ARMRIT CNI Study Guide

Shim coils are small electro or permanent magnets that are best characterized by:

Adjustments to correct

for inhomogeneities of the

B0 magnetic field

Which of the following causes thermal injuries in the MRI suite?

RF (radio frequency pulse)

An increase of which of the following does not increase the specific absorption rate in a pulse sequence?

RBW (receiver bandwidth)

What are the FDA maximum limits for specific absorption rates?

Whole body 4.0 w/kg

Head 3.2 w/kg

Specific absorption rate (SAR) measures the delivery of which of the following to the body during an MRI exam?

RF energy deposition

In MRI, SAR (specific absorption rate) is calculated using which of the following units of measurements?

Watts per Kilogram

Per the American College of Radiology, a pregnant patient may safety undergo an MRI a the stage of gestation.

ANY stage

Per the FDA, peripheral nerve stimulation is categorized as what type of concern?

Safety

When should patients with implantable cardioverter defibrillators (ICD) be scanned?

Only after the ICD of that patient has been determined to be safe to be scanned,

The Vendor technologist is present for scan,

Cardiology nurse present to monitor,

Cardiologist and radiologist approve

Which of the following methods does not reduce SAR (specific absorption rate)?

Decreasing Slice Thickness

Which of the following areas within an MRI department does not require a screening form in order to gain access?

Zone 2

Which of the following MRI areas is considered to be a general public area?

Zone 1

Due to translation forces in the main magnetic field, the projectile effect is witnessed in which of the following areas?

Zone 4

Which of the following contrast agents is most commonly used in MRI?

Blood Pool Agents

IV Contrast agents are used in which of the following types of ions as primary contrast mechanism in MRI?

Gadolinium

To form a chelate, a gadolinium ion is chemically bonded with which of the following?

Ligand

Compared with the contrast agents used in CT, the incidence of adverse reaction from MRI gadolinium based contrast agents are:

Significantly lower

Why is administering a gadolinium-based contrast agents to a pregnant patient considered to be high risk?

The contrast agent across placenta to fetus

What is the correct gadolinium-based contrast agents for a patient weighing 100 lbs?

10 mL

Per the FDA, the use of gadolinium-based contrast agents should be avoided for patients with glomerular filtration rate (GFR) of:

30 mL/min/1.73m2

Which of the following is known as an adverse reaction and not a side effect:

Altered taste

A patient with which of the following conditions has the greatest risk for developing nephrogenic systemic fibrosis?

Acute Kidney Failure

Patient screening forms are to be completed and review by the operating MRI tech before a patient enters which of the following zone?

Zone 3

Which of the following best describes the protocol for allowing a family member or friend to accompany a patient into the scan room?

Individuals must complete screening forms for contradictions and remove any metallic before emerging the scan room

When does the patient screening begin?

When MRI Technologist meets the patient prior to the exam

For patients who are unresponsive, otherwise cannot answer screening questions, screening is performed by and in consultation with which of the following individuals?

Lead Radiologist,

Nurse providing care of patient,

referring physician,

whoever is most qualified to provide responses

A patient indicates having a metallic implant, what the necessary steps prior to entering the magnet room?

Confirm MRI safety using facilities to establish a safety processes

Which of the following is NOT considered to be short-term effect caused by gadolinium contrast injections?

NSF: Nephrotic Systemic Fibrosis

In an emergency, an MRI technologist should take which of the following actions?

Implement department policies and procedures

In an emergency, who is responsible for deciding who enters the magnet room?

MRI Technologist

What is the greatest risk associated with an uncontrolled magnet quench?

Gas from helium, displacing oxygen, leading to asphyxiation

Which of the following protocols would be included in an emergency plan for an outpatient MRI facility?

Advanced agreement with outside emergency personnel

Hazards of cryogenic in the MRI environment do not include which of the following?

RF (radio frequency) burns

Which of the following factors is not a part of the formula for calculating the estimate glomerular filtration (eGFR)?

BUN: Blood Urea Nitrogen

Which of the following is the primary route for the administration of gadolinium?

Intravenous

Patient develops hives after gadolinium contrast administration, which following medications should radiologist se to treat reaction?

Antihistamine

Before administering IV Gadolinium contrast, it is necessary to confirm that the patient:

Is eligible to receive IV Gadolinium contrast based on appropriate safety standards

What blood test results are necessary prior to administering contrast?

Creatinine

When is it safe to administer a gadolinium injection to a pregnant patient?

Gadolinium injections are NOT safe during pregnancy

Which of the following terms refers to the type of measurement the FDA uses to monitor the amount of RF (radio frequency) energy deposited in a patients body for each pulse sequence?

SAR: Specific Absorption Rate

Which of following courses of action is best to take when scanning an anxious claustrophobic patient?

Monitor patient visually and communicate verbally reassuring patient throughout the exam

At a minimum, during an exam patient monitoring includes which of the following?

Continuous verbal contact with patients ensuring they're not having difficulty

Which type of patient may be unattended during MRI procedure?

None

In MRI environment, which of the following provides the greatest risk of spreading infectious disease?

Human Hands

Per the Center for Disease Control and Prevention, which of the following is the leading cause of hospital acquired infections?

