SIM1
Digital radiography has the ability to produce 16,000 shades of gray. What appropriate bit depth (dynamic range) does this represent? Multiple choice question 10 bit depth. 12 bit depth. 14 bit depth. 16 bit depth.
2 raised to the fourteenth power = 16,384. Bit depth is the image receptor's ability to display shades of gray. Each pixel has the ability to be turned on (white) or off (black), therefore each bit depth equals 2 raised to the depth power. 2 to the tenth power equals 1,024. 2 to the twelfth power equals 4,096. 2 to the sixteenth power equals 65,536.
Which central ray (CR) angulation is recommended for an anteroposterior (AP) axial projection of the toes? Multiple choice question 5 degrees toward the heel. 15 degrees toward the heel. 30 degrees toward the heel. 40 degrees toward the heel.
A 15-degree angle toward the heel is recommended to demonstrate open metatarsophalangeal (MTP) joint spaces on an AP projection of the toes. The other CR angles described result in closed MTP joint spaces, as well as undesirable shape distortion.
Which projection will most clearly show a clay shoveler's fracture? Multiple choice question Lateral wrist. Oblique hand. Lateral cervical. Axiolateral hip.
A clay shoveler's fracture results from a cervical hyperflexion mechanism that causes avulsion of the spinous processes of C6 through T1. This finding is best demonstrated on the lateral cervical spine projection. This injury will not be demonstrated in the areas of the upper or lower extremities.
Whatroute of transmission is responsible for transmitting a disease to a patient through an improperly cleaned x-ray table? A. Direct contact. B. Vector. C. Fomite. D. Vehicle.
A fomite is an innanimate object, such as an x-ray table, that transmits a disease. Direct contract requires transmitting a disease through direct contact between a host and an infected individual. A vector requires contact with an insect carrier of a disease. a vehicle is any medium such as food or water that transports a disease.
A fixed kilovolts peak (kVp)-variable milliampere (mA) chart recommends exposure factors of 70 kVp and 32 mAs for an anteroposterior (AP) abdomen projection on an average-size patient. Based on this chart, which fixed kVp technique is most appropriate for an AP projection of a double contrast upper gastrointestinal (UGI) image? A. 90 kVp, 8 mAs. B. 80 kVp, 16 mAs. C. 70 kVp, 42 mAs. D. 60 kVp, 64 mAs.
A kVp range of 90 to 100 is recommended for adequate penetration of the barium-filled AP stomach and small intestines on a double contrast UGI series. According to the 15% kVp rule, a technique of 90 kVp and 8 mAs will provide density that is comparable to the recommended non contrast technique, while affording enough penetration to visualize the barium-coated surfaces. Although digital systems are capable of adjusting contrast levels post-exposure, low kVp techniques will result in under-penetration as well as increased dose.
Which will increase the appearance of noise in a digital image, assuming only the named factor in each response is changed? Multiple choice question Short SID. Large matrix. Increased mAs. High kVp technique.
A large matrix contains a large amount of small pixels, resulting in fewer photons per pixel and a greater likelihood for image noise. A short SID increases the intensity of the beam, which results in less image noise. Increasing mA and kVp increases the amount of photons that reach the image receptor, which also decreases image noise.
How does a radiographer maximize signal to digital image receptors? (Select the three that apply.) A. Longer exposure time. B. Lower milliamperage (mA). C. Compression of the body part. D. Longer source to image receptor distance (SID). E. Shorter source to image receptor distance (SID).
A longer exposure time increases photon flux to the image receptor. Compression of the body part makes it thinner, increasing photon flux to the image receptor. A shorter SID increases photon flux to the receptor by inverse square law. On the other hand, reducing mA lowers the photon flux to the image receptor. A longer SID reduces photon flux by inverse square law. Since photon flux (exposure) is the major variable in Signal to Noise Ratio (SNR). This is why radiographers are so often tempted to overexpose patients in digital radiography.
What should be demonstrated on a properly exposed supine image of the abdomen? A. Shadow of the spleen. B. Perirenal fat. C. Kidneys. D. Bladder.
A properly exposed supine radiographic image of the abdomen should demonstrate the following five things: the inferior liver shadow, transverse processes of the lumbar spine, pubic symphysis, and perirenal fat. The shadow of the spleen may be seen, but is not a requirement. The kidneys are not visualized, but rather the shadow of the kidneys that is created by the perirenal fat. The bladder is not visualized, but identifying the pubic symphysis demonstrates the entirety of the bladder region.
Which position/projection of the elbow best demonstrates the trochlear notch of the ulna? A. Anteroposterior (AP). B. Anteroposterior (AP), internal oblique. C. Anteroposterior (AP), external oblique. D. Lateral, lateromedial projection.
A properly positioned lateral elbow radiograph demonstrates the distal humerus seated within the trochlear notch of the proximal ulna. AP projections of the elbow do not demonstrate this appearance.
What is the annual effective dose limit in millisievert (mSv) for a radiography student who is less than 18-years-old? Multiple choice question 0.1 mSv. 0.5 mSv. 1 mSv. 5 mSv.
A radiography student under the age of 18 can only have a maximum of 1 mSv per year. 0.1 mSv and 0.5 mSv do not represent any annual effective dose limits. 5 mSv is the annual effective dose limit for the general public (infrequently exposed).
Which type of exposure technique chart would allow the radiographer to make small, fine adjustments for orthopedic work? Multiple choice question Fixed kilovolts peak (kVp). Variable kilovolts peak (kVp). Automatic exposure control (AEC). Anatomically programmed radiography (APR).
A variable kVp exposure system will allow the radiographer to make fine changes in technique for small body parts. A fixed kVp exposure system is good for most other radiography and decreases patient exposure. AEC can be used only for bucky work. APR gives an average technique for body part and may be a combination of manual technique and AEC.
If all the bucky digital images from one radiographic room seem to appear excessively noisy, what might the radiographer suspect? Multiple choice question The x-ray room may need recalibration. There is a problem with the digital receptor. It could be an anomaly and should continue to be monitored. The automatic exposure control (AEC) is set at an inappropriate speed class.
AEC can be set for any "speed" of image receptor. If images using AEC are underexposed, it is possible that the AEC is set for a "faster" system than the one in current use. If all images display quantum mottle, the x-ray output should be checked, not recalibrated, if AEC proves to be properly set after all. Problems with digital receptors usually occur in small areas of the matrix and not the entire image receptor. Any results out of the ordinary should be investigated, not just monitored.
How are automatic exposure control (AEC) devices for mammography different than those used with diagnostic radiography? A. Fewer detectors are available. B. Greater accuracy is required. C. Detector location is fixed. D. Exposures are indirectly terminated.
AEC devices for mammography differ from those used in diagnostic radiography in that greater accuracy is required. AEC devices in mammography must be capable of maintaining optical density (OD) within +/- 0.15; AEC in diagnostic radiography must hold OD to +/- 0.20. AEC devices in mammography often provide more cells, not fewer, to image varying densities of breast tissue. Detector location can be moved to image nipple and chest wall breast locations with greater accuracy. Exposures are terminated directly by the AEC just as they are in routine diagnostic exams.
