Browsing by Subject "Image segmentation"

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    Reliability and accuracy assessment of morphometric measurements obtained with software for three-dimensional reconstruction of brain aneurysms relative to cerebral angiography measures
    (SAGE Publications, 2020-09-01) Munarriz, Pablo M.; Bárcena, Eduardo; Alén, José F.; Castaño León, Ana M.; Paredes, Igor; Moreno Gómez, Luis Miguel; García Pérez, Daniel; Jiménez Roldán, Luis; Gómez, Pedro A.; Lagares, Alfonso; Farmacología; Facultades de la UMU::Facultad de Medicina
    Objective To analyze the reliability and accuracy of morphological measurements of software employed to three-dimensionally reconstruct aneurysms and vessels (VMTKlab, version 1.6.1,) with computed tomography angiography (CTA) as the source of images. Agreement with measurements from three-dimensional digital subtraction angiography (3 D-DSA) was evaluated. Methods We evaluated 40 patients presenting with aneurysmal subarachnoid hemorrhage (aSAH). We analyzed four main variables of the aneurysm morphology: absolute height (size), neck (maximum neck width), perpendicular height, and maximum width. The CTA images were uploaded to the software and then segmented to reconstruct the aneurysm. This new method was compared to the current gold standard—3D reconstruction of pretreatment cerebral angiography. We used intraclass correlation coefficient (ICC) and Bland-Altman plot analyses to evaluate the agreement between these methods. Results The ICCs obtained for absolute height, neck, perpendicular height, and maximum width were 0.85, 0.57, 0.85, and 0.89, respectively. This implied good agreement except for the neck of the aneurysm (moderate agreement). Bland-Altman plots are presented for the four indexes. The average of the differences was not significant in terms of absolute height, perpendicular height, and maximum width indicating good agreement. However, it was significant for the neck of the aneurysm. Conclusions We report good agreement between the values generated using VMTKlab and cerebral angiography for three of the four main variables. Discrepancies in neck diameter are not surprising and its underestimation with a traditional delineation from cerebral angiography has been reported before.
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    The influence of aneurysm morphology on the volume of hemorrhage after rupture
    (American Association of Neurological Surgeons (AANS), 2021-09-17) Munarriz, Pablo M.; Navarro Main, Blanca; Alén, José F.; Jiménez Roldán, Luis; Castaño León, Ana María; Moreno Gómez, Luis Miguel; Paredes, Igor; García Pérez, Daniel; Panero, Irene; Eiriz Fernández, Carla; Esteban Sinovas, Olga; Bárcena, Eduardo; Gómez, Pedro A.; Lagares, Alfonso; Farmacología; Facultades de la UMU::Facultad de Medicina
    OBJECTIVE Factors determining the risk of rupture of intracranial aneurysms have been extensively studied; however, little attention is paid to variables influencing the volume of bleeding after rupture. In this study the authors aimed to evaluate the impact of aneurysm morphological variables on the amount of hemorrhage. METHODS This was a retrospective cohort analysis of a prospectively collected data set of 116 patients presenting at a single center with subarachnoid hemorrhage due to aneurysmal rupture. A volumetric assessment of the total hemorrhage volume was performed from the initial noncontrast CT. Aneurysms were segmented and reproduced from the initial CT angiography study, and morphology indexes were calculated with a computer-assisted approach. Clinical and demographic characteristics of the patients were included in the study. Factors influencing the volume of hemorrhage were explored with univariate correlations, multiple linear regression analysis, and graphical probabilistic modeling. RESULTS The univariate analysis demonstrated that several of the morphological variables but only the patient’s age from the clinical-demographic variables correlated (p < 0.05) with the volume of bleeding. Nine morphological variables correlated positively (absolute height, perpendicular height, maximum width, sac surface area, sac volume, size ratio, bottleneck factor, neck-to-vessel ratio, and width-to-vessel ratio) and two correlated negatively (parent vessel average diameter and the aneurysm angle). After multivariate analysis, only the aneurysm size ratio (p < 0.001) and the patient’s age (p = 0.023) remained statistically significant. The graphical probabilistic model confirmed the size ratio and the patient’s age as the variables most related to the total hemorrhage volume. CONCLUSIONS A greater aneurysm size ratio and an older patient age are likely to entail a greater volume of bleeding after subarachnoid hemorrhage.