access icon free Evaluation of local B 1 field as dosimeter of RF heating for implant in MRI

Radio frequency (RF) heating is a serious risk for a patient with an elongated implant during MRI scan. The conventional dosimeter of specific absorption rate (SAR) and the recently proposed B 1+rms may not accurately indicate the implant heating. The local B 1 field around the tip of a lead and its relationship with the RF heating were studied by numerical simulations. It was found that regardless of the route of the lead, the angle or position of placement, there was a strong linear correlation between the averaged square of local B 1 field and the rise in temperature. The evaluation range had an effect on the linearity. Generally, the local B 1 field performed better as a dosimeter of RF heating than SAR or B 1+rms at the isocentre.

Inspec keywords: biomedical MRI; prosthetics; radiofrequency heating; dosimeters

Other keywords: dosimeter; RF heating; local B1 field; implant heating; MRI; elongated implant; serious risk; specific absorption rate; radiofrequency heating

Subjects: Medical magnetic resonance imaging and spectroscopy; Patient diagnostic methods and instrumentation; Biothermics; Radiation protection and dosimetry; Prosthetics and other practical applications; Biomedical magnetic resonance imaging and spectroscopy; Radiation dosimetry in medical physics; Prosthetics and orthotics

References

    1. 1)
      • 5. Milne, A.A.: ‘Current issues in MRI safety’, in Anthony, B. (Ed.): ‘Advances in medical physics’ (Medical Physics Publishing, Madison, WI, USA, 2012), pp. 195203.
    2. 2)
    3. 3)
      • 3. Faulkner, W.: ‘New MRI safety labels & devices’, Signals, 2016, 5, (1), available at https://www.ismrm.org/smrt/E-Signals/2016FEBRUARY/eSig_5_1_hot_2.htm.
    4. 4)
      • 7. ASTM F2182-11a: ‘Standard test method for measurement of radio frequency induced heating on or near passive implants during magnetic resonance imaging’, 2011.
    5. 5)
    6. 6)
    7. 7)
    8. 8)
http://iet.metastore.ingenta.com/content/journals/10.1049/el.2018.6857
Loading

Related content

content/journals/10.1049/el.2018.6857
pub_keyword,iet_inspecKeyword,pub_concept
6
6
Loading
Correspondence
This article has following corresponding article(s):
Beside the point