Feasibility of three-dimensional reconstruction and automated measurement of fetal long bones using 5D Long Bone
Authors
Hyewon Hur ; Young Han Kim ; Hee Young Cho ; Yong Won Park ; Hye-Sung Won ; Mi-Young Lee ; Bo Hyon Yun ; Kwang Hee Lee ; Sung Yoon Kim ; Junsang Yoo ; Ja-Young Kwon
5D Long Bone ; Fetal biometry ; Fetal long bone ; Three-dimensional ultrasound ; Two-dimensional ultrasound
Abstract
OBJECTIVE: To evaluate the feasibility of five-dimensional Long Bone (5D LB), a new technique that automatically archives, reconstructs images, and measures lengths of fetal long bones, to assess whether the direction of volume sweep influences fetal long bone measurements in three-dimensional (3D) ultrasound and 5D LB, and to compare measurements of fetal long bone lengths obtained with 5D LB and those obtained with conventional two-dimensional (2D) and manual 3D techniques.
METHODS: This prospective study included 39 singleton pregnancies at 26+0 to 32+0 weeks of gestation. Multiple pregnancies, fetuses with multiple congenital anomalies, and mothers with underlying medical diseases were excluded. Fetal long bones of the lower extremities-the femur, tibia, and fibula were measured by 2D and 3D ultrasound, and 5D LB, by an expert and non-expert examiner. First, we analyzed the 3D ultrasound and 5D LB data according to 2 different sweeping angles. We analyzed intra- and inter-observer variability and agreement between ultrasound techniques. Paired t-test, interclass correlation coefficient, and Bland-Altman plot and Passing-Bablok regression were used for statistical analysis.
RESULTS: There was no statistical difference between long bone measurements analyzed according to 2 different volume-sweeping angles by 3D ultrasound and 5D LB. Intra- and inter-observer variability were not significantly different among all 3 ultrasound techniques. Comparing 2D ultrasound and 5D LB, the interclass correlation coefficient for femur, tibia, and fibula was 0.91, 0.92, and 0.89, respectively.
CONCLUSION: 5D LB is reproducible and comparable with conventional 2D and 3D ultrasound techniques for fetal long bone measurement.