…
3D and 4D ultrasound
Three-dimensional (3D) ultrasound adds the third dimension to the conventional two-dimensional image; four-dimensional (4D) is the same image in motion. In gynaecology it gives a fuller picture of the womb, the ovaries and the fallopian tubes.
What it adds to the conventional scan
A two-dimensional scan of the womb shows its longitudinal and transverse sections. The picture of the womb and of any lesions therefore remains incomplete. 3D imaging examines the womb in the third dimension as well, giving a much fuller picture of the organ and of any underlying pathology.
In practice this means better visualisation of lesions, a more accurate estimate of their volume, the ability to process the images after the examination is over, and more complete storage of the data. Accurate localisation of a lesion also helps in planning any surgical treatment.
With 3D power Doppler we also assess the network of blood vessels in abnormal tissue. Increased blood supply, known as angiogenesis, is a feature observed in malignant tumours for more than a hundred years. Combined with measurement of blood flow, it is a useful diagnostic clue both for the womb and for the adnexa, that is, the ovaries and fallopian tubes.
In the womb
With 3D imaging we assess the texture of the womb, the presence of fibroids, their exact position within the wall and their relationship to the cavity, as well as the presence of adenomyosis. We check whether the uterine cavity is intact, and identify congenital anomalies such as a bicornuate, septate or didelphys uterus. Endometrial polyps, adhesions, endometrial hyperplasia and endometrial cancer can also be detected.
With 3D saline infusion sonography, that is, instilling saline into the uterine cavity before the transvaginal scan, we can precisely locate findings inside the cavity, such as polyps. With 3D power Doppler we can see the vessel that feeds a polyp.
In the ovaries and fallopian tubes
3D ultrasound allows the ovaries and fallopian tubes to be assessed in all three dimensions at the same time. This lets us investigate simple ovarian cysts, endometriotic cysts, dermoid cysts and findings suspicious of malignancy in more detail. 3D power Doppler shows the blood supply of a mass and helps, as far as possible, in distinguishing benign from malignant.
In diseases of the fallopian tubes, 3D/4D imaging is particularly valuable in cases of hydrosalpinx, pyosalpinx and tubo-ovarian abscess, where it distinguishes the anatomical structures and their relationship to neighbouring organs. In ectopic pregnancy, assessing new blood vessel growth with 3D power Doppler helps to locate the ectopic sac.
Frequently asked questions
Does 3D replace the ordinary scan?
No, it complements it. The two-dimensional scan gives the longitudinal and transverse sections. 3D adds the third dimension, allows a more accurate estimate of the volume of a lesion and lets us process the images after the examination. If it is useful in your case, we will tell you during the scan.
I have fibroids. How does 3D help?
It shows the exact position of each fibroid within the wall of the womb and its relationship to the cavity, as well as its volume. This accuracy matters when any surgical treatment is being planned. Bring your previous scans so that we can compare.
What is 3D saline infusion sonography?
It is a transvaginal scan performed after a small amount of saline has been instilled into the uterine cavity. The saline opens up the cavity, so that findings inside it, such as endometrial polyps, can be located precisely. If you need it, we will explain the procedure before scheduling it.
Can 3D tell whether an ovarian cyst is benign?
3D power Doppler shows the blood supply of a finding, and increased blood supply is a feature linked to malignancy. This helps, as far as possible, in distinguishing benign from malignant, but it does not replace a full work-up. We always discuss the finding with you and, where needed, further investigation follows.