Chapter 2 Flashcards
“1.What is the frequency of ACR Accreditation?
(A)Every year
(B)Every 2 years
(C)Every 3 years
(D)Every 5 years
“(C) The ACR Accreditation takes place every 3 years. It is recognized as the gold standard and helps assuring the patients that they are getting a high-quality imaging performed and interpreted by qualified individuals. The ACR Accreditation also ensures that the facility meets all equipment quality assurance.”
“2.The material used for the exit port of the mammography tube is necessary because
(A)the intensity of the beam is less on the anode side than on the cathode side
(B)regular glass would harden the emerging beam
(C)the intensity of the beam is more on the anode side than on the cathode side
(D)regular glass would soften the emerging beam”
“(B) Mammography uses very low energy x-ray beams, and it is important that the x-ray tube window does not attenuate the low-energy photons, thereby hardening the beam. The proper filter shapes the emission spectrum of the x-ray beam and makes it compatible with the detector and breast characteristics of each patient. In general, mammography units have beryllium as the port window. Borosilicate glass is another option that can be used.”
“3.The intensity of the x-ray beam from the cathode side of the tube is generally higher because
(A)soft characteristic radiation emerges from the anode side
(B)the cathode side is directed to the thickest part of the breast
(C)the heel effect causes variation in the intensity of the x-ray beam
(D)the heel effect increases the intensity of the beam at the anode side”
“(C) The heel of the anode reduces the intensity of the x-ray beam only on the anode side. When comparing the beam intensity on the cathode side with the anode side, the intensity on the cathode side will be higher. To compensate for this varying intensity, the mammography tube is turned to position the thickest portion of the breast (posterior) at the cathode end of the tube. In general, the smaller the anode angle, the larger is the heel effect because there is an increased absorption of the rays (Fig. 2–1).”
“The design of the lip of the compression paddle (both height and angle along the chest wall) affects all of the following except
(A)it prevents the posterior and axillary fat from overlapping the body of the breast
(B)it allows uniform compression of the posterior breast tissue
(C)it helps increasing the structural strength of the compression paddle
(D)it ensures higher compression of the anterior breast tissue
“(D) Both the height and angle of the compression paddle make a difference in the final image, and the overall design is considered to increase the structural strength of the compression paddle. A compression device with a rounded or gently sloping posterior edge would not allow uniform compression of the posterior area of the breast. The height of the compression reduces the chance of chest tissue overlapping on the mammogram. The design of the lip has a lesser effect on the anterior aspect of the breast (Fig. 2–2).”
“The primary goal of compression is to
(A)reduce the object-to-image detector distance (OID) of the lesion
(B)allow uniform penetration of structures within the breast
(C)reduce the possibility of motion during the exposure
(D)reduce the radiation dose to the breast”
“B) Compression fulfills all the options (A−D ), but its primary goal is to reduce the breast thickness uniformly, separate breast structures, and allow uniform penetration by the x-ray beam.”
“6.What features of the high-transmission cellular (HTC) grid allow these grids to maintain equal or less radiation dose to the patient compared with linear grids?
(A)These grids use lead as the strips and wood as the interspace material
(B)They have copper as the strips and air as the interspace material
(C)They use aluminum as the strips and air as the interspace material
(D)They use wood as the strips and copper as the interspace material”
“(B) HTC grid used in some units has the characteristics of a crossed grid. It can reduce scattered radiation in two directions rather than in one direction as in the linear or focused grid. These grids use copper, rather than lead, as the grid strip, and air, rather than wood or aluminum, as the interspace material. Compared with a linear grid of similar ratio, HTC grids result in equal or less radiation dose to the patient. All grids result in an increased exposure and patient dose but improved contrast (Fig. 2–3).”
“7.The grid ratio can vary in modern mammography units. A common grid ratio used is
(A)8:1
(B)6:1
(C)5:1
(D)2:1”
“(C) Typical grid ratio in mammography is 5:1 (can be as low as 3:1) with frequencies of 30 to 50 line pairs per centimeter (30 lp/cm is most common). Grids in mammography are designed to improve contrast by 15% to 70% depending on the composition and thickness of the breast. Most mammography grids are focused grids with the grid strips angled to match the emerging beam. They are linear grids with carbon fiber or other low-attenuation material as the interspace material. Scatter absorption depends on the grid ratio (grid ratio = height of the lead strips/the distance between the strips [h/d]) and the frequency (number of grid lines per centimeter). Higher ratio means higher scatter absorption but requires higher technical factors. On average, mammography grids have a lower grid ratio compared with general radiography grids (Fig. 2–4).”
