X-Ray

 

X-Ray or Roentgen rays.

P.K.Ghatak, MD

No.70.

X-ray was discovered by Wilhelm Roentgen in 1895, and he was the first person to receive the Nobel Prize in Physics in 1801, for this discovery.

History.

Wilhelm Roentgen was born in Prussia and was educated at different schools and universities of Europe and obtained PhD in Physics from the University of Zurich in 1869. Subsequently he moved to the University of Wurzburg in Germany as a Professor in Physics.

He was experimenting with vacuum tubes and external effects of passing an electric discharge through a vacuum tube, He covered the exit port of the vacuum tube with Barium Platinocyanide painted cardboard. While experimenting, he observed his own skeleton was flourishing on the cardboard. A few days later, he took picture of his wife's hand. When she saw her own skeleton, she said: “I saw my death” and X-ray was born.

Madam Marie Curie revolutionized radiology by creating portable X-ray machine which was used in WW I battle fields.

How X-ray is generated in the X-ray clinics:

X- Ray tube is the essential part of the X-ray machine. It is a vacuum tube; two electrical terminals are made of Tungsten or alloy of tungsten are attached. Tungsten can generate electron continuously without melting. The tip of tungsten filament at the cathode end, is capped with Molybdenum or Nickle and it directs electrons hitting the target, the tungsten Anode.

When a high voltage electric charge is applied at the heated cathode, the charged is magnified and it hits the tungsten filament at the anode end. It knocks off an electron from the inner circle of the tungsten atom. The empty space is immediately filled by electrons from the outer circles and energy is generated. This energy is X-ray photons.

By varying the voltage of electricity and using different screens, X-ray of different energy levels can be generated and used in everyday X-rays.

The application of X-ray in the medical field are mainly two categories.

 1. Diagnostic

  2. Therapeutic.

Diagnostic radiology.

Five types of X-rays are used in diagnostic radiology.

1, General x-ray. Use to detect fractures of bones, and dislocation of joints. Bone diseases, chest and abdominal x-rays. Detection of instruments left behind in the abdomen during surgery, lead shots, sharp nails, and fragments of metals.

2, Computerized tomography, better known as CT scan.

3, Fluoroscope. Used for heart characterization, angioplasty. Placing stents, catheters and electronic monitors inside the body.

4, Angiography. Here radio opaque dye is used to delineate blood vessels and block or ruptures. It is modified as Subtraction Angiography by extracting of all other shadows except where the dye is present.

5, Mammography.

Therapeutic use of X-ray and Gama rays.

Gamma rays are high energy X-ray used to treat certain cancers along with other forms of radiotherapist in solid organ cancers and cancers with metastasis.

Radiopaque Substances.

All metals are radiopaque. However, not all are equally opaque, metals like gold, platinum, and tantalum are highly radiopaque, whereas aluminum is difficult to detect.

Bones, and enamel of teeth, lead shots, bullets, sharp nails, broken knife ends, needles and forgotten surgical instruments lodged in abdomen are radiopaque. And also dyes containing iodine used in angiography. These radiopaque substances are also used in radiology. Barium, gadolinium. Microbubbles, Bismuth, Tantalum and Tungsten.

Non- Medical Uses of X-ray.

1, X-ray scanning at airports, government offices, courthouses, shipping terminals, container shipping boxes.

2, Oil and Gas industries. To verify integrity of joints of pipes and hairline fractures of metals.

3, Aviation industries. To check metal fatigue and fractures.

4, Metal industries. To check composition of materials.

5, Electronics. To verify soldering and alignment of parts.

6, Automobile. Rotor, brake shoe and casting of engines.

7, Forestry. Foreign objects embedded in wood.

8, Scientific research.

9, Forensic works.