Fig 1.
MRI pelvis with Sagittal T2 spin echo sequence demonstrating normal uterine morphology (left) with volume measurement (right) using a summation of area within the region of interest (ROI) from each contiguous image slice through the visualised uterus.
Table 1.
Pubmed ID, first author and year of publication are given for sources of extracted data, together with number of measurements and age ranges.
Table 2.
Excluded uterine volume data summary.
Pubmed ID, first author and year of publication are given for sources of non-extracted data, together with number of measurements. Each publication met the inclusion and exclusion criteria for consideration as a data source, but either contained descriptive statistics of uterine volume rather than extractable data in the form of scatter plots, or data on uterine length (rather than volume).
Fig 2.
Log-adjusted data and normative model.
The observed volumes (blue points) are shown with the predicted volume (red line), the 95% confidence interval for the predicted volume (brown lines), and the 95% prediction limits for the model (purple lines).
Fig 3.
The residuals are the variations in log-adjusted observed values from the log-adjusted age-related mean value predicted by the model. The residuals have excellent goodness of fit to an ideal Gaussian curve (r2 = 0.99). 71% of the residuals are within one standard deviations (SD) of the mean, 94% within 2 SD, and 98% within 3SD. The percentages for an ideal Gaussian distribution are 68%, 95% and 99% respectively.
Table 3.
Also given are the standard error and T statistic for the values, and the upper and lower 95% confidence limits for the values.
Table 4.
MSE denotes mean square error. Training error and test error for the 5-folds of the data set. The first and third cross validation sets show slight overfit (error is higher for data not used to fit the model); the second and fourth sets show slight underfit. The overall error of 5.5% is similar to the error found at the cross validation stages.
Fig 4.
Predicted uterine volume for ages from birth to 40 years, with one and two standard deviations prediction limits– 68% of measurements at a given age are expected to be between the green lines; 95% are expected to be between the blue lines.
Fig 5.
Predicted uterine volume for ages from 8 to 18 years, with one and two standard deviations prediction limits– 68% of measurements at a given age are expected to be between the green lines; 95% are expected to be between the blue lines.
Fig 6.
The first derivative of our uterine volume model as a percentage of the peak pubertal velocity is shown in red. For comparison, the height velocity for girls (based on data from [30]) is shown in blue.
Table 5.
Mean volumes (50th centile) in cm3 are given for ages 0 to 40. Also given are volumes at one standard deviation from the mean (16th and 84th centiles) and at two standard deviations from the mean (2.5 and 97.5 centiles).