Ultrasound measurement of fetal posterior fossa at 11 to 13⁺⁶ gestational weeks for screening open spina bifida / 南方医科大学学报

<p><b>OBJECTIVE</b>To establish the normal reference ranges of transabdominal ultrasound measurements of the posterior fossa structure in fetuses at 11 to 13⁺⁶ gestational weeks and explore their clinical value in screening open spina bifida (OSB).</p><p><b>METHODS</b>Between January, 2013 and September, 541 randomly selected normal fetuses underwent nuchal translucency at the gestational age 11 to 13⁺⁶ weeks. The parameters of the posterior fossa were measured in mid-sagittal view of the fetal face and the axial view of the transverse cerebellum insonated through the anterior fontanel by transabdominal ultrasound to establish the normal reference ranges. The measurements were obtained from 3 fetuses with OSB for comparison with the reference ranges.</p><p><b>RESULTS</b>In normal fetuses, the parameters of the posterior fossa measured in the two views showed no significant differences (P>0.05). Two high echogenic lines were observed in normal fetuses, as compared with one in fetuses with OSB representing the posterior border of the brain stem and the anterior border of the fourth ventricle. The line between the posterior border of the fourth ventricle and the anterior border of the cisterna magna was not displayed in fetuses with OSB. The anteroposterior diameters of the brain stem, the fourth ventricle, and cisterna magna all increased in positive correlation with the crown-lump length in normal fetuses. In the 3 OSB fetuses, the anteroposterior diameter of the brain stem exceeded the 95th percentile and the anteroposterior diameter of fourth ventrical-cisterner magena was below the 5th percentile of the reference range for CRL; the brain stem to fourth ventrical-cisterner magena anteroposterior diameter ratio was increased to above 1.</p><p><b>CONCLUSION</b>The established normal reference ranges of the parameters of fetal posterior fossa may provide assistance in early OSB detection. The absence of the posterior border of the fourth ventricle and the anterior border of the cisterna magna and a brainstem to fourth ventrical-cisterner magena anteroposterior diameter ratio greater than 1 can be indicative of OSB at 11 to 13⁺⁶ gestational weeks.</p>

Clinical application of ultrasound three perpendicular planes plus special planes in diagnosis of fetal cleft lip/palate / 中华医学超声杂志（电子版）

Objective To study the clinical significance of the method of three perpendicular planes plus special planes in diagnosing fetal cleft lip /palate by prenatal ultrasound .Methods The approach of three perpendicular planes and special planes were used in diagnosing 110 cases of cleft lip/palate.The sonogram features in each section were analyzed and the outcomes were recorded during follow-up.Results On prenatal ultrsound ,110 cases were examined with three perpendicular planes method .The coronary section could be displayed at 100%cases (110 cases), sagittal section 76.4%cases (84 cases),transverse section 96.4%cases (106 cases) and parasagittal section 25.5%cases (28 cases).With special planes method,74 cases were examined .The section through pyriform aperture could be displayed in 47 cases,in 45 cases on the section through the lower lip/lower jaw/submandibular triangle ,and in 16 cases on the section through the cheek.Combining the three perpendicular planes and special planes methods ,94.5%(104/110) cases could be diagnosed definitely.Six cases (5.5%,6/110) were missed because of fetal position or oligoamnios . Conclusions The method of three perpendicular planes plus special planes is effective in prenatal ultrasound diagnosing cleft lip/palate,which is of great help in improving prenatal diagnostic accuracy of fetal cleft lip/palate.