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LMRT-Radiography Essentials exam with
verified solutions
Which of the following changes in (KVP) will result in the greatest reduction of patient dose, when (MAS) is adjusted to compensate for the change? - correct answer ✔ Increase kVp by 30% Which of the following (IR) system speeds will result in the lowest patient dose?
- correct answer ✔ Faster speed IR system What is the primary purpose of using gonad shields during radiography? - correct answer ✔ Reduce the likelihood of genetic effects Contact & shadow are two types of gonad shield - correct answer ✔ TRUE When should gonad shields be used? - correct answer ✔ When the gonads are within 5cm of the radiation field The greatest cause of unnecessary radiation to patients that can be controlled by the limited operator are: - correct answer ✔ repeat exposures The limited operator can reduce repeat exposures by: - correct answer ✔ clearly instructing patients
How does x-ray beam restriction minimize patient exposure - correct answer ✔ It limits the radiation field to the area of interest What is the device that allows the limited operator to vary the size of the radiation field - correct answer ✔ Collimator How does filtration reduce patient exposure - correct answer ✔ Removes longer wavelength photons What is the National Council on Radiation Protection and Measurements (NCRP) recommendation for the amount of total filtration - correct answer ✔ 2.5mm Al Equivalent What are the three principal methods used to protect limited operators from unnecessary radiation exposure? - correct answer ✔ 1. Time
- Distance
- Shielding Which of the following is NOT a type of personnel radiation shielding? - correct answer ✔ a. Apron b. Glove c. Thyroid shield d. Shadow******** CORRECT Personnel shielding must be worn on the rare occasion during which the limited operator may need to remain in the radiographic room during an exposure to assist the patient in maintaining the proper position. What is the source of the
What is the NCRP recommended monthly effective (or equivalent) dose limit to the fetus for a prego worker? - correct answer ✔ 0.05 rem (0.0005 Sv) Radiation monitoring of personnel is required when what percentage of the annual occupational effective dose limit is likely to be received - correct answer ✔ 10% What is the conventional (British system) radiation unit to express radiation intensity in air? - correct answer ✔ Roentgen The conventional unit commonly used to report occupational dose to radiation workers in the U.S. is the: - correct answer ✔ rem What is the conventional (British system) radiation unit of absorbed dose - correct answer ✔ Rad According to the Bergonie Tribondeau law, which of the following types of cells are most radiosensitive? - correct answer ✔ Embryonic tissue cells Which type of x-ray photon interaction with the body is primarily responsible for the radiation dose absorbed by the pt? - correct answer ✔ Photoelectric What is the (NCRP) recommendation for lead equivalency of aprons used for personnel protection? - correct answer ✔ 0.5 mm
What is erythema, as it relates to radiation exposure? - correct answer ✔ reddening of the skin caused by a high radiation dose What is the guiding philosophy of radiation protection? - correct answer ✔ ALARA as low as reasonably achievable Which of the following statements reflects current scientific opinion regarding the effects of diagnostic levels of ionizing radiation - correct answer ✔ There is an increased risk of cancer, leukemia, birth defects, and cataracts Which of the following changes will decrease patient dose? - correct answer ✔ *using a faster-speed class imaging system *Increasing the kVp using the 15% rule while decreasing the mAs to compensate When radiation exposure occurs during pregnancy, the greatest risk of birth defects occurs when the exposure: - correct answer ✔ 1. exceeds 5 rad to the uterus
- occurs within the first trimester of pregnancy At what kVp levels do Compton interactions occur - correct answer ✔ They occur throughout the diagnostic radiology kVp range What is the principal source of scatter radiation in radiography - correct answer ✔ the IR What are the four essential elements required for x-ray production - correct answer ✔ 1. target
What is the standard control limit for the beam (central ray) alignment test? - correct answer ✔ within 1 degree of perpendicular How often should lead aprons and gloves be checked for cracks or holes - correct answer ✔ every 6 months How can detector fog be prevented when using computed radiography cassettes