For which lumbar spine projections should a shaped contact shield be applied to provide protection for the gonads of a male patient? (Select the three that apply.) A. Anteroposterior (AP). B. Anteroposterior (AP) oblique, right posterior oblique position. C. L5-S1 lateral spot. D. Posteroanterior (PA) oblique, left anterior oblique position. E. Posteroanterior (PA).
AP, AP oblique, and lateral projections can be obtained with a contact shield covering the male gonads. Shaped contact shields do not provide protection during PA and PA oblique projections because the x-ray beam enters the posterior surface of the patient.
Which practices are considered violations of the Health Insurance Portability and Accountability Act (HIPAA)? (Select the two that apply.) A. Displaying images on a PACS monitor where others may see. B. Looking up test results of a family member. C. Posting a sign-in sheet in the reception area. D. Accessing medical images of a coworker. E. Calling out a patient's name in the waiting room.
Accessing private health information of a family member or a coworker is considered a violation of the HIPPA Privacy Rule. The other instances described are examples of incidental disclosures and are permitted under the Privacy Rule.
According to "Merrill's Atlas," where should the central ray (CR) be centered to best demonstrate the rami for a posteroanterior (PA) mandible projection? Multiple choice question The point of contact between the lips. The occlusal plane. The acanthion. The glabella.
According to "Merrill's Atlas," the CR should be centered to the acanthion. Other sources list the point of contact between the lips or the occlusal plane. The glabella is simply erroneous.
According to the American Heart Association (AHA) guidelines, which is the correct rate of chest compressions when administering cardiopulmonary resuscitation (CPR) to a 6-month-old patient? A. At least 60 per minute. B. At least 100 per minute. C. At least 120 per minute. D. At least 80 per minute.
According to the 2010 CPR guidelines from the American Heart Association, therecommended rate of chest compressions is at least 100 per minute for all patients, regardless of age. All other rates listed are not consistent with AHA guidelines for CPR.
An image of the abdomen demonstrates appropriate density and scale of contrast, but motion blur is present due to peristalsis. If the original image was obtained with a 200 milliampere (mA) station and an exposure time of 0.35 seconds, which set of technical factors will produce a comparable exposure while minimizing motion artifact? A. 500 mA and 0.14 seconds. B. 400 mA and 0.35 seconds. C. 300 mA and 0.23 seconds. D. 100 mA and 0.7 seconds.
According to the reciprocity law, an increase in mA with a compensatory decrease in time will produce the same radiographic density while reducing the effects of involuntary motion. In this instance, a 500 mA station and an exposure time of 0.14 seconds will produce the same mAs (density) at less than half the exposure time. An mA of 400 at 0.35 seconds represents an increase in mAs with the same exposure time.An mA of 300 at 0.23 seconds will produce the same density, but is more likely to result in motion blur than a time of 0.14 seconds. An mA of 100 at 0.7 seconds will produce the same density, but with a greater likelihood of motion blur.
Which effect does a step-up transformer have on voltage and current? A. Voltage and current are decreased. B. Voltage and current are increased. C. Voltage is increased and current is decreased. D. Voltage is decreased and current is increased.
According to the transformer law, a step-up transformer increases voltage and decreases current. A step-down transformer decreases voltage and increases current. The other choices provided represent violations of the transformer law.
Which method should be the first choice to reduce exposure to the reproductive organs in every radiographic exam? A. Collimate to include only the anatomy of interest. B. Use gonadal shielding. C. Reduce exposure time. D. Employ high kilovolts peak (kVp) techniques.
Adequate and precise collimation of the x-ray beam to include only the anatomy of interest is the most effective method of gonadal protection, regardless of the anatomy of interest. Gonadal shielding is generally recommended only when it does not obstruct the area of interest. Reducing exposure time is not practical for all exams, for example, those for which a breathing technique is recommended. High kVp techniques are not suitable for all exams, particularly for thin body parts or low subject contrast.
How does aliasing appear radiographically when using computed radiography (CR)? A. A white line along the length of the image. B. Two superimposed images, slightly out of alignment. C. Black lines, branching across the image. D. Excessive noise on the image.
Aliasing results in two superimposed images, slightly out of alignment. A white line across the image may be dirt in the IR or dust in the reader. Black lines branching across an image may be due to static. Excessive noise has a number of causes, including using small milliampere-seconds (mAs).
What is the maximum allowable tabletop intensity in high-level control (HLC) fluoroscopic procedures? A. 50 mGya/min. B. 100 mGya/min. C. 150 mGya/min. D. 200 mGya/min.
Although the intensity of the x-ray exposure at the tabletop should not exceed 100 mGya/min for fluoroscopic procedures without HLC mode, the maximum allowable tabletop intensity for HLC fluoroscopy is 200 mGya/min. The other values given are below the maximum allowable intensity.
Which radiographic appearance results when the anterior surface of the patient's elbow is rotated 45 degrees medially for an anteroposterior (AP) elbow projection? A. The olecranon process is seen in profile. B. The radial head and neck are free of superimposition. C. The coronoid process is seen in profile. D. The medial and lateral epicondyles are superimposed.
An AP medial oblique elbow projection demonstrates the coronoid process in profile. The other appearances described are not seen on a standard medial oblique elbow image.
On a radiograph of a shoulder, the greater tubercle is visualized in profile. Which projection was taken? Multiple choice question Anteroposterior (AP), internal rotation. Anteroposterior (AP), external rotation. Scapular-Y. Transthoracic lateral (Lawrence method).
An AP with the arm in external rotation visualizes the greater tubercle in profile. The internal rotation does not demonstrate the greater tubercle in profile. The scapular-Y will make the scapula appear like a "Y" in shape and may not well visualize the greater tubercle. The transthoracic lateral (Lawrence method) projection is a trauma position and will visualize the affected shoulder through the chest.
breathing technique is planned for a right anterior oblique (RAO) sternum radiograph. The intended exposure is 50 milliampere-seconds (mAs) at 75 kilovolts peak (kVp) at 100 centimeter source to image receptor distance (SID). Which milliampere (mA) station is preferred, assuming the radiographer ensures exposure occurs during the act of inspiration? Multiple choice question 10. 25. 50. 100.
An exposure time of 1 second is optimal for breathing technique, provided the radiographer ensures exposure occurs during the act of inspiration. To obtain 50 mAs at an exposure time of 1 second means use of the 50 mA station. 10 mA is too small, as this would cause an exposure time of 5 seconds...a virtual guarantee of sternal motion on the image. Even 25 (B) mA is too small as this means 2 seconds of exposure, again producing likely motion. 100 mA is too large, as the exposure time is 0.5 second, too short to be useful at blurring ribs and lung markings.
Which best describes anode heel effect? Multiple choice question A phenomenon where x-ray intensity is greater under the cathode. A phenomenon where x-ray intensity is greater under the anode. Absorption of part of the x-ray beam by the focusing cup. Absorption of part of the x-ray beam by the target track.
Anode heel effect is a phenomenon where x-ray intensity is greater under the cathode, but actually somewhat less under the anode, not greater under the anode. Part of the x-ray beam is not absorbed by the focusing cup. The target track does not absorb part of the beam. The heel of the anode (outside the target track, part of the molybdenum anode disk) actually absorbs some of the x-ray emission from the target track, which is in that direction. That absorption by the anode heel produces the phenomenon, the anode heel effect.
