Introduction

When taking pets to the hospital for medical examination, the terms "CT", "MRI", "X-ray", "B-ultrasound" and other medical examinations are familiar to pet owners. However, the price gap between these similar-looking medical imaging equipment is quite different. It's so big that it often makes the owner "dumb and confused". Why do we use "CT" sometimes and "MRI" sometimes? Is it because the condition is getting worse? In fact, they work on different principles and have their own division of labor. How to perform correct and appropriate inspections without wasting inspection fees is a topic of concern to pet owners.

When arriving at the hospital, pet owners often do not know the purpose of various examinations prescribed by doctors, which causes many patients to misunderstand and think that they have spent more money; sometimes doctors may lack experience or be too lazy to examine patients and directly prescribe the most expensive ones for them. inspection items. Therefore, a preliminary understanding of the characteristics, advantages and scope of application of these examinations will help patients save examination time and costs.

Different principles and different advantages:

It is understood that CT (Computed Tomography) means X-ray computed tomography, which uses X-ray beams to perform tomography on a certain part of the body to obtain a cross-sectional or three-dimensional image of the examined part of the body. CT can provide complete three-dimensional information of the examined part of the body, clearly visualize organs and structures, and clearly display lesions.

X-rays are highly penetrating rays that can penetrate the body. X-rays are used to inspect the interior of the body for perspective or photography. The principle is to utilize the penetrating effect of X-rays. When penetrating the body, it is absorbed and weakened by calcium-containing components (bones), water (blood, etc.), soft tissues (muscles), etc., so it can show the basic shape of the area being inspected.

Unlike CT and X-ray, B-ultrasound examination uses the principle of ultrasound to produce echo. Ultrasound can propagate in a certain direction and can penetrate objects. If it encounters an obstacle, it will produce an echo. People use instruments to collect this echo and display it on the screen, which can be used to understand the internal structure of the object and assist in diagnosis. B-ultrasound is two-dimensional ultrasound information, which forms a flat figure and reflects the structure of the body.

With the emergence of color-Doppler ultrasound technology, color ultrasound (color B-ultrasound) appeared, that is, color Doppler was added to black-and-white B-ultrasound, and color ultrasound alsoIt also provides rich information on hemodynamics, and its practical application has received widespread attention and welcome. Color ultrasound is often used in clinical practice.

MR, MRI (nuclear magnetic resonance imaging), that is, magnetic resonance. MR is a biomagnetic spin imaging technology that uses the characteristics of the spin motion of atomic nuclei to generate signals after being excited by radio frequency pulses in an external magnetic field, which is detected by a detector and input into a computer, where it is converted into an image.

Unlike CT and X-ray, the biggest advantage of MR is that it does not cause damage to the body and there is no ionizing radiation damage. Compared with CT tomography, MR can obtain multi-directional native three-dimensional cross-sectional imaging, such as three-dimensional images of the brain and spinal cord. It is particularly accurate in diagnosing bones, joints, spinal cord, pelvic organs, prostate, bladder, uterus, ovaries, cardiac and macrovascular diseases and myocardial infarction.

For the examination of the lungs, X-ray or CT is better than MR. For the examination of the liver, pancreas, adrenal gland, and prostate, MR is not superior to CT, but the cost is high. In addition, it is not suitable to undergo MR examination if there are metal objects in the body, those in the early stages of pregnancy, those with pacemakers, or critically ill pets.

X-ray or CT for chest examination:

Chest X-ray can examine the heart, lungs, mediastinum, ribs, pleura, and aorta, such as increased lung markings, pulmonary calcification points, aortic node calcification, etc.

Compared with X-ray, chest CT examination shows more obvious structural clarity, and its sensitivity in detecting chest lesions and accuracy in displaying lesions are better than conventional chest X-ray. Chest CT examination is helpful in detecting minor lesions and hidden lesions and showing the characteristics of the lesions, which is especially decisive for the diagnosis of early-stage lung cancer. However, the radiation dose of CT examination is significantly higher than that of X-ray.

In addition, X-ray is one of the important examination methods in clinical orthopedics. Its effect is to check whether there are organic lesions in bones, spine, joints, etc., to clarify the location, size, extent and relationship with surrounding soft tissues of the lesions, and to provide reference for treatment. . CT can diagnose bone lesions, fractures or dislocations, bone joints and soft tissue lesions, etc.

Gallbladder disease B-ultrasound

According to experts, B-ultrasound is highly accurate in diagnosing gallbladder diseases, such as gallbladder stones, with a general accuracy rate of more than 95%, while the diagnostic accuracy of CT is low.

"Since CT scans every 1 to 5 seconds, it is difficult to obtain accurate information when examining organs such as the heart," explained experts. "Normal animals breathe at least once every 3 seconds when they are calm. Abdominal organs affected by breathing, such as the liver, Spleen, breathing must be suspended during CT examination. Young people, mentally ill people, and those with pulmonary insufficiency cannot cooperate and cannot be examined. There is no such restriction for B-ultrasound."

B-ultrasound examination is the most commonly used method for clinical examination of biliary tract diseases. It can diagnose gallbladder stones, gallbladder inflammation, tumors, etc. Moreover, B-ultrasound has a high accuracy in detecting cirrhosis, fatty liver, splenomegaly, liver cancer, and intestinal lesions. .

In addition, the purpose of B-ultrasound examination during pregnancy is to determine whether the fetal growth is consistent with the gestational age, determine whether the fetus is malformed, and understand whether the fetus is safe in the womb.

CT is commonly used for tumor diagnosis

It is understood that CT has a higher resolution of tumors than B-ultrasound. For small masses of 1 to 2 cm, CT has a display rate of 88%, while B-ultrasound is 48%. For the diagnosis rate of kidney cancer, CT has an accuracy of 90%, while B-ultrasound has a detection rate of 90%. Super is 44%. CT is quite accurate in showing renal cancer and renal pelvis cancer, and can determine the size of the tumor, the extent of infiltration, and adjacent and distant lymph node metastasis.

For the liver and pancreas, CT can diagnose liver cancer, liver hemangioma, fatty liver, pancreatic cancer, acute pancreatitis, chronic pancreatitis, etc., while MR is suitable for examining primary liver cancer and other diseases.

CT is better than ultrasound in diagnosing kidney, adrenal gland, bladder and prostate diseases. CT can not only display the renal pelvis, renal calyces and bladder lumen, but also the renal parenchyma and bladder wall, and can diagnose adrenal tumors, renal subcapsular hemorrhage, etc.

Choose MR for soft tissue diseases:

MR can examine muscles and soft tissues. MR uses a completely different imaging principle from X-ray. The resolution of soft tissue is far higher than that of CT and X-ray. It is mainly used to observe soft tissues in the spinal canal such as nerves and spinal cord. Therefore, it can be used to detect and diagnose central nervous system diseases, Lumbar disc herniation.