What Are the Functions of the Kidneys?
Kidneys are bean-shaped organs present in pairs in the lower abdomen.
Functions of the kidneys are-
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Production of urine by filtering the blood.
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Removing extra fluid and waste materials from the body.
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Regulating blood pressure by releasing hormones.
Kidney functions can be impaired by the presence of calculi, cysts or tumors, abscesses, and the presence of infection, which can be detected using ultrasound. Ultrasound is also called sonography or ultrasonography. Ultrasound uses high-frequency sound waves to create images of the internal structures of the body.
What Is a Kidney Ultrasound?
The study of kidneys is called nephrology, and the physician who specializes in the study of the kidneys is a nephrologist. A kidney ultrasound or renal ultrasound is advised by a nephrologist to study and diagnose if any kind of kidney dysfunction is present.
Ultrasound uses high-frequency sound waves, which are sent by a transducer pressed on the skin. The sound waves move through the body, rebound on the organs, and reflect back to the transducer. These sound waves from the ultrasound are used to create images from inside the kidneys and related organs.
Ultrasound is used in nephrology for scientific studies of the kidneys and urinary tract infection and to guide procedures, such as the insertion of catheters and needles in kidney biopsy (a procedure in which a small piece of the kidney tissue is taken out and studied under a microscope for any changes than normal).
Ultrasound of the kidneys is essential in the diagnosis and management of kidney-related diseases. The kidneys can be examined, and the most pathological changes in the kidneys can be found with ultrasound. It is safe as there is no exposure to the radiation, non-invasive as it does not involve any instrumentation to the body, and easily performed as it can be carried out at the bedside or in the office.
When Is a Kidney Ultrasound Required?
Ultrasound images are used to know-
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The location of the kidneys.
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The size of kidneys - Kidney length in adults, maybe between 10 to 12 cm, but varies with body size.
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The shape of the kidneys.
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Blood flows to the kidneys.
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The urinary space, the vasculature, and the presence of masses.
A nephrologist may recommend a kidney ultrasound when there is a concern about -
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A kidney injury.
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Presence of infection.
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A blockage in the urinary tract.
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Accumulation of urine inside the kidneys - Hydronephrosis.
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Cyst or tumor inside the kidney.
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Kidney stone or renal calculi.
Other reasons include -
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Serve as a guide to inserting a needle for a tissue or fluid kidney biopsy.
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To place a tube into the kidney
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To check for the transplanted kidney.
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To check for the urinary bladder (the organ that stores urine).
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To check if there is fluid collection inside the kidneys.
What Is a Sonogram?
Ultrasound, also called sonography, is a method of using sound waves to create images of the structures inside the body. These images formed from the ultrasound are the sonograms. These echos are recorded and converted into video or images of the tissues and organs selected for examination. The sonogram is then read by a radiologist for the results.
What Is the Procedure of a Kidney Ultrasound?
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The procedure starts with changing the normal outfit into a hospital gown.
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A gel will be applied on the skin where the examination needs to be done. This gel serves to increase contact between the transducer and the skin, improving sound wave transmission into the body. This gel helps to conduct the sound waves produced by the transducer.
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The transducer emits sound waves into the body. These waves will reflect off the kidney and other internal structures and are digitally converted into images and videos of the internal organs.
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The images created by the ultrasound are stored digitally for future reference.
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Multiple images of your bladder, both before and after urination, will be taken. This helps in interpreting the ultrasound data because of the close working relationship between the kidneys and bladder.
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These findings are then sent to a radiologist for interpretation and are received by the consulting physician, which may require one to two days.
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This is a painless procedure that may require 30 minutes to complete.
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After the ultrasound, there is no special type of care required.
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Resume normal diet and activities unless your physician has advised you differently.
How Are Kidney Stones Detected?
Kidney and bladder stones are solid substances made from minerals and proteins found in urine. Certain bladder conditions and urinary tract infections can increase the chance of developing stones. Kidney stones can be diagnosed using:
- Urine Tests - Urine tests are done to detect the presence of blood and minerals forming kidney stones.
- Blood Tests - Blood tests to check elevated levels of uric acid and calcium.
- Imaging Tests -
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Abdominal or pelvic ultrasound.
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Abdominal and pelvic computed tomography (CT).
What Do Colors Mean on Ultrasound?
The color on the ultrasound is color Doppler. It detects movement and is used to know the blood flow in arteries and veins. The different colors indicate in which direction the blood flow is going and also verify the intensity or velocity of the flow. The dark color means the velocity is higher.
The color is blue or red depending on whether the blood movement is towards the transducer or away from it. Blue represents that the blood flow is away, and red represents that the blood flow is towards the transducer. Red means flow in one direction, while blue means flow in the opposite direction.
Color improvement is done using Doppler imaging, where tones of red indicate blood flow away from the transducer and tones of blue indicate blood flow towards it. This color-coding is used to check for any blockages present.
When the Doppler imaging is done in the pelvic region, it can help find:
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Blood flows to the kidneys, ureter, bladder, and pelvic area.
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Blood flows to the baby during pregnancy.
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This test helps best to diagnose deep vein thrombosis (DVT).
Conclusion:
Ultrasound is a non-invasive and painless procedure and does not require any special instruments other than the ultrasound machine. It is a safe procedure as it does not involve any radiation exposure. Doppler imaging is a precise technique to find any obstruction in the blood flow. Kidney stones can be best detected using ultrasound. A kidney ultrasound includes imaging of the kidneys as well as bladder and ureter so the exact location of the kidney stones can be found. No special care, and no diet changes are required after the ultrasound.