Which pathologic condition will result in the greatest attenuation of the beam? Multiple choice question Ascites. Emphysema. Gout. Multiple Myeloma.
Ascites, or fluid in the abdomen, causes increased beam attentuation. Emphysema, gout, and multiple myeloma are destructive conditions because they decrease attenuation of the beam.
In cassette-based computed radiography (CR) systems, the photostimulable phosphor plate is made of which material? A. Cesium iodide. B. Barium fluorohalide. C. Amorphous silicon. D. Calcium tungstate.
Barium fluorohalide is commonly used as the phosphor in CR imaging plates. Cesium iodide is used as the phosphor layer for indirect capture digital radiography (DR) systems. Amorphous silicon is used in direct capture DR systems. Calcium tungstate was used in conventional radiographic screens before the development of rare earth screens.
Which image, when performed according to normal standards, will demonstrate the greatest magnification of the anatomy of interest? A. Anteroposterior (AP) lumbar spine. B. Posteroanterior (PA) hand. C. Lateral cervical spine. D. Lateral forearm.
Because lateral cervical spine xrays typically have large object-to-image-receptor (OID) distances, the cervical spine anatomy is magnified. The OID for an AP lumbar spine may be minimized by asking the patient to bend his or her knees to bring the spine closer to the image receptor (IR). PA hands and lateral forearms have minimal magnification.
How can the contrast scale be modified on a digital image? (Select the two that apply.) Multiple selection question Decrease the kilovolts peak (kVp). Collimate more closely. Alter the window width. Alter the window level. Increase the kilovolts peak (kVp).
Close collimation positively impacts the contrast scale on digital imaging by decreasing the amount of scatter radiation produced. Altering the window width can change the contrast scale in digital imaging to demonstrate a wide dynamic range of grays. Altering the kVp does not impact the displayed image contrast because the histogram selected determines the optimum contrast for the selected body part. Altering the window level changes the displayed brightness.
Which is described as an interaction between an x-ray photon and an outer-shell electron, weakly bound to an atom of the absorbing medium? Multiple choice question Coherent scattering. Compton scattering. Photoelectric effect. Pair production.
Compton scattering interactions occur between x-ray photons and loosely bound outer-shell electrons. Coherent scatter causes the whole atom to be excited momentarily. In pair production, the incoming x-ray photon interacts with the nucleus of an atom. Photoelectric interactions occur in the inner shell of the absorbing medium, usually the K-shell.
Place the following types of dosimeters in proper order from least radiosensitive to most radiosensitive. 1.Optically stimulated luminescent dosimeter (OSL).<br/> 2. Thermoluminescent dosimeter (TLD).<br/> 3. Pocket ionization chamber.<br/> 4. Film badge.<br/>
Correct Answer: 1. Film badge.<br/> 2. Thermoluminescent dosimeter (TLD).<br/> 3. Optically stimulated luminescent dosimeter (OSL).<br/> 4. Pocket ionization chamber.<br/> *Film badges are the least radiosensitive dosimeter, detecting doses to 10 millirem (mrem). TLDs can detect down to 5 mrem, while OSLs can detect 1 mrem. Pocket ionization chambers are the most radiosensitive.
How will the dose area product (DAP) be affected during a 4 Roentgen exposure if the collimated field is reduced from 8 X 8 cm to 4 X 4 cm? A. DAP will remain the same. B. DAP will be 1/2 of the original. C. DAP will be 1/4 of the original. D. DAP will double.
DAP is a measure of the dose received per square centimeter of collimated field. An 8 X 8 cm field yields a DAP of 256 R/cm2 (8 X 8 X 4 R). At a 4 roentgen dose, a 4 X 4 cm field yields aDAP of 64 R/cm2 (4 X 4 X 4 R). None of the other options are mathematically plausible.
In which way can the radiographer minimize motion due to peristalsis? Multiple choice question Decrease exposure time. Give the patient explicit instructions. Expose the radiograph on expiration. Expose the radiograph on inspiration.
Decreasing exposure time will decrease the effects of motion on the radiograph. Because peristalsis is involuntary, giving the patient explicit instructions (B) will not decrease motion. Again, because of peristalsis, it does not matter whether the radiograph is exposed on expiration or inspiration (D).
Which type of pathology is defined as inflammation of an outpouching of the colon? A. Diverticulosis. B. Colitis. C. Ulcerative colitis. D. Diverticulitis.
Diverticulitis is an inflammation of the outpouching of the colon. Diverticulosis is simply the condition of having outpouchings in the colon. Colitis is a general inflammation of the colon. Ulcerative colitis is an inflammatory lesion in the colon.
Which x-ray tube orientation represents the correct application of the anode heel effect? A. The cathode end is positioned toward the knee for an anteroposterior (AP) femur projection. B. The anode end is positioned toward the elbow for a lateral forearm projection. C. The cathode end is positioned toward the elbow for a lateral humerus projection. D. The anode end is positioned toward the head for an anteroposterior (AP) thoracic spine projection.
Due to the angle of the target, the x-ray beam has greater intensity at the cathode end. Placing the anode end toward the head for an AP thoracic spine projection results in a more uniform radiographic density. The other examples describe incorrect applications of the anode heel effect.
Which are by-products of photoelectric absorption? A. Photoelectron and Compton scattered electrons. B. Low-energy scattered x-ray photon and characteristic photon. C. Low-energy scattered x-ray photon and Compton scattered electron. D. Photoelectron and characteristic photon.
During the process of photoelectric absorption, a photoelectron and a characteristic photon are created and emitted. Compton scattered electrons and low-energy scattered x-ray photons are not created in this process.
Which post-processing techniques may be used with digital imaging? (Select the three that apply.) A. Electronic masking. B. Smoothing. C. Automatic brightness control (ABC). D. Quantum noise. E. Filtering.
Electronic masking is one word for post-exposure collimation. Smoothing refers to low-pass filtering, which removes high-frequency noise. Filtering, which may refer to high- or low-pass filtering, averages pixel strength. ABC is used in fluoroscopy. Quantum noise is seen in digital imaging, but is not a post-processing technique.
What could cause a computed radiography image with very noticeable lines uniformly in the same direction over the entire image? (Select the three that apply.) Multiple selection question Cassette exposed to the wrong side. Cassette was exposed to background radiation. Noise resulting from the plate reader electronics. Grid used with grid frequency equal to the image reader's laser scan lines. Grid utilized with grid lines running parallel to the laser scan lines of the image reader device.
Electronic noise can produce noticeable white or dark lines of varying thicknesses running in the same direction across an image. Utilizing a grid with a frequency the same as the laser raster pattern, or a grid with the lead strips running parallel to the direction of the laser raster pattern, will create a Moire artifact. A cassette exposed from the backside will create an image with a fine wide grid covering the image. A cassette exposed to background radiation will display a degraded image.
During an esophagram, which action may demonstrate esophageal varices? Multiple choice question Instruct the patient to do the Valsalva maneuver. Have the patient swallow a barium tablet. Position the table in the Fowler position. Perform images in the upright position.
Esophageal varices may be demonstrated when the patient performs the Valsalva maneuver. Barium tablets are used to demonstrate esophageal strictures. Esophageal varices are best demonstrated when barium has to flow against gravity. Therefore, the Fowler position and the upright position should not be used.
