Pitfalls in femur length measurements.

Abstract

The following study was performed to determine the precise anatomic correlate for the end points of sonographic measurement of the fetal femur. A cadaveric fetal thigh was dissected in layers and correlated with sonographic images. The margins of the osseous portion of the femur were determined on sonograms. Potential for underestimating femur length (oblique images) and overestimating femur length (including nonosseous portions of the femur in measurement) can be eliminated by requiring a view of the femur which includes the epiphyseal cartilages. In this way, the margins of the osseous portion may be accurately estimated, and there is assurance that the entire shaft has been visualized. Images of the dissected specimen indicate that the "distal femur point," which may cause confusion in measurement, is not a part of the osseous femur, but probably represents a specular reflection from the lateral surface of the distal epiphysis.

Preventable Maternal Risk Factors and Association of Genital Infection with Fetal Growth Restriction

“…In case of doubt, the fetal transcerebellar diameter at 15-20 weeks was measured as an additional maker to improve the gestational age estimation [10] . Serial ultrasound and Doppler examinations were performed, using the standard techniques [11][12][13] .…”

Fetal Biometry in Early Pregnancy

“…This makes it an ideal parameter for quick estimation of gestational age, but care must be taken in order to obtain an accurate measurement. One should be able to see the femoral head or greater trochanter proximally and the femoral condyle distally, and measurement should only include the ossifi ed portion of the bone [ 43 ]. This measurement should not be taken in isolation, as it is known that there are some normal variations between ethnic groups.…”

Investigation of Bone Ratios for Prenatal Fetal Assessment in Taiwanese Population

“…In addition, the transducer needed to be aligned to the long axis of the limb bone to obtain a proper plane of the section. The ossified portion of diaphysis and metaphysics were measured, while the cartilaginous ends of the limb bones were excluded [23,24]. To assess repeatability of the intraobserver, two repeated measurements were obtained from 44 fetuses randomly chosen during the process of ultrasound screening.…”