ARRT LMRT Core Mock Exam Questions.

Line Compensator

Component that corrects voltage variation in x-ray machines.

Tachypnea

Most likely respiratory rate of an adult with tachypnea is 30 breaths/minute.

Cesium iodide and gadolinium oxysulfide

Scintillation phosphors that emit light when absorbing X-ray photon energy.

Fetal dosimeter

Pregnant radiographers should wear it at the waist under the apron.

Normal blood pressure range

In a healthy adult, systolic less than 120/diastolic less than 80 mmHg.

Sandbags

Used as positioning aids for lateral cervical spine procedures.

Flat-panel detectors

Use indirect conversion technology to convert X-rays to visible light.

Automatic Rescaling

Process that corrects for slight under-exposure or overexposure errors made by the technologist.

Characteristic X-rays

Result from the ionization of the target atom through total removal of an inner-shell electron.

Glass Enclosure

Component that maintains a vacuum inside the x-ray tube.

Focused grid

A grid that has lead strips angled to match the divergence of the x-ray beam.

Quality factors affected by SID change

Size distortion and receptor exposure.

Purpose of using a grid

To improve image contrast during a radiographic procedure.

Indirect Effect

Occurs when radiation strikes water molecules (cytoplasm).

Exposure at 80" SID

If an x-ray of a fractured shoulder was imaged at 40" SID with a resulting exposure of 100 mR, the new exposure at 80" would be 25 mR if no changes were made to compensate.

Positive Beam Limitation (PBL)

Ensures x-ray fields are no larger than receptor exposure.

PSP imaging plate

Requires periodic erasure due to its ability to record for 48 hours.

Beam restriction

Used to reduce patient dose; increasing beam restriction decreases scatter produced by irradiating tissue.

Cracks in the imaging plate

Can be caused by removing and replacing the plate in the reader.

Compton interaction

Type of interaction depicted in the image.

Incident electron energy conversion

During x-ray production, 1% of incident electron energy is converted to x-rays.

Radiosensitive tissues

Skin, bone, and gonads are more radiosensitive.

Radiation detection device

Thermoluminescent dosimeter (TLD) is specifically used for occupational radiation monitoring.

Pathologic conditions requiring decreased technical factors

Emphysema requires a decrease in technical factors to maintain acceptable image receptor exposure.

Low contrast

Contrast that displays more shades of gray with little differences.

Electrons

Subatomic particle that carries a negative charge.

Technical factors for fiberglass cast

Increase in kVp and mAs when imaging a patient with a fiberglass cast.

ARS gastrointestinal syndrome dose

A dose of 8 Gy may cause ARS gastrointestinal syndrome.

Shades of gray

4096 shades of gray can be displayed.

Skin dose

Most affected quality factor when changing from non-grid to an 8:1 grid.

Short SID

Would give a better exam.

Amorphous selenium

A material that can convert light into an electrical charge.

Underexposure

A radiographic pattern resulting from insufficient exposure to radiation.

Dose-response curve

A graphical representation that shows the relationship between the dose of radiation and the biological response.

Extremities

Refers to the limbs of the body in the context of radiographic imaging.

PACS

A networked group for storage and management of digital medical images.

Stochastic effects

A type of radiation effect that occurs by chance and is not dose-dependent.

Exposure Density control

An automatic exposure control (AEC) feature that adjusts exposure based on patient factors.

Dose Area Product (DAP)

A unit of measure that quantifies the total amount of radiation delivered to a patient.

Variable collimator

The most commonly used beam restricting device in radiology.

Photomultiplier tube

A device that collects light signals released by photostimulable phosphors in the plate reader.

Kvp

Kilovolt peak, a factor that can be increased to decrease patient dose in digital imaging.

Indirect Radiography

A flat panel detector system where x-ray energy is first released as light and then converted into an electrical signal.

Compton Scattering

An interaction where an x-ray in the diagnostic range interacts with an outer-shell electron, scattering the x-ray and reducing its energy.

Contrast resolution

The ability of a digital system to display subtle changes in shades of gray.

Smoothing

A post-processing application that averages pixel frequencies with surrounding pixel values to remove noise.

0.5mm Pb

The minimum lead equivalent thickness for personnel protective lead aprons as per the National Council on Radiation Protection (NCRP).