Which is the proper amount and direction of heel rotation recommended for a posteroanterior (PA) projection of the patella? A. 5 to 10 degrees laterally. B. 5 to 10 degrees medially. C. 10 to 15 degrees laterally. D. 10 to 15 degrees medially.
For a PA projection of the patella, the heel is rotated 5 to 10 degrees laterally so that the plane of the patella is parallel with the IR. Other options represent excessive or otherwise incorrect rotation, which would likely result in foreshortening of the patella.
At which location is the ionization chamber located in an automatic exposure control (AEC) device? A. Between and the x-ray tube and the patient. B. Between the grid and the image receptor (IR). C. Between the patient and the image receptor (IR). D. Between the image receptor (IR) and the wall.
For automatic exposure control, the ionization chamber is placed between the gird and the IR so the x-rays can interact with the chamber, which creates an electrical charge. This charge becomes a signal to terminate the exposure. The other locations aren't appropriate ionization chamber locations.
Which characteristics are true of both x-rays and gamma rays? (Select the three that apply.) Multiple selection question Are low linear energy transfer (LET) radiation. Are electromagnetic radiation. Originate outside of the nucleus. Damage biologic tissue through indirect action. Possess the same frequencies and energy.
Gamma rays and x-rays are considered low LET radiation. Both are sparsely ionizing and do not give up their energy readily. X-rays and gamma rays are considered electromagnetic radiation. When either x-rays or gamma rays cause damage to biologic tissue, it typically occurs through an indirect action and can often be reversed by repair enzymes within the cell. Gamma rays originate in the nucleus, while X-rays originate in the electron shells. Gamma rays possess higher frequency than X-rays and therefore higher energy photons.
For which purpose is gonadal shielding recommended? A. To reduce the probability of transient infertility. B. To reduce the probability of sterility. C. To reduce the probability of genetic mutations. D. To reduce the population genetically significant dose.
Gonadal shielding is recommended for some patients in order to reduce the probability of genetic mutations. Transient infertility is not necessarily caused by exposure to radiation. Sterility can be caused by a dose of 500 to 600 rad, which is not typical in diagnostic radiography. The genetically significant dose is the average annual dose gonadal equivalent dose to members of the population.
A trauma patient arrives to the emergency department unconscious with tachycardia and hypotension. The patient has lost a significant volume of blood. The patient is experiencing which condition? A. Cardiogenic shock. B. Neurogenic shock. C. Hypovolemic shock. D. Septic shock.
Hypovolemic shock occurs when blood fails to flow to vital organs. Cardiogenic shock occurs when heart function is disrupted. Neurogenic shock occurs from trauma to the central nervous system. Septic shock results from a microbial infection of the blood.
When using digital imaging, which has the greatest influence on contrast? A. Kilovolts peak (kVp). B. Milliampere-seconds (mAs). C. Lookup table (LUT). D. Modulation transfer function (MTF).
In digital imaging, a LUT (C) assigns predetermined grayscale values. KVp (A) controls contrast in film-screen imaging. MAs (B) does not affect contrast. MTF (D) is related to spatial resolution.
In the event that a pregnant patient is inadvertently irradiated, who should perform the calculations necessary to determine fetal dose? Multiple choice question Radiographer performing the examination. Imaging department manager. Radiologic physicist. Radiologist.
In the event that a pregnant patient is inadvertently irradiated, the radiologic physicist should perform the calculations necessary to determine fetal dose, not the radiographer performing the examination, the imaging department manager, or the radiologist.
What is the maximum leakage radiation quantity permitted for a diagnostic x-ray tube housing when measured 1 meter from the housing? Multiple choice question 1 mGya/hour. 10 mGya/hour. 100 mGya/hour. 1000 mGya/hour.
Leakage radiation must be less than 1mGya/hour 1 meter from the source. While the leakage radiation may be less than that, it cannot exceed 1.
Which advantage does a 500 milliampere (mA) station have over a 200 mA station? Multiple choice question Longer exposure time. Greater visibility of detail. Higher load on the x-ray tube. Increased photon flux to the image receptor (IR).
Increased photon flux is obtained with 500 mA. A longer exposure time is not needed for a given mAs value with 500 mA. Greater visibility of detail is obtained with a small focal spot...definitely not a feature of a 500 mA station. There is a higher load on the x-ray tube with 500 mA, but this is not advantageous.
Which advantage is gained by increasing the standard source to image receptor distance (SID) from 40 inches to 48 inches? A. Increased radiographic contrast. B. Increased signal to noise ratio (SNR). C. Increased image resolution. D. Increased x-ray tube life.
Increasing the SID will increase resolution by reducing image magnification and penumbra. Radiographic contrast is primarily controlled by factors other than SID (kilovolts peak in conventional film-screen systems, and automatic rescaling in digital radiography systems). Increasing the standard SID should not affect SNR, since a commensurate increase in exposure factors will accompany this change. Due to the necessary increase in exposure factors, x-ray tube life (D) is adversely affected.
Which procedure is most effective for reducing localized image blurring caused by involuntary patient motion? A. Take exposures during suspended respiration. B. Use immobilization techniques. C. Decrease exposure times. D. Clearly explain each procedure.
Involuntary motion, often due to peristalsis or tremors, may result in localized image unsharpness. This type of motion artifact is most effectively minimized by short exposure times. The other methods described are effective for preventing more generalized blurring caused by voluntary motion. (Although breathing is mostly under autonomic control,respiration can normally be controlled temporarily by will, and is therefore considered a voluntary activity for the duration of a typical x-ray exposure.)
Why is it important for the radiographer to observe the milliampere seconds (mAs) readout at the end of each exposure when using automatic exposure control (AEC)? Multiple choice question This value may be used to estimate patient dose. It provides a visual cue to release the exposure switch. It provides an indication that the proper amount of exposure was used. This value may be used as a basis for calculating manual techniques.
It is important for the radiographer to make note of the mAs readout for each exposure, as this value can be used as a point of reference for the calculation of manual techniques. Digital radiography (DR) systems use dose area product (DAP) to estimate patient dose, since mAs does not directly correlate with radiation dose. The exposure switch is released at the end of the exposure, which is signaled by an audible sound; when the sound ends, the exposure ends and the switch may be released. The amount of exposure is indicated by the exposure index in computed radiography (cassette-based) systems, and by DAP in DR systems.
According to the Food and Drug Administration (FDA), what is the maximum air kerma rate for fixed fluoroscopic units? A. 2 cGy/min. B. 4 cGy/min. C. 5 cGy/min. D. 10 cGy/min.
Kerma measures kinetic energy released to electrons in air and has replaced dose area product on many modern fluoroscopy units. The FDA (which controls the manufacture of x-ray equipment) limits exposure to no more the 10 cGy/min, unless the unit has high-level control features. The other answers are incorrect rates.
Which type of radiation causes cells to demonstrate the greatest increase in radiosensitivity when in an highly oxygenated state? Multiple choice question Ions of heavy nuclei. Diagnostic x-rays. Alpha particles. Fast neutrons.
Low Linear Energy Transfer (LET) radiation demonstrates the greatest increase in radiosensitivity in an oxygenated state, and diagnostic x-rays are the only low LET option. Ions of heavy nuclei, alpha particles, and fast neutrons are high LET radiations.
