Toshihiro Yanagihara

Three-dimensional sonographic assessment of fetal behavior in the early second trimester of pregnancy.

To evaluate the fetal behavior pattern in the early second trimester of pregnancy by use of specially developed abdominal dynamic three‐dimensional sonography.

Three‐dimensional sonographic features of fetal central nervous system anomaly

Objective. To visualize an intracranial structure of the fetal central nervous system (CNS) anomaly using transabdominal three‐dimensional (3D) sonography.

Four-dimensional sonographic assessment of fetal facial expression early in the third trimester

Objective: To evaluate the characteristic patterns of facial expression in fetuses aged from 28 to 34 weeks using 4‐dimensional (4‐D) ultrasonography.

Three-Dimensional Sonographic Visualization of Fetal Skeleton in the Second Trimester of Pregnancy

Purpose: To demonstrate the potential of using three-dimensional (3D) sonography to reveal anomalies of fetal skeleton. Materials and Methods: Forty-two normal fetuses and 3 anencephalic fetuses from 14 to 27 weeks’ gestation were studied with a specially developed abdominal 3D transducer (3.5 MHz). This imaging system provided conventional two-dimensional (2D) sonographic images and also generated within seconds high-quality 3D images in the surface and transparent mode with no need for an external workstation. Results: Using this imaging system, we obtained 2D and 3D images of fetal skeleton (skull, scapula, spine, rib, humerus, ulna/radius, pelvis, femur, and tibia/fibra) at two gestational ages. The percentages of fetal skeletal visualization at less than 20 weeks of gestation using 3D sonography were 78–100%, whereas those with 2D sonography were all 100%. The percentages of skeletal structures revealed after 20 weeks’ gestation using 3D sonography were 82–100%, whereas those with 2D sonography were all 100%. We found no significant differences in detection rates of the fetal skeleton between 2D and 3D sonography. However, 3D sonographic images generally provided a more comprehensive view of the fetal skeleton than did conventional 2D sonography. In 2 cases with anencephaly, 3D sonography clearly revealed the defect of cranium. Conclusion: The new 3D sonographic technology can generate within seconds high-quality 3D images of the fetal skeleton. The 3D technology seems to perform at least as well as conventional 2D sonography. Our results suggest that 3D sonography has the potential to supplement 2D sonography and might be useful in identifying malformations of the fetal skeleton and chromosomal abnormalities in utero.

Three-dimensional sonographic measurement of liver volume in the small-for-gestational-age fetus

To assess the growth of the fetal liver in normal pregnancies and to evaluate the ability of fetal liver volume measurement for prediction of small‐for‐gestational‐age fetuses.

Maternal Circulating Nitrite Levels Are Decreased in both Normal Normotensive Pregnancies and Pregnancies with Preeclampsia

Objective: To evaluate whether maternal nitric oxide synthesis in pregnancies with preeclampsia is different from that in normal normotensive pregnancies. Materials: Maternal circulating combined nitrate and nitrite levels or nitrite level were compared between 10 normotensive nonpregnant women, 30 normotensive pregnant women (10 first-trimester, 10 second-trimester, and 10 third-trimester pregnancies), 20 normotensive postpartum women (10 at 1 week after delivery, and 10 at 4 weeks after delivery), and 13 preeclamptic women (32 to 40 weeks’ gestation). End-products of nitric oxide synthesis were measured from maternal venous blood samples using a fluorometric assay. Results: Maternal circulating nitrite levels in nonpregnant women (1.13 ± 0.22 μM) were significantly higher than those in the first-trimester pregnant women (0.68 ± 0.13 μM), second-trimester pregnant women (0.65 ± 0.13 μM), third-trimester pregnant women (0.48 ± 0.17 μM), first puerperal week women (0.36 ± 0.16 μM), and fourth puerperal week women (0.67 ± 0.17 μM), respectively (p < 0.05). Maternal circulating nitrite level was decreased with advancing gestation, still remained low just after delivery, and was increased 4 weeks later. There was no significant difference in maternal circulating nitrite level between preeclamptic women (0.40 ± 0.17 μM) and third-trimester pregnant women (0.48 ± 0.17 μM). However, there were no significant differences in maternal circulating combined nitrate and nitrite levels among the gorups. Conclusion: These results suggest that the maternal nitric oxide synthesis is not changed in normal normotensive pregnancies and pregnancies with preeclampsia. However, plasma nitrite level, which has stronger spasmolytic activity than the activity of the nitrate, was decreased in both normal normotensive pregnancies and pregnancies with preeclampsia.

Four-dimensional sonographic assessment of inter-twin contact late in the first trimester

To evaluate the total number of inter‐twin contacts between monochorionic diamniotic (MD) and dichorionic diamniotic (DD) twins using four‐dimensional (4D) sonography late in the first trimester of pregnancy.

Nuchal Translucency Thickness and Fetal Cardiac Flow Velocity in Normal Fetuses at 11–13 Weeks of Gestation

Objective: To investigate the relationship between nuchal translucency thickness and cardiac flow velocity in normal fetuses at 11–13 weeks of gestation. Subjects and Methods: Eighteen normal pregnancies were prospectively studied with transvaginal sonography and pulsed and color Doppler ultrasound. Flow velocities at the fetal atrioventricular valves (mitral and tricuspid valve) and outflow tract levels (ascending aorta and pulmonary artery), and at the descending aorta were recorded. Nuchal translucency thickness was also measured. Results: Mitral peak velocity during early diastolic filling correlated with gestational age. Mitral peak velocities during early diastolic filling and atrial contraction, tricuspid peak velocity during early diastolic filling, ascending aorta peak velocity, and pulmonary artery peak velocity correlated well with nuchal translucency thickness. There was an inverse correlation between umbilical artery pulsatility index and gestational age. Conclusions: These results suggest that the increase of nuchal translucency thickness in normal fetuses at 11–13 weeks of gestation may be the consequence of changes in fetal cardiac functions.

Naturally conceived twin pregnancy with hyperreactio luteinalis, causing hyperandrogenism and maternal virilization

Hyperreactio luteinalis (HL) is a marked cystic enlargement of the ovary due to multiple benign theca lutein cysts (1). It is an uncommon condition, and the cause of this disorder is not well known. HL is believed to be induced by elevated serum levels of human chorionic gonadotropins (hCG) (1). It occurs commonly in pregnant patients with trophoblastic disease, occasionally in multiple pregnancies, and rarely in normal pregnancy (2). Maternal virilization occurs in approximately 15% of cases with HL (3). We herein report a case of HL with maternal virilization in spontaneously conceived twin pregnancy. We also report twoand three-dimensional ultrasonographic and MRI features of HL, and discuss its management.

Four‐dimensional sonography with B‐flow imaging and spatiotemporal image correlation for visualization of the fetal heart

To use B‐flow imaging with 4‐dimensional (4D) sonography and spatiotemporal image correlation (STIC) in the evaluation of normal fetal heart and congenital heart disease during pregnancy.