Comparison of automated and manually computed RV/LV diameter ratios.

<p>A) Correlation plot. A linear model is fitted to the data. The intercept’s value is -0.16, the slope is 1.11, Person’s correlation coefficient is R = 0.81, 95% CI [0.76–0.86]. B) Bland-Altman comparison. The mean difference is -0.023 (95% CI [-0.061 0.003], p = 0.08), is depicted with a red line and its 95% CI as dotted red lines. Dot-dashed blue line: 95% limits of agreement of manual vs. automated measurement. Dashed green line: 95% CI limits of agreement between two expert readers. 72.1% (132/183) cases are within the limits of inter-reader variability.</p

Mean and standard deviation values for the automated and manual axial ventricular diameter estimations and RV/LV diameter ratios.

<p>P-values are obtained using paired t-tests.</p><p>Mean and standard deviation values for the automated and manual axial ventricular diameter estimations and RV/LV diameter ratios.</p

Algorithm description.

<p>First, the right ventricle and the left ventricle are detected on each axial slice. The detections are clustered to position seeds for further segmentation. The seeds are used to detect the septum. Using the seeds and the septum, the ventricles are segmented and the calipers positioned. Finally the right ventricular to left ventricular axial diameter ratio is estimated.</p

Area under the curve (AUC) comparison for the different methods and clinical outcomes.

<p>P-values are obtained with Chi-Square Goodness of Fit Tests.</p

Axial images of a computed tomography pulmonary angiography of a 27 years old female with acute pulmonary embolism.

<p>Top row: manually estimated axial ventricular diameters. Bottom row: automatically estimated axial ventricular diameters and depiction of the different steps followed to compute them: ventricle detection (red boxes), seed positioning (green dots), interventricular septum estimation (blue line), ventricle segmentation (blue areas) and ventricular diameter estimation (yellow lines).</p

Prediction of clinical outcome.

<p>ROCs curve for the manual (dashed blue line) and automated (red line) logistic regression models when used to predict: A) 30 days PE-related mortality and B) 30 days PE-related mortality or the need for intensive therapies. Areas under the curve are 0.75 for the manual method and 0.72 for the automated method for Fig 6A and 0.78 for the manual method and 0.75 for the automated method in Fig 6B.</p

Mean and standard deviation values of the RV/LV diameter ratios computed manually and automatically for two clinical outcomes.

<p>P-values are obtained using paired t-tests.</p><p>Mean and standard deviation values of the RV/LV diameter ratios computed manually and automatically for two clinical outcomes.</p

Interface designed to visualize the automatically computed axial ventricular diameters.

<p>The system automatically locates the diameters and adjusts the viewing window to maximize contrast. The RV/LV diameter ratio is shown between the two images.</p

Tukey outlier box plot of manually and automated extracted ventricular diameters and diameter ratios.

<p>The box is placed at the median of the distribution. Top and bottom limits of the boxes represent 1^st and 3^rd quartiles of the data respectively. Whiskers length is 1.5 inter-quartile distances. Individual dots are considered outliers. While both RV and LV are underestimated by the automated method, the manually and automated estimated ratios are not significantly different, as shown in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0127797#pone.0127797.t001" target="_blank">Table 1</a>.</p