Which is more important, renal function test or renal ultrasound?

Renal function tests and renal color ultrasound are two completely different examination methods that play different roles in the diagnosis of kidney disease, but they complement each other.

Renal color ultrasound, also known as renal Doppler color ultrasound, is an examination method that uses medical imaging instruments to detect kidney morphology, position, and local pathological changes. Based on the higher-definition B-ultrasound, the introduction of color Doppler technology can change blood flow imaging from the original black and white to color, making it easier for doctors to evaluate renal blood flow. Not only that, color ultrasound has significantly improved the image resolution compared to B-ultrasound, and it also has tissue harmonic imaging function, which can reduce artifact interference caused by other factors such as gas and fat inside the body, improve clarity, and clearly display the relevant details of changes around and inside the lesions, discover lesions at an earlier stage of the disease, improve the early diagnosis rate, and better examine the relevant parenchyma and ectopic lesions of both kidneys.

Differences between renal ultrasound and renal function test

If the kidney is likened to a filtered water dispenser in the body, then color ultrasound or B-ultrasound examination is like taking a photo of the water dispenser outside the body. It can capture the appearance of the water dispenser and help the repairman determine whether its bucket is deflated, whether its faucet is blocked, or even whether it is missing a screw, which is an organic change. However, by looking at the photos taken by color ultrasound, the repairman cannot determine whether there are bacteria growing in the bucket, whether the filter device in the water dispenser is expired, whether there are impurities in the filtered water, or whether the screws are covered with rust. The kidney function test helps the repairman confirm these details that cannot be captured by taking photos, such as checking the impurities in the water to help determine how long the filtered water dispenser can be used, so as to explore how to extend its life.

It can be said that color ultrasound examination focuses on judging the shape, while renal function examination focuses on judging the quality. The two complement each other and are indispensable, providing sufficient basis for the diagnosis of the patient's condition and the selection of treatment plans.

Renal ultrasound is required before renal puncture

Before patients undergo renal puncture, they must first undergo a renal ultrasound examination. The kidney includes the renal cortex and renal medulla. Generally, renal puncture is to collect renal cortex for examination, because the renal medulla is full of blood vessels. If the medulla is punctured, the patient may experience severe bleeding. Therefore, it is particularly important to check the thickness of the patient's renal parenchyma before puncture. Secondly, some patients have congenital horseshoe kidneys, that is, two kidneys are connected together, or there is only one kidney, which also needs to be confirmed by ultrasound examination in advance. Because the patient has only one kidney, renal puncture is a contraindication. Although the risk of renal puncture is extremely low and generally no adverse reactions will occur, the conditions of each patient vary greatly, and it cannot be completely ruled out that the punctured kidney will not have adverse risks such as renal failure. In addition, not only is an ultrasound examination required before renal puncture, but during renal puncture, in order to accurately see the position and thickness of the puncture needle and the renal cortex, it is also necessary to perform renal puncture more safely and efficiently under the guidance of ultrasound.

Things to note before doing a renal ultrasound

If you are doing an ultrasound examination of the kidneys or ureters, you generally do not need to prepare for anything, nor do you need to fast. You only need to fully expose the examined area, follow the doctor's instructions, and lie on your side or prone. However, if the doctor suspects that the patient has kidney stones, ureteral stones, or bladder stones, the patient needs to drink a lot of water and fill his bladder before the examination.