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221 midterm
221 physics midterm
| Question | Answer |
|---|---|
| Fluoroscopy was developed so that radiologists could view ____ images. | dynamic |
| What is the milliamperage used during fluoroscopy? | < 5 mA |
| The image intensifier improved fluoroscopy by increasing image _____. | brightness |
| The ability of the eye to detect differences in brightness levels is termed ____. | contrast perception |
| X-rays that exit the patient and enter the image intensifier first interact with the _____. | input phosphor |
| The input phosphor converts _____ to _____. | x-rays, light |
| The _____ in the image intensifier emits electrons when it is stimulated by light photons. | photocathode |
| Light produced at the output phosphor of the image intensifier has been increased ____ times in intensity. | 50-75 |
| An image intensifier tube is identified by the diameter of its _____. | input phosphor |
| Fluoroscopy for an air contrast barium enema is generally done at _____ kVp. | 80-90 |
| Viewing the fluoroscopic image in magnification mode increases _____. a. contrast resolution b. spatial resolution c. patient dose d.all of the above | d.all of the above |
| Television monitoring allows _____ to be controlled electronically. a. brightness b. contrast c. bandwidth d. both a & b | both a and b |
| Automatic brightness control (ABC) maintains the brightness of the image by varying ____. | kVp and mA |
| The most common risk for the angiography patient is____. | bleeding at the puncture site |
| During an interventional procedure, _____ must be maintained on the patient. a. pulse oximetry b. blood pressure easurement c. electrocardiography d. all of the above | d. all of the above |
| The focal spot used for magnification of small vessels cannot be larger than ____ mm. | 0.3 |
| The size and construction of the ____ determines the anode heat capacity. | anode disk |
| The power rating for an interventional radiography tube should be at least _____ kW. | 80 |
| When imaging a flow of contrast from the abdomen to the feet, a ____ is used. | stepping table |
| The patient table is moved with a floor switch to maintain a _____. | sterile field |
| The _____ artery is the one most often accessed for arteriograms. | femoral |
| A patient must have _____ prior to having an angiography or interventional procedure. a. a history and physical exam b. orders for IV hydration c. a diet of clear liquids d. all of the above | d. all of the above |
| The use of _____ reduces the risk of a drug reaction during angiographic procedures. | nonionic contrast |
| A technologist who passes the ARRT exam in cardiovascular and interventional radiography may add _____ after the RT(R). | CI |
| In soft tissue radiography, all of the tissues being imaged have similar ____. a. effective atomic numbers b. mass densities c. Compton interaction d. all of the above | d. all of the above |
| The breast tissue tends to be increasingly ____ in older women. | fatty |
| About 80% of breast cancer occurs in ____ tissue. | ductal |
| It is recommended that women obtain their first baseline mammogram before the age of ___. | 40 |
| A dedicated mammography unit should have an automatic adjustable ____ device. | compression |
| Every dedicated mammography unit is equipped with a _____. | low ratio grid |
| Breast compression has the advantge of lowering what three things? | patient dose, motion blur, superimpositions |
| Breast compression is used to _____ patient dose and ____ focal spot blur. | lower, reduce |
| Breast compression increases what two things? | contrast resolution, spatial resolution |
| Mammograms are taken with _____ cassettes. | single screen |
| Mammography currently uses ____ film. | single-emulsion |
| Screening mammography requires _____ view(s) of each breast, whereas diagnostic mammography requires _____ views. | 2, 2 or more |
| Computer hardware includes the _____. a. keyboard b. central processing unit c. motherboard d. all of the above | d. all of the above |
| The _____ is an example of computer input hardware. a. printer b. CPU c. mouse d. diskette | c. mouse |
| A tape, diskette, hard disk or optical disk is used to _____. a. archive files b. process data c. convert data d. perform calculations | a. archive files |
| The ____ represents zero or one. | bit |
| In computer language, ____ is a "word". | 2 bytes |
| How many bits make a byte? | 8 |
| Spacial resolution in _____ is pixel limited. | DR |
| Contrast resolution is more important than _____ resolution for soft tissue radiology. | spatial |
| As pixel size is _____, spatial resolution improves but at the expense of the patient radiation dose. | reduced |
| This digital mammogram is repeated several times at different angles. | DMT |
| Digital radiography is NOT more efficient in time, space, and personnel than screen-film radiography. | false |
| Each CT projection is _____. | stored on the computer |