- correct answer ✔ protect the cassette before and after exposure Which of the following will result in increased radiographic density - correct answer ✔ Increased: mA, exposure time, and kVp If the radiographic image is overexposed, which of the following changes in exposure factors should be used to correct the problem - correct answer ✔ Decrease the mAs The relationship between SID and beam intensity is expressed in the: - correct answer ✔ Inverse square law What are the four primary factors of radiographic quality (photographic and geometric properties)? - correct answer ✔ Density Contrast Distortion Recorded detail Contrast is primarily controlled by altering the: - correct answer ✔ kVp
Scatter radiation fog affects radiographic quality by causing - correct answer ✔ decreasing contrast A change from small focal spot to the large focal spot will result in: - correct answer ✔ decreased image sharpness/detail An increase in object image receptor distance (OID) will result in: - correct answer ✔ Increased magnification Motion of the patient, the tube, or the IR during the exposure will result in decreased: - correct answer ✔ recorded detail What does quantum mottle (noise) look like on a radiographic image? - correct answer ✔ finely speckled or grainy areas Quantum mottle with a digital imaging system is caused by: - correct answer ✔ the mAs being set too low Which of the following will increase recorded detail? - correct answer ✔ *increase in SID *Decrease in focal spot size What is the appearance of a high signal to noise ratio image - correct answer ✔ highly detailed, with very little quantum mottle
Technique charts are based on patient part measurements obtained using an x- ray caliper and are expressed as: - correct answer ✔ Thickness in centimeters Which of the following pathologic conditions would require a decrease in exposure - correct answer ✔ 1. Multiple myeloma
- Emphysema
- Osteoporosis How will the anode heel effect, if present, be seen on an image? - correct answer ✔ The image will be lighter on the anode end than on the cathode end. What radiographic quality factor is most affected by angulation of the central ray, part, or IR? - correct answer ✔ Distortion What is the recommendation for a hard-copy image that is mislabeled? - correct answer ✔ A sticker with the correct information should be applied to the hard copy image. Which of the following will result in a screen or film image with low density - correct answer ✔ IR exposure with an mAs less than needed for the particular anatomic structures Which of the following will result in a screen or film image with low contrast? - correct answer ✔ IR exposure with a kVp higher than needed for the particular anatomic structures
When viewing a digital image on a monitor, how do you determine if the proper mAs was selected? - correct answer ✔ Evaluate the exposure index value Which of the following will result in an image with poor detail? - correct answer ✔ patient motion Which of the following will result in an image with excessive magnification of image structure? - correct answer ✔ IR exposure at an OID greater than recommended for a particular body part Which of the following will result in an image with excessive distortion of anatomic structures - correct answer ✔ improper central ray angulation for the selected radiographic projection poor film or screen contact is seen on a radiographic as a decrease in what radiographic quality factor? - correct answer ✔ Recorded detail or spatial resolution Which screen or film image artifact look like lightning? - correct answer ✔ static artifact Which of the following would be a violation of patient confidentiality? - correct answer ✔ A limited operator talks to his or her friend during lunch about a patients imaging procedure Which of the following are true regarding informed consent - correct answer ✔ informed consent may be revoked at any time
- Mucous membranes The process of reducing the probability that infectious organisms will be transmitted to a susceptible individual is called: - correct answer ✔ Asepsis A health care workers single best protection against disease is: - correct answer ✔ frequent hand washing A limited operator who does not change linens between patients is: - correct answer ✔ providing an opportunity for famite What is anaphylaxis? - correct answer ✔ A severe allergic reaction What is the basis life support system used to ventilate the lungs and circulate the blood in the event of cardiac or respiratory arrest - correct answer ✔ CPR When a patient in cardiac arrest presents with a rapid, weak, and ineffective heartbeat, what device is used to return the heart to a normal rhythm? - correct answer ✔ AED Which of the following vita signs can be assessed with out touching the patient?
