Tracking and Monitoring Pulsatility of a Portion of Inferior Vena Cava from Ultrasound Imaging in Long Axis (original) (raw)
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Diagnostics, 2022
Ultrasound (US)-based measurements of the inferior vena cava (IVC) diameter are widely used to estimate right atrial pressure (RAP) in a variety of clinical settings. However, the correlation with invasively measured RAP along with the reproducibility of US-based IVC measurements is modest at best. In the present manuscript, we discuss the limitations of the current technique to estimate RAP through IVC US assessment and present a new promising tool developed by our research group, the automated IVC edge-to-edge tracking system, which has the potential to improve RAP assessment by transforming the current categorical classification (low, normal, high RAP) in a continuous and precise RAP estimation technique. Finally, we critically evaluate all the clinical settings in which this new tool could improve current practice.
Journal of Ultrasonography, 2017
Background: Ultrasound measurement of the inferior vena cava diameter and its respiratory variability are amongst the predictors of fluid volume status. The primary purpose of the present study was to compare the consistency of inferior vena cava diameter measurements and the collapsibility index, obtained with convex and cardiac transducers. A secondary aim was to assess the agreement of the patient's allocation to one of the two groups: "fluid responder" or "fluid non-responder", based on inferior vena cava collapsibility index calculation made with two different probes. Methods: 20 experienced clinicians blinded to the purpose of the study analysed forty anonymized digital clips of images obtained during ultrasound examination of 20 patients. For each patient, one digital loop was recorded with a cardiac and the second with a convex probe. The participants were asked to determine the maximal and minimal diameters of the inferior vena cava in all presented films. An independent researcher performed a comparative analysis of the measurements conducted with both probes by all participants. The calculation of the collapsibility index and allocation to "fluid responder" or "fluid non-responder" group was performed at this stage of the study. Results: The comparison of measurements obtained with cardiac and convex probes showed no statistically significant differences in the measurements of the maximal and minimal dimensions and in the collapsibility index. We also noticed that the decision of allocation to the "fluid responder" or "non-responder" group was not probe-dependent. Conclusion: Both transducers can be used interchangeably for the estimation of the studied dimensions.
International Journal of Cardiovascular Imaging, 2003
Volumetric analysis of coronary arteries can be performed using intravascular ultrasound (IVUS) images selected at 1 mm intervals without ECG gating. However, there are few data regarding the influence of coronary pulsation on this volumetric analysis. We developed two models of consecutive area measurements consisting of duplicated area measurements from short coronary segments and virtual measurements based on a sine function. These models allowed the re-calculation of volumes using different sets of frames from the same simulated segments. The variability of the volume determinations was evaluated by its percent standard deviation [%SD = (SD/the mean value) × 100]. The relation of the variability to the extent of external elastic membrane (EEM) area change during the cardiac cycle (amplitude) and heart rates (frequency) were examined. In 58 short coronary segments of 15 patients, consecutive IVUS images were measured [%EEM area change: 12.3 ± 7.7 %, heart rate 78 ± 21 beats/min (bpm)]. In both models, %SD of the volume calculations was directly proportional to the %EEM area change and showed two peaks at heart rates of 60 ± 2 and 90 ± 2 bpm. In the model based on actual coronary measurements, the %SD of volume calculations of a segment with 10% EEM area change was 0.7% except for heart rates of 60 ± 2 and 90 ± 2 bpm. The variability of a volumetric analysis based upon measuring IVUS images at constant intervals without ECG gating is affected by coronary pulsation, extent of cross-sectional area changes, and heart rate. Despite these limitations, this method is feasible and provides reproducible volume measurements.
Journal of intensive care, 2015
Determination of a patient's volume status remains challenging. Ultrasound assessments of the inferior vena cava and lung parenchyma have been shown to reflect fluid status when compared to the more traditional static and dynamic methods. Yet, resource-limited intensive care units (ICUs) may still not have access to bedside ultrasound. The vascular pedicle width (VPW) measured on chest radiographs remains underutilized for fluid assessment. In this study, we aimed to determine the correlation between ultrasound assessment and vascular pedicle width and to identify a discriminant value that predicted a fluid replete state. Eighty-four data points of simultaneous VPW and inferior vena cava measurements were collected on mechanically ventilated patients. VPW measurements were compared with lung comet scores, fluid balance, and a composite variable of inferior vena cava diameter greater than or equal to 2 cm and variability less than 15 %. A VPW of 64 mm accurately predicted fluid r...