Which factor will have the greatest impact on decreasing recorded detail or spatial resolution? A. Focal spot size. B. Motion. C. Source-to-image-receptor-distance (SID). D. Object-to-image-receptor-distance (OID).
Motion will cause the greatest decline in spatial resolution or recorded detail. Larger focal spot sizes decrease recorded detail, but not to the extent that motion does. Smaller SIDs and larger OIDS cause degraded recorded detail as well.
Which factors will impact the radiation barrier calculations for an x-ray room? (Select the three that apply.) A. People in adjoining rooms. B. Number of repeat exposures. C. Types of exams performed in the room. D. How often the room is used. E. Number of occupational workers in the room.
Occupancy factor in adjoining rooms, types of exams performed, and how often the room is in use are factors used to calculate barrier thickness. Number of repeated exposures is not a consideration, since this is unknown prior to shielding the room. Number of occupational workers in the room also has no bearing on shielding.
A radiographer critiques an anteroposterior (AP) ankle projection. The medial mortise joint is open while the lateral mortise joint is closed. How can the radiographer adjust the ankle to correct this image? Multiple choice question Dorsiflex the foot. No correction needed. Increase internal rotation. Increase external rotation.
On an AP ankle projection, the medial mortise joint should be open and the lateral mortise joint should be closed so no correction is needed. If the foot is dorsiflexed too much, the joint may appear narrower. Internal or external rotation would obscure the medial mortise joint.
Which is an advantage of digital imaging systems compared to traditional film-screen systems? A. Reduced image noise. B. Higher spatial resolution. C. Less sensitivity to scatter. D. Improved contrast resolution.
One advantage digital systems have over film-screen receptors is improved contrast resolution, or a greater ability to distinguish between structures of similar densities (this is also termed improved dynamic range). Digital systems are no less susceptible to image noise than traditional film-based systems. Spatial resolution is decreased relative to film-screen imaging due to the size of the pixel. Digital systems are more sensitive to scatter radiation than film-screen receptors.
Which statement describes the presence of patient rotation on a lateral cervical spine image? A. Anterior to posterior displacement of zygapophyseal joints. B. Superior to inferior displacement of zygapophyseal joints. C. Anterior to posterior narrowing of intervertebral foramina. D. Superior to inferior narrowing of intervertebral foramina.
Patient rotation on a lateral cervical spine image will be evident when the zygapophyseal joints are displaced anterior to posterior. Superior to inferior displacement of zygapophyseal joints indicates tilting of the patient. Intervertebral foramina are only demonstrated on oblique cervical spine images.
A radiographer prepares to do an excretory urogram on a patient who has a history of asthma. At this institution, policies are in place to select the type of contrast used based on the needs of the patient. Which type of contrast should be used in this situation? Multiple choice question Iodinated, ionic. Iodinated, nonionic. The exam would be cancelled. This condition does not define type of contrast given.
Patients who have a history of asthma are at an increased risk for contrast reactions. Because nonionic contrast agents are considered to be safer, the local policy would indicate use of iodinated, nonionic contrast media. Iodinated, ionic contrast media are widely believed to increase the incidence of contrast reactions. Unless there are other factors contraindicating the use of contrast media, the exam would not be cancelled. Because asthma is a risk factor for contrast reactions, it is a condition that warrants special treatment and often does define the type of contrast given.
Which history factor has an increased risk of aspiration during an upper gastrointestinal study? A. Dizziness. B. Steroid therapy. C. Colon biopsy. D. Constipation.
Patients with a history of dizziness have an increased risk of aspiration during upper gastrointestinal series. Long-term steroid therapy patients have an increased risk of colon perforation. Any patient having a colon biopsy within 2 weeks have a contraindication for lower gastrointestinal studies. Patients with a resent onset of constipation and diarrhea have an increased risk of colon perforation or tumor rupture.
Identify the proper medical record documentation of medication administration. A. 5 mcg/min, Epinephrine, IV, 11/12/2007, 0940. B. 07/13/2005, 1:35 p.m., two 25 mg Benadryl tablets. C. 20 mg, Prednisone, PO, 09/16/2011. D. 0.5% Lidocaine, 2.5 mg/kg, IV, 03/13/2010, 8:45 a.m.
Proper documentation of medication administration includes the date, time of day, drug name, dosage, and administration. The other options are missing crucial pieces of information.
Which term is used to describe the intensity of the x-ray beam? A. Milliampere seconds (mAs). B. Quantity. C. Half-value layer (HVL). D. Density.
Quantity refers to the intensity, or total number of x-ray photons in the primary beam. MAs is the product of tube current and exposure time, which is a primary controlling factor of intensity. HVL is a measure of beam quality, or energy. Density refers to the mass per unit volume of tissue, or to the amount of blackness on a radiographic image.
Which is the most appropriate response to a patient who asks what the term "peritonitis" means? A. "There are plenty of medical websites that can answer your questions." B. "Peritonitis is an inflammation of the abdomen." C. "That's a good question to ask your doctor." D."Peritonitis is an infection of the peritoneum that can result in death."
Questions related to medical terminology should be answered using simple but straightforward language. Although many informative medical websites are available via the Internet, such recommendations are best left to the patient's physician. While patients will often ask questions that should only be addressed by the radiologist or the patient's physician, the radiographer should be prepared to competently answer questions regarding medical terminology. Discussing potential clinical outcomes is beyond the purview of the radiographer and should be avoided.
Which protective features are designed to reduce exposure to the patient during fluoroscopic procedures? (Select the three that apply.) Multiple selection question Foot switch. Bucky slot cover. Protective curtain. Automatic collimation. Five-minute reset timer.
Radiologists are trained to repeatedly depress and release the fluoroscopic foot switch in order to reduce beam-on time and patient exposure. Automatic collimation also protects the patient by reducing the volume of tissue irradiated. A reset timer that produces an audible signal when fluoroscopy time exceeds five minutes reminds the radiologist that considerable beam-on time has elapsed, so that overexposure may be prevented. The bucky slot cover and protective curtain are designed to reduce exposure to personnel, rather than to the patient.
Which function are Radiology information system (RIS) networks are capable of performing? Multiple choice question Recording and retrieving diagnostic images. Tracking radiology scheduling information. Processing laboratory reports. Tracking billing information.
Radiology information system (RIS) contains radiology scheduling information. PACS is a computerized system that stores digital images into a central computer system for retrieval. Laboratory reports may be processed by a hospital information system (HIS), or one of its medical sub-systems. An HIS tracks billing information.
Which anatomical structure is the most medial? A. Radial head. B. Radial notch. C. Coronoid fossa. D. Coronoid tubercle.
Rationale The coronoid tubercle is the most medial. The other structures are more lateral within the elbow.
What is the annual occupational effective dose limit for a non-pregnant radiation worker? A. 0.5 mSv. B. 5 mSv. C. 50 mSv. D. 500 mSv.
Recommendations are set by the National Council on Radiation Protection and Measurements (NCRP) in report No. 116 that specify dose limits. The annual dose limit for a non-pregnant radiation worker is 50 mSv.
