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Temperature measurement on neurological pulse generators during MR scans.

Kainz W, Neubauer G, Uberbacher R, Alesch F, Chan DD - Biomed Eng Online (2002)

Bottom Line: Temperature increases in other locations were low compared to the one at the lead tip.The measured temperature increase of 2.1 degrees C can not be considered as harmful to the patient.Comparison with the results of other studies revealed the avoidance of loops as a practical method to reduce heating during MRI procedures.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Mobile Communications Safety, ARC Seibersdorf Research, Austria. kainz@gmx.com

ABSTRACT
According to manufacturers of both magnetic resonance imaging (MRI) machines, and implantable neurological pulse generators (IPGs), MRI is contraindicated for patients with IPGs. A major argument for this restriction is the risk to induce heat in the leads due to the electromagnetic field, which could be dangerous for the surrounding brain parenchyma. The temperature change on the surface of the case of an ITREL-III (Medtronic Inc., Minneapolis, MN) and the lead tip during MRI was determined. An anatomical realistic and a cubic phantom, filled with phantom material mimicking human tissue, and a typical lead configuration were used to imitate a patient who carries an IPG for deep brain stimulation. The measurements were performed in a 1.5 T and a 3.0 T MRI. 2.1 degrees C temperature increases at the lead tip uncovered the lead tip as the most critical part concerning heating problems in IPGs. Temperature increases in other locations were low compared to the one at the lead tip. The measured temperature increase of 2.1 degrees C can not be considered as harmful to the patient. Comparison with the results of other studies revealed the avoidance of loops as a practical method to reduce heating during MRI procedures.

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Measurement positions on the implant case (dimensions in mm)
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Figure 2: Measurement positions on the implant case (dimensions in mm)

Mentions: The measurements were performed in a 1.5 T MR Imager from Siemens (Magnetom) working at 63.6 MHz. The temperature was measured at four positions: at two points at the surface of the implant (see Fig. 2: P2 and P3), at the surface of the lead-tip (electrode pole # 3) and in air 5 cm above the back of the phantom. The air temperature was measured as a reference temperature for the measurements at the implant surface and at the lead-tip. The two experiments had two different fields of view (FOV) which were changed electronically. One FOV was situated in the head above the lead tip and the other was in the chest region directly over the implant. In both cases the TSE sequence was used (see Tab. 3).


Temperature measurement on neurological pulse generators during MR scans.

Kainz W, Neubauer G, Uberbacher R, Alesch F, Chan DD - Biomed Eng Online (2002)

Measurement positions on the implant case (dimensions in mm)
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC130994&req=5

Figure 2: Measurement positions on the implant case (dimensions in mm)
Mentions: The measurements were performed in a 1.5 T MR Imager from Siemens (Magnetom) working at 63.6 MHz. The temperature was measured at four positions: at two points at the surface of the implant (see Fig. 2: P2 and P3), at the surface of the lead-tip (electrode pole # 3) and in air 5 cm above the back of the phantom. The air temperature was measured as a reference temperature for the measurements at the implant surface and at the lead-tip. The two experiments had two different fields of view (FOV) which were changed electronically. One FOV was situated in the head above the lead tip and the other was in the chest region directly over the implant. In both cases the TSE sequence was used (see Tab. 3).

Bottom Line: Temperature increases in other locations were low compared to the one at the lead tip.The measured temperature increase of 2.1 degrees C can not be considered as harmful to the patient.Comparison with the results of other studies revealed the avoidance of loops as a practical method to reduce heating during MRI procedures.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Mobile Communications Safety, ARC Seibersdorf Research, Austria. kainz@gmx.com

ABSTRACT
According to manufacturers of both magnetic resonance imaging (MRI) machines, and implantable neurological pulse generators (IPGs), MRI is contraindicated for patients with IPGs. A major argument for this restriction is the risk to induce heat in the leads due to the electromagnetic field, which could be dangerous for the surrounding brain parenchyma. The temperature change on the surface of the case of an ITREL-III (Medtronic Inc., Minneapolis, MN) and the lead tip during MRI was determined. An anatomical realistic and a cubic phantom, filled with phantom material mimicking human tissue, and a typical lead configuration were used to imitate a patient who carries an IPG for deep brain stimulation. The measurements were performed in a 1.5 T and a 3.0 T MRI. 2.1 degrees C temperature increases at the lead tip uncovered the lead tip as the most critical part concerning heating problems in IPGs. Temperature increases in other locations were low compared to the one at the lead tip. The measured temperature increase of 2.1 degrees C can not be considered as harmful to the patient. Comparison with the results of other studies revealed the avoidance of loops as a practical method to reduce heating during MRI procedures.

Show MeSH
Related in: MedlinePlus