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Magnetic Resonance Imaging Compatibility of the Polymer-based Cochlear Implant.

Kim JH, Min KS, An SK, Jeong JS, Jun SB, Cho MH, Son YD, Cho ZH, Kim SJ - Clin Exp Otorhinolaryngol (2012)

Bottom Line: In both devices, alignment magnets were removed for safety.In the 3.0 T images, the metal-based device on the left side generated the significant amount of artifacts.Furthermore, it will be also useful for functional MRI studies of the auditory perception mechanism after cochlear implantations as well as for positron emission tomography-MRI hybrid imaging.

View Article: PubMed Central - PubMed

Affiliation: School of Electrical Engineering and Computer Science, College of Engineering, Seoul National University, Seoul, Korea.

ABSTRACT

Objectives: In this study, we compared the magnetic resonance (MR) image artifacts caused by a conventional metal-based cochlear implant and a newly developed liquid crystal polymer (LCP)-based device.

Methods: The metal-based cochlear implant system (Nurobiosys Co.) was attached to side of the head of a subject and the LCP-based device was attached to opposite side. In both devices, alignment magnets were removed for safety. Magnetic resonance imaging (MRI) was performed on a widely used 3.0 T and an ultra-high 7.0 T MRI machine. 3.0 and 7.0 T MR images were acquired using T1- and T2(*)-weighted gradient echo sequences, respectively.

Results: In the 3.0 T images, the metal-based device on the left side generated the significant amount of artifacts. The MR images in the proximity of the metal package were obscured by the artifacts in both axial and sagittal views. On the other hand, the MR images near the LCP-based device were relatively free from the artifacts and clearly showed the brain structures. 7.0 T MR images showed the more severe distortion in the both sides but the metal-based cochlear implant system caused a much larger obscure area than the LCP-based system.

Conclusion: The novel LCP-based cochlear implant provides a good MRI compatibility beyond present-day cochlear implants. Thus, MR images can be obtained from the subjects even with the implanted LCP-based neural prosthetic systems providing useful diagnostic information. Furthermore, it will be also useful for functional MRI studies of the auditory perception mechanism after cochlear implantations as well as for positron emission tomography-MRI hybrid imaging.

No MeSH data available.


Related in: MedlinePlus

T2*-weighted ultra-high 7.0 T magnetic resonance images of the head: axial (A) and sagittal (B) plane views when the metal- and liquid crystal polymer-based cochlear implants are attached to the left and right side of the head, respectively.
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Figure 4: T2*-weighted ultra-high 7.0 T magnetic resonance images of the head: axial (A) and sagittal (B) plane views when the metal- and liquid crystal polymer-based cochlear implants are attached to the left and right side of the head, respectively.

Mentions: Fig. 4A and B are the T2*-weighted 7.0 T MR images of the axial and sagittal plane of the head, respectively. Since the spatial resolution is higher than the 3.0 T images, sulcus, gyrus, white matter, and gray matter are clearly distinguished. An identical device configuration was used to compare the artifact between the two implants. Similar to the 3.0 T images, severe artifacts created by a metal-based implant were observed on the left side of the metal packaged cochlear implant, while mild artifacts were observed on the right side. In 7.0 T images, a magnitude of the artifacts caused by LCP-based implant was slightly larger than 3.0 T images. It is likely that the LCP-based planar coil (inset of the Fig. 1B) is more interactive with the RF coil of the 7.0 T MRI machine than the 3.0 T MRI.


Magnetic Resonance Imaging Compatibility of the Polymer-based Cochlear Implant.

Kim JH, Min KS, An SK, Jeong JS, Jun SB, Cho MH, Son YD, Cho ZH, Kim SJ - Clin Exp Otorhinolaryngol (2012)

T2*-weighted ultra-high 7.0 T magnetic resonance images of the head: axial (A) and sagittal (B) plane views when the metal- and liquid crystal polymer-based cochlear implants are attached to the left and right side of the head, respectively.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3369977&req=5

Figure 4: T2*-weighted ultra-high 7.0 T magnetic resonance images of the head: axial (A) and sagittal (B) plane views when the metal- and liquid crystal polymer-based cochlear implants are attached to the left and right side of the head, respectively.
Mentions: Fig. 4A and B are the T2*-weighted 7.0 T MR images of the axial and sagittal plane of the head, respectively. Since the spatial resolution is higher than the 3.0 T images, sulcus, gyrus, white matter, and gray matter are clearly distinguished. An identical device configuration was used to compare the artifact between the two implants. Similar to the 3.0 T images, severe artifacts created by a metal-based implant were observed on the left side of the metal packaged cochlear implant, while mild artifacts were observed on the right side. In 7.0 T images, a magnitude of the artifacts caused by LCP-based implant was slightly larger than 3.0 T images. It is likely that the LCP-based planar coil (inset of the Fig. 1B) is more interactive with the RF coil of the 7.0 T MRI machine than the 3.0 T MRI.

Bottom Line: In both devices, alignment magnets were removed for safety.In the 3.0 T images, the metal-based device on the left side generated the significant amount of artifacts.Furthermore, it will be also useful for functional MRI studies of the auditory perception mechanism after cochlear implantations as well as for positron emission tomography-MRI hybrid imaging.

View Article: PubMed Central - PubMed

Affiliation: School of Electrical Engineering and Computer Science, College of Engineering, Seoul National University, Seoul, Korea.

ABSTRACT

Objectives: In this study, we compared the magnetic resonance (MR) image artifacts caused by a conventional metal-based cochlear implant and a newly developed liquid crystal polymer (LCP)-based device.

Methods: The metal-based cochlear implant system (Nurobiosys Co.) was attached to side of the head of a subject and the LCP-based device was attached to opposite side. In both devices, alignment magnets were removed for safety. Magnetic resonance imaging (MRI) was performed on a widely used 3.0 T and an ultra-high 7.0 T MRI machine. 3.0 and 7.0 T MR images were acquired using T1- and T2(*)-weighted gradient echo sequences, respectively.

Results: In the 3.0 T images, the metal-based device on the left side generated the significant amount of artifacts. The MR images in the proximity of the metal package were obscured by the artifacts in both axial and sagittal views. On the other hand, the MR images near the LCP-based device were relatively free from the artifacts and clearly showed the brain structures. 7.0 T MR images showed the more severe distortion in the both sides but the metal-based cochlear implant system caused a much larger obscure area than the LCP-based system.

Conclusion: The novel LCP-based cochlear implant provides a good MRI compatibility beyond present-day cochlear implants. Thus, MR images can be obtained from the subjects even with the implanted LCP-based neural prosthetic systems providing useful diagnostic information. Furthermore, it will be also useful for functional MRI studies of the auditory perception mechanism after cochlear implantations as well as for positron emission tomography-MRI hybrid imaging.

No MeSH data available.


Related in: MedlinePlus