Which effect will a low signal-to-noise ratio (SNR) have on the appearance of a digital radiographic image? A. Decreased dynamic range. B. Decreased brightness. C. Decreased contrast resolution. D. Decreased spatial resolution.
SNR is largely dependent on the number of photons available for image formation. Fewer available photons results in a low SNR, which in turn results in higher image noise and decreased contrast resolution. Dynamic range refers to the ability of an imaging system to display a range of intensities; the wide dynamic range inherent in digital systems yields superior contrast resolution to that of conventional film-screen systems. Brightness levels are determined automatically, based on a preselected histogram. Spatial resolution is dependent upon detector element size and spacing.
A patient receives an entrance skin dose of 5 mGy during a lumbar spine procedure. How much exposure will the radiographer receive when standing 1 meter from the patient? Multiple choice question 0.01 mGy. 0.005 mGy. 0.025 mGy. 0.015 mGy.
Scatter radiation is 0.1% of the original exposure at 1 meter. Therefore, the exposure received by the radiographer is 5 mGy X .001 = 0.005 mGy. The other exposure levels given are incorrect for a distance of 1 meter from the source of scatter.
Which type of x-ray photons are present in the remnant x-ray beam, but not in the primary beam? Multiple choice question Bremsstrahlung. Characteristic. Unattenuated. Scattered.
Scattered x-rays are present in the remnant beam, but not in the primary beam.Bremsstrahlung, characteristic, and unattenuated x-rays are present in both the primary and remnant beams.
A 14-year-old female patient arrives in the radiology department for a scoliosis series. Which option provides both the best image quality and lowest radiation dose for this patient? A. High milliampere-seconds (mAs), low kilovolt-peak (kVp) technique. B. Use of a posteroanterior (PA) projection only. C. Use of an anteroposterior (AP) projection only. D. Employ shadow shields.
Shadow shields are only useful for AP projections of the spine in reducing radiation exposure to sensitive breast tissue. The use of a shadow shield along with this projection maximizes image quality and protection. Use of high mAs and low kVp would increase exposure to the patient. Using a PA projection helps to lower dose, but increases magnification and decreases resolution of the image. Using an AP projection causes more exposure to the breast which is directly exposed to x-ray.
When a radiographer asks a patient to lie down on the imaging table and the patient complies, which type of consent has the patient given? A. Informed consent. B. Implied consent. C. General consent. D. Simple consent.
Simple consent is given when a patient follows a caregiver's directions, such as lying down on an imaging table at the radiographer's request. Informed consent is written consent prior to a proposed treatment or procedure. Implied consent applies to unconscious patients. A general consent to treatment is typically signed by the patient upon admission; this gives hospital staff permission to touch the patient during the course of care.
Which method of respiration is recommended for a soft tissue neck exam to evaluate the trachea? A. Suspended inspiration. B. Suspended expiration. C. Shallow breathing. D. Deep breathing.
Suspended inspiration increases tracheal air, which helps differentiate the trachea from adjacent soft tissue. Suspended expiration would result in less air in the trachea, reducing subject contrast. Shallow or deep breathing techniques may result in motion blur.
How many posterior ribs should be visible above the diaphragm on a posteroanterior (PA) chest projection? A. Seven. B. Eight. C. Nine. D. Ten.
Ten posterior ribs should be visible above the diaphragm on an optimal PA chest projection. PA chest radiographs that demonstrate fewer than 10 ribs may be considered less than optimal and should be repeated as necessary.
Which projection is a radiographer performing if the patient's hand is turned in extreme internal rotation, with the central ray directed perpendicular to the first metacarpophalangeal joint? Multiple choice question Lateral thumb. Oblique thumb. Posterior-anterior (PA) hand. Anteroposterior (AP) thumb.
The AP thumb projection is described here. For this, a radiographer has the patient rotate the arm internally which will cause the posterior portion of the thumb to rest on the image receptor. The lateral thumb projection will have the patient's thumb resting on the lateral side. An oblique thumb projection is with the thumb abducted and the palm facing down on the image receptor. For a PA hand projection the central ray is perpendicular to the third metacarpophalangeal joint.
An image demonstrates the patella superimposing the medial condyle of the knee and little superimposition between the head of the fibula and the proximal tibia. Which projection of the knee has been correctlly performed? Multiple choice question Anteroposterior (AP) with medial rotation. Anteroposterior (AP). Anteroposterior (AP) with lateral rotation. Mediolateral lateral.
The AP with medial rotation is described here. An AP with no rotation will demonstrate the patella in the center of the femur. Superimposition of the fibular head and proximal tibia will occur on an AP knee with lateral rotation and the mediolateral lateral projection.
At which location is the central ray (CR) directed for an anteroposterior (AP) projection of the thoracic spine? A. 3 to 4 inches below the sternal angle. B. 7 to 8 inches below the vertebra prominens. C. At the level of the inferior angles of the scapulae. D. Midway between the sternal notch and the xiphoid process.
The CR is directed at a point midway between the sternal (jugular) notch and the xiphoid process, which corresponds to the level of T7, for an AP projection of the thoracic spine. The sternal angle is located at a level only 1 to 2 inches above T7. The vertebra prominens and the inferior angles of the scapulae are useful for CR positioning on posteroanterior and lateral projections.
Where should the central ray (CR) enter the patient for a lateral sacrum projection? A. 2 inches posterior to the anterior superior iliac spine (ASIS). B. 2 inches posterior and 2 inches inferior to the anterior superior iliac spine (ASIS). C. 3-4 inches posterior to the anterior superior iliac spine (ASIS). D. 3-4 inches posterior and 2 inches inferior to the anterior superior iliac spine (ASIS).
The CR should enter the patient 3-4 inches posterior to the ASIS for a lateral projection of the sacrum. Centering anterior to this point may cause the posterior aspect of the sacrum to be projected outside the field of view; automatic exposure control may shut off prematurely as well, due to poor centering. The CR for the lateral projection of the coccyx is located 3-4 inches posterior and 2 inches inferior to ASIS.
At a 50 inch source-to-image-receptor-distance (SID), how closely must the x-ray beam and the light field be aligned? Multiple choice question 0.5 inches. 1 inch. 2 inches. 5 inches.
The x-ray beam and the light beam must correspond to 2% of the SID, so, at 50 inches, this is 1 inch. This is found by multiplying 50 inches and .02 (2%). Therefore, all other answers are incorrect.
The center of the x-ray beam must be aligned to the center of the bucky tray to within what percent of the source to image receptor distance (SID)? A. 1%. B. 2%. C. 3%. D. 4%.
The center of the x-ray beam must be aligned to the center of the bucky tray to within 1% of the SID.
The Holmblad method is performed to demonstrate which radiographic appearance? A. Open intercondylar fossa. B. Open tibiofemoral joint space. C. Superimposed medial and lateral condyles. D. Patella in profile.
The Holmblad method is used to demonstrate the open intercondylar fossa of the knee. An open femorotibial joint is demonstrated on the anteroposterior knee projection. Superimposed medial and lateral condyles are seen on an optimal lateral knee projection. The patella is seen in profile on a tangential patella projection (or in lateral profile on a lateral knee projection).
Which whole-body dose most closely approximates the LD 50/30 for humans? A. 1 Sievert (Sv). B. 2 Sievert (Sv). C. 3 Sievert (Sv). D. 5 Sievert (Sv).
