Rad 113 Midterm Review
If the lead strips are 4.0 mm high and are separated by an interspace of 0.25 mm, what is the grid ratio?
16:1
A satisfactory abdominal radiograph is produced using a 12:1 grid (grid-conversion factor [GCF] = 5.5), 30 mAs, and 85 kVp. A second film is requested using a 16:1 grid (GCF = 6.75). What mAs is needed to produce the second radiograph with comparable radiographic density?
36.8 or 37 mAs
If the lead strips are 2.0 mm high and are separated by an interspace of 0.25 mm, what is the grid ratio?
8:1
The primary source of radiation exposure for occupational personnel is due to A. Compton scatter B. Photoelectric absorption C. Classical scatter D. Coherent scatter
A. Compton scatter
Computer-related communications involving healthcare information such as patient demographics, that are widely adopted throughout medical community adhere to A. HL 7 B. DICOM regulations C. grayscale display standards D. FDA regulations
A. HL 7
All of the following pathological conditions would warrant an increase in exposure EXCEPT A. anorexia nervosa B. osteopetrosis C. ascites D. bronchiectasis
A. anorexia nervosa
DR panels that are connected to the radiographic unit with a "hard wired" connection cable A. are considered to be "tethered" B. can operate throughout the hospital C. operate in a wireless mode D. have excellent positioning flexibility
A. are considered to be "tethered"
An eight-bit word is called a A. byte B. RAM C. bit D. kernel
A. byte
The area of a DR detector DEL that is insensitive to x-ray exposure A. consists of the DEL electronics B. is the same between manufacturers C. has little to do with the fill factor D. all of the above
A. consists of the DEL electronics
DR detector element saturation can result in image A. data drop B. detector shut off to protect the patient C. image reversal due to photon saturation D. improved spatial resolution
A. data drop
The relationship between detector "fill-factor" and spatial resolution is A. direct B. indirect C. not a factor in detector quality D. indirect based on the DEL depth
A. direct
Each pixel in a digital display matrix is located according to its A. electronic address B. voxel position C. DICOM address D. field of view (FOV)
A. electronic address
Attenuation is greater for elements with more ____ with which the photons may interact. A. electrons B. protons C. neutrons D. positrons
A. electrons
Production of a grainy, reticulated image that cannot be corrected in digital postprocessing is the result of A. failure to use a high enough mAs setting B. failure to use a high enough kVp setting C. failure to use the correct algorithm D. failure to use the proper SID.
A. failure to use a high enough mAs setting
If the radiographer applied an ankle LUT to a chest radiograph data set, the image would demonstrate A. high contrast B. low contrast C. very high resolution D. low resolution
A. high contrast
The greatest source of scatter during a radiographic examination is the A. patient B. table top material C. image receptor D. AEC detector
A. patient
As a radiographer, you are looking at an image you had just taken, on the review monitor. The image looks marginally noisy. Your next step should be to A. refer to the Exposure Index# to confirm the image appearance B. return to the patient and repeat the image at a higher kVp C. send the image for interpretation since the radiologist's monitor will correct the noise D. repeat the image at a shorter SID to increase exposure to the detector
A. refer to the Exposure Index# to confirm the image appearance
Grid suppression software is intended to A. remove the visibility of grid lines B. blur out the grid lines through dynamic visual motion C. lower image contrast for the viewer, to reveal low contrast objects D. amplify the visibility of the radiopaque grid strips
A. remove the visibility of grid lines
A common feature between indirect and direct DR technology is A. thin film technology (TFT). B. a scintillation layer C. cassettes. D. imaging plates (IP).
A. thin film technology (TFT).
Which statement about radiographic grids is incorrect? A. Grids may have grid strips running in perpendicular directions B. A grid is a series of lead strips that alternate with radiopaque interspace strips. C. The radiopaque strips are typically made of thin lead D. The interspace strips are usually made of aluminum
