1818
The Journal of Maternal-Fetal and Neonatal Medicine, 2012; 25(9): 1818–1821
© 2012 Informa UK, Ltd.
ISSN 1476-7058 print/ISSN 1476-4954 online
DOI: 10.3109/14767058.2011.644364
Objective: To assess the fetal lumbosacral spine by three-dimen-
sional (3D) ultrasonography using volume contrast imaging (VCI)
omni view method and compare reproducibility and agreement
between three different measurement techniques: standard
mouse, high definition mouse and pen-tablet. Methods: A
comparative and prospective study with 40 pregnant women
between 20 and 34 + 6 weeks was realized. 3D volume datasets
of the fetal spine were acquired using a convex transabdominal
transducer. Starting scan plane was the coronal section of fetal
lumbosacral spine by VCI-C function. Omni view manual trace
was selected and a parallel plane of fetal spine was drawn
including interest region. Intraclass correlation coefficient (ICC)
was used for reproducibility analysis. The relative difference
between three used techniques was compared by chi-square
test and Fischer test. Results: Pen-tablet showed better reli-
ability (ICC = 0.987). In the relative proportion of differences, this
was significantly higher for the pen-tablet (82.14%; p < 0.01).
In paired comparison, the relative difference was significantly
greater for the pen-tablet (p < 0.01). Conclusion: The pen-tablet
showed to be the most reproductive and concordant method
in the measurement of body vertebral area of fetal lumbosacral
spine by 3D ultrasonography using the VCI.
Keywords: Fetal spine, reliability, agreement, pen-tablet,
three-dimensional ultrasound, volume contrast imaging
Introduction
Spina bifda is the most common congenital abnormality of the
spine with an incidence of 1/1000 live births. Usually detected
at second trimester routine scan, spina bifda is commonly asso-
ciated with Arnold-Chiari II syndrome. Other less common
congenital spine abnormalities, also diagnosed at second trimester
scan, include structural defects of fetal spine, abnormal vertebral
curvature secondary to fetal defects [1,2] and nondevelopment
vertebral defects like caudal regression syndrome and sacral
agenesis [3]. Despite the incidence of hemivetebrae in 1/1000 live
births [4], it is poorly reported at worldwide literature [1,2,4].
Tree-dimensional (3D) ultrasonography increased fetal
vertebral examination providing a coronal view, inaccessible at
two-dimensional (2D) ultrasonography. Wallny et al. [5] frst
reported fetal spine examination by 3D ultrasonography using
multiplanar method. Tese authors used a coronal plane to obtain
spinal canal area. Following, Schild et al. [6] determined lumbo-
sacral vertebral volumes by multiplanar method and established
reference intervals.
Volume contrast imaging (VCI; General Eletric, Medical
System, Kretz, Zipf, Austria) is a new technique that enriches
B mode imaging contrast and resolution of 2D ultrasonography
providing a better evaluation of fetal structures. VCI technique
is a real time volume datasets using small sweep angles. Volume
datasets include surface rendering boxes that can be selected
by operator in 3, 5, 10 or 15 mm options. VCI technique can be
applied on plane A of multiplanar view, like 2D-ultrasonography
sagittal starting scan plane, or on coronal plane (C-plane) that is
orthogonal to original 2D plane [7].
Recently, Omni view (General Eletric, Medical System, Kretz,
Zipf, Austria) sofware, increased examination of nonlinear struc-
tures like fetal spine using linear or curves planes determined by
operator. Tis sofware has successfully been used for fetal brain
evaluation [8]. Despite vertebral area is useful for diagnosis of
vertebral anomalies, especially hemivertebrae, there are no preview
studies until the present time describing VCI technique for vertebral
area evaluation of fetal spine. Of line analysis of fetal spine volumes
datasets using 4D-view sofware (General Eletric, Medical System,
Kretz, Zipf, Austria) usually take place by standard computer
mouse (S-mouse). Tis tool provides 400 points per inch image
resolution. Otherwise, higher resolution tools are available like a
high-defnition mouse (HD-mouse) that provides 1000 points
per inch and the pen-tablet (5080 points per inch). Comparative
studies demonstrate that pen-tablet has a higher accuracy and
speed time contour than S-mouse in human organ measurements
[9,10]. However, there are no literature reports comparing S-mouse
and pen-tablet measurements for fetal sonographic analysis.
Te aim of this study is to evaluate reproducibility and agree-
ment between three diferent measurement techniques S-mouse,
SHORT REPORT
Delineation of vertebral area on the coronal plane using three-
dimensional ultrasonography advanced volume contrast imaging (VCI)
Omni view: intrarater reliability and agreement using standard mouse,
high definition mouse, and pen-tablet
Edward Araujo Júnior
1
, Luis Henrique Martinez
1
, Christiane Simioni
1
, Wellington P. Martins
2,3,4
, Luciano M.
Nardozza
1
& Antonio F. Moron
1
1
Department of Obstetrics, Federal University of São Paulo (UNIFESP), São Paulo, SP, Brazil,
2
Departamento de Ginecologia e
Obstetrícia, Faculdade de Medicina de Ribeirão Preto da Universidade de São Paulo (FMRP-USP), Ribeirão Preto, SP, Brazil,
3
Escola de Ultra-sonografa e Reciclagem Médica de Ribeirão Preto (EURP), Ribeirão Preto, SP, Brazil, and
4
Instituto Nacional
de Ciência e Tecnologia (INCT) de Hormônios e Saúde da Mulher, Ribeirão Preto, SP, Brazil
Correspondence: Edward Araujo Júnior, Department of Obstetrics, Federal University of São Paulo (UNIFESP), Rua Carlos Weber, 950 apto. 113 Visage,
Alto da Lapa, São Paulo–SP, Brazil, CEP 05303-000. Telephone/Fax: 55-11-37965944. E-mail: araujojred@terra.com.br