2.Why You Shouldn’t Empty Your Bladder When Preparing for an Ultrasound
There are 5 reasons why it is important to have a full bladder for an ultrasound and why you should not empty your bladder when preparing for an ultrasound.
1.A Full Bladder Clears the Way for Ultrasound Waves
A large urine volume causes bladder distention or enlargement. Under normal circumstances, a distended bladder is not a healthy situation. But, for ultrasound scanning, an enlarged full bladder helps produce a clear ultrasound image.
That’s because the enlarged bladder pushes the bowels and other pelvic organs out of the way of ultrasound waves. As such, the waves are transmitted directly to the targeted organs, bringing back precise and clear ultrasound images.
2.Ultrasound Waves Travel Better Through Fluid
Fluid has a higher wave transmission speed and intensity than soft tissue. That explains why ultrasound waves move to and return from the organs faster through a fluid-filled bladder. Also, the fast speed of ultrasound waves through bladder fluid facilitates higher wave intensity.
As a result, the image produced is high-quality, better than what would be if the ultrasound waves had to navigate through dense body tissues.
It's worth noting that the speed of ultrasound waves through a fluid also depends on the probe frequency. For example, portable ultrasound machines have a 2Mhz probe frequency. This frequency can be higher in high-tech brands like the BladGo 2.0, which has a 2.5 MHz probe frequency and produces high-quality images.
3.A Full Bladder Acts as Good Sound Medium
To be transmitted, sound needs a medium to travel through. The medium should have enough density but not too heavy. Gas has little density compared to liquids and solids. So, between urine, body tissues, and gas, body tissues are too dense, gas has insufficient density, while urine (fluid) has the appropriate density for ultrasound wave transmission.
Luckily, gas is not a natural occurrence in the bladder. It only happens with bladder infections and inflammations, as in the case of cystitis. However, having a full bladder before a scan will eliminate the gas in these cases and aid the transmission of ultrasound waves.
4.A Full Bladder has Clearer Urine for Better Visualization
Drinking a lot of water makes your urine clear. When you fill your bladder to prepare for an ultrasound by drinking plenty of water, you create a clear fluid through which the sonographer can clearly see the bladder, its contents, and the organs in the pelvic area.
As a result, the sonographer can position the ultrasound probe in the best spot for a clear image. And that also means precise interpretation of the ultrasound image and proper diagnosis.
Most healthcare practitioners will tell you to drink 1 liter (around 32 ounces) of water before the ultrasound. They will also advise you to empty your bladder 2-3 hours before the ultrasound so you can fill it again for the scan.
5.An Empty Bladder Makes Space for Solid Body Tissue
When you empty your bladder, it shrinks to its usual size. That causes two things to happen:
●The bladder presents as a solid pouch of tissue.
●The pelvic organs around the bladder take up the freed space.
When you take an ultrasound with an empty bladder, the soundwaves will be working with solid body tissues, which are denser. That means poor soundwave transmission and, consequently, a poor ultrasound image.