EXPOSURE LIBRARIES
cls
MRIxViP1.5T

MRIxViP1.5T

The MRIxViP1.5T library is a standard library consisting of 6,884 3D-distributions of electromagnetic fields (EMF) that are representative of the 64 MHz radio-frequency exposure of any person undergoing any magnetic resonance imaging (MRI) exam. The library is unique in that it allows for the effective and comprehensive evaluation of potential risks posed by EM exposures of MRI (important for e.g., patients with active or passive implants).

The local fields induced in the human body are a function of multiple factors:

  • the birdcage (port excitations, dimensions);
  • the anatomy (age, height, weight, body mass index, posture, etc.);
  • the landmark position.

In order to guarantee the appropriate population coverage, the library combines birdcage variations covering all of the installed MRI birdcages (BCLib of Sim4Life), anatomical variations (Virtual Population ViP 3.x) and all landmark positions in 5 steps from head to feet, where the 0 landmark is the scan position where the RF-coil iso-center is at the head center imaging position. The IT'IS Tissue Property Database is used to assign the dielectric properties of all tissues.

For each of the variations, the library includes the induced 3D electric and magnetic fields at a resolution finer than 2x2x2 mm for both ports separately, such that any polarization can be obtained by superposition.

MRIxViP1.5T V2.0 Configurations

ViP Model RF-Coil Parameters Imaging Position MDDT

Bore

(cm)

ID

(cm)

Length

(cm)

Duke

65 60 50,60,70 0, 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, 100, 105, 110, 115, 120, 125, 130, 135, 140, 145, 150, 155, 160 yes
75 70 40,50,60,70
80 75 50,60,70

Ella

65 60 50,60,70 0, 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, 100, 105, 110, 115, 120, 125, 130, 135, 140, 145, 150 yes
75 70 40,50,60,70
80 75 50,60,70

Ella
BMI 26

65 60 50,60,70 0, 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, 100, 105, 110, 115, 120, 125, 130, 135, 140, 145, 150
75 70 40,50,60,70
80 75 50,60,70

Ella
BMI 30

65 60 50,60,70 0, 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, 100, 105, 110, 115, 120, 125, 130, 135, 140, 145, 150
75 70 40,50,60,70
80 75 50,60,70

Billie

65 60 50,60,70 0, 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, 100, 105, 110, 115, 120, 125, 130 yes
75 70 40,50,60,70
80 75 50,60,70
Thelonious 65 60 50,60,70 0, 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, 100


yes
75 70 40,50,60,70
80 75 50,60,70

Fats

75 70 40,50,60,70 0, 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, 100, 105, 110, 115, 120, 125, 130, 135, 140, 145, 150, 155, 160 yes
80 75 50,60,70

Fats
BMI 29

75 70 40,50,60,70 0, 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, 100, 105, 110, 115, 120, 125, 130, 135, 140, 145, 150, 155, 160
80 75 50,60,70
Glenn

65 60 50,60,70 0, 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, 100, 105, 110, 115, 120, 125, 130, 135, 140, 145, 150, 155, 160

yes
75 70 40,50,60,70
80 75 50,60,70
Louis

65 60 50,60,70 0, 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, 100, 105, 110, 115, 120, 125, 130, 135, 140, 145, 150, 155, 160

yes
75 70 40,50,60,70
80 75 50,60,70
Eartha 65 60 50,60,70 0, 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, 100, 105, 110, 115, 120

yes
75 70 40,50,60,70
80 75 50,60,70
Yoon-sun

65 60 50,60,70 0, 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, 100, 105, 110, 115, 120, 125, 130, 135, 140, 145, 150, 155, 160
75 70 40,50,60,70
80 75 50,60,70

Validation

The library has been thoroughly validated and the protocol and validation report are available upon request. The MRIxViP V1.0 libraries have been qualified by the FDA as part of the MDDT, IMAnalytics With MRIxVIP1.5T/3.0T and BCLib.

Coverage

The library is maintained and continuously expanded (e.g., new birdcages, anatomical models, postures) considering feedback from customers and regulators. The population coverage of the ViP models in the latest version of MRIxViP is shown below (males: blue squares; females: black circles) with age-dependent statistical data¹; dashed lines: 50th percentile; solid lines: 5th and 95th percentiles. Morphed ViP models are used to improve the population coverage. 

¹sources: 2 – 20 years from National Center for Health Statistics (2000); 25 – 80 years approximated from Ogden et al. (1)(2).

VIP BMI tg v3

Version History and Tracking

The IT'IS Foundation warranties that a copy of all released versions can be obtained for at least 10 years after the initial release.

Version Release Specifications DOI
2.0 March 12, 2019 Includes four new models (Yoon-sun, Fats BMI 29, Ella BMI 26 and 30) and a maintenance update for Fats (now V3.2).

10.13099/MRIxViP1.5T-02-0

1.0 September 19, 2017 Initial release of MRIxViP1.5T. Qualified by the FDA as part of the MDDT.

10.13099/MRIxViP1.5T-01-0

Note that the DOIs do not vary with builds but with versions. Changes to the libraries that are likely to influence simulation results are associated with changes in version number.