Improved Repeatability of the Estimation of Pulsatility of Inferior Vena Cava

Abstract

The inferior vena cava (IVC) shows variations of cross-section over time (referred to as pulsatility) induced by different stimulations, like as breathing and heartbeats. The amplitude of these pulsations is affected by the volume status of the patient and can be investigated by ultrasound (US) mea

Biomedical Image Processing and Classification

“…Two automated methods have been introduced to delineate the IVC edges along sections either transverse or longitudinal to the blood vessel [25][26][27]. Preliminary results have shown the importance of using these automated methods to obtain more repeatable, reliable, and accurate information on IVC pulsatility than when using subjective clinical methods [28][29][30][31]. In this Special Issue, the two views are used to extract features that, integrated by a classification algorithm, can result in improved performance in diagnosing the volemic status of patients [24].…”

Automated Volume Status Assessment Using Inferior Vena Cava Pulsatility

“…The algorithm proposed in [20] (and already applied in [13,25,31]) was used. In the first frame of the clip, the user located the vein and the region of interest, indicating two reference points to be tracked to compensate for IVC movements and deformations, the leftmost and rightmost lines to be considered and the location of the borders of the vein in the leftmost line.…”

“…However, this non-invasive method has shown limitations [10,11]. Important problems are due to the lack of standardization [12] and to the subjectivity of the measurement [13]. Indeed, both B-mode and M-mode US scans have been used, followed by a subjective identification of the IVC maximal and minimal diameters [6,14].…”

“…Specifically, IVC pulsatility can be expressed in terms of the caval index (CI), defined as the variation of the vessel diameter during a respiratory cycle relative to the maximum diameter: minimum and maximum diameters are measured by the operator from a B-mode video or an M-mode trace considering inspiration and expiration, respectively. This clinical approach is not standardized [12,15] (e.g., either long [16] or short axis [17] visualizations are used), and is operator-dependent [13] and prone to measurement errors, e.g., due to movements [18] and non-uniform pulsatility of IVC [15]. In particular, the M-mode registration allows to visualize a section of the vein over time at high frequency along a fixed direction in space [19].…”

“…Indeed, breathing and heartbeats provide the main stimulations affecting IVC pulsatility. Separating the effects of the two contributions could possibly help to counteract these limitations [13,25].…”