B. A grid is a series of lead strips that alternate with radiopaque interspace strips.
Which of the following elements would attenuate a greater percentage of the x-ray beam? A. Hydrogen B. Calcium C. Oxygen D. Carbon
B. Calcium
All of the following are true of Compton scatter EXCEPT A. It contributes no meaningful information the final image B. Its production increases as tissue density increases C. It is a significant contributor to occupational radiation exposure D. It is not a factor of exposure technique selection
B. Its production increases as tissue density increases
Storage of medical images on a short term basis (3-6 months), providing quick, rapid access, is achieved through the use of A. cloud storage B. RAID storage C. digital "jukebox" storage device D. portable, external computer hard drive
B. RAID storage
All of the following are related EXCEPT A. air B. barium C. fat D. bone
B. barium
Computers operate using a(n) ____ language. A. monosyllabic source language B. binary machine C. logarithmic machine D. alphanumeric source language
B. binary machine
Each binary number is called a A. pixel B. bit C. byte D. voxel
B. bit
The window width controls A. darkness B. contrast C. speed D. resolution
B. contrast
As a general rule, a radiographic grid is employed A. for procedures below 60 kVp B. for part thicknesses above 10 cm C. for pediatric studies to improve contrast D. in order to improve positioning latitude
B. for part thicknesses above 10 cm
A graphical analysis of signal values from minimum to maximum values in a data set is termed a A. look up table B. histogram C. pixel spread sheet D. exposure index
B. histogram
Auto-detection technology with a DR panel A. requires a vendor-specific generator communication. B. is often referred to as a trigger panel. C. will not work with automatic exposure control (AEC). D. does not require a charge being placed on the TFT layer.
B. is often referred to as a trigger panel.
Spatial resolution is controlled by A. bit depth B. pixel size C. matrix size D. byte size
B. pixel size
The ratio of the height of the lead strips to the distance between the lead strips is the grid A. selectivity B. ratio C. frequency D. speed
B. ratio
Analog to digital conversion involves two steps. They are quantification and ___________. A. rescaling B. sampling C. pixelization D. toning
B. sampling
When matrix size is increased and pixel size goes down, A. spatial resolution decreases B. spatial resolution increases C. contrast increases D. both A and C
B. spatial resolution increases
Diagnostic medical images would have the highest display resolution if they are A. acquired using a 512 × 1025 × 8 matrix B. stored and retrieved using lossless compression C. acquired at 1024 × 1024 × 10 and archived with lossy compression D. displayed using a 0.5 megapixel monitor
B. stored and retrieved using lossless compression
All of the following will improve DR radiographic image resolution, EXCEPT: A. using a small focal spot B. using lower kVp values C. increasing the SID D. high mA and and shorter exposure times.
B. using lower kVp values
The atomic interaction that produces scatter radiation is A. Bremsstrahlung B. photoelectric C. Compton D. photodisintegration
C. Compton
When the quality of a digital detector is inspected for purchase, the preferred detector for purchase would have a A. DQE of 65 percent and MTF of 0.55. B. DQE of 40 percent and MTF of 0.80. C. DQE of 68 percent and MTF of 0.80. D. DQE of 55 percent and MTF of 0.35.
C. DQE of 68 percent and MTF of 0.80.
Of the choices below, select the choice that is NOT RELATED to the others A. router B. bridge C. LAN D. hub
C. LAN
Select the TRUE statement with regard to complementary metal oxide semiconductor (CMOS) technology. A. They are used with direct DR panels B. They are considered an efficient detector of x-ray energies C. They are not widely used with flat panel DR technology D. They function as the scintillating layer of a direct DR panel
C. They are not widely used with flat panel DR technology
With the perfusion of iodinated contrast material into the kidneys A. a greater degree of Compton scatter is produced from the kidneys B. the kidneys will demonstrate lower subject contrast. C. a greater degree of photoelectric interactions will occur in the kidneys D. there is less distinction between kidney structures
C. a greater degree of photoelectric interactions will occur in the kidneys
Indirect DR uses ________ as the photoconductor material. A. calcium tungstate B. amorphous selenium C. amorphous silicon D. gadolinium oxysulfide
C. amorphous silicon
The purpose of an LUT is to A. determine the exposure index. B. create the histogram C. apply a predetermined scale of contrast to the digital data set. D. perform geometric processing in order to reorient the image on display
