The answer is simple: one of the most common areas on the body to be examined through an ultrasound scan is the abdomen. Depending on the internal structure that is to be scanned, the bladder may need to be full for better visualization. This is because of the nature of sound waves and the way they move though different mediums such as air or fluids. If you have ever had your head underwater, you may have noticed that sounds are more muffled.
In the same way, your bladder acts as a reservoir of fluid, which helps the sound waves bounce back for better visibility and more detailed images. In such cases, you should not empty your bladder, because the extra fluid is necessary for the ultrasound.
Not every ultrasound requires a full bladder. It really depends on the specific body area being imaged. Fluid can increase visibility in some cases, but it can also obstruct the view of some internal structures. There are only a few ultrasound scans that require you to have a full bladder, and your doctor will inform you when the time comes if yours should be full or empty.
Full or Empty Bladder Ultrasound Scans:
- Pregnancy Ultrasound (in early stages) – If the pregnancy is in the early stages, before the 20th to 24th week, then it is necessary to have a full bladder for an ultrasound. This is needed to provide better visualization of the pelvic organs. In the later stages of pregnancy, the fetus moves from the pelvis and is surrounded by amniotic fluid, which serves as a medium for visualization, and it’s no longer necessary to have a full bladder. In fact, in this case, a full bladder may distort the imaging.
- KUB Ultrasound – KUB (Renal Ultrasound) is used to evaluate the urinary tract, including the kidneys, urinary bladder (and ureters if female, the prostate gland and seminal vesicles if the patient is male). KUB ultrasound is used to observe if there are changes in the kidneys that can point to signs of damage, structural abnormalities, and even the presence of kidney stones, tumors, or cysts. Patient must often drink a liter of water one hour before the ultrasound is performed. In this case, the full bladder is necessary to evaluate the urinary bladder properly as the bladder volume will be measured during the scan.
- Transvaginal Ultrasound – Transvaginal ultrasound uses an ultrasound probe or transducer that is inserted into the vagina. The transvaginal ultrasound is used to view female reproductive organs like the uterus, cervix, and ovaries. Although the transvaginal ultrasound can be used during pregnancy to view the placenta or monitor fetal growth in the early stages of pregnancy, it is also used to diagnose ectopic pregnancy, fibroid tumors, and cysts. It can also be used to evaluate infertility, menstrual problems, or pelvic pain. A full bladder in this case would not only distort the image of the uterus but it will also be uncomfortable for the woman. The bladder for this ultrasound needs to be empty.
- An empty or full bladder can mean the difference in how accurate the ultrasound imaging is. Knowing what imaging procedure you are scheduled for can determine whether or not you need to have an empty or full bladder.
If you, or a loved one needs an ultrasound scan, or any other imaging services, or if you would like to schedule an appointment for an ultrasound examination, please call 561-795-5558 today, or go online to make an appointment. Our board-certified radiologists are right here in the Lake Worth, Wellington, Belle Glade, or Royal Palm Beach areas.