ASTM

Podcast Beta

Play an AI-generated podcast conversation about this lesson

Questions and Answers

What must be reported in the report?

The weight of the tested device

The dimensions of the device (correct)

The serial number of the device

The temperature of the device

What should be ensured when suspending the device from the string?

The string length is more than 1% of the device's weight

The string length is less than 1% of the device's weight (correct)

The string length is equal to 1% of the device's weight

The string length is not relevant

What is the MR Conditional icon?

The letters “MR” within a yellow equilateral triangle with a thick black band around the perimeter. (correct)

The letters “MR” surrounded by a red circle with a diagonal red bar across the letters extending from the upper left quadrant to the lower right quadrant of the circle and oriented at 45° from the horizontal.

The letters “MR” within a green equilateral triangle with a thick black band around the perimeter.

The letters “MR” surrounded by a black circle with a diagonal black bar across the letters extending from the upper left quadrant to the lower right quadrant of the circle and oriented at 45° from the horizontal.

What is the primary purpose of this test method?

To determine if a medical device may cause injury during a magnetic resonance examination Signup and view all the answers

What should be done with items placed in the MR environment?

Evaluate and mark them as "MR safe" Signup and view all the answers

What information should be included in the report for each specimen tested?

Device product description Signup and view all the answers

What is the purpose of the test method for MR images?

To assess image artifacts Signup and view all the answers

What is the primary purpose of the terms MR safe, MR unsafe, and MR conditional?

To describe the safety of devices in and near MR scanners Signup and view all the answers

What must be reported in the report in terms of the device's center of mass?

The coordinates of the center of mass Signup and view all the answers

What should be included in the report regarding the artifact measurement?

The method used Signup and view all the answers

What type of magnetic field should the device be tested in?

Static magnetic field oriented horizontally and parallel to the bore Signup and view all the answers

What is an incorrect assumption often made about items labeled MR safe or MR compatible?

They are safe or compatible for any MR environment Signup and view all the answers

What type of device is the test method specific to?

Passive implants Signup and view all the answers

What type of torque is considered in this test method?

Magneto-static torque Signup and view all the answers

What should be included on the product packaging label?

The MR Conditional icon Signup and view all the answers

What should be done before permitting any uncertain items into the MR environment?

Use critical judgment Signup and view all the answers

What is the relationship between torque and deflection angle?

τ = k∆θ Signup and view all the answers

What is the MR Unsafe marking?

The letters “MR” surrounded by a red circle with a diagonal red bar across the letters extending from the upper left quadrant to the lower right quadrant of the circle and oriented at 45° from the horizontal. Signup and view all the answers

What information should be included about the MRI system?

Make and model Signup and view all the answers

What should be done to the device prior to testing?

It should be left as is Signup and view all the answers

What is required for images containing both the device being tested and the reference object?

Two sets of images Signup and view all the answers

What is the best way to assess MR Conditional requirements?

By reading the MR equipment user manual Signup and view all the answers

What should be included on patient information cards for devices that require them?

A statement about image artifact Signup and view all the answers

What must be reported if the device deflects during the test?

The position at which the device deflects Signup and view all the answers

What type of pulse sequence should be used to assess the device?

Gradient echo Signup and view all the answers

What should be done if anything is used to hold the device during the test?

The added mass should be less than 1% of the weight of the device Signup and view all the answers

What are some potential risks and hazards associated with MR imaging equipment?

Magnetically induced displacement force Signup and view all the answers

What should be included about the solution used to immerse the device?

The solution concentration Signup and view all the answers

What can cause image artifacts?

Geometric distortion Signup and view all the answers

What must be reported in terms of the magnetic field?

The magnitude of the magnetic field Signup and view all the answers

What is the sensitivity of the torque measurement apparatus required to be?

Greater than 1/10 the “gravity torque” Signup and view all the answers

What type of testing is necessary to characterize the behavior of the item in the MR environment?

All of the above Signup and view all the answers

What is the MR Safe icon?

The letters “MR” within a green equilateral triangle with a thick black band around the perimeter. Signup and view all the answers

What must be reported in terms of the deflection angle?

The mean deflection angle Signup and view all the answers

What must be adjusted to achieve pixel dimensions to accurately measure the artifact?

Field of view Signup and view all the answers

What is the device evaluated in this test method?

A specimen Signup and view all the answers

What is the main risk associated with items that are in contact with MR equipment?

Electric shock Signup and view all the answers

What is the maximum deflection force for ferromagnetic materials?

At the location where |B| is a maximum Signup and view all the answers

How can methods for assessing image artifact vary?

Depending on the manufacturer Signup and view all the answers

What information should be included in the report regarding the device?

Product description Signup and view all the answers

How is the torque measured at 10° increments?

By rotating the device around two principal axes Signup and view all the answers

What must be reported in terms of the weight?

The weight of the device Signup and view all the answers

What is the primary factor that determines the forces and torques associated with MR imaging equipment?

The spatial gradient of the field Signup and view all the answers

What should be done with items that present no additional risk within the MR environment?

Permit them into the MR environment Signup and view all the answers

How many images must be acquired to assess the device?

