29/03/2020Medical Imaging(Senior Class Physics Study by Topics) 0Comments by Gate Academy Welcome to your Medical Imaging(Senior Class Physics Study by Topics) NAME EMAIL PHONE NUMBER 1. The spatial resolution of an imaging system is most directly related toVisibility of noisy images.Visibility of anatomical detail.Visibility of soft tissues.Visibility of large low contrast objects.2. The main advantage of a charged-coupled device (CCD) compared to a television camera tube include all the following EXCEPTIt is associated with a reduced contrast resolution or low contrast detectabilityIt is less sensitive to mechanical stressesIt is generally much smallerIt has greater sensitivity at lower light levels3. The vidicon and plumbicon are the most commonly employed ______for a modern radiography departmentTelevision camera tubesImage intensifier tubesCinefluoroscopic tubesFluoroscopic xray tubes4. The individual picture elements, which contribute to the smallest segment of an image matrix are termedBitsBytesPixelsROMs5. In the radiology literature the relationship between the sensitivity and specificity of a diagnostic procedure is generally shown using aMTF curve.True-positive/false-positive ratio.ROC curve.True-negative/false-negative ratio6. In order to accommodate human eye integration time, each frame of a television image must be presented in less than1/2 second1 second1/10 second1/30 second7. Which of the following statements is true?X-rays with longer wavelengths penetrate farther than x-rays with shorter wavelengths.Electromagnetic radiation with lower frequency has more penetrating power through space and matter.X-rays with shorter wavelengths penetrate farther than x-rays with longer wavelengths.Gamma rays are required for the production of a radiograph8. All of the following are true exceptIndividuals younger than 18 years of age may not assist with animal restraint while radiographs are taken.Exposure to radiation can affect the lens by causing cataracts. .Animals cells are not as susceptible to damage from irradiation as human cells. .Radiation can affect the body's ability to produce red and white blood cells9. Which of the following is a type of somatic damage caused by radiation?SterilityCataractsGene mutationNone of the above10. Gradual decrease in X-ray beam intensity as it passes through material is calledattenuationradioactivitydecayimaging11. A small amount of air within the glass envelope is beneficial because it helps to dissipate heat.FalseTrue12. Air trapping within the trachea and bronchial tree may be optimally demonstrated with multiplanar volume reconstruction (MPVRs) of the thorax known asShaded-surface displays (SSDs)Minimum intensity projections (min-IPs)Maximum intensity projections (MIPs)3D volume renderings13. The most frequently used device for the production of a hard copy image in radiology is aDisplay terminalPhoto-spot cameraFloppy diskLaser printer14. The principle advantage of image intensified fluoroscopic technique compared to routine radiographic imaging is that it allows for:1. an increase in the degree of spatial resolution in the images2. a reduction in the amount of exposure the patient will receive 3. the ability to visualize dynamic motion of the tissue1 only1, 2, and 33 only2 only15. Which of the following terms is used to describe a fibroid tumor of the uterus?EndometriosisCystic teratomaLeiomyomaCorpus luteum16. Genetic damage is not detectable until future generations are producedTrueFalse17. Digital imaging in radiography is the general term used to describe a number of techniques that can be used to enable the digital acquisition of the information contained in the radiation beam after it exits the patient. All of the following terms are used to describe these processes EXCEPT?Direct-to-digital radiography (DDR)Indirect electronic radiography (IER)Computed radiography (CR)Digital fluoroscopy (DF)18. Bundles of energy that travel in a wave are calledAll of the abovePhotonsNone of the aboveQuanta19. The volume and density of calcium measured in the coronary arteries on MDCT examination are quantified with use of a value called theAgatston scoreHousfield numberEuler constantLambert-Beer value20. The reduction of brightness at the periphery of image display of an image intensified fluoroscpoe is termedDimunitionLateral dispersionModulation transferVignetting21. After initiation of rapid bolus administration of an iodinated contrast agent, the arterial phase of hepatic contrast enhancement occurs at aproximately:120-180 secs60-70 secs25-35 secs15-20 secs22. Attenuation coefficient of bone is 600 m-¹ for x-rays of energy 20 keV and intensity of beam of x-rays is 20 Wm-², then intensity of beam after passing through a bone of 4mm is2.0 Wm-²3 Wm-²1.8 Wm-²2.5 Wm-²23. The device that receives the image formation radiation exiting the patient, converts it into light, and then increases the brightness of the light is theSpot film cameraCine cameraTelevision monitorImage intensifier24. The still viable ischemic cerebral tissue that surrounds the infarct core in a patient with an acute stroke is termed theThrombolytic zoneIschemic penumbraStrocke volumeHemorrhage focus25. The sensitivity of most computed radiographic (CR) imaging systems is about the same as (an)800 speed film-screen combo1000 speed film-screen combo400 speed film-screen combo200 speed film-screen combo26 out of 25Time is Up!
