Go to the hospital , "CT", " NMR ", "X ray ", "B super " , etc. These medical checks for people who are not familiar with the term , but these looks similar medical imaging equipment , but often people " silly can not tell . " Why sometimes with "CT", sometimes with " NMR " because sicker yet ? In fact , they work different from each division . How to do the right and proper inspection, inspection fees is that people do not waste a topic of concern .
 
Current guests:
 
Beijing Union Medical College Hospital, director of gynecology physician Sun Xiaoguang
 
Peking University First Hospital Radiology Zhang
 
To the hospital, patients often do not know the purpose of the various checks doctor , so that many patients have a misconception that spent the money more than their own ; sometimes doctors may lack experience, or too lazy to check the body for patients directly to prescribe the most expensive check the project, so a preliminary understanding of the characteristics , advantages and scope of these checks will help check the patient time and cost savings.
 
Principle is different , different strengths
 
It is understood , CT (Computed Tomography) means the X -ray computed tomography , X-ray beam is used for tomography unit of the body , the human being to obtain a stereoscopic image detecting section or portion. According to Peking University First Hospital Radiology Physician Zhang introduced , CT can provide complete three-dimensional information by checking the body parts , organs and structures can clearly developed, clearly show the lesions.
 
X-rays are highly penetrating radiation that can penetrate the human body , the use of X-ray photography or inspection methods for internal human body , its principle is to use the penetration of X-rays . When penetrating the human body, the composition is calcium (bone ) , water ( such as blood ) , soft tissue ( muscle ) decreased absorption , etc. , thus showing the basic form of the examination site .
 
With CT, X line different , B -ultrasound is the use of ultrasonic echo principle to generate checks . Beijing Union Medical College Hospital, director of gynecology physician Sun Xiaoguang explained that ultrasound can spread to a certain direction , and can penetrate the body , if you encounter obstacles , it will produce an echo , echo people through this instrument will be collected and displayed on the screen , you can use to understand the internal structure of the object, the secondary diagnosis. B- is a two -dimensional ultrasound information , constitute planar graph reflects the structure of the human body .
 
With Color - Doppler ultrasound technology generation, appeared ultrasound ( color B ) , that is based on black and white plus color Doppler B- on the ultrasound while providing a wealth of information hemodynamic actual application has been widely appreciated and welcome in the current clinical ultrasound is often used .
 
MR, MRI (nuclear magnetic resonance imaging), i.e. MRI . MR imaging is a bio-magnetic spin technique using motion characteristics of nuclear spin in the magnetic field , generated by the excitation RF pulse signal detected by the detector and the computer, and converted into an image .
 
With CT, X -line is different, the biggest advantage of MR is no harm to the human body , there is no ionizing radiation damage . Compared to CT tomography , MR can get a native three-dimensional multi-dimensional cross-sectional image , such as a stereoscopic image of the brain and spinal cord . For the diagnosis of bone , joint, spinal , pelvic organs , prostate , bladder , uterus, ovaries , heart, vascular disease and myocardial infarction is particularly accurate.
 
For the examination of the lungs , or the selection of X-ray CT is superior to MR, examination of the liver, pancreas, adrenal gland, prostate , MR advantageous than CT , but the high cost . In addition, there are metal body , within three months of pregnancy , critically ill patients with a pacemaker or are not doing MR examination.
 
Chest X-ray or CT examination
 
Zhang introduced , chest X-ray to check the heart, lungs , mediastinum , and ribs, pleura , aorta, such as increased lung markings , lung calcification , aortic calcification .
 
Compared to X-ray , chest CT showed more obvious structural clarity , showing the accuracy of lesion detection sensitivity and breast lesions are better than conventional X-ray . Chest CT scan detected a slight favor lesions and subtle lesion , showed lesions characteristic , especially for the early diagnosis of lung cancer have a decisive significance. However, the radiation dose was significantly higher than that of CT X-rays .
 
In addition , X-ray examination is one of the important means of clinical orthopedics , and its effect is to examine the relationship between bone , spine, joints, or without organic disease , a clear lesion location, size , extent and with the surrounding soft tissue , providing a reference for the treatment of . The CT can diagnose bone disease itself , fracture or dislocation, bone and joint and soft tissue lesions .
 
Gallbladder disease Charles B-
 
According to experts , B ultrasound in the diagnosis of gallbladder disease , such as gallstones, there is a high degree of accuracy, the general accuracy rate above 95 %, while the lower CT diagnosis rate .
 
"As of 1 to 5 seconds per CT scan to check for heart and other organs is not easy to get accurate information , " Peking University First Hospital, ultrasound diagnostic center circle Meng Feng explained, " when normal quiet breathing for at least 3 seconds once, by respiratory effects abdominal organs such as the liver , spleen, should the patient stop breathing for a CT examination, small children , mental disorders , pulmonary insufficiency can not match , it can not be checked , do B had no such restrictions . "
 
B -ultrasound examination biliary tract disease is the most common method in clinical , can be diagnosed gallstones, cholecystitis , cancer , etc., and , B- cirrhosis , fatty liver, splenomegaly , liver , intestinal lesions have a higher accuracy rate .
 
In addition, Sun Xiaoguang introduction, B-ultrasound done during pregnancy purpose is to determine whether the gestational age of fetal growth , to determine whether the fetus malformation know whether the fetus in the womb safety .
 
Multi- CT cancer diagnosis
 
It is understood , CT for tumor resolution higher than B-, for 1 to 2 cm of small lumps , CT display rate of 88%, B 48% over ; diagnosis rate for kidney cancer , CT accuracy rate of 90%, B ultra is 44%. CT display kidney, renal pelvis carcinoma fairly accurate , can determine tumor size, extent of invasion , neighboring and distant lymph node metastasis.
 
For liver and pancreas speaking , CT can diagnose liver cancer, liver hemangioma , fatty liver , pancreatic cancer, acute pancreatitis , chronic pancreatitis , and MR examination of primary liver cancer and other diseases fit .
 
CT in the diagnosis of kidney, adrenal gland , bladder and prostate disease is better than ultrasound , CT not only can show the renal pelvis and bladder lumen light , but also show renal and bladder wall , can be diagnosed adrenal tumors , renal subcapsular hemorrhage.
 
MR soft-tissue disorders election
 
MR can check the muscles and soft tissue. MR adoption and X-ray imaging principle is completely different , far from soft tissue resolution than CT and X-ray energy is mainly used to observe the spinal nerve and soft tissue and spinal cord , it can be used to detect and diagnose central nervous system diseases, after lumbar disc protrusion.