CT Physics Quizzes 5 DR

During a radiographic examination, which of the following combinations of technical exposure factors reduce patient radiation dose?

Higher kVp, lower mAs

Which website resource provides essential radiation safety for the pediatric community?

Image Gently®

How is dose area product usually specified?

In units of mGy-cm2

What is used to measure exposure?

Ionization chamber

The much smaller structures that make up nucleic acids are called

nucleotides

If bone marrow cells have not been destroyed by exposure to ionizing radiation, they can:

repopulate after a period of recovery

If two anatomic structures have the same density and atomic number but one is twice as thick as the other, the thicker structure will absorb

twice as many x-ray photons

The radiosensitivity of ova

varies considerably throughout the lifetime of the germ cell

Compton scattering is synonymous with

incoherent scattering

What technical factor determines the penetrating power of the photons coming from the X-ray tube?

kVp

Which technique factor determines the quantity of photons (dose) incident on the patient for the duration of the exposure?

mAs

True or False: The customer driven management model will work only for the radiology department

False

After the Chernobyl disaster in 1986, an attempt was made to prevent thyroid cancer in Poland and some other countries, resulting from the accidental overdose of iodine-131. _______________ was administered to children as a substitute to block the gland's uptake of iodine-131.

Potassium iodide

Which of the following is not a step in the processing of an object-based model into a simulated 3D image?

Preprocessing

Studies showed that postpartum patients treated with ionizing radiation for relief of mastitis are a group of individuals in whom the results of radiation exposure to healthy breast tissue via scattered radiation indicate that radiation

can cause breast cancer

If a person receives radiation exposure sufficient to cause the gastrointestinal syndrome, fatality occurs primarily because of

catastrophic damage to the epithelial cells that line the gastrointestinal track, resulting in the death of the exposed person within 3 to 5 days from a combination of infection, fluid loss, and electrolytic imbalance.

For C-arm devices with similar fields of view, the dose rate to personnel located within a meter of the patient is

comparable to that of routine fluoroscopy.

The symbol Z indicates

atomic number of an atom

The cell components that contain the centrioles are the

centrosomes

Equipment for 3D image processing does not include:

MRI scanner console

Currently, evidence of radiation-induced hereditary effects has not been observed in persons employed in diagnostic imaging or in persons undergoing radiologic examinations. Even with this information, it is still recommended that 1. gonadal shielding be effectively used. 2. all radiation exposure be maintained as low as reasonably achievable (ALARA). 3. alternative procedures be substituted for x-ray procedures whenever diagnostic information must be obtained.

1 and 2 only

Which of the following is/are considered low-LET radiation(s)? 1. X-rays 2. Alpha particles 3. Gamma rays

1 and 3 only

Diagnostic efficacy includes 1. determining if an imaging procedure is justified. 2. obtaining images with minimal radiation exposure. 3. adhering to radiation safety guidelines. 4. revealing the presence or absence of disease in a patient.

1, 2, 3, and 4

In general, which of the following can human cells do? 1. Move, grow, react, and protect themselves 2. Repair damage and regulate life processes 3. Reproduce

1, 2, and 3

Which of the following are considered to be benefits of an aggressive repeat analysis program? 1. Increased awareness among staff and student radiographers of the need to produce optimal quality recorded images from the start. 2. Radiographers become more careful in producing radiographic images because they are aware that images are being reviewed. 3. When the repeat analysis program identifies problems or concerns, in-service education programs covering these specific topics may be designed for imaging personnel.

1, 2, and 3

Among physicians, cancer deaths attributed to x-ray exposure were reported as early as

1910

Which of the following are responsibilities of a health care facility's radiation safety committee (RSC)? 1. Delegate operational funds in the budget for the radiation safety program 2. Provide guidance for the radiation safety program 3. Facilitate the ongoing operation of the radiation safety program

2 and 3 only

Which of the following statements below is true? A. It appears that no safe dose level exists for radiation-induced malignant disease. B. The ALARA principle establishes a dose level for radiation-induced malignancy. C. The BERT method establishes a dose level for radiation-induced malignancy. D. The NEXT program and reference values establish a dose level for radiation-induced malignancy.

A. It appears that no safe dose level exists for radiation-induced malignant disease.

Which of the following groups of cells is least radiosensitive?

Adult nerve cells

____________ are those items which identify process outcomes. A. Models B. IMprovements C. Specifications

C. Specifications

Which of the following curves illustrates the radiation sensitivity of a particular type of cell?

Cell survival curve

Who was the first American radiation worker to die from radiation-induced cancer in October of 1904?

Clarence Madison Dally

Which of the following is not a start-up step in the CDM model? A. Identify customer's expectations and professional standards B. Balance customer's needs with operational requirements C. Decide on outcomes and processes measurements D. Report results and provide feedback

D. Report results and provide feedback

What dose descriptor is used to describe a measurement of the total amount of exposure for a series of scans?

DLP

Which of the following provides the basis for determining whether an imaging procedure or practice is justified?

Diagnostic efficacy

Which registry collects CT exam doses and transmits them to the American College of Radiology (ACR) to provide feedback and compare institutions?

Dose Index Registry (DIR)

During the preimplantation stage of development, the fertilized ovum divides and forms a ball-like structure containing undifferentiated cells. If this structure is irradiated with a dose in the range of 0.05 to 0.15 Gyt which of the following will result?

Embryonic death

Factors directly affecting CT dose cannot be controlled by the technologist.

False

Who should determine the exact shielding requirements for a particular imaging facility?

Medical physicist

Which of the following generates sagittal, coronal, and paraxial images from transaxial slices?

Multiplanar reconstruction

Which of the following are classified as early tissue reactions of ionizing radiation?

Nausea, epilation, and intestinal disorders

Which of the following is frequently a problem in diagnostic pediatric radiography?

Patient motion

Which of the following statements is true concerning patients who receive radiation exposure from a routine radiographic procedure such as a chest x-ray?

Patients are not expected to sustain appreciable damage to either the blood or the blood-forming organs as a consequence of the examination.

What portion of the collimated beam contributes to the patient's radiation dose but does not contribute to the produced image?

Penumbra

Which of the following types of ionizing radiation produce virtually the same biologic effect in body tissue for equal absorbed doses?

X-rays, beta particles, and gamma rays

The essential concept underlying radiation protection is that

any organ in the human body is vulnerable to damage from exposure to ionizing radiation.

When LET increases, the chance of producing a significant biologic response in the radiosensitive DNA macromolecule

grows

Moist and dry desquamation can be caused by

high radiation doses

Regarding exposure to ionizing radiation, patients who are educated to understand the medical benefit of an imaging procedure are more likely to

suppress any radiation phobia and be willing to assume a small chance of possible biologic damage.