Four-dimensional (4D) ultrasound (real-time volume sonography), which has been used in China since the last decade for the determination of gender as well as for bonding and entertainment of the parents, has become widely available in the rest of the world in this decade. 4D ultrasound or live 3D ultrasound is real-time depiction of the real lifelike foetal images produced by post-processing of grey-scale two-dimensional images. 4D imaging has a role to play in obstetric and gynaecological imaging, and has few other applications (barring telemedicine and education). In gynaecology, it is used for imaging of congenital uterine anomalies, the endometrial cavity, cornual ectopic pregnancy and adnexal lesions, among other things. In obstetrics, its uses include the assessment of foetal anomalies involving the face, brain, thorax, heart, spine and limbs. In most countries, 4D imaging technology is used for “Meet the Baby” ultrasound scans, which allow the parents and relatives to watch the intrauterine foetus in a comfortable family-theatre environment, under the premises of parental– foetal bonding and gender determination. 4D ultrasound has permeated rapidly and most ultrasound clinics offer it with enticing foetal images. Though there are no stand-alone centres offering the examinations, it is available here at Antai.
The difference between a 3D-Ultrasound and a 4D-ultrasound is that a 4D-ultrasound has an extra time dimension in the generated output, resulting in a real-time broadcast of a 3D-ultrasound “moving-image”, much like a video.
In early pregnancy, this diagnostic tool can accurately identify embryonic demise, ectopic pregnancies. In late pregnancy stages towards labour, the information it can provide helps doctors determine the best delivery method for the safety of both mother and child, evaluation of the state of the cervix etc. Early Pregnancy Scan Transvaginal ultrasonography is essential in the assessment of pregnancy of unknown location, which can be due to early pregnancy, miscarriage, or ectopic pregnancy. It is important to avoid making a false-positive diagnosis of miscarriage by using transvaginal sonography, careful measurement of mean sac diameter and crown rump length, and using safe cut-off values of these measurements in defining miscarriage. A recent study showed that amniotic sac sign (the presence of amniotic sac without a live embryo) is a reliable marker of miscarriage. While the presence of an extrauterine gestational sac with yolk sac and/or embryo with or without cardiac activity is indicative of ectopic pregnancy, the presence of an inhomogeneous adnexal mass (‘blob’ sign) or extrauterine sac-like structure (‘bagel’ sign) is very suggestive of a tubal ectopic pregnancy. In women with prior Caesarean section, ultrasound features of Caesarean scar pregnancy including low implantation of the gestational sac within or in close proximity to a Caesarean scar as well as classical signs of placenta accreta spectrum disorders should be looked out for.
Some of the variables that can be checked with this tool are such as:
- Baby’s development progress
- Baby’s heartrate
- Baby’s position in the uterus
- Any potential defects of the baby
- Positions of the placenta
- Neighbouring structures and organs around the baby
4D-ultrasound includes the following features:
- Allows a live feed of the imaging for patients to view
- Patient does not need to hold in urine for this procedure
- 3-dimensional and depth perception view of the embryo/ fetus
- Large stereoscopic visual field for allows for a clearer output
A lot of hospitals tend to dismiss 4D-Ultrasound as being medically unnecessary, costly, or simply a lack of this service; and usually just recommend a standard transvaginal ultrasound. However, this diagnostic tool provides in-depth detail and information about the baby’s development progress, allowing us to closely monitor any potential abnormal growth, fetal demise or threatened miscarriages. Especially for patients with a history of recurrent miscarriages, our 4D-ultrasound can accurately identify the current blood-flow demands of the fetus during pregnancy by looking at the surrounding blood vessels and also accurately observe the shape and size of your uterus (uterine septate, naïve uterus etc), allowing our doctors to anticipate and prevent potential miscarriages.
Our medical staff in Antai Hospital are well trained and highly proficient in this diagnostic tool, providing greater sensitivity and accuracy of the output image, far surpassing the capabilities of a conventional transvaginal ultrasound. It has slowly developed into one of the most significant and irreplaceable parts of our prenatal evaluation procedure.