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V-MODE APPLIED TO BIOMETRY AND BIOVOLUMETRY.
V-MODE
APPLIED TO BIOMETRY AND BIOVOLUMETRY.
V-Mode ultrasound allows to perform linear and volumetric measurements
the acquired ultrasonographic volume.
(A)
Linear measurements: biometry.
Linear measurements are obtainable selecting the plane - either original
or more often non original and reformatted - in the acquired volume, and
using measuring instruments supplied by the software. A significant volume
allows the acquisition of precise linear measurements: multiplanar rendering
(MP rendering) allows the selection of the elective planes in order to
perform the biometry.
Nuchal
translucency measurement (NT).
Our group has recently applied V-Mode in the measurement of NT in the
screening of chromosomopathy with the aim to select the optimal sagiptal
plane. Initial results of our studies put in evidence the advantages of
multiplanar rendering in:
• transabdominal ultrasound screening (between the 11th and 14th
week gestation). MP rendering allows the selection of the optimal sagiptal
plane and the comparison between the latter and the transversal plane
in order to obtain a precise biometry.
• trans-vaginal ultrasound screening. The volume acquisition allows
the overcoming of problems attached to the position of the fetus in
the uterus by selecting non original and reformatted scans. Limits are
related to the significance of the volume: if the acquisition is obtained
from a fetus in latero-lateral position, the volume will not be significant
and the reformatted non original imaging is poor as a result.
Linear
measuring of the ovaries in women undergoing hyperstimulation.
The acquisition of a significant trans-vaginal volume in 3-6 seconds allows
to reduce the time of examination thus reducing discomfort for the patient.
(B)
Volumetric measurements : biovolumetry.
Volumetric examination allows the measurement of sub-volumes contained
in acquired volume. It is peculiarity of V-Mode being necessary the acquisition
of a ultrasonographic volume which graphically reproduce the real volume
of the fetus. Validity and precision of multiplanar rendering applied
to calculation of sub-volumes has been evaluated by Brenner and coworkers.
The volume of the follicles was calculated a few minutes before the aspiration
of follicular fluid using the multiplanar rendering, and then was compared
to the volume of fluid collected transvaginally by needle: volume measurement
by MP rendering results precise and affordable.
Biovolumetry
and obstetric:
V-Mode
ultrasound results useful in the calculation of:
• fetal cardiac volume (Chang et al);
• fetal pulmonary volume: there are two published studies, the
first carried out by Laundy and the second by Pohls and Rempens;
• fetal hepatic volume. Biometry of hepatic volume is aimed in
order to evaluate and quantify fetal well-being: fetal IUGR infact presents
a reduced growth of abdominal circumference and of fetal hepatic volume.
Brinckly et al in the early 1980's already concluded that: '3D acquisition
of the head and trunk provided more accurate measurements of the fetal
volumes' in order to obtain the more precise measurements of weight.
Chang shows the advantage of V-Mode ultrasound in fetal hepatic biovolumetry.
Biovolumetry
and gynaecology.
Brunner et al have applied 3D ultrasound in volume biometry of over-stimulated
ovaries follicles.
(C)
Measurement of functional parameters.
Our group is evaluating the residual end diastolic volume of the fetal
heart ventricles by selecting precise scans by MP rendering in oreder
to measure the aortic and pulmonary valves area (see heart ESPERT ZONE
> HEART page).
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