“The chest wall edge of the compression paddle should be aligned just beyond the chest wall edge of the detector to
(A)avoid pushing the patient’s chest away and losing breast tissue
(B)properly position and compress the breast
(C)permit uniform exposure and reduce patient discomfort
(D)avoid projecting the chest wall edge of the paddle on the mammogram
“(D) The compression paddle/plate is specifically designed for proper positioning and compression of the breast while reducing discomfort to the patient. The placement of the lip, just beyond the chest wall edge of the detector, prevents the projection of an image of the chest wall edge of the paddle on the mammogram.”
“Which of the following affects focal spot size?
(A)Angle of the anode
(B)A decrease in the source-to-image detector distance (SID)
(C)Decreasing the size of the collimated beam
(D)Changing the relationship between the object-to-image detector distance (OID) and the SID”
“(A) The focal spot is the area where electrons strike on the target. In the design based on the line-focus principle, the target is angled allowing a larger area for the electrons to strike while maintaining a small, effective focal spot size. The effective focal spot is the area projected onto the patient or detector. It is also the value quoted when identifying a small or large focal spot size. The smaller the target angle, the smaller the focal spot size. Although the spatial resolution (the ability of the system to visualize individual microcalcifications as separate entities) is related to the focal spot size, changes in the SID, OID, and size of the collimated field do not affect the focal spot size (Fig. 2–5).”
“Which of the following is the commonly used focal spot size for routine work in mammography?
(A)3 mm
(B)0.3 mm
(C)1 mm
(D)0.1 mm”
“(B) Mammography units generally have two focal spot sizes. The large focal spot size may be 0.4 mm or less (generally 0.3 mm), and the small focal spot size ranges from 0.15 to 0.1 mm (generally 0.1 mm). Routine work uses the large focal spot size. The small focal spot size is used for magnification.”
“11.Which of the following mammography quality control tests is performed as needed?
(A)Phantom image quality
(B)Visual checklist
(C)Repeat analysis
(D)Mammography equipment evaluation (MEE)”
“12.The general criteria to pass the new American College of Radiology—Digital Mammography (ACR DM) phantom require a minimum of _______ masses.
(A)2
(B)3
(C)4
(D)5”
“What is the compression thickness indicator test?
(A)A check of the minimum and maximum compression force on automatic compression
(B)A check of the minimum and maximum compression force on manual compression
(C)A check to ensure that the indicated compression thickness is within normal range
(D)A check of the compression on the breast”
“What is the name given to the test to determine whether the unit has consistent detector signal-to-noise level for all breast thickness?
(A)kVp accuracy
(B)Visual checklist
(C)Acquisition workstation (AWS) QC
(D)AEC test”
“15.A technologist test that is performed semiannually is
(A)phantom image test
(B)visual checklist
(C)compression force test
(D)repeat analysis”
“Repeats are
(A)images taken during a breast stereolocalization
(B)images used for QC
(C)images that involve unnecessary exposure to the patient
(D)all discarded images”
“17.To get a meaningful analysis, the repeat analysis needs a patient volume of at least ____ patients.
(A)200
(B)150
(C)300
(D)250”
“18.Mammography facilities can receive certification from
1.ACR
2.FDA
3.States as Certifiers (SACs)
(A)1 or 2 only
(B)2 or 3 only
(C)1 or 3 only
(D)1, 2, or 3”
“19.Aluminum filtration is likely to be matched with __________ targets.
(A)molybdenum
(B)rhodium
(C)tungsten
(D)beryllium”
“Which of the following visual checklist tests must be performed before clinical use?
(A)Paddles/face shield must not be cracked
(B)Indicators must be working correctly
(C)C-arm motion must be smooth
(D)Collimator light must be working”
“21.What tool is used to evaluate for artifacts?
(A)Phantom
(B)SMPTE test pattern
(C)TG18 test pattern
(D)Monitor calibration tool”
“A single binary digit of data, such as “0” or “1,” is called a
(A)pixel
(B)matrix
(C)bit
(D)byte
“23.In general, higher magnification will require the use of a
(A)larger focal spot size
(B)smaller OID
(C)smaller focal spot size
(D)larger SID
“If the magnification mammography is performed without using a small focal spot size, the resulting image will be magnified
(A)and blurred
(B)and sharply outlined
(C)with increased subject contrast
(D)with increased detail”