C. apply a predetermined scale of contrast to the digital data set.
The purpose of moving the grid during the radiographic exposure is to A. activate the digital detector B. remove unwanted contrast C. blur out the radiopaque strips D. activate the AEC detectors
C. blur out the radiopaque strips
DR panels have published specifications from the manufacturer that outline performance conditions. DR panels are particularly vulnerable to A. extended exposure times B. very high kVp values C. bodily fluids D. sterile fields and temperatures in surgery
C. bodily fluids
In today's complex, medical community, guidelines have been established to assist ordering practitioners when they select medical imaging exams for their patients. Many hospitals have incorporated a ________ to assist with these complex decisions A. DICOM standard B. voice activated dictation system C. clinical decision support system D. electronic medical record system
C. clinical decision support system
Considering the data volume needs of a modern medical imaging department, current Internet-based computing takes advantage of A. RAM storage B. portable storage devices C. cloud computing D. in house archival technologies
C. cloud computing
Grid replacement software is designed to A. hide the grid lines from the viewer B. allow the radiographer to select a grid ratio for postprocessing C. create a nongrid image that looks like a grid was employed D. all of the following
C. create a nongrid image that looks like a grid was employed
In an effort to manage the huge file sizes of medical images in a radiology department, the technology of ___________ is employed A. electronification B. laser digitizing C. data compression D. network protocols
C. data compression
Clinically speaking from a diagnostic viewpoint, the only useful radiation exposure is that radiation A. absorbed in the patient B. produced from Compton interactions C. detected by the receptor D. that traverses through the grid
C. detected by the receptor
Elimination of extraneous light from the edges of a digital radiographic image, is achieved through A. adjusting window and level controls B. the application of veil glare software C. electronic masking D. reassignment of a different look-up table
C. electronic masking
Bone produces less image receptor ____ because it attenuates the x-ray beam more than soft tissue does. A. detail B. contrast C. exposure D. distortion
C. exposure
The number of grid lines per inch is the grid A. ratio B. focus C. frequency D. speed
C. frequency
Angulation across the long axis of a linear grid causes A. grid shadowing B. cross hatched impressions C. grid cut off D. grid convergence
C. grid cut off
In an emergency situation when a radiographic grid is unavailable, a convenient practice to employ, that creates a "grid-like image" when one was not used is A. grid suppression software B. to turn the digital detector over, to use the back of the detector as an absorber C. increase the OID to create an air-gap D. all of the above
C. increase the OID to create an air-gap
Because of its tissue composition, the human breast A. is a high subject contrast structure B. yields a high contrast image C. is a low subject contrast subject D. is considered a high attenuator of xray energy
C. is a low subject contrast subject
A DR detector that is integral to the x-ray system means that the detector A. must be used with a generator interface B. uses wireless technology and is connected to the system by way of a router C. is built in to the design of the x-ray equipment and the radiographer cannot access it. D. is not "hard-wired" to the x-ray unit
C. is built in to the design of the x-ray equipment and the radiographer cannot access it.
A key feature of DR/CR technologies is the increased sensitivity of the receptor to a wider range of remnant radiation energies, when compared to conventional film-screen systems. The feature is referred to as A. DEL spectrum sensing B. diagnostic acuity C. low contrast resolution (LCR) D. modulation transfer function (MTF)
C. low contrast resolution (LCR)
The DICOM standard has A. ensured optimum radiographic image quality B. established minimum ALARA standards C. permitted the acquisition, transfer, storage, and display of medical images D. been adopted by the Federal government as regulated entity
C. permitted the acquisition, transfer, storage, and display of medical images
The component that converts light to an electronic signal in a digital detector is the A. thin film transistor (TFT) B. scintillator C. photoconductor. D. detector element (DEL)
C. photoconductor.
The acronym PACS stands for A. pixel and computed system B. picture and communication system C. picture archiving and communication system D. portable archival computer system
C. picture archiving and communication system
A voxel is different than a pixel in that a voxel A. has only two dimensions B. controls the volume of audio C. possesses a third dimension D. controls the pixel dimensions
C. possesses a third dimension
The Health Insurance Portability and Accountability Act of 1996 (HIPAA) intends to A. streamline patient billing and accounts receivable for the provider B. consolidate major medical insurance companies into regional insurance co-ops C. protect a patient's medical information from unauthorized usage and access D. prevent the duplication of medical procedures and billings without prior authorization
C. protect a patient's medical information from unauthorized usage and access
Which of the following is the greatest attenuator of the x-ray beam? A. pneumonic lung B. pericardial fat C. psoas muscle D. perirenal fat
C. psoas muscle
The primary purpose of using a radiographic grid is to A. intercept remnant radiation B. remove undesired primary photons. C. remove a percentage of scatter photons D. decrease skin exposure to patients
C. remove a percentage of scatter photons
All of the following are related EXCEPT A. clinical fine tuning B. making phantom test exposures C. selecting optimum phantom images from the internet D. clinical trial
C. selecting optimum phantom images from the internet
Gray scale bit depth determines A. pixel size B. pixel pitch C. the number of gray shades D. image resolution
C. the number of gray shades
With the patient in the posterior-anterior projection of the abdomen (prone), A. renal stones would have high resolution B. the lumbar vertebrae would have high resolution C. the psoas muscles would have high resolution D. the anterior ribs would have high resolution
C. the psoas muscles would have high resolution
Essential to ALARA compliance is A. optimizing LUT application B. consistently using the correct focal spot size C. using accurate exposure techniques based upon patient measurement. D. using auto-detection technology DR panels to increase patient comfort
