Skeletal dysplasia may be associated with abnormal lungs volumes of foetus

Skeletal dysplasia may be associated with abnormal foetal lung volumes.Lung volumetry by three dimensional sonography: can it help to identify the lethality of skeletal dysplasia ?? Ans:- . Fetal lung volumetry by 3 D sonography has been performed using two techniques multiplanar and VOCAL . Nomograms for lung volumetry using 3 D sonography are available in the literature . Both the 3D multiplanar and 3 D VOCAL modes can be used to measure fetal lung volumes an observation that was subsequently . A potential advantage of the VOCAL technique is the possibility of obtaining fine contours of the lungs which may be particularly valuable when the outline of the organ is irregular such as in cases of congenital diaphragmatic hernia. In contrast obtaining lung volume measurements using the 3D multiplanar technique is faster taking usually less than 5 minutes to perform . Volumes are best estimated when datasets are acquired using a transverses view of the fetal thorax. compared volumetric measurements of the fetal lungs obtained using the VOCAL method with lung volumes calculated at the time of autopsy in 8 cases of congenital diaphragmatic hernia and in 25 control fetuses without pulmonary malformation. The mean relative error of 3D sonography to estimate the actual lung volume was -7.19 % in cases of congenital diaphragmatic hernia and -0.72 % in normal fetuses .Fetuses with skeletal dysplasia and measured the total lung volume using VOCAL . an abnormally reduced lung volume was defined as below the 5th percentile for gestational age . From 18 fetuses diagnosed at birth with lethal pulmonary hypoplasia. 83% had a total lung volume below the 5th percentile for gestational age. Lung volume more accurately predicted pulmonary hypoplasia than thoracic circumference thoracic circumference / abdominal circumference ratio and thoracic area/ cardiac area ratio .