Why do we need to do bilateral kidney ECT after completing the renal function test?

Many kidney disease patients have undergone renal function tests. Many patients are also advised by doctors to undergo a renal ECT examination after undergoing a renal function test. So what is the difference between the two? Is it necessary to do an ECT examination?

What is ECT?

Renal ECT is a "gold standard" for evaluating renal function that has gradually developed in recent years. During the examination, a radioactive drug needs to be introduced into the patient's body. The radioactive drug will flow between the diseased area and normal tissue in the kidney, forming a difference in radioactive concentration. These differences are then processed by a high-end diagnostic instrument that can dynamically examine bilateral renal function, and these detected differences are imaged to form the examination results in the patient's hands.

Functions of ECT

There are many methods to check glomerular filtration rate, and ECT is one of them. The most accurate is the inulin method, which requires patients to continuously infuse inulin intravenously to maintain a stable inulin plasma concentration and collect urine regularly. However, this method is cumbersome to operate and lacks a simple inulin measurement method, so it is difficult to promote clinically and is often used to evaluate the accuracy of other methods.

The most commonly used method in clinical practice is to estimate the glomerular filtration rate by using a formula to calculate the value of race, gender, serum creatinine, cystatin C, age, height, weight, etc. It is not as accurate as the inulin method, but it is simple to operate and has a lower cost.

ECT examination is very important for the diagnosis of some patients. Its results can not only provide more objective clinical diagnostic data for patients with abnormal renal function, but also monitor the specific location of kidney disease, providing doctors with a positional diagnosis basis. It can objectively reflect the filtration rate of each kidney, the effective blood supply and vascular perfusion of the bilateral glomeruli, and can also provide some reliable evidence of renal function, such as tubular reabsorption, concentration, dilution and whether the urinary tract is unobstructed.

However, it should be noted that not every patient needs renal ECT. Renal ECT is an examination that provides an important reference for formulating treatment plans for patients who need to clarify the unilateral renal filtration rate, renal vascular perfusion, etc. It is also an examination that cannot be replaced by other examinations. ECT is a nuclear medicine examination that is radioactive and expensive. It is not routinely used to evaluate renal function, and its results need to be viewed with caution because the depth of the kidney affects the probe count, and there are also subjective factors in the image processing process.

Is the radiation from ECT harmful?

Millisievert is often used as a unit of radiation dose. If the annual radiation is less than 100 millisieverts, no effect on the human body will be observed; when it is higher than 1000 millisieverts, the human body will be damaged. The radiation dose of an ECT examination is only 2 millisieverts. What is the concept of 2 millisieverts? Under natural conditions, the radiation we are exposed to in the surrounding air is also about 2 millisieverts per year.

Renal ECT is not performed frequently, and a shorter interval between examinations is meaningless. It is usually not necessary to have a follow-up examination until more than a year later. The radiation from this frequency of examinations is safe.