29/03/2020 Medical 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 volume and density of calcium measured in the coronary arteries on MDCT examination are quantified with use of a value called theAgatston scoreEuler constantLambert-Beer valueHousfield number2. The two principle advantages that digital fluoroscopy (DF) has over image intensified fluoroscopy (IIF) areAn improved ability to eliminate patient motion and reduce patient exposuresA higher speed of spot image acquisition and the ability to post process the imageImages with long scale contrast and higher spatial resolutionA lower contrast detectability and a reduced noise level3. The sensitivity of most computed radiographic (CR) imaging systems is about the same as (an)800 speed film-screen combo400 speed film-screen combo1000 speed film-screen combo200 speed film-screen combo4. The anode's target Is composed of tungsten.All of the aboveUsually has a copper base.Reaches temperatures in excess of 1000 degrees C during x-ray production.5. Which of the following is an advantage of digital imaging over conventional imagingMore exposure latitudeMore resolutionLess noiseLess exposure time6. The release of trapped energy in a meta-stable F center (Europium electron holes) of a BaFBr (Barium fluorobromide)crystal in the photostimulable phosphor imaging plate (PSP) of a CR imaging system are triggered by the exposure to teh visible (laser) light in theUltraviolet spectrumRed spectrumGreen spectrumBlue-violet spectrum7. On the electromagnetic spectrum, in relation to visible light, x-raysHave a lower frequencyHave a longer wavelength.Have a shorter wavelength.Are closer in wavelength to infrared rays than light waves8. Which of the following is a type of somatic damage caused by radiation?SterilityCataractsNone of the aboveGene mutation9. What is the definition of amorphousA non crystaline state of an otherwise crystaline materialStoring electrical charge for digital viewingThe process of emitting light when stimulated by xraysConverting xrays to light10. Which of the following layers are found on the input side of an image intensifier tube?1. incandescent screen 2. fluoroscent screen 3. photocathode1 and 32 and 31, 2, and 31 and 211. Which of the following CT studies of the head is typically performed without a contrast agent?Coronal scan to r/o pituitary tumorCt of brain to r/o metastatic diseaseCt angiogram for circle of WillisCT of brain to r/o subdural hematoma12. During a spiral or helical CT examination, the scanner acquires dataIn the form of a complete volumetric data setContinuously as the patient travels through the gantryA & COne section at a time13. Gradual decrease in X-ray beam intensity as it passes through material is calledattenuationradioactivityimagingdecay14. Which system is capable of the highest resolutionRadiographic filmFluoroscopic screenIntensifying screenHuman eye15. The most common material used in the formation of the input phosphor of a modern image intensifier isBarium lead sulfateCesium iodideZinc cadmium sulfideCalcium tungstate16. In x-ray tubes, the majority of energy produced by the movement of electrons is in the form ofX-ray energyLightHeatSound17. The most frequently used device for the production of a hard copy image in radiology is aDisplay terminalPhoto-spot cameraLaser printerFloppy disk18. The major factors effecting the amount of brightness gain in an image intensifier areMinification ratio and flux gainsDispersion and retinal gainsFocal and scoptic vision gainsAdaptation and vignestting gains19. A radiograph is synonymous with an x-rayFalseTrue20. Which of the following phases of renal contrast enhancement best demonstrates transitional cell carcinoma (TCC) of the bladder?ExcretoryNephrographicCorticomedullaryEarly arterial21. With either an amorphous selenium or cesium iodide amorphous silicon digital radiographic imaging, the latent image is formed by an electronic signal that is stored byAn array of thin-film transtors (TFT's)A series of quantum detectorsAn array of photodiodesA vidicon television camera tube22. Electrons travelToward the cathode in an x-ray tube.Within the nucleus of an atom.Away from the anode in an x-ray tubeToward the anode in an x-ray tube.23. 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 tissue2 only3 only1, 2, and 31 only24. The negatively charged particle of an atom is theElectronNucleusNeutronProton25. Most modern image intensifiers utilize an input fluorescent screen layer which is composed ofZinc cadmium sulfiedCesium iodideBarium lead sulfateCalcium tungstate26 out of 25Time is Up!
