Important Short Questions and Answers: Radiological Equipments

RADIOLOGICAL EQUIPMENTS

1.  List the important features of CRT.

Size

Operating voltages

Deflection voltages

Viewing screen .

2.  What is meant by deflection sensitivity in CRT?

The deflection sensitivity of the CRT is usually stated as the DC voltage required for each cm of deflection of the spot on the screen.

3.  What is meant by recurrent sweep in CRT?

When the saw tooth, being an AC voltage alternates rapidly, the display occurs respectively, so that a lasting image is seen by the eye. This repeated operation is known as recurrent sweep.

4.     Mention the methods that are used for generating the 2 electron beams within the CRT.

The methods that are used for generating the 2 electron beams within the CRT are the double gun tube and split beam method.

5.  Explain CRO and its function.

Cathode Ray Oscilloscope (CRO) is a very careful and versatile laboratory instrument used for display measurement and analysis of waveforms and other phenomena in electrical and electronic circuits. is in fact a very fast X-Yplotter displaying an input signal versus another signal or time.

6.Name the components of a CRO.

CRO consists of a cathode ray tube (CRT) along with electron gun assembly, deflection plate assembly, fluorescent screen, glass envelope and base.

7.What is an electron gun?

The source of focused and accelerated electron beam is the electron gun.The electron gun which emits electrons and forms them into a beam consists of a heater, a cathode, a grid a pre-accelerating anode, a focusing anode and an accelerating anode.

8.Name the basic circuitry of CRO.

Vertical (Y) deflection system

Horizontal (X) deflection system

Synchronization

Blanking circuit

Intensity (z-axis) modulation

Positioning controls

Focus control

Intensity control

9.Write notes on LVDT

It is the linear variable differential transformer which is used to translate the linear motion into electrical signals. It consists of a single primary winding and 2 secondary winding.

10.What is a digitizer?

It  is  a  digital  encoding  transducer  that  enables  a  linear  or  rotary  displacement  to

be directly converted into digital form without intermediate forms of analog to digital (A/D) conversion.Heart is a pumping organ which eats regularly and continuously for years. Itbeats seventy times a minute at rest. Contraction is systole and relaxation is diastole.

11.Define circulation and respiration?

We can define from the engineering point of view, the circulation is a high resistance circuit with a large pressure gradient between the arteries and veins.The exchange of any gases in any biological process is termed as respiration

12.What is mean by transducer?

It is a device which detects or senses the bio signal and converts it in to an electrical signal for bio signal processing

13.Define strain gauge?

It is a electrical device which is used to measure stress or pressure in terms of strain using the principle of change of resistively due to mechanical stress

14.How are transducer are classified?

They can be classified into different types based on the energy conversion, application and so on. They are two types

Active transducer:

Passive transducer

15.What are applications of X-ray?

1.To visible skeletal structures 2.TO take chest radiograph 3.o identify lung tumors

4.Gastroimtestinal tract and urinary tract can be examined.

16.Define macro shock.

A physiological response to a current applied to the surface of the body that produces unwanted stimulation like tissue injury or muscle contraction is called macro shock.

17.Define micro shock

A physiological response to a current applied to the surface of the heart that results in unnecessary stimulation like muscle contraction or tissue injury

18.What are the devices used to protect against electrical hazards ?

1.Ground fault interrupter 2.Isolation transformer

19.        What are advantages of laser surgery?

High sterile

Highly localized and precise

Non contact and bloodless surgery

  Short period of surgical time and painless surgery

20.Name the types of lasers used in medicine

Pulsed Nd-YaG laser

Continuous wave CO2 laser

Continuous wave organ ion laser

21 .List the advantages of LVDT

High range of displacement measurement

Friction & electrical isolation

Immunity from external effects

High I/p and high sensitivity

Ruggedness

Low hysterisis & low power consumption.

Ionizing Radiation - ionizing radiation is harmful and potentially lethal to living beings but can have health benefits in radiation therapy for the treatment of cancer and thyrotoxicosis.

Deterministic effects- (harmful tissue reactions) due in large part to the killing/ malfunction of cells following high doses

Stochastic effects, i.e., cancer and heritable effects involving either cancer development in exposed individuals owing to mutation of somatic cells or heritable disease in their offspring owing to mutation of reproductive (germ) cells.

Alpha particles - Alpha particles consist of two protons and two neutrons bound together into a particle identical to a helium nucleus

Beta particles - Beta particles are high-energy, high-speed electrons or positrons emitted by certain types of radioactive nuclei, such as potassium-40

Positron - The positron or ant electron is the antiparticle or the antimatter counterpart of the electron.

Cancer - Cancers are growths of cells (cancerous tumours) which are out of control. As a result of this, they do not perform their intended function

Static Imaging - There is a time delay between injecting the tracer and the build-up of radiation in the organ. Static studies are performed on the brain, bone or lungs scans

Collimator - It is placed between the patient and aluminium filter. It is nothing but an aperture