- correct answer ✔ Respiration What is the most common site for palpitation of a patients pulse? - correct answer ✔ Radial artery at the wrist
When pt is facing the IR for a chest x-ray the x-ray goes through the back & hits the IR to create the image-what is this called? - correct answer ✔ Posterior anterior or PA What structure separates the thoracic cavity from the abdominal cavity? - correct answer ✔ The diaphragm Which of the following organs are found within the mediastinum? - correct answer ✔ Heart & Trachea Three lobes are present in which lungs? - correct answer ✔ Right lung What is the name of the upper portion of the lung? - correct answer ✔ Apex The inferior lateral corners of the lungs, visible on a PA chest radiograph, are called the: - correct answer ✔ castophrenic angles When taking a PA projection of the chest the recommended source image receptor distance (SID) is: - correct answer ✔ 72 inches What is the purpose of the 72in SID used for chest radiography? - correct answer ✔ Minimize magnification of the heart shadow Which of the following describe the importance of using an upright position for chest radiography? - correct answer ✔ 1. The upright position demonstrates air- fluid levels
Lateral projection of the chest are taken with the left side against the IR because: - correct answer ✔ magnification of the cardiac silhouette is reduced with the left side nearer the IR How much should the central ray be angled cephalad for an AP axial projection of the chest if the patient cannot assume the lordotic position - correct answer ✔ 15 degrees Which chest projection and position are needed to demonstrate free pleural fluid along the dependent chest wall? - correct answer ✔ AP & lateral decubitus Which of the following projections is best for demonstration of the apices of the lungs with out bony superimposition? - correct answer ✔ AP axial & lordotic position Why is a grid used for routine chest radiography? - correct answer ✔ To reduce scatter frog caused by use of a high kVp Which of the following bones are in the hind foot portion of the foot? - correct answer ✔ Calcaneus & Talus The anatomic name for the bone commonly known as the kneecap is the: - correct answer ✔ Patella The palpable portion at the distal end of the tibia is called the: - correct answer ✔ Medial Malleolus
When the ankle is flexed to raise the foot, the movement is termed: - correct answer ✔ dorsiflexion What device may help provide an even density on a radiograph of an anteroposterior (AP) axial projection of the foot? - correct answer ✔ Wedge compensating filter Which of the following is true regarding the correct positioning of the ankle for a lateral projection? - correct answer ✔ The central ray enters perpendicular to the medial malleolus When the leg is extended in the supine position, the ankle is maximally dorsiflexed, and the central ray is directed 40 degrees cephalad through the plantar surface of the foot, the resulting image will demonstrate: - correct answer ✔ An axial projection of the calcaneus Which of the following are true regarding the correct position for an AP projection of the lower leg? - correct answer ✔ *The leg should be extended and resting on the IR. *The ankle should be dorsiflexed so that the foot forms a 90 degree angle with the lower leg. Where should the central ray enter the patient for the PA projection of the knee? - correct answer ✔ 0.5 inches below apex of the patella When a lateral projection of the knee is taken, flexion of the knee joint should be limited to 10 degree when there is suspicion of: - correct answer ✔ a fracture of the patella
What is the proper patient position for the AP projection of the forearm? - correct answer ✔ elbow extended, wrist and elbow parallel to the IR, hand supinated Which of the following describes the proper method for positioning the humerus for an AP projection? - correct answer ✔ upper limb adducted, elbow extended, humeral epicondyles parallel to the IR What specific anatomy is demonstrated w/o superimposition in the AP oblique projection in 45 degree lateral rotation? - correct answer ✔ Radial head and capitulm What change is technical factors is required when a wrist in a fiberglass cast must be radiographed? - correct answer ✔ No change is required Where is the central ray entrance point for the AP projections of the shoulder? - correct answer ✔ 1 inch medial and inferior to the coracoid process What are the proper patient instructions for the AP projection of the shoulder - correct answer ✔ Stop breathing, and do not move What is the name of the large, rounded, projection that can be felt on the superior lateral surface of the shoulder? - correct answer ✔ Acromion Which of the following cranial bones are paired (right & left)? - correct answer ✔ Parietal & Temporal
What structure serves as the passage way for the spinal cord to exit the skull and pass into the spinal canal of the vertebral column? - correct answer ✔ Foramen Magnum When taking a poserioranterior (PA) axial projection (Caldwell method) of the skull, the central ray is directed: - correct answer ✔ 15 degrees caudad Which radiographic bvaseline is used to position the PA axial projection (Caldwell method) of the cranium? - correct answer ✔ OML (orbital meatal line) Which cranial projection best demonstrates the occipital bone? - correct answer ✔ AP (Anteriorposterior) Axial (Towne method) The patient is in a prone oblique position with the midsagittal plane of the head parallel to the IR and the interpupillary line perpendicular to the IR. The central ray is directed 2 inches superior to EAM-WHAT PROJECTION? - correct answer ✔ Lateral The patient is positioned supine with the midsagittal plane and OML perpendicular to the IR. The central ray is angled 30 degrees caudad and enters the midsagittal plane at approximately 2.5 inches superior to the glabella. What projection will be imaged on the radiograph? - correct answer ✔ AP axial (towne method) What positioning accessory can be used to assist the patient in holding the correct position for an AP axial projection of the skull? - correct answer ✔ A wedge filter