C. using accurate exposure techniques based upon patient measurement.
The shape and distribution of values on an x-ray exposure histogram is specific to selected anatomy and the exposure used for the exam. In the histogram, the data is analyzed to identify the __________. A. line spread function B. point spread function C. values of interest (VOI) D. modulation transfer function (MTF)
C. values of interest (VOI)
Which grid would have the greatest distance between lead strips? A. 15:1 B. 12:1 C. 8:1 D. 5:1
D. 5:1
The service class and object class combine to form a A. DICOM byte B. DICOM bit. C. local area network (LAN). D. SOP unit
D. SOP unit
As kVp increases, A. secondary radiation increases B. scatter radiation increases C. image receptor exposure increases D. all of the above
D. all of the above
Distortion is the misrepresentation of the ____ of an object. A. length B. width C. shape D. all of the above
D. all of the above
The amount of scatter radiation produced increases with a/an A. increase in patient thickness B. larger field size C. decrease in atomic number of tissue D. all of the above
D. all of the above
The recorded detail of a structure is dependent on A. its position within the body. B. the placement of the body in relationship to the IR. C. the size of the part D. all of the above
D. all of the above
The use of a radiographic grid requires A. attention to central ray angulation B. an awareness of the SID C. an increase in exposure factors D. all of the above
D. all of the above
When an x-ray beam passes through the body, A. it will pass through the body unaffected B. it will be absorbed by the body C. it will interact with the body and change direction D. all of the above
D. all of the above
Which is an advantage to the digital environment over film? A. Digital images can be manipulated without re-exposure to patients B. Digital images can be sent to remote locations C. Digital images require less physical storage D. all of the above
D. all of the above
Viewing monitors that are used for final image interpretation A. are typically flat screen displays with 1024 × 1024 × 8 resolution B. are the same quality as the review monitors used by staff radiographers C. offer high-resolution CRT displays of 1-3 megapixels D. are medical grade quality, high resolution, and typically 3-5 megapixels
D. are medical grade quality, high resolution, and typically 3-5 megapixels
The purpose of a charge-couple device (CCD) when used with a DR detector is to A. convert x-ray energy into light energy. B. act as a photoconductor C. collect the light from the scintillator and convert it to electrons D. both B and C
D. both B and C
The window level controls image A. resolution B. contrast C. speed D. brightness
D. brightness
According to the AAPM, a DI value of 4 indicates A. a mid-range exposure that is acceptable, based upon department target values B. underexposure and an image that will demonstrate low brightness C. optimum exposure D. overexposure and an ALARA violation
D. overexposure and an ALARA violation
In a digital detector, the term "fill-factor" refers to the A. size of the DEL B. load capacity of the detector surface C. file size of the total data D. sensing area of the detector element
D. sensing area of the detector element
With a patient in the supine position, the anatomical structure that would demonstrate the greatest subject detail would be the A. nasal bones B. sternum C. liver D. spinous processes
D. spinous processes
What is DICOM? What does DICOM stand for?
Digital imaging and communication in medicine used to produce, store, share, display, send, query, process, retrieve and print medical images, as well as to manage related workflows.
What is SNR? Do we want high or low SNR?
Signal to noise ratio. High SNR
A portable radiograph is taken of a thick body part using a 10:1 stationary grid. The image produced demonstrates a contrast factor (K) of 1.7. A second radiograph is taken with a different grid of unknown specifications, and the K-value is 2.2. What conclusion can you reach regarding the two grids?
The second grid must have had a higher grid ratio and required more technique anything over 1.5 K number is noticeable on the image. the first grid probably did not produce a good image
What is a kernel?
common processing code
If a patient has a large pneumothorax, is that considered an additive or destructive/subtractive condition? WHY?
destructive condition because free air in the pleural cavity displaces normal lung tissue and results in decreased density within the thoracic cavity
What is high pass filtering?
edge enhancement
What is dose creep?
excessive radiation dose that creeps in even when its not supposed to
What is the difference between a hemothorax and a hydrothorax?
hemothorax is blood and hydrothorax is serous fluid
When your patient has an additive condition, what exposure factor must be changed and by how much?
increase kVp 5-15
what is low pass filtering?
smoothing
What is osteomalacia?
softening of the bone
You have discovered two underutilized radiographic grids in your department. Both grids have the same grid ratio, but grid A is noticeably heavier than grid B. What conclusion can you reach regarding these two grids?
these grids are made of two different material
What are the steps in the indirect conversion with a scintillator in DR?
x-ray radiation is converted to light and then the light is converted to digital signal