| The first generation of CT use _____ detector(s). | one |
| The principal drawback of the first-generation CT scanner was the _____. | long scanning time |
| The reduction in _____ was the principal advantage of the second-generation CT scanners. | scanning time |
| Many CT x-ray tubes have the capacity for millions of ___ with each exam. | heat units |
| The patient dose in CT is determined by the ____ collimator. | prepatient |
| CT scanners operate on ____ voltage generation. | high frequency |
| The time from the end of CT imaging to image appearance is called the _____ time. a. reconstruction b. translation c. projection d. Hounsfield | reconstruction |
| Each pixel of information in the CT image contains numerical information in ____ units. | Hounsfield |
| Filtered back projection in CT refers to ___. | image reconstruction |
| CT imaging has excellent ____ because of the narrow beam collimation. | contrast resolution |
| The CT scanner must be calibrated so that ____ is at CT number zero. | water |
| A high variation in pixel values in a homogenous phantom is a measure of ____. | image noise |
| Image noise in CT scanning depends on _____. a. pixel size b. detector efficiency c. slice thickness d. all of the above | d. all of the above |
| Noise appears on the image as _____. | graininess |
| Water has a CT number of _____. | 0 |
| Air has a CT number of _____. | -1000 |
| Bone has a CT number of _____. | +3000 |
| Computed radiography cassettes and film/screen cassettes can be used interchangeable with any x-ray imaging system. | true |
| Computed radiography screens respond to radiation with _____. | photostimulable luminescence |
| A photostimulable phosphor in a metastable state will emit light _____ I. immediately II. when stimulated by light III. Over time | I, II and III |
| The computed radiography cassette is called a(n) _____ plate. | imaging |
| The photostimulable phosphor screen is handled in a _____. | reader |
| The four steps of creating an image with computed radiography are _____. | metastable state, stimulate, read, and erase |
| The digital imaging plate can sit for some time after the erase cycle. | false |
| The laser is one of the _____ features of the computed radiography reader. | optical |
| The output signal from the photostimulable phosphor plate is converted from analog to digital by the _____. | computer controls |
| Computed radiography and screen-film imaging both have a(n) _____. | latent image |
| Spatial resolution, contrast resolution, noise, and artifacts are identical in screen-film imaging and computed radiography. | false |
| The principal source of noise in computed radiography is _____. | scatter radiation |
| The 400 speed film-screen systems are still faster than computed radiography image receptors. | false |
| The computed radiography image has _____. a. narrow exposure latitude b. wide exposure latitude c. improved contrast resolution d. both B and C | d. both B and C |
| When switching from screen-film imaging to computed radiography, which step is eliminated? | reloading the cassette |
| _____ is prevented by flooding the erased imaging plate with bright light. | ghosting |
| Computed radiography imaging produces ____ gray levels. | 10,000 |
| Switching from screen-film imaging to computed radiography can _____ patient dose. | reduce |
| The _____ is responsible for supervising quality assurance. | chief radiologist |
| The purpose of a quality assurance program is to maintain the maximum ____ with the minimum ____. | quality of mammogram, patient dose |
| The mammography quality control program is outlined by the _____ | Mammography Quality Standards Act |
| The average glandular dose to mammography patients must be tested annually by the _____. | medical physicist |
| The team of _____ is responsible for mammography quality control. | mammographer, radiologist, medical physicist |
| The medical physicist is responsible for ____ performance evaluation of the imaging equipment. | annual |
| The ____ is responsible for measurement of the mammogram viewing conditions. | medical physicist |
| The medical physicist is responsible for the _____. | annual artifact evaluations |
| The role of medical physicist includes ____. a. doing annual performance evaluations of equipment b. consulting with the mammographers concerning QC c. reviewing the QC records to check for compliance d. all of the above | d. all of the above |
| The mammographer should _____ on a monthly basis. | complete a visual checklist |
| How often should the mammographer perform the quality control test for screen-film contact? | semi-annually |
| Once control valves are set, the daily speed index (mid density) and contrast index (density difference) should not vary more than ____ from the control. | 0.15 |
| The sensitometry strip step with the optical density closest to, but not less than, ____ is the speed index (mid density) step. | 1.2 |
Created by:
twiford
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