 – 26 ).…”

“…Then, we analyzed the association of these variables with all patterns of AWE and circumferential AWE in all unruptured IAs and the subgroup of unruptured IAs small than 7 mm. We used the optimal cutoff value of 0.5 for CRstalk to differentiate circumferential AWE from non-circumferential AWE in unruptured IA with a 3D HR-VWI T1-weighted sequence ( 19 , 24 ).Then, we analyzed the association of these variables with CRstalk ≥0.5 in unruptured IAs.…”