Sumir Chawla

1. Sumir Chawla

2. Medical imaging is a technique used to create images of the human body in order to reveal, examine and diagnose disease. • In its clinical sense it is carried out by radiologists. 2 Sumir Chawla

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4. This is the oldest and most commonly used form of medical imaging. • X-rays use ionising (high-energy) radiation, which are emitted from the X-ray tube, and are directed by the lead shielding to a specific part of the body. • As the X-rays passes through the body, the photons are absorbed at different rates so that denser parts (bones) absorb more than softer material (heart). • There is a photographic plate below the body, which capture a snapshot of the image, and is directly connected to a computer. 4 Sumir Chawla

5. The ionising radiation can theoretically cause mutations in DNA. • However the doses are very low and similar to levels of background radiation. • Lead shields are used to prevent unnecessary exposure to radiation. • For pregnant women, X-rays that directly target the womb are not recommended. 5 Sumir Chawla

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7. The CT scanner is a large circular machine, which contains an X-ray scanner that rotates around and uses a series of X-ray beams to produce a detailed tomogram (image). • Since there are more beams of radiation, the images are more detailed. • The bed is motorised and you will be moved in and out. • You many be given a contrast medium, either orally or injected, in order to improve the images of certain vessels and tissues. 7 Sumir Chawla

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9. The patient lies inside a large cylindrical magnet. • The body is largely made up of water, and at the nucleus of a hydrogen atom is a proton. • The radio waves affect the body’s atoms, forcing the protons to move in a certain way. When they move back, they transmit a radio signal which can be detected. • Therefore tissues which have the most hydrogen atoms (fatty tissue) look much brighter than those that have fewer ( bones). • The MRI produces detailed picture by changing changing the timing of the radiowave pulses. 9 Sumir Chawla

10. Britain has fewer high-tech medical machines than Estonia and Turkey http://www.telegraph.co.uk/health/healthnews/8413647/Britain-has-fewer-high-tech-medical-machines-than-Estonia-and-Turkey.html

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12. Ultrasound is simply a procedure that creates images using high frequency sound waves, which are directed at a part of the body using transducers. • When the sound waves hit an object, it will bounce back as an echo and is recorded on the computer as an image. 12 Sumir Chawla

13. Angiography

14. Angiography It is a type of X-ray, where a special dye (contrast medium) is injected into to the body in order to allow better examination of blood vessels, since they do not show up clearly on normal X-rays. The patient is numbed by local anaesthetic, and then the catheter is inserted into a blood vessel , usually on the leg. Using the catheter the surgeon will inject the dye which shows up on the angiograms as the blood is pumped around .

15. Thank You