Quantification of Intracranial Aneurysm Volume Pulsation with 7T MRI

R. Kleinloog; J.J.M. Zwanenburg; B. Schermers; E. Krikken; Y.M. Ruigrok; P.R. Luijten; F. Visser; L. Regli; G.J.E. Rinkel; B.H. Verweij

doi:10.3174/ajnr.a5546

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

Journal of NeuroInterventional Surgery ◽

10.1136/neurintsurg-2019-015336 ◽

2019 ◽

Vol 12 (6) ◽

pp. 632-636 ◽

Cited By ~ 1

Author(s):

Brieg Dissaux ◽

Julien Ognard ◽

Mourad Cheddad El Aouni ◽

Michel Nonent ◽

Karim Haioun ◽

...

Keyword(s):

Intracranial Aneurysm ◽

Intracranial Aneurysms ◽

Cardiac Cycle ◽

Intraclass Correlation ◽

Three Dimensional ◽

High Rate ◽

Time Resolved ◽

Volume Variation ◽

Aneurysm Volume

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.

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Abstract W MP48: Measurement of Intracranial Aneurysm Growth

Stroke ◽

10.1161/str.46.suppl_1.wmp48 ◽

2015 ◽

Vol 46 (suppl_1) ◽

Author(s):

Qianyi Yu ◽

Xin Yang ◽

Tim Cheng ◽

Feng Liang ◽

Aichi Chien

Keyword(s):

Intracranial Aneurysm ◽

Gradient Descent ◽

Active Contours ◽

Signal To Noise Ratio ◽

Time Interval ◽

Geodesic Active Contours ◽

Time Points ◽

Aneurysm Growth ◽

Aneurysm Volume ◽

The Difference

Purpose: The aim of this study is to develop a method to accurately measure 3-D growth of intracranial aneurysms using geodesic active contours segmentation and gradient descent registration algorithms. The method is expected to generate fast and reliable indication of aneurysm growth in clinical settings. Method: The geodesic active contours algorithm was implemented to perform 3-D aneurysm segmentation. 3-D CT Angiography images of 10 subjects with follow up aneurysm images were included in this study. Each subject had images acquired at two distinct time points (average time interval: 126.8 ± 80.1 days). 5 subjects were known to have aneurysm growth between the two time points (growth group). The other 5 subjects were known to have stable aneurysm sizes between the two time points (non-growth group). Segmentation and registration algorithms were used on images from all 10 subjects in an attempt to reproduce the diagnosis results. This study also included 7 sets of computer-built 3-D models and dimensions, for the purpose of validation. Result: Based on segmentation results, the growth group showed an average 21.7 ± 10.2% increase in aneurysm volume, and non-growth group showed an average 0.2 ± 1.3% increase in aneurysm volume. The difference in sample means between the growth group and non-growth group was statistically significant (p ≤ 0.05). For subjects in the growth group, the registration algorithm was able to identify and to label the growing region. For validation, segmentation and registration algorithms were also used on 7 sets of computer built models; growth was correctly labeled. The average runtime for processing segmentation under 4th Generation Intel Core i7-4500U Processor (3.0GHz) was 31.7 ± 38.4 seconds, and 45.2 ± 40.3 for registration. Input images had Signal-to-Noise Ratio (SNR) within a range of 1.8 to 5.9. Conclusion: Geodesic active contours segmentation and gradient descent registration offer an efficient way of measuring and monitoring intracranial aneurysm growth. Further improvements in algorithms are expected to reduce runtime and numerical errors.

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