1、Designation:F211907(Reapproved 2013)Standard Test Method forEvaluation of MR Image Artifacts from Passive Implants1This standard is issued under the fixed designation F2119;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,the year of
2、last revision.A number in parentheses indicates the year of last reapproval.Asuperscript epsilon()indicates an editorial change since the last revision or reapproval.1.Scope1.1 This test method characterizes the distortion and signalloss artifacts produced in a magnetic resonance(MR)image bya passiv
3、e implant(implant that functions without the supply ofelectrical or external power).Anything not established to beMR-Safe or MR-Conditional is excluded.1.2 The values stated in SI units are to be regarded asstandard.No other units of measurement are included in thisstandard.2.Referenced Documents2.1
4、 ASTM Standards:2F2052 Test Method for Measurement of Magnetically In-duced Displacement Force on Medical Devices in theMagnetic Resonance EnvironmentF2182 Test Method for Measurement of Radio FrequencyInduced Heating On or Near Passive Implants DuringMagnetic Resonance ImagingF2213 Test Method for
5、Measurement of Magnetically In-duced Torque on Medical Devices in the Magnetic Reso-nance EnvironmentF2503 Practice for Marking Medical Devices and OtherItems for Safety in the Magnetic Resonance Environment3.Terminology3.1 Definitions:3.1.1 artifact width,nthe maximum distance(mm)fromthe edge of th
6、e implant to the fringe of the resulting imageartifact found in the entire set of images acquired using this testmethod.3.1.2 image artifact,na pixel in an image is considered tobe part of an image artifact if the intensity is changed by atleast 30%when the device is present compared to a referencei
7、mage in which the device is absent.3.1.3 magnetic resonance(MR)environment,nvolumewithin the 0.50 mT(5 gauss(G)line of an MR system,whichincludes the entire three dimensional volume of space sur-rounding the MR scanner.For cases where the 0.50 mT line iscontained within the Faraday shielded volume,t
8、he entire roomshall be considered the MR environment.3.1.4 magnetic resonance imaging(MRI),nimaging tech-nique that uses static and time varying magnetic fields toprovide images of tissue by the magnetic resonance of nuclei.3.1.5 MR-Conditional,adjan item that has been demon-strated to pose no known
9、 hazards in a specified MR environ-ment with specified conditions of use.Field conditions thatdefine the specified MR environment include field strength,spatial gradient,dB/dt(time rate of change of the magneticfield),radio frequency(RF)fields,and specific absorption rate(SAR).Additional conditions,
10、including specific configurationsof the item,may be required.3.1.6 MR-Safe,adjan item that poses no known hazards inall MR environments.NOTE1MR-Safe items include nonconducting,nonmagnetic itemssuch as a plastic petri dish.An item may be determined to be MR-Safe byproviding a scientifically based ra
11、tionale rather than test data.3.1.7 MR-Unsafe,adjan item that is known to posehazards in all MR environments.NOTE2MR-Unsafe items include magnetic items such as a pair offerromagnetic scissors.3.1.8 tesla(T),nthe SI unit of magnetic induction equal to104G.4.Summary of Test Method4.1 Pairs of spin ec
12、ho images are generated both with andwithout the implant in the field of view.Image artifacts areassessed by computing differences outside the region corre-sponding to the implant between reference and implant images.Once the worst case conditions using the spin echo pulsesequence are ascertained,a
13、pair of gradient echo images areacquired under the same conditions.5.Significance and Use5.1 This test method provides a quantified measure of theimage artifact produced under a standard set of scanningconditions.1This test method is under the jurisdiction ofASTM Committee F04 on Medicaland Surgical
14、 Materials and Devices and is the direct responsibility of SubcommitteeF04.15 on Material Test Methods.Current edition approved March 1,2013.Published March 2013.Originallyapproved in 2001.Last previous edition approved in 2007 as F2119 07.DOI:10.1520/F2119-07R13.2For referenced ASTM standards,visit
15、 the ASTM website,www.astm.org,orcontact ASTM Customer Service at serviceastm.org.For Annual Book of ASTMStandards volume information,refer to the standards Document Summary page onthe ASTM website.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United
16、States1 5.2 This test method applies only to passive implants thathave been established to be MR-Safe or MR-Conditional.6.Apparatus6.1 An MR imaging system with a static field strength of 1.5T or 3.0 T is recommended.The MRI system must have theability to swap readout and phase-encode directions.6.2 A reference object made from a nondistorting medium,such as 0.5-in.diameter nylon rod.7.Test Specimen7.1 The implant for which image artifact is to be measuredshall serve as the test specimen.7.2 For
