A Novel Semiautomated Fractional Limb Volume Tool for Rapid and Reproducible Fetal Soft Tissue Assessment

Abstract

The purpose of this study was to document the reproducibility and efficiency of a semiautomated image analysis tool that rapidly provides fetal fractional limb volume measurements. Fifty pregnant women underwent 3-dimensional sonographic examinations for fractional arm and thigh volumes at a mean menstrual age of 31.3 weeks. Manual and semiautomated fractional limb volume measurements were calculated, with the semiautomated measurements calculated by novel software (5D Limb Vol; Samsung Medison, Seoul, Korea). The software applies an image transformation method based on the major axis length, minor axis length, and limb center coordinates. A transformed image is used to perform a global optimization technique for determination of an optimal limb soft tissue boundary. Bland-Altman analysis defined bias with 95% limits of agreement (LOA) between methods, and timing differences between manual versus automated methods were compared by a paired t test. Bland-Altman analysis indicated an acceptable bias with 95% LOA between the manual and semiautomated methods: mean arm volume ± SD, 1.7% ± 4.6% (95% LOA, -7.3% to 10.7%); and mean thigh volume, 0.0% ± 3.8% (95% LOA, -7.5% to 7.5%). The computer-assisted software completed measurements about 5 times faster compared to manual tracings. In conclusion, semiautomated fractional limb volume measurements are significantly faster to calculate when compared to a manual procedure. These results are reproducible and are likely to reduce operator dependency. The addition of computer-assisted fractional limb volume to standard biometry may improve the precision of estimated fetal weight by adding a soft tissue component to the weight estimation process.

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

“…Small systematic errors observed in this cohort may be caused by using automated fractional limb volume with weight prediction models that had been previously developed from manually traced limb soft tissue borders on a different ultrasound system. In this context, we had previously reported an excellent correlation (0.993 to 0.998) between manually traced fractional limb volume and automated measurements with the same model of ultrasound system used in this investigation …”

“…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) .…”

“…Fractional limb volume measurements were calculated with a WS80A ultrasound system (5D Limb Vol; Samsung Medison). 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.…”

“…[7][8][9][10][11][12][13][14] The recent introduction of a commercially available software tool now makes it possible to efficiently automate fractional limb volume measurements that are about 5 times faster than results obtained from manual tracing. 15 This pilot study examined the use of automated fractional limb volume for this purpose, since these computer-assisted measurements have been recently demonstrated to be reproducible, as well as more efficient, when compared with the slower method of manually tracing limb soft tissue borders. "…”

Foetal fractional thigh volume: an early 3D ultrasound marker of neonatal adiposity

“…We believe that TVol measurement is easy to perform in 4DView, but we also experienced the technical limitations described earlier We expect that the ongoing development of automated image analysis tools with higher precision and faster calculations will increase the clinical feasibility of TVol measurement as an additional bedside‐available technique for monitoring of foetal growth .…”