Two Signup and view all the answers

What should be included in the report regarding the MRI system?

Coil used Signup and view all the answers

What is the test location for the device?

At the entrance of the MR system bore and on the axis of the bore Signup and view all the answers

What is the minimum information required for MR marking?

Mark the item as MR Safe, MR Conditional, or MR Unsafe using the icons as shown in Tables 1 and 2. Signup and view all the answers

What must be determined for each image pair?

All of the above Signup and view all the answers

What safety issues should be addressed in addition to the test method?

Magnetically induced force Signup and view all the answers

What should be used when evaluating items placed in the MR environment?

Judgment Signup and view all the answers

What should be included in the report regarding the artifact measurement?

The method used Signup and view all the answers

What is the most accurate description of the terms MR safe, MR unsafe, and MR conditional?

They are used to describe the safety of devices in and near MR scanners Signup and view all the answers

What should the MR marking not compromise?

Function Signup and view all the answers

What must be reported if the deflection angle is greater than 45°?

The mean magnetically induced displacement force Signup and view all the answers

What type of structure is used to hold the device in place?

A sturdy, nonmagnetic structure Signup and view all the answers

What should be included in the report for each specimen tested?

Device product description Signup and view all the answers

When can the test method be used?

During product development Signup and view all the answers

What must be calculated if the maximum allowable spatial gradient of the magnetic field is known?

The mean magnetically induced displacement force Signup and view all the answers

What is the orientation of the MR Conditional icon?

The triangle is oriented with its horizontal side below the letters “MR.” Signup and view all the answers

How should items that are uncertain be treated in the MR environment?

Evaluate and mark them as "MR safe" Signup and view all the answers

What type of force is present at the test location?

Magnetically induced force, Fm Signup and view all the answers

What is NOT addressed in this test method?

Dynamic torque Signup and view all the answers

What is an important factor to consider when determining the safety of an item in a different MR system?

The conditions in which the device was tested Signup and view all the answers

How many specimens must be tested with the device?

Three Signup and view all the answers

What should be included about the solution used to immerse the device?

The solution concentration Signup and view all the answers

What is the product of device weight and the largest linear dimension referred to in the text?

Gravity torque Signup and view all the answers

When color reproduction is not practical, what is the icon printed in?

Black and white Signup and view all the answers

What should be done if the weight of the holding material exceeds 1% of the weight of the device?

The weight of the holding material should be reported Signup and view all the answers

What is the purpose of acquiring a complete set of spin echo image pairs?

To assess the device Signup and view all the answers

What should be used when permitting any uncertain items into the MR environment?

Judgment Signup and view all the answers

What is the most common risk associated with MR equipment?

False information on the screen Signup and view all the answers

What must be ascertained in order to acquire a pair of gradient echo images?

The worst case conditions Signup and view all the answers

What is strongly encouraged for the added visibility and information provided by the color?

The use of the colored icon Signup and view all the answers

What is the primary source of information for assessing MR Conditional requirements?

The MR equipment user manual Signup and view all the answers

What should be done to avoid potential injury or delay in scanning?

Mark the device as described in this practice Signup and view all the answers

What is the device NOT placed in to measure the torque?

A lead wire Signup and view all the answers

What information should be included in the report for each specimen tested?

Representative set of spin echo images Signup and view all the answers

Is this test method sufficient for determining if a device is safe in the MR environment?

No Signup and view all the answers

What must be reported in terms of the device identification?

All of the above Signup and view all the answers

Study Notes

Medical devices and other items can interact with the MR environment and cause injuries and death to patients.
The practice provides a system for marking items to indicate the conditions under which they are safe to use in the MR environment.
Testing is necessary to characterize the behavior of the item in the MR environment. This includes testing for magnetically induced displacement force, magnetically induced torque, and RF heating.
MR marking should be included on the product packaging label (e.g. on the box), and the package label should clearly indicate the item(s) inside the packaging to which the MR marking applies.
The MR marking should not compromise performance or function of the marked item and should remain readable over the anticipated service life of the item.
Minimum information—mark the item as MR Safe, MR Conditional, or MR Unsafe using the icons as shown in Tables 1 and 2.
The use of the colored icon is strongly encouraged for the added visibility and information provided by the color.
The MR Conditional icon consists of the letters “MR” within a yellow equilateral triangle with a thick black band around the perimeter.
The triangle is oriented with its horizontal side below the letters “MR.”
The MR Conditional icon may be supplemented by supplementary marking which includes the appropriate information from Section 5 and describes the conditions for which the item has been demonstrated to be MR Condional.
The MR Unsafe marking consists of the letters “MR” surrounded by a red circle with a diagonal red bar across the letters extending from the upper left quadrant to the lower right quadrant of the circle and oriented at 45° from the horizontal.
When color reproduction is not practical, the icon may be printed in black and white.
The use of the colored icon is strongly encouraged for the added visibility and information provided by the color.

Studying That Suits You

Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

Description

Learn about the system for marking medical items to indicate their safety for use in the MR environment. Discover the criteria for MR Safe, MR Conditional, and MR Unsafe markings, as well as testing requirements and packaging label guidelines.