Improper hand and equipment washing after each use

To reduce the risk of infections in a magnet room, a pillow should?

Have a waterproof cover

It is recommended that gloves and gowns should be worn by MRI staff if a patient displays which of the following?

An open wound or history of infection

The complete elimination of all pathogens and microorganisms is referred to as which of the following?

Sterilization

Which of the following approaches best improves SNR?

Decrease phase encoding steps,

Using smaller surface coil

Which of the following field strengths has the highest SNR?

3.0 Tesla

Doubling the NSA/NEX results in what percentage of SNR?

40%

Increasing slice thickness increases SNR by which following?

Sampling more spins and excitation area

How does increasing the number of frequencies encoding steps affect SNR (signal-to-noise)?

SNR decreases

How is the SNR affected when the FOV is decreased?

SNR decreases

What effect does increasing TR have on SNR?

Increases SNR

Why does a 3.0 Tesla magnet have inherently higher SNR than a 1.3 T magnet?

More hydrogen protons contributing to the net magnetic vector

Large voxels produce higher SNR than small voxels due to which of the following?

More Hydrogen Nuclei

Which of the following sets of parameters will provide the high SNR, if all the other parameters remain the same:

Matrix 256 x 256, 3 mm slice thickness, FOV 200

Keeping other parameters consistent, decreasing the matrix 512 x 512 to 320 x 320, yields what effect?

SNR increasing

What is the effect on SNR when reducing the RBW (receiver bandwidth) of pulse sequence?

SNR increases

Increasing slice thickness by 50%, has what effect on SNR?

SNR increases by 50%

Decreasing the FOV will have an effect on SNR?

SNR will decrease

Increasing NEX/NSA yields which of the following?

Increase Scan time

Increase SNR

For the human eye to detect an increase in SNR of an image, SNR must be increased by minimum approximately what percent?

20%

Doubling the NEX/NSA in pulse sequence yield increases SNR by what percent?

40%

Which of the following parameters would not increase SNR?

Increase RBW

Which of the following parameters has a direct effect on scan time?

Repetition time (TR)

The dimension of a voxel used in the acquisition to obtain a matrix is also known as which of the following?

Spatial Resolution

What is the formula for calculating the scan time in a basic Spin echo pulse?

Phase encoding matrix x TR x NEX

Which of the following ETL would theoretically produce the shortest scan time?

Choose the option with the (longest ETL)

Which of the following parameters affects scan time?

Number of slices

Matrix

TR

Increasing the TR results which have the following effects on scan time?

Lengthen scan time

In MRI spatial resolution is defined by which of the following characteristics?

Voxel size

Which of the following imaging techniques uses an accelerated K-Space filling to decrease scan time and/or increase temporal resolution?

Parallel imaging

To increase spatial resolution without affecting scan time and all other parameters staying the same, an MRI technologist can do which of the following?

Decrease FOV

Decreasing the FOV increases spatial resolution but decreases which of the following?

SNR

Which of the following best describes temporal resolution?

Time required to complete a single acquisition in a multi- acquisition pulse sequence

As voxel size decreases, how much is image quality affected?

Spatial resolution improves

Which of the following 3 parameters controls the size of the voxel and image spatial resolution?

FOV

Matrix

Slice Thickness

As slice thickness increases, spatial resolution decreases due to corresponding increase of which of the following?

SNR: Signal-to-noise ratio

As phase encoding steps increase, spatial resolution will increase due to which of the following?

Voxel size decrease

In which order would the following 3 gradients be switched on and off, for standard pulse sequence?

GS: Slice Select Gradient

GP: Phase Encoding Gradient

GF: Frequency Encoding Gradient

Which of the following types of resolution provided the ability to distinguish between two-times points as separate and distinct?

Spatial

Keeping other factors, how is the voxel size affected by changing the FOV from rectangular to square?

Stay the same

Which of the following imaging applications requires knowledge of temporal resolution?

Cardiac MRI CINE technique

Which of the following is most likely to cause zipper artifact?

Scanner room door being left open during acquisition

Which of the following would cause a phase mismapping artifact?

Anatomical motion

Motion artifacts appear in which direction?

Phase encoding direction

Aliasing artifacts are caused by which of the following?

FOV being smaller than area of excitation

Cardiac motion can be significantly reduced by which of the following?

EKG or peripheral gating

Picture of an artifact that is repeated twice:

Ghosting

Slice excitation pulses that excite protons in an adjacent slice causing artifactual contrast changes are known as?

Cross excitation

Which of the following provides the best strategy for reducing chemical/shift artifacts?

Increase receiver bandwidth

Which of the artifacts results from VENC used in phase contrast MRA, lover than velocity of the flow?

Aliasing

Motion artifacts can be identified by which of the following?

Blurring and ghosting in phase encoding direction

An extension of breast tissue axilla is known as?

Axillary Tail

MRCP is utilized for which of the following areas?

Biliary and pancreatic ductal structures

What is the role of an MR MD on questionable implants?

Advise and execute

What is the role of an MR safety official on questionable implants?

To Decide

Perfusions refer to the matrix ratio of blood flow through the:

Capillary