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International audience; The clinical reliability of 3-D ultrasound imaging (3-DUS) in quantification of abdominal aortic aneurysm (AAA) was evaluated. B-mode and 3-DUS images of AAAs were acquired for 42 patients. AAAs were segmented. A 3-D-based maximum diameter (Max3-D) and partial volume (Vol30) were defined and quantified. Comparisons between 2-D (Max2-D) and 3-D diameters and between orthogonal acquisitions were performed. Intra- and inter-observer reproducibility was evaluated. Intra- and inter-observer coefficients of repeatability (CRs) were less than 5.18 mm for Max3-D. Intra-observer and inter-observer CRs were respectively less than 6.16 and 8.71 mL for Vol30. The mean of normalized errors of Vol30 was around 7%. Correlation between Max2-D and Max3-D was 0.988 (p < 0.0001). Max3-D and Vol30 were not influenced by a probe rotation of 90°. Use of 3-DUS to quantify AAA is a new approach in clinical practice. The present study proposed and evaluated dedicated parameters. Their reproducibility makes the technique clinically reliable.

International audience; OBJECTIVES: Maximum diameter is a determinant parameter for the clinical management of asymptomatic abdominal aortic aneurysm (AAA). However, its measurement is not standardised. We review the different methods used to measure AAA maximum diameter, with ultrasound (US) or computed tomography (CT). METHODS: A review of maximum diameter measurement methods with US and CT was performed, focussing on screening, surveillance before repair and decision for intervention. Diameter measurement methodology was described according to four parameters: plane of acquisition, axis of measurement, position of callipers and selected diameter. A quality score to evaluate methodology descriptions was defined (plane, axis, callipers placement and selected diameter), ranging from 0 (worst) to 4 (best). RESULTS: Review showed a wide range of definitions and practices. The mean value of the quality score was 2.52 in screening studies, 1.66 in guidelines for screening, 2.81 in follow-up studies and 1.63 in studies describing decision for intervention. CONCLUSION: To improve the efficiency of AAA management (in screening programmes, follow-up and decision for intervention), and enable comparison between future studies, a standardised methodology for AAA maximum diameter measurement is necessary. Until such a consensus is reached, publications should at least clearly report the method of measurement.

International audience; Follow-up of abdominal aortic aneurysm (AAA) consists in monitoring its maximal diameter with 2D ultrasound (2D U/S). But this technique has limits. An original protocol for 3D U/S analysis of AAA including U/S volume acquisitions and software prototype was developed. This protocol allows : 3D visualization of the AAA geometry in space, navigation in the volume along axial, sagittal and coronal, planes and diagnostic review at any time, automatic and manual selections of the cross-section of interest, automatic extraction of quantification parameters. Its accuracy was evaluated for AAA diameter measurements. The complete version of this document is available on the EPOS website by using the doi: 10.1594/ecr2011/C-0493

Objectifs : Evaluer la faisabilité de l'imagerie volumique ultrasonore des anévrysmes de l'aorte abdominale (AAA) natifs ou traités par endoprothèse dans le but clinique d'améliorer leur suivi. Mise au point d'un prototype de quantification volumique. Matériels et Méthodes : Les acquisitions volumiques d'AAA natifs ou traités par endoprothèse ont été effectuées chez respectivement 4 et 13 patients à l'aide d'une sonde 3D mécanique (V6-2) sur un échographe IU22 (Philips, the Netherlands), après réalisation d'une imagerie conventionnelle en 2D à l'aide de la sonde abdominale C5-1. Le traitement des acquisitions a été réalisé en différé sur un ordinateur muni du logiciel d'analyse QLab. Résultats : Après transfert des images, l'outil a permis sans limitation dans le temps : (a) la navigation dans le volume de l'AAA selon les trois plans de l'espace, (b) la reconstruction surfacique de l'AAA et sa visualisation 3D, et a donné l'accès à de nouveaux paramètres en échographie tels que le volume ou une mesure de diamètre sur une incidence optimisée. Conclusion : Ce travail préliminaire a montré que l'échographie volumique des AAA était envisageable et autorise l'évaluation clinique de l'outil.

ISBN 13: 978-88-7711-663-5; The use of specific 3 dimensional (3D) ultrasound equipment now enables to (i) explore a volume in real time and navigate inside using a virtual plane; (ii) perform 3D reconstruction and visualization of structures of interest in off-line post-processing. This technique is based on the same concept as the other modes of imaging (CT, MR) and thus allows: diagnostic review at any time, better reproducibility of measurements, volume measurements, less operator-dependent examinations. 3D ultrasonography has not yet been widely used in vascular pathology while it should be of major interest in two main applications: (a) abdominal aortic aneurysms, for which angio-CT demonstrated that volume follow-up is superior to diameter measurement, and (b) carotid plaque, with evaluation and monitoring of plaque volume, morphology, and surface (ulcerating lesions).

International audience; Usual imaging after endovascular aneurysm repair (EVAR) of abdominal aortic aneurysm (AAA) consists of AAA diameter monitoring and endoleak detection. Among additional predictor parameters previously proposed to help clinicians in better identifying subgroups of AAA still at risk of rupture, AAA wall motion after EVAR has been studied, but its value was not clearly established. Tissue Doppler imaging (TDI) is an ultrasonographic modality which allows wall motion measurements along an arterial segment. The aim of the current study was to analyze AAA wall motion with TDI before and after EVAR and to describe its evolution in patients with more than 1 month of follow-up. Twenty-five consecutive patients undergoing EVAR between February 2005 and June 2007 gave informed consent to be prospectively investigated with the TDI system before EVAR and at each visit during follow-up. The mean (SD) follow-up was 13.7 (9.7) months. Maximum mean segmental dilation (MMSD), segmental compliance, dilation at maximum diameter, pressure strain elastic modulus (Ep), and stiffness were compared between three periods (before stenting, before discharge, and at last follow-up), and their relation with AAA diameter was analyzed. A significant decrease in AAA compliance was immediately observed after successful EVAR and remained stable during later follow-up. On the other hand, AAA diameter progressively decreased along time and was statistically lower at the last control compared to the initial value. MMSD, segmental compliance, and dilation at maximum diameter were positively related to AAA diameter. This means that the larger the AAA diameter after stenting, the higher the value for these parameters can be expected. On the contrary, percentage of AAA diameter decrease and percentage of MMSD decrease were not related after successful EVAR. There was no parallelism between loss in compliance and diameter decrease along time, and there is not a unique pattern of AAA diameter and compliance evolution after EVAR. Even if comparison between patients without and with endoleak was weak due to the small sample of the latter group (five patients with endoleak), compliance tended to be greater in case of endoleak. AAA wall motion after successful EVAR reflects complex interactions between all the components of the stented aneurysm which evolve over time, including true compliance of the aneurysm wall itself; intra-aneurysm sac pressure with possible different effects for peak, mean, and pulse pressures; remodeling of the thrombus; stiffness characteristics of the graft; and systemic pressure. Combining simultaneous MMSD records with actual intrasaccular pressure measurements in patients with and without endoleak would improve our understanding of the clinical pulsatility mechanism within AAA after EVAR.