Comparison of gestational sac volume by 3D-sonography using planimetric, virtual organ computer-aided analysis and extended imaging virtual organ computer-aided analysis methods between 7 and 11 weeks of pregnancy.
OBJECTIVE
To compare different three-dimensional (3D) methods in the assessment of gestational sac volume (GSV).


METHODS
Cross-sectional study involving 74 normal pregnancies between 7 and 11 weeks.


METHODS
Department of Obstetrics, São Paulo Federal University (UNIFESP).


METHODS
GSV was measured through 3D ultrasound using the planimetric, virtual organ computer-aided analysis (VOCAL) and extended imaging virtual organ computer-aided analysis (XI VOCAL) methods. The planimetric method used a sequence of adjacent planes that are 3 mm thick. For the VOCAL methods, six adjacent planes and a 30 degrees rotation were used. A total of 15 adjacent planes were used for the XI VOCAL method. Regression models with a determination coefficient (R(2)) were created to assess the correlation between GSV and gestational age (GA). Intraclass correlation coefficient (ICC) and Bland-Altman graphs were used to assess the correlation between the three methods and ANOVA was used to compare means.


RESULTS
All three methods showed a correlation between GSV and GA (R(2) = 0.65 for XI VOCAL, R(2) = 0.65 for planimetric and R(2) = 0.66 for VOCAL). There was a strong correlation between the three methods (XI VOCAL vs. planimetric ICC = 0.995; XI VOCAL vs. VOCAL ICC = 0.998 and planimetric vs. VOCAL ICC = 0.995) without any significant differences according to the Bland-Altman graphs or ANOVA (p < 0.002).


CONCLUSIONS
The three 3D ultrasound methods used for GSV assessment between 7 and 11 weeks are concordant. These methods can be used interchangeably during the first trimester of pregnancy to measure GSV.
Nardozza
Luciano Marcondes Machado
LM
Department of Obstetrics, São Paulo Federal University , São Paulo, SP, Brazil.
Rolo
Liliam Cristine
LC
Araujo Júnior
Edward
E
Nowak
Paulo Martin
PM
Filho
João Bortoletti
JB
Moron
Antonio Fernandes
AF
D000328:Adult; D000704:Analysis of Variance; D003430:Cross-Sectional Studies; D005260:Female; D005865:Gestational Age; D006801:Humans; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D021621:Imaging, Three-Dimensional / Q000379:methods*; D011247:Pregnancy; D011261:Pregnancy Trimester, First; D012044:Regression Analysis; D016216:Ultrasonography, Prenatal / Q000379:methods*; D014584:User-Computer Interface