(Ultrasound Review) The objective of a study by obstetricians at King’s College Hospital, London, was to scrutinize the feasibility and repeatability of three-dimensional ultrasound for measurement of nuchal translucency (NT).
"Forty consecutive women with uncomplicated singleton pregnancies attending for Down syndrome screening at 11-14 weeks’ gestation were included in this prospective crossover trial," the authors wrote in the December issue of Ultrasound in Obstetrics and Gynecology.
A number of pitfalls reduce the success rate for NT measurement. When the fetus is lying in an unfavorable position measurement of the NT is difficult. Sonographer experience and system-related image quality also influence measurement accuracy.
The authors investigated whether 3-D might overcome these limitations. "The main theoretical advantage of using 3-D ultrasound would be in cases when nuchal translucency measurement cannot be completed due to an unfavorable fetal position, they said." Rotating and re-slicing 3-D volumes enables the user to overcome this limitation, they added.
Two 3-D volumes were obtained. "The initial plane for the first volume contained a clear image of the nuchal region (sagittal), whilst the initial plane of the second volume was selected randomly regardless of fetal position. It was demonstrated that repeat NT measurements were possible in 95% of sagittal volumes and 60% of random volumes.
The resulting difference, between 2-D and 3-D NT measurements, were -0.097mm for sagittal volumes and 0.225mm for random volumes. They found that many (74%) of the 2-D midsagittal scans were in fact not the true midsagittal but the measurement error was insignificant. 2-D measurements took less time to perform, mainly because 3-D measurements can only be performed when there is no fetal movement.
They found that successful nuchal translucency measurement was possible using re-slicing of random volumes in only 60% of women. They emphasized that successful 3-D measurements were only possible using sagittal volumes when the initial plane included a good quality image of the nuchal region.
The authors concluded "re-slicing of stored 3-D volumes can be used to replicate nuchal translucency measurements only when nuchal skin can also be clearly seen on two-dimensional ultrasound." They asserted that because of this, the role of 3D for detecting Down syndrome at 11-14 weeks’ gestation was limited.
"Measurement of fetal nuchal translucency thickness by three-dimensional ultrasound"C Paul et al
Early Pregnancy and Gynaecology Assessment Unit, Dept of Obstetrics and Gynaecology, King’s College Hospital, London UK
Ultrasound Obstet Gynecol 2001 (December); 18:481-484
By Ultrasound Review
January 4, 2002
Copyright © 2002 AuntMinnie.com
![Examples of ultrasound findings and techniques. (A) Images in a 39-year-old male patient with a mass in the left thigh. The mass is heterogeneous on the B-mode US image (compared with the patient in D) and showed increased microvascularity (superb microvascular imaging [SMI]) and shear-wave elastography (SWE) values. Undifferentiated pleomorphic sarcoma was diagnosed at biopsy (with pleomorphic rhabdomyosarcoma in surgical specimen). (B) Images in an 18-year-old male patient with a mass in the left leg. The mass is hypoechoic on the B-mode image, with no other findings suggestive of malignancy. The lesion is in contact with the cortex of the tibia, which is slightly irregular. CT revealed a doubtful anteromedial tibial erosion. The microvascular study demonstrated high vascularization, suggestive of malignancy. Periosteal Ewing sarcoma was diagnosed with both histologic and immunohistochemical confirmation. (C) Images in a 69-year-old female patient with a lump growing on the outside of the left leg. Multiple SWE examinations were performed (please note the high values obtained in the measurements, whereas the color map highlights the stiffness relative to adjacent tissues). SMI showed areas of increased vascularization to target for sampling. Undifferentiated spindle cell sarcoma was diagnosed at biopsy, with residual leiomyosarcoma in the surgical specimen after neoadjuvant therapy. (D) Images in a 56-year-old female patient with a mass in the right thigh. The mass is heterogeneous at both B-mode ultrasound (similar to patient A) and MRI (coronal T2-weighted spectral attenuated inversion recovery [SPAIR]; T1-weighted pre-contrast and postcontrast imaging), which even shows uptake after the administration of paramagnetic contrast material, which is traditionally suggestive of malignancy. Low values at SMI and elastography are suggestive of benignity. Spindle cell lipoma was diagnosed at biopsy, with atypical spindle cell lipomatous tumor in the surgical specimen.](https://img.auntminnie.com/mindful/smg/workspaces/default/uploads/2026/08/images-radiol250278fig2.APCFLSvX6p.jpg?auto=format%2Ccompress&fit=crop&h=100&q=70&w=100)
![Examples of ultrasound findings and techniques. (A) Images in a 39-year-old male patient with a mass in the left thigh. The mass is heterogeneous on the B-mode US image (compared with the patient in D) and showed increased microvascularity (superb microvascular imaging [SMI]) and shear-wave elastography (SWE) values. Undifferentiated pleomorphic sarcoma was diagnosed at biopsy (with pleomorphic rhabdomyosarcoma in surgical specimen). (B) Images in an 18-year-old male patient with a mass in the left leg. The mass is hypoechoic on the B-mode image, with no other findings suggestive of malignancy. The lesion is in contact with the cortex of the tibia, which is slightly irregular. CT revealed a doubtful anteromedial tibial erosion. The microvascular study demonstrated high vascularization, suggestive of malignancy. Periosteal Ewing sarcoma was diagnosed with both histologic and immunohistochemical confirmation. (C) Images in a 69-year-old female patient with a lump growing on the outside of the left leg. Multiple SWE examinations were performed (please note the high values obtained in the measurements, whereas the color map highlights the stiffness relative to adjacent tissues). SMI showed areas of increased vascularization to target for sampling. Undifferentiated spindle cell sarcoma was diagnosed at biopsy, with residual leiomyosarcoma in the surgical specimen after neoadjuvant therapy. (D) Images in a 56-year-old female patient with a mass in the right thigh. The mass is heterogeneous at both B-mode ultrasound (similar to patient A) and MRI (coronal T2-weighted spectral attenuated inversion recovery [SPAIR]; T1-weighted pre-contrast and postcontrast imaging), which even shows uptake after the administration of paramagnetic contrast material, which is traditionally suggestive of malignancy. Low values at SMI and elastography are suggestive of benignity. Spindle cell lipoma was diagnosed at biopsy, with atypical spindle cell lipomatous tumor in the surgical specimen.](https://img.auntminnie.com/mindful/smg/workspaces/default/uploads/2026/08/images-radiol250278fig2.APCFLSvX6p.jpg?auto=format%2Ccompress&dpr=2&fit=crop&h=167&q=70&w=250)