The LD 50/30 refers to the whole-body dose that can be lethal to 50% of the population over 30 days; for humans, this dose is reached is between 3 and 4 Sv.
Fetal exposure, in excess of which level, warrants possible termination of a pregnancy? Multiple choice question 50 mGy. 100 mGy. 150 mGy. 250 mGy.
The National Council on Radiation Protection (NCRP) states that exposure to radiation in excess of 150 mGy increases the risk of damage to the fetus and only in excess of this level or above should elective termination of a pregnancy be considered appropriate. Therefore, 250 mGy is the correct answer. Studies at or below this level all indicate low probability of biologic impact to the fetus.
Which is an advantage of an optically stimulated luminescence dosimeter (OSL)? Multiple choice question Incredibly expensive device to purchase, especially for departments with a large radiology staff. Classifies various energy levels of radiation received. Very sensitive to heat and humidity exposure. The device can be used for up to 90 days.
The OSL has very few disadvantages; but one particular advantage is classifying various energy levels of radiation received. An expensive device to purchase is actually the pocket ionization chamber; the OSL is more cost effective. The tamperproof blister pocket prevents damage due to heat and humidity. The thermoluminescent dosimeter (TLD) can be used up to 3 months, but the OSL can be used up to 1 year.
What is the annual occupational effective dose limit for a 43-year-old radiographer? Multiple choice question 5 millisievert (mSv). 4.3 millisievert (mSv). 50 millisievert (mSv). 43 millisievert (mSv).
The annual occupational effective dose limit for radiographers is 50 mSv and does not change based on age.
Which bony landmark is commonly used for central ray location on an anteroposterior (AP) chest projection? Multiple choice question Jugular notch. Xiphoid process. T7 spinous process. Vertebrae prominens.
The jugular notch, which is located 3 to 4 inches above T7, is used as a landmark to help ensure proper central ray location for an AP chest radiograph. The xiphoid process is a commonly used positioning landmark for abdominal radiography. The spinous process of T7 and the vertebrae prominens are commonly used landmarks for posteroanterior (PA) chest radiography.
Which exam may be used to assess cruciate ligament pathology? Multiple choice question Knee arthrogram. Shoulder arthrogram. Three view elbow series. Wrist including navicular views.
The cruciate ligaments are found in the knee, so a knee arthrogram is the exam that may be used. All other answers are incorrect.
Which projection of the foot demonstrates the cuboid bone in profile with the least bony superimposition? Multiple choice question Lateral. Anteroposterior (AP). Anteroposterior (AP), lateral oblique. Anteroposterior (AP), medial oblique.
The cuboid bone, which lies on the lateral side of the foot between the calcaneus and the fourth and fifth metatarsals, is demonstrated in profile on the AP medial oblique foot projection. The AP, lateral, and AP lateral oblique projections demonstrate the cuboid bone with superimposition.
A radiograph of optimal density is produced at 15 milliampere seconds (mAs) and a source to image receptor distance (SID) of 40 inches. Which mAs value is required to produce the same radiographic density if this exam is repeated at an SID of 48 inches? A. 10. B. 16. C. 18. D. 22.
The density maintenance formula, mAs1/mAs2 = D1 squared/D2 squared, provides a method of compensating for changes in SID. In this instance, 15/x = (40)2/(48)2; 1600x = 34,560; x = 34,560/1600 = 22 mAs. The other answers result from math errors.
Which organ has the highest tissue weighting factor? A. Thyroid. B. Breast. C. Lung. D. Gonads.
The gonads are the most radiosensitive organ, with a weighting factor of 0.20. The weighting factor for both the thyroid and breast is .05. The weighting factor for lung tissue is .12.
Body habitus can affect many things, including the position of the gallbladder. Place the body habitus in order from which habitus will cause the gallbladder to occupy the highest position in the abdominal cavity to the habitus that will cause the gallbladder to occupy the lowest position in the abdominal cavity.
The hypersthenic body habitus results in the gallbladder holding a high, horizontal position within the abdominal cavity. Next, a sthenic body habitus has a slightly lower gallbladder position. The hyposthenic position has a more vertical and lower gallbladder than the previous two. An asthenic position has the lowest, closest to midline, and vertically directed gallbladder of the four body habitus.
Historically, rhenium was alloyed to the tungsten in the filament of valve tubes to increase electron emission. What is the major reason this isn't used in x-ray tube filaments? Multiple choice question To permit fine control of electron emission by filament heating current. To maximize the melting point of the filament. To increase the working life of the filament. To reduce the vaporization of the filament.
The major reason that rhenium isn't used is to permit fine control of electron emission (mA) by filament heating current. Valve tubes were essentially avalanche devices; that is, every time the valve tube conducted current, a maximum number of electrons was needed to cross the cathode-anode gap. Conversely, x-ray tubes are current limited devices by design. The other options are correct statements, but they just aren't the most important reason rhenium is not used in x-ray tube filaments.
For a lateral femur, if a patient is rotated too far anteriorly, what will happen to the condyles on the distal femur? Multiple choice question They will superimpose. Medial condyle will be inferior to the lateral condyle. Medial condyle will be anterior to the lateral condyle. Medial condyle will be posterior to the lateral condyle.
The medial condyle will be anterior to the lateral condyle, because the patient is rotating forward and moving the medial surface anteriorly. The condyles are superimposed if there was no extra rotation of the patient, and they were in true lateral position. Anterior or posterior rotation will not cause the medial condyle to be inferior to the lateral condyle. The medial condyle would be posterior to the lateral condyle if the patient was rotated too far posteriorly.
If a radiographic image is requested to show the nephrogram phase of an intravenous urogram (IVU), how long after IV contrast administration should this image be obtained? A. 30 seconds to 1 minute. B. 5 minutes. C. 10 to 15 minutes. D. 20 minutes.
The nephrogram phase of an IVU should be obtained within the first 30 seconds to one minute post injection in order to show the initial blush as contrast enters the nephrons, but has not yet reached the collecting tubules. Longer delays will not demonstrate this appearance.
There are several methods to overcome sagging of the lumbar spine in the lateral position. Where should the radiographer begin? Multiple choice question Assessing the line connecting the spinous processes relative to the tabletop. Using a 5 degree caudal central ray angle to open up the intervertebral joints. Building up under the lowest part of the spine to place the spine parallel to the table. Flexing the hips and knees more than 90 degrees to engage spinal alignment muscles.
The radiographer should begin by assessing the line connecting the spinous processes. This enables the radiographer to choose an appropriate method for correcting any sag. A 5 degree caudal angle and building up under the side are both useful for average sized patients in dealing with this issue, but assessment should precede the solution. Flexing the hips and knees more than 90 degrees should not ever be done. This may cause some alignment issues to be masked in the image and cause a missed diagnosis.
A patient is having a lengthy procedure done in the medical imaging department. The patient seemed to be anxious at the beginning of the procedure and starts wheezing. What should the radiographer do next? Multiple choice question Initiate oxygen therapy. Call for medical assistance. Allow the patient to use an inhaler. Ask the patient if they have a history of asthma.