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Background: Assessment of intravascular volume status is an essential parameter for the diagnosis and management of critically-ill patients. In order to assess the intravascular volume status noninvasively, we conducted a study to to find the correlation, if any, between sonographic IVC collapsibility index and Central Venous Pressure to assess the volume status in ICU patients. Methods: The Institutional Ethics Committee approval was obtained. 60 spontaneously breathing post-operative patients with a functioning central venous catheter were recruited for this study. The distal port of the catheter was connected to a pressure transducer and the pressure displayed on the monitor in mmHg was noted. Simultaneously the IVC diameters during end inspiration and end expiration were measured in the longitudinal and transverse orientations using the M-mode of the ultrasound machine. The Collapsibility Index was calculated from the IVC diameters. Collapsibility Index? 50% suggested hypovolemia and Collapsibility Index <50% suggested euvolemia or hypervolemia. This was compared with the measured Central Venous Pressure to find the correlation between the two. Additionally the change in IVC diameter with Central Venous Pressure was observed. The IVC Collapsibility Index for longitudinal and transverse orientations were calculated separately and they were compared with each other to find which among them correlated the best with the Central Venous Pressure. Results: In our study the IVC Collapsibility Index correlated well with the Central Venous Pressure. The sensitivity and specificity of IVC Collapsibility to Central Venous Pressure were also found to be statistically significant. The change in IVC diameters were also found to be statistically significant when compared to Central Venous Pressure. The sensitivity of the IVC Collapsibility Index in the longitudinal orientation was much better than that of the transverse orientation to detect low CVP. Conclusion: IVC Collapsibility Index can be used as an alternative to CVP measurement to guide us in the fluid management of patients in the ICU.
Rationale and Objectives. Color velocity imaging-quantitative (CVI-Q) is a new sonographic technique designed to measure volume flow (VF) in blood vessels. We attempted to validate VF measurements with CVI-Q in an in vitro model of the circulation. Methods. We validated CVI-Q in a flow phantom mimicking physiologic conditions by connecting isolated porcine arteries 4-14 mm in diameter to a calibrated perfusion roller pump generating pulsatile flow with porcine blood. Pump flow was varied stepwise from 0 to 1,000 ml/min. CVI-Q VF measurements were performed using a 7.5-MHz linear array transducer. VF results then were compared with pump flow calibration values through linear regression. Results. A good correlation (r 2 = .98-.99, slope = 0.88-1.02) was obtained from 0 to 400-600 ml/min. The degree of correlation depended on vessel diameter, with linearity being maintained over a somewhat larger range in medium-sized vessels. At higher flows, variability increased significantly. Conclusion. VF measurements with CVI-Q are accurate in a physiologic flow range. At supraphysiologic flow rates, as are encountered within arte-riovenous fistulae, CVI-Q may give inaccurate results. Awareness of possible pitfalls and limitations of the technique is important for obtaining accurate and reproducible results.
Journal of nuclear medicine : official publication, Society of Nuclear Medicine, 1986
A strategy for displaying and archiving dynamic quantitative data from scintigraphic imaging is described and applied to diagnosing obstructed thoracic veins. A prospective series of 25 patients with concurrent radiographic contrast and tracer venograms along with 49 controls showed a 33% sensitivity, comparable to previously published data. The use of first harmonic Fourier analysis enhanced the screening value of the test by identifying all abnormals. Moreover, this format captured the dynamic physiologic data on a single photograph. This technique is readily available to nearly any nuclear imaging laboratory equipped with a gamma camera and a computer.
Pakistan Journal of Medical Sciences, 1969
and compartment syndrome. 2 Measurements of central venous pressure (CVP), pulmonary arterial catheterization, esophageal Doppler ultrasonography (Ultrasound), and transesophageal echocardiography may be used to determine the volume status of critically ill patients. 3 CVP refers to the pressure of the right atrium or superior vena cava and helps inform emergency departments and critical care units about what fluid and diuretic treatment to apply. 4 However, hemodynamic monitorization with central venous ultrasound catheterization is limited in being costly and invasive. 5 Considering complications such as infections, bleeding, and pneumothorax, it is better to assess fluid status using noninvasive methods. 6 Ultrasound is a good method for noninvasive hemodynamic motorization by emergency physicians, and it may be more helpful than other noninvasive methods such as measuring urine output, pulse rate, and arterial blood pressure. New technological improvements have made Ultrasound mobile, easy to use and inexpensive. 7