Volume variation may be a relevant metric in the study of aneurysm pulsatility: a study using ECG-gated 4D-CTA (PULSAN)

Abstract

​Background and purposeIntracranial aneurysms are a frequently occurring disease, with an estimated prevalence of 2–5% in the general population. They usually remain silent until rupture occurs, with a mortality rate of 35–50% and a high rate of morbidity, including long-term disability. However, preventative treatments have their own risk of complications and morbi-mortality rates, including stroke and hemorrhage. ECG-gated four-dimensional CT angiography (4D-CTA) allows the acquisition of time-resolved three-dimensional reconstructions. The aim of our study was to evaluate different intracranial aneurysm metrics over the cardiac cycle using ECG-gated 4D-CTA.​Materials and methodsECG-gated 4D-CTA datasets were acquired in patients presenting with intracranial aneurysms. Seven aneurysm metrics, including aneurysm height, aneurysm length, ostium width, aspect ratio, ostium area, volume, and volume-to-ostium ratio, were analysed over different cardiac phases. Intra-reader agreement, inter-reader agreement, and inter-cycle agreement were calculated through the intraclass correlation coefficient.​ResultsTwenty-one aneurysms from 11 patients were considered for inclusion. Post-processing failed for three aneurysms, and 18 aneurysms were finally analysed. There was good intra-reader agreement for each metric (ICC >0.9). Agreements among three consecutive cardiac cycles were calculated for six aneurysms and were especially good for the volume metric (ICC >0.9). Volume variation appears to be the most relevant metric and seems especially perceptible for aneurysms larger than 5 mm.​ConclusionsQuantification of aneurysm volume changes during the cardiac cycle seems quantitatively possible and reproducible, especially for aneurysms larger than 5 mm. Further studies need to be conducted to validate this parameter for intracranial aneurysm assessment.

Dynamic evaluation of unruptured intracranial aneurysms by 4D-CT angiography: comparison with digital subtraction angiography (DSA) and surgical findings

“…Unlike 3D-CTA, 4D-CTA can acquire time-resolved three-dimensional reconstructions to provides dynamic information on aneurysm wall and visualizes wall motion during cardiac cycle. Therefore, irregular pulsation detected by 4D-CTA could be a novel imaging marker of aneurysm vulnerability [ 12 ]. The objective of this proof-of-concept study is to investigate the association of the morphological risk factors characterized by 4D-CTA and DSA.…”

In-vivo cerebral artery pulsation assessment with Dynamic Computed Tomography Angiography

“…When comparing our study to the literature on cerebral arteries, one other clinical study assessed the reproducibility between multiple pulsation cycles for intracranial aneurysms. [13] This study showed high reproducibility in measuring the maximum volume change per cardiac cycle, for aneurysms exceeding 5 mm, with variations of approximately 0.5 mm. It is essential to note that our study differs in scope as we comprehensively assessed the entire pulsation pattern, unlike this previous study which focused on the maximum volume change measurement.…”

Correlation between the rate of morphological changes and rupture of intracranial aneurysms during one cardiac cycle analyzed by 4D-CTA

“…Although no significant difference existed between unruptured aneurysms and normal intracranial arteries, there was still a slight distinction ( 21 ). 4D-CTA is a feasible method for quantitatively analyzing the volume changes of aneurysms during a cardiac cycle, providing a theoretical basis for further research ( 22 , 23 ). In this study, the comparison between ruptured and unruptured aneurysms revealed a significant difference in volume change rate between the two groups.…”