What is ultrasound scanning?

Ultrasound scanning is an imaging diagnostic method. The ultrasonographer would place a probe near the region to be investigated, and the image can be shown on the monitor. Patient would not feel any pain during the procedure.

How does ultrasound scanning differ from other imaging methods?

Traditional imaging methods (e.g. X Ray test) usually involve irradiation. It is particularly undesirable to certain organs (e.g. ovary, fetus). Ultrasound scanning, however, would not emit any irradiation, and it is therefore safer. In addition, ultrasound scanning can produce real-time imaging. It is necessary for the assessment of moving object, like fetus. Therefore, ultrasound scanning is commonly used in the field of obstetrics and gynaecology.

Application of ultrasound scanning in obstetrics and gynaecology

Ultrasonographer would place the probe on the lower abdomen or inside vagina, and the female pelvis can be assessed. The upper genital tract, namely uterus and both ovaries, is included. For pregnant ladies, the fetal structure and fetal growth can also be assessed by ultrasound scanning.

Do I need ultrasound scanning?

There is no evidence supporting the use of routine scanning in regular basis, which is different from other screening tests like cervical smear. For women who feel unwell, they should consult their doctors first. Ultrasound scanning can then be arranged if indicated.

Lady Helen Woo Women Diagnostic and Treatment Centre

Since 1st March 2004, Lady Helen Woo’s Women Diagnostic and Treatment Centre at Tsan Yuk Hospital accept referral for pelvic ultrasound scanning. The procedure is performed by qualified obstetrician and gynaecologist specialists of The University of Hong Kong. After the scanning, the findings and recommendation will be explained in detail. Certain gynaecological tests (e.g. cervical smear taking) can also be arranged in same visit.

What is three-dimensional (3D)/four-dimensional (4D) ultrasound?
3D/4D imaging is a new technology. In contrast to conventional two-dimensional (2D) ultrasound in which an image is displayed in a single plane, 3D ultrasound allows the acquisition of a volume and the display of the volume either as a multi-planar image or as a surface rendered image. In 4D imaging, three-dimensional sonographic images can be displayed continuously.

Applications
In general, there are several studies that suggest that 3D ultrasound is advantageous in demonstrating abnormalities of fetal structures including face, brain, spine and extremities. More information related to an abnormality can be obtained. The use of 3D sonography can help in counselling

Another important application is the calculation of volume measurements. Using 3D ultrasound is more accurate to calculate volume measurement than 2D ultrasound.

Limitations
The quality of 3D images can be affected by artifacts or overlying structures and hence the diagnostic accuracy of fetal abnormalities will be impaired. So, 3D ultrasound examination cannot be performed alone and should be accompanied by a 2D ultrasound examination.

Our Service
Lady Helen WOO Women’s Diagnostic and Treatment Centre is under the Department of Obstetrics and Gynaecology, the University of Hong Kong. All doctors inside the centre are specialists in obstetrics and gynaecologists. We perform 2D and 3D/4D ultrasound examination on a pregnant woman to detect fetal abnormalities, and will provide follow up management. Please click to see the charges.