Feasibility of three-dimensional reconstruction and automated measurement of fetal long bones using 5D Long Bone

Abstract

ObjectiveTo 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.MethodsThis 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.ResultsThere 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.Conclusion5D LB is reproducible and comparable with conventional 2D and 3D ultrasound techniques for fetal long bone measurement.

The Accuracy of Prediction of Birth Weight by Automated Measurement of Fetal Long Bones Using 5D Long Bone versus VOCAL 3D and Conventional 2D Weight Formulae

“…In an effort to overcome this drawback, long bone automated detection system by 5D was introduced to create an operator independent, quick and efficient method for accurate estimation of fetal birth weight. In the current trial, this fully automated system revealed absolute birth weight estimation error of 0.95% which is comparable to the previous work of Hurr et al, who reported an overall error rate of 5.4% in a larger sample [8].…”

“…Despite the obvious superiority of 3D ultrasound in estimation of fetal birth weight, the technique is still operator dependent and requires a learning curve for proper acquisition and manipulation of volume data [8]. In an effort to overcome this drawback, long bone automated detection system by 5D was introduced to create an operator independent, quick and efficient method for accurate estimation of fetal birth weight.…”

“…Subsequently, the long bone length was measured by another analyzer using the 5D LB with the following procedures described by Hurr et al [8]. "The volume data used in the manual 3D-ultrasound measurement were dis played in an offline multiplanar mode, and the 5D LB set key was pressed on the system, wherein the system automatically analyzed the 3D volume data, reconstructed the 3D image of the long bones, and displayed the measured lengths of the long bones on the screen".…”

Automated Fractional Limb Volume Measurements Improve the Precision of Birth Weight Predictions in Late Third‐Trimester Fetuses

“…Fractional limb volume measurements were calculated with a WS80A ultrasound system (5D Limb Vol; Samsung Medison) . Each end of the limb diaphysis was automatically detected with a previously described software tool (5D Long Bone) . The partial limb volume was automatically subdivided into 5 equidistant cross‐sectional image slices that were centered along the midarm or midthigh.…”

“…7,15 Each end of the limb diaphysis was automatically detected with a previously described software tool (5D Long Bone). 16 The partial limb volume was automatically subdivided into 5 equidistant cross-sectional image slices that were centered along the midarm or midthigh. An image transformation procedure required the examiner to identify the major and minor axis diameters of each limb cross section and to mark the location of the bony diaphysis.…”