Comparison between multiplanar and rendering modes in the assessment of fetal atrioventricular valve areas by 3D/4D ultrasonography Comparação entre os modos multiplanar e renderizado na avaliação da área das valvas atrioventriculares fetais por meio da ultrassonografia 3D/4D

OBJECTIVE: To compare the agreement of multiplanar and rendering modes in the assessment fetal atrioventricular valves (mitral and tricuspid) areas by three-dimensional (3D) ultrasonography using the software spatio-temporal image correlation (STIC). METHODS: We conducted a prospective cross-sectional study with normal pregnant women, with single fetuses, between 18-33 weeks. To measure the areas, we used the plan of four-chamber view. In the case of multiplanar, the plane was rotated on the axis "Z" form the heart to position at 9h. For rendering, the green line (region of interest - ROI) was placed from the atria of the heart perpendicular to the crux. The agreement was assessed by a Bland-Altman (limits of agreement) using the relative difference between the measures: ((rendering mode) - (multiplanar mode)) / (average). RESULTS: 328 fetuses were evaluated. We have not identified the occurrence of systematic error between methods: the average relative difference was 1.62% (-2.07% to 5.32%, confidence interval 95%) in the mitral and 1.77% (- 1.08% to 4.62%) in the tricuspid valve. The limits of agreement between methods were -65.26% to 68.51% for the mitral and -49.91% to 53.45% for the tricuspid. CONCLUSIONS: There was no systematic error between modes and thus the observed values for the area of fetal atrioventricular valves can be used for comparisons needs to be corrected. However, relatively large variations may be observed when repeating the measurement area by different modes.OBJETIVO: Avaliar a concordância entre as medidas das áreas das valvas atrioventriculares (mitral e tricúspide) fetais realizadas por ultrassonografia tridimensional (3D) pelo software spatio-temporal image correlation (STIC) usando os modos multiplanar e renderizado. MÉTODOS: Estudo prospectivo de corte transversal avaliando fetos de gestações únicas, consideradas saudáveis, entre 18 a 33 semanas de idade gestacional. Para a medida das áreas, utilizou-se o plano de quatro câmaras cardíacas. No caso do multiplanar, o plano foi rodado no eixo "z" de forma o coração se dispuser em 9h. Para o renderizado, a linha verde (região de interesse - ROI) foi posicionada a partir dos átrios, perpendicular à cruz do coração. A concordância foi avaliada pelo método de Bland-Altman (limites de concordância) utilizando a diferença relativa entre as medidas: ((modo renderizado) - (modo multiplanar)) / (média).< RESULTADOS: 328 fetos foram avaliados. Não identificamos a ocorrência de erro siste