ISO TS 10974:2018
(Main)Assessment of the safety of magnetic resonance imaging for patients with an active implantable medical device
Assessment of the safety of magnetic resonance imaging for patients with an active implantable medical device
ISO/TS 10974:2018 is applicable to implantable parts of active implantable medical devices (AIMDs) intended to be used in patients who undergo a magnetic resonance scan in 1,5 T, cylindrical (circular or elliptical cross-section) bore, whole body MR scanners operating at approximately 64 MHz with whole body coil excitation.
NOTE 1 Requirements for non-implantable parts are outside the scope of this document.
The tests that are specified in this document are type tests that characterize interactions with the magnetic and electromagnetic fields associated with an MR scanner. The tests can be used to demonstrate device operation according to its MR Conditional labelling. The tests are not intended to be used for the routine testing of manufactured products.
NOTE 2 Modification of these tests for particular device types is left to particular product committees.
NOTE 3 Other interested parties, such as device manufacturers, regulatory agencies, and particular product committees, are responsible for setting specific compliance criteria and determining risk.
NOTE 4 Safety requirements for MR scanners can be found in IEC 60601‑2‑33.
NOTE 5 The scope is limited to AIMDs that do not use sensing functions or to AIMDs that are programmed not to use sensing functions to affect therapy delivery during an MR scan.
General Information
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Standards Content (Sample)
TECHNICAL ISO/TS
SPECIFICATION 10974
Second edition
2018-04
Assessment of the safety of magnetic
resonance imaging for patients with
an active implantable medical device
Évaluation de la sécurité de l'imagerie par résonance magnétique
pour les patients avec un dispositif médical implantable actif
Reference number
ISO/TS 10974:2018(E)
©
ISO 2018
ISO/TS 10974:2018(E)
© ISO 2018
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Published in Switzerland
ii © ISO 2018 – All rights reserved
ISO/TS 10974:2018(E)
Contents Page
Foreword .vii
Introduction .viii
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Symbols and abbreviated terms . 6
5 General requirements for non-implantable parts . 6
6 Requirements for particular AIMDs . 6
7 General considerations for application of the tests of this document .6
7.1 Compliance criteria . 6
7.2 Use of tiers . 7
7.3 Test reports . 7
7.3.1 General. 7
7.3.2 Description of the AIMD under test . 7
7.3.3 Test methods and results . 7
8 Protection from harm to the patient caused by RF-induced heating .8
8.1 Introduction . 8
8.2 Outline of the Stage 1 four-tier approach . 8
8.3 Measurement system prerequisites for all tiers .10
8.3.1 RF field source .10
8.3.2 Tissue simulating phantom .10
8.3.3 Definition of power deposition .12
8.3.4 Measurement system validation .12
8.4 Determination of RF-induced power deposition in a tissue simulating medium .12
8.4.1 General.12
8.4.2 Determine location of hot spots around the AIMD .13
8.4.3 Determination of spatial (3D) distribution of power deposition for each
hot spot .13
8.4.4 Determine the final power deposition .14
8.5 Proximity effect of electrodes from multiple leads .16
8.6 Modelling prerequisites for Tier 2, Tier 3, and Tier 4 .17
8.7 Tier selection for RF-induced power deposition .17
8.7.1 General.17
8.7.2 Tier 1 .17
8.7.3 Tier 2 .18
8.7.4 Tier 3 .19
8.7.5 Tier 4 .20
8.8 In vitro model validation .21
8.9 Overall uncertainty analysis .23
8.10 In vivo analysis of power deposition .24
8.11 RF-induced heating assessment flow chart.24
9 Protection from harm to the patient caused by gradient-induced device heating .27
9.1 Introduction .27
9.2 Testing considerations .28
9.2.1 General.28
9.2.2 Determination of |dB/dt| rms exposure limits .29
9.2.3 Determination of test duration .29
9.3 Test requirements .29
9.3.1 General.29
9.3.2 In vitro test phantom or other suitable container .30
9.3.3 Gelled solution .30
ISO/TS 10974:2018(E)
9.3.4 Temperature survey to determine orientation and hot spots .30
9.3.5 Minimum temperature instrumentation .31
9.3.6 Definition of dB/dt test waveform .31
9.3.7 Characterization of applied dB/dt .32
9.4 Lab testing using simulated MR gradient field .32
9.5 MR scanner testing .32
9.6 Analysis of gradient heating test .33
10 Protection from harm to the patient caused by gradient-induced vibration .33
10.1 Introduction .33
10.2 Overview of tiers .34
10.3 MR environmental conditions .35
10.3.1 General.35
10.3.2 Determination of maximum clinical dB/dt .35
10.3.3 Determination of clinical B .
0 35
10.3.4 Determination of clinical dB/dt × B .
0 35
10.3.5 Test frequencies .35
10.3.6 Test duration .36
10.3.7 Test temperature .37
10.4 General test procedure .37
10.4.1 Measurement of gradient field and determination of AIMD location .37
10.4.2 AIMD/test unit setup .37
10.5 Method 1 — MR scanner .38
10.6 Method 2 — Shaker table .39
10.6.1 General.39
10.6.2 Determine scanner input .39
10.6.3 AIMD vibration response .39
10.6.4 Determine shaker table amplitude (dB/dt scaling) .40
10.6.5 Perform vibration exposure using a shaker table .
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