Increasing Kvp

A technique to minimize patient exposure while maintaining diagnostic image quality.

Aluminum Backing

A feature of the PSP cassette that helps stop exposure from backscatter.

SID

Source-to-image distance, a factor that influences the exposure of the image receptor.

Decrease Scatter

The effect of increasing beam restriction on the production of scatter radiation.

Removing & replacing the plate

An action that can cause cracks in the imaging plate.

1%

The percentage of incident electron energy converted to x-ray photons during x-ray production.

Thermoluminescent dosimeter (TLD)

A radiation detection device specifically used for occupational radiation monitoring.

Emphysema

A pathologic condition that would require a decrease in technical factors to maintain acceptable image receptor exposure.

Increase in Kvp & mAs

Technical factor changes recommended when imaging a patient with a fiberglass cast.

8 Gy

The dose of radiation that may cause Acute Radiation Syndrome (ARS) gastrointestinal syndrome.

What is the ncrp

National council of radiation

The unit correctly used to report the effective dose to occupational workers in the US is?

SV (sieverts)

The NCRP makes___ regarding dose limits

Recommendations

Effects that are limited to the exposed population are?

Somatic effects

What is the principal response of the blood caused by radiation exposure?

Decrease in lymphocytes

Death from a single dose of whole body irradiation primarily involves damage to the?

Bone marrow

Which of the following is not an acute local tissue effect of radiation exposure?

Cataracts

Which of the following is not an early response to irradiation?

Breast cancer

Which of the following would be considered an early response to irradiation?

Erythema

Which acyte radiation syndrome has an average survival time that is an independent dose?

CNS syndrome

Following radiation exposure to the bone marrow which are the first cells to be reproduced?

Lymphocytes

The reproductive cells of the female are termed

oogonia

The reproductive cells of a male are termed?

spermatogonia

For the acyte radiation syndrome in the 10-50Gy range, death is most the result of the damage to the _______system

Gi

Radiation sickness is known as

ARS acute radiation syndrome

Relative risk is

observed cases/expected cases

______ is a stochastic effect of radiation exposure

Cancer

Radiation induced leukemia has a latent period of

4-7 years

Radiation protection guidelines are based on

stochastic effects of radiation

Radiation has been shown to cause?

Chromosome damage

Radiation induced skin cancer in radiotherapy patients has occurred with a

a threshold dose-response

Studies of A-bomb survivors indicate that leukemia has a _____ dose-response relationship to radiation.

linear, nonthreshold

It's difficult to link cancer to radiation exposure bc it occurs ____ in the population

In high proportion

The theory of radiation hormesis suggests that radiation doses below 0.1 mGy are _____.

beneficial

ankylosing spondylitis patients treated with radiation showed an increases incidence of?

Leukemia

Our information on the genetic effects of radiation has come from studies of _____.

mice and fruit flies

Chronic low doses of radiation have ___ effect on fertility

no effect

Data showing radiation-induced human genetic abnormalities _____.

does not exist

A _____effect increases in incidence but not severity as the dose increase

Stochastic

Personnel Monitoring Devices-include all the following accept the ____ dosimeter

Scintillation

Which instrument detects the presence of radiation rather than measuring it ?

Geiger-Mueller counter

The concept of effective dose accounts for the ____

different types of radiation and RBE and relative radiosensitivity of various tissues and organs

The output intensities of reproduced exposures should not vary more than _____% from one another

5%

A cumulative timer is designed to_____

Make radiologist aware

The design of an uncontrolled area in radiology is based on the NCRP recommended limit ____msv/year for the public

1msv

When using the inverse square law during fluoroscopy, the patient should be considered a(n) _____ source of radiation.

point

The collimatir light must be accurate within ___% of the SID

2%

The dose limit for the general public is _____ the dose limit for occupational exposure.

1 msv/yr

The dose limits established by the NCRP are derived from

BEIR and NSC reports

Dose limits are described as

effective dose

A quantity that reflects both dose and volume of tissue irradiated is the _____.

dose area product

Occupational radiation monitoring is required when it is likely that an individual will receive more than what fraction of the annual dose limit?

10%

The source-to-skin distance must be no less than _____ cm on stationary fluoroscopes.

38cm