The radiographer should first ask if the patient has a medical issue, like asthma. Stress can increase the likelihood of an asthma attack. Oxygen therapy should not be initiated at this stage. The situation is not severe enough to call for medical assistance. The patient should be allowed to use an inhaler or other bronchodilators after medical evaluation.
When imaging the toes, how much is the central ray (CR) angled for the anteroposterior (AP) axial image? A.No angle. B. 5 degrees. C. 15 degrees. D. 25-30 degrees.
The radiographer uses a 15 degree angle to image the toes. This opens the metatarsophalangeal and interphalangeal joints of the toes. Using no angle makes it harder to visualize the joints. A 5 degree is too little and will not open the joint spaces. The angle of 25-30 degrees is too much and may elongate the toes.
A patient is scheduled for an interventional radiological procedure that requires general anesthesia. Who is the most appropriate person to obtain informed consent for the procedure in this situation? Multiple choice question Interventional nurse. Anesthesiologist. Radiographer. Radiologist.
The radiologist performing the procedure is the most appropriate one to explain the benefits, risks, and possible alternatives to the procedure. An interventional nurse must be present during the procedure, but is not qualified to provide information necessary for informed consent. An anesthesiologist may be present to administer anesthesia, but will not be performing the procedure. A radiographer is not qualified to explain the benefits and risks of the procedure.
Computed radiography (CR) imaging creates images with poorer resolution than that of film screen. What compensates for this loss of resolution? Multiple choice question The wide latitude. Use of high-pass filtering. Use of edge enhancement. The ability to reprocess images.
The wide latitude (dynamic range in electronic terms) of the CR system and its ability to demonstrate such a wide spectrum of grays offsets the loss of geometric detail with CR. The use of filtering and edge enhancement eliminates or amplifies selected frequencies from an image to make subtle viewing differences. Reprocessing an image is more frequently used to alter the displayed brightness and contrast and may or may not enhance perceived resolution.
A radiographer is performing a portable abdomen is using an image receptor with an 8:1 grid. The radiographer knows a technique for the abdomen using a 12:1 grid is 80 kilovolts peak (kVp) using 50 milliampere-seconds (mAs). Which would the new technique be in order to maintain image quality? Multiple choice question 80 kVp @ 60.5 mAs. 80 kVp @ 40 mAs. 80 kVp @ 30 mAs. 80 kVp @ 25 mAs.
This requires knowing the grid conversion factors (GCF). The GCF for a 12:1 grid is 5, and the GCF for an 8:1 grid is 4. The formual is GCF1:GF2::mAs1:mAs2; so mAs2 = (mAs1 x GCF2)/GCF1. So mAs2 = ((50 mAs)(4))/5 = 40 mAs. All other responses are incorrect due to math errors or incorrect application of the formula.
When attempting to demonstrate air-fluid levels, what is the correct central ray orientation for an anteroposterior (AP) semierect chest projection? A. Parallel to the floor. B. Parallel to the midsagittal plane. C. Perpendicular to the image receptor. D. Perpendicular to the midcoronal plane.
To demonstrate air-fluid levels when pleural effusion is suspected, chest images should be taken with the central ray parallel to the floor. Although the fluid line will slant relative to the coronal plane of the patient in the semierect position, the air-fluid level is still demonstrated with a horizontal beam. If the patient is not rotated, the central ray will also be parallel to the midsagittal plane. However, even with slight rotation, air-fluid levels may be seen if the central ray is horizontal. If a semierect chest projection is ordered to evaluate pathology other than air-fluid levels, the central ray should be placed perpendicular to the image receptor and the midcoronal plane.
Which central ray (CR) angle is recommended to demonstrate the coronoid process of the elbow using the Coyle method? A. 45 degrees toward the shoulder. B. 45 degrees away from the shoulder. C. 35 degrees toward the shoulder. D. 35 degrees away from the shoulder.
To visualize the coronoid process using the Coyle method, the CR is directed 45 degrees away from the shoulder. A 45-degree CR directed toward the shoulder is recommended to visualize the radial head using the Coyle method. A 35-degree CR angle is not recommended for this procedure.
An electrically neutral sodium atom has 1 valence electron. What chemical event happens when the sodium atoms encounter a chlorine atom with 7 valence electrons? Multiple choice question Attraction. Repulsion. Ionic bonding. Covalent bonding.
Under the scenario conditions, the sodium atom will tend to give up its valence electron to the chlorine atom, converting both atoms to ions. These ions will ionically bond to form a molecule of salt. Attraction does not occur until the ions have formed; so, the elemental atoms are not attracted. These two atoms do not repel one another. Covalent bonding involves the sharing of valence electrons, which does not happen here.
Which fluoroscopic kilovolts peak (kVp) factor is most appropriate for optimal patient radiation protection? Multiple choice question 60 - 70 kVp. 70 -80 kVp. 80 - 90 kVp. 100 - 110 kVp.
Use of high kVp along with low (milliampere-second) mAs values provide the best radiation protection to the patient. Use of lower kVp would increase patient dose since lower energy photons are less likely to exit the body and as a result will increase tissue ionization.
What results from utilizing a lower ratio grid? Multiple choice question Lower contrast, but less leeway in positioning the central ray (CR) to the grid. Lower contrast, but greater error margin in central ray (CR) placement. Higher contrast and greater latitude in central ray (CR) positioning. Higher contrast and less latitude in central ray (CR) positioning.
Using a grid with a lower ratio will allow more scatter to pass through and strike the image receptor (IR) which lowers contrast. However, lower grid ratios allow greater latitude in central ray positioning and grid placement. A lower contrast image will be created with a low ratio grid, but the radiographer does not need to be as precise in CR placement or grid placement as with a high ratio grid, so there is a greater margin for error with lower ratio grids, not less. High contrast images require a high ratio grid.
Which disease requires the infected patient to be placed on airborne precautions? Multiple choice question AIDS. MRSA. Pneumonia. Chickenpox.
Varicella, or chickenpox, is a disease requiring airborne precautions. AIDS is not acquired by casual contact; therefore airborne precautions are not required. Contact precautions are used to prevent transmission of multi-resistant wound infections caused by Methicillin-Resistant Staphylococcus Aureus (MRSA). Pneumonia is a disease requiring the use of droplet precautions.
A step-up transformer with 300 turns in the primary coil is supplied with 220 volts to this primary. How many secondary turns are needed to produce a 66,000 volt output? Multiple choice question 1 turn. 14 turns. 66,000 turns. 90,000 turns.
With an input voltage of 220 and an output voltage of 66, 000 volts (66 kilovolts (kV), the necessary turns ratio is 66,000/220 = 300: 1. If there are 300 turns in the primary, and 300 times that in the secondary, then 300 x 300 = 90, 000 secondary turns are needed to produce a 66 kV output. All other responses result from math errors or misunderstandings of step up transformers.
Which property describes x-rays? Multiple choice question Are electrically negative. Are focused by the collimator. Cause biological and chemical changes. Travel faster than 186,282 miles per second.
X-rays cause biological and chemical changes by breaking chemical bonds and/or damaging DNA. Even though electrons are used in the production of x-rays, the x-rays created are electrically neutral, not negative. Collimators limit the x-ray beam, but they are unable to focus it. X-rays travel at the speed of light, or 186,282 miles per second, but do not travel faster than that speed of light.