Validation of an automated software (Smartpelvic?) in assessing hiatal area from three dimensional transperineal pelvic volumes of pregnant women: comparison with manual analysis

Objectives: The aim of this investigation was to evaluate the agreement between a manual and an automatic technique in assessing levator hiatus area (LHA) during pregnancy from three-dimensional (3D) pelvic floor volumes obtained by trans-perineal ultrasound (TPUS).Methods: 3D volumes were acquired during rest, maximum pelvic floor contraction and Valsalva maneuver from 66 pregnant women. Manual selection of LHA and automatic software (Smart Pelvic (TM)) were applied on TPUS volume starting from a C-plane view. To evaluate intra- and inter-observer variability measurements of LHA were performed twice by the same operator and once by a second sonographer. Reference hiatal contours obtained manually by the first operator were compared with the automated ones. Reproducibility was evaluated by intraclass correlation coefficients (ICC) and Bland-Altman plots.Results: LHA measurement, using automatic software, achieved excellent intra-observer and inter-observer reproducibility in pregnant women both at rest and after dynamic analysis (ICC>0.9). Further, an excellent agreement resulted between manual selection of the LHA and automatic imaging (ICC>0.9). The average time taken to obtain LHA manually was significantly longer when compared to the automatic analysis (p <= 0.0001).Conclusions: Smart pelvic software resulted from a reliable method for automatically measuring the LHA, showing high reproducibility and accuracy.