Two-Dimensional Aortic Size Normalcy: A Novelty Detection Approach

Figures

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  Figure 1. Heatmap of Q-score obtained by an OC-SVM model. As an illustrative example, this heatmap of Q-score predicting normalcy by using only proximal ascending aorta (PAA) and sinuses of Valsalva (SOV) diameters (blue dots) is reported. As a reference, the thoracic aorta dilatation region [defined as diameter (D) > 40 mm for at least one aortic segment] has been slightly darkened, and patients represented as stars. Inside the blue region, Q-scores are > 4% indicating normalcy. The black solid contour lines correspond to the level sets Q-score = 2% and 4%. Orange triangles are patients with Marfan syndrome, green diamonds patients with bicuspid aortic valve (BAV).

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  Figure 2. Kernel density estimates of demographics, anthropometrics and aortic sizes by sex. Distribution of height, weight, age and body surface area (BSA) are in (A). Distribution of aortic size at the annulus (AAn), sinuses of Valsalva (SoV), sino-tubular junction (SJ) and proximal ascending aorta (PAA), are reported as raw values (B) and after indexation for height (h; C) and BSA (D). (**** p < 0.0001; *** p < 0.001; ** p < 0.01 (Kolmogorov–Smirnov two-sided test)).

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  Figure 3. Scatterplots of individual patient aortic size related to age and body size. Individual patient data are reported to illustrate the relationship between either age or body surface area (BSA) and aortic size at the annulus (AAn; A,B), sinuses of Valsalva (SoV; C,D), sino-tubular junction (SJ; E,F) and proximal ascending aorta (PAA; G,H). Colored lines (or curves) represent the distribution of the variance of aortic size for the given values of age and BSA.

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  Figure 4. Outputs of both Z-score and Q-score in one patient. Representative output using the web calculator in a 43 year-old male with mildly steno-insufficient bicuspid aortic valve. The first two columns report the different aortic levels and their respective size in mm. The third column reports results of the Z-score for each aortic level, while the last one provides the regional and global Q-scores. Z-score values greater than 2 (abnormal) are in bold. Q-score values smaller than 2% (abnormal) are highlighted in red, while values between 2% and 4% (borderline) are colored in yellow. Q-values greater than 4% (normal) are in green.