Imaging Techniques
Man has always been inquisitive to know about the interior of his body. But his inquisitiveness often turned into a pressing need when it was found necessary to know the kind of fault, injury or damage that sometimes occurred inside the body. The most common examples of such fault are bone fractures or enlarged lives. In this direction, the first revolutionary technique was that of x-ray. Today techniques are available to get an insight into practically every body organ. These are some of the imaging techniques, which provide a pictorial or graphic representation of the body part suspected to be functioning improperly. The techniques are :
- Electrocardiography (ECG) is a graphic display of electrical voltages produced by heart muscle during cardiac cycle. The waves (P,Q,R,S & T) which have a fixed normal pattern show deviations in abnormal functioning of heart.
- Electro encephalography (EEG) involves recording electrically activity of brain. EEG tracings show wave patterns which are different in different mental states (eye open, eye closed, sleep etc.) EEG is used in detecting several brain disorders such as Epilepsy, Brain infections, metabolic & drug effects on the brain, study of sleep and its disorders and in the determination of brain death.
- Computerized Tomography (CT) uses x-rays. It gives excellent image of internal organs of human body. It is very useful in detecting tumours and other abnormalities. Its repeated exposure is harmful.
- Magnetic Resonance Imaging (MRI) is based on the interaction of molecules, specifically atomic nuclei such as hydrogen with radio frequency field in the presence of an enternal magnetic field. MRI is completely non-invasive, non harmful and no x-rays are used. It gives 2 and 3 dimensional picture of any organ of human body. It is superior to CT and gives good soft tissue contrast. Images of any direction and plane are possible. It is useful for detecting tumours, cancers, infections etc and also used for studying blood flow and in the study of functions of brain, heart etc. Ultrasound imaging makes use of vibrations within 1-15 MHz frequency range. These being inaudible to humans are termed ultrasound. The key material in this technique are certain crystals like lead zirconate. Ultrasound is very useful and is becoming increasingly popular in diagnosing defects in internal organs.
No comments:
Post a Comment