What's the Difference Between Color Ultrasound and Black and White Ultrasound?

Color ultrasound, built upon the foundation of black and white ultrasound, includes color Doppler flow imaging. This means that in addition to the grayscale ultrasound images, it can also display colors such as red and blue to indicate different blood flow directions and velocities. Compared to traditional black and white ultrasound, color ultrasound offers more functionalities, provides a broader range of diagnostic pathways, and offers more precise disease diagnosis. Its image resolution is also superior to regular black and white ultrasound machines, especially when diagnosing malignant tumors.

Is Ultrasound Safe?

The safety of ultrasound for the human body depends on the ultrasound dose, which is the product of ultrasound intensity and exposure time. High-intensity and prolonged ultrasound exposure can cause harm to the human body or the fetus. Generally, legitimate ultrasound equipment strictly controls the output power of ultrasound, and medical professionals continuously monitor and control the ultrasound dose. Under these conditions, the use of ultrasound for gynecological examinations is safe. So far, standard ultrasound has not shown any significant adverse reactions, and there have been no reports of ultrasound examinations causing fetal abnormalities. However, this does not mean that ultrasound examinations can be done recklessly or in excessive duration and frequency.

Why Is It Necessary to Hold Urine for an Ultrasound Examination?

The uterus and ovaries are situated deep in the pelvic cavity, and the small intestine often extends into the pelvic cavity. During abdominal ultrasound, the peristalsis and contents of the intestines can interfere with the imaging of the uterus and ovaries, causing poor visibility. Therefore, before the examination, it's necessary to drink a large amount of water to fill the bladder, which pushes the intestines upward. If the bladder is not filled, performing an ultrasound may result in overlapping of gas inside the bladder and the uterus, leading to misdiagnosis or missed diagnoses. However, not all gynecological transabdominal ultrasounds require holding urine. For example, after the 8th week of pregnancy, when the uterus has grown and moved into the abdominal cavity and amniotic fluid is present, there's no need to hold urine when observing the fetus.

How Full Should the Bladder Be?

30 minutes to 1 hour before the examination, it is advisable to drink approximately 6-8 cups of water. In general, it's best to hold urine until there is a strong urge to urinate. An excessively full bladder can compress and displace pelvic organs, masking subtle lesions such as small uterine fibroids and ovarian cysts. Signs of pregnancy (such as the gestational sac and embryo) can become flattened and less visible due to this compression. Therefore, both excessive and insufficient urine holding can pose diagnostic challenges and errors.

What Can You Drink to Accelerate Filling the Bladder?

Water alone may take too long to fill the bladder. Drinking caffeinated beverages like coffee and tea, which have a diuretic effect on the body, can expedite the process. So, if you want to speed up the process of filling the bladder, drinking water alone may not be enough. In addition to water, consider drinking some coffee, tea, or other beverages that contain caffeine. After an ultrasound examination, it is recommended to rehydrate with water because the diuretic effect of strong tea or coffee can disrupt the body's fluid balance, leading to cellular dehydration. Besides caffeinated drinks, you can also choose some fruit juices. Moreover, moving around or standing up while drinking water can further facilitate the production of urine.

How Does Transabdominal Ultrasound Differ from Transvaginal Ultrasound?

Transabdominal ultrasound can be cumbersome as it requires holding urine, while transvaginal ultrasound is relatively simple. Both types of ultrasound use the same equipment; the difference lies in the unique probe used. During transvaginal ultrasound, a probe is covered with a thin membrane (usually a condom) and inserted into the vagina for the examination, enabling visualization of pelvic structures.

Why Do Ultrasound Results Differ?

Many people have experienced discrepancies in the position of the uterus between two ultrasound examinations. Sometimes the uterus appears anterior, and at other times, it appears posterior. Is this due to the ultrasound being inaccurate, or does the uterus actually move? In fact, the uterus can have different positions—anterior, middle, or posterior—all of which are considered normal. Generally, the chance of conception is higher when the uterus is in the anterior position and lower when it's in the posterior position. If the tissues surrounding the uterus have not become infected or adhered, the position of the uterus can vary. Therefore, the uterus changing position is a normal occurrence.

大为医疗 (Dawei Medical) is a B-ultrasound machine manufacturer that offers a variety of B-ultrasound and color ultrasound machine models. If you have difficulty choosing, Dawei Medical can provide detailed product information and assist in recommending suitable products. They can even provide hands-on experience to ensure you make a confident purchase."