Intra-observer repeatability when assessing the foetal urinary bladder volume by the Virtual Organ Computer-aided AnaLysis and SUM-OF-CYLINDERS methods: A pilot study

IntroductionThe aim of this study was to compare the intra-observer repeatability when using two different methods for estimating the volume of foetal urinary bladders.MethodThe urinary bladders of 20 foetuses were documented by three-dimensional ultrasound. Standard deviation was compared when the volumes of identical bladder images were repeatedly estimated using the Virtual Organ Computer-aided AnaLysis and the experimental SUM-OF-CYLINDERS methods.ResultsNo systematic deviation was found between the estimated volumes when using these two methods. Standard deviation was smaller for the SUM-OF-CYLINDERS compared to the Virtual Organ Computer-aided AnaLysis method (p < 0.0001). In relation to bladder volumes of 5–25 ml, standard deviation was 11–14% for the Virtual Organ Computer-aided AnaLysis and 4–5% for the SUM-OF-CYLINDERS method.ConclusionsUsing three-dimensional ultrasound images adapted for the Virtual Organ Computer-aided AnaLysis method, foetal urinary bladder volumes can also be estimated usin...