Design of an Intraoral Dipole Antenna for Dental Applications

Özen, Ali Çağlar; Idiyatullin, Djaudat; Adriany, Gregor; Jungst, Steve; Kobayashi, Naoharu; Groenke, Beth R.; Bock, Michael; Nixdorf, Donald R.

doi:10.1109/tbme.2021.3055777

Cited by 13 publications

(9 citation statements)

References 70 publications

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“…In addition, the pulse sequences and parameters used in the present study to assess BMAT could be adapted for clinical studies, with intraoral coils made specifically for the evaluation of the maxilla and mandibles of patients. Intraoral coils 35 can reduce the distance from the coil conductors to the alveolar bone to increase the filling factor, thus providing higher sensitivity and enhanced SNR and image quality, or reduced scan time. The MRI technique has some disadvantages, such as poor accessibility, high cost, patient claustrophobia, patient motion artifacts, and dental restoration artefacts, 36 and is also contraindicated for patients with cardiac pacemakers.…”

Section: Discussionmentioning

confidence: 99%

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Correlation among alveolar bone assessments provided by CBCT, micro-CT, and 14 T MRI

Choi¹,

Pinhata-Baptista

Ferraço

et al. 2022

Dentomaxillofacial Radiology

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Objectives: The aim of this study was to evaluate bone mineral adipose tissue (BMAT) volume in 21 alveolar bone specimens, as determined by 14 T magnetic resonance imaging (MRI), and correlate them to the radiodensity values obtained preoperatively of regions of interest by cone beam computed tomography (CBCT), and to the BV/TV ratio values obtained by micro-CT, the gold-standard for morphometric data collection. Methods: Partially edentulous patients were submitted to a CBCT scan, and the radiographic bone densities in each ROI were automatically calculated using coDiagnostiX software. Based on the CBCT surgical planning, a CAD/CAM stereolithographic surgical guide was fabricated to retrieve a bone biopsy from the same ROIs scanned preoperatively, and then to orientate the subsequent implant placement. The alveolar bone biopsies were then collected and scanned using the micro-CT and 14 T MRI techniques. Pearson’s correlation test was performed to correlate the results obtained using the three different techniques. Results: In the 21 eligible bone specimens (6 females, 15 males), age (mean age 52.9 years), micro-CT, and 14 T MRI variables were found to be normally distributed (p > 0.05). The strongest—and only statistically significant (p < 0.05)—correlation was found between micro-CT and 14 T MRI values (r = 0.943), and the weakest, between 14 T MRI and CBCT values (r = –0.068). Conclusions: The findings suggest that 14 T MRI can be used to evaluate BMAT as an indirect marker for bone volume, and that CBCT is not a reliable technique to provide accurate bone density values.

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Section: Discussionmentioning

confidence: 99%

“…Progress is being made in high performance MRI coils that could enable clinical MRI with spatial resolution approaching that achieved in the current study. 35…”

Section: Discussionmentioning

confidence: 99%

Correlation among alveolar bone assessments provided by CBCT, micro-CT, and 14 T MRI

Choi¹,

Pinhata-Baptista

Ferraço

et al. 2022

Dentomaxillofacial Radiology

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“…Hence, Rx sensitivity around teeth is significantly reduced, and a restricted FOV setting is impracticle. For this reason, intraoral coils are preferable because they can be placed closer to the teeth 11–15 …”

Section: Introductionmentioning

confidence: 99%

An improved intraoral transverse loop coil design for high‐resolution dental MRI

Özen

İlbey

Jia

et al. 2023

Magnetic Resonance in Med

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PurposeTo improve intraoral transverse loop coil design for high‐resolution dental MRI. MethodsThe transverse intraoral loop coil (tLoop) was modified (mtLoop) by overlapping the feed port conductors, bending the posterior section, introducing a parallel plate capacitor, optimizing the insulation thickness, and using it in receive‐only mode. In addition, an MR‐silent insulation was introduced. The performances of the mtLoop and tLoop coils were compared in terms of sensitivity, image SNR, and eddy currents using electromagnetic simulations and MRI measurements at 3T. ResultsThe receive‐only mode of the mtLoop increases the sensitivity at the apices of the roots, and the overlapped feed port design eliminated signal voids along the incisors. The bent posterior section with the parallel plate capacitor reduced the unwanted signal of the tongue by a factor of 2.3 in the selected region off interest and lowered the eddy currents by 10%. The proposed new coil provided higher SNR by elevenfold and 2.5‐fold at the incisors and apices of the molar roots within the selected regions of interest, respectively, in the experiments, as well as improved comfort. Optimal insulation thickness was determined as 1 mm. With the mtLoop, a (250 μm)3 isotropic resolution of the dental arch could be realized using a UTE sequence within 2 min total acquisition time. A T2‐SPACE protocol with (350 μm)2 in‐plane resolution was also demonstrated. ConclusionThe proposed new coil offers higher SNR at the incisors and apices of the molar roots, less unwanted signals from tongue, lower eddy currents, and improved patient comfort.

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“…So far, no research has been conducted on magnetic stimulation to the base of the brain with an excitation coil placed inside the oral cavity. Intraoral coils have been researched and developed, but they are the radiofrequency coils for dental MRI [8,9]. As a basic experiment for the purpose, we designed and manufactured an exciting coil with a size that ts inside the oral cavity (hereinafter referred to as an intraoral coil), and measured the magnetic ux density at various positions at the base of the brain by changing the coil angle.…”

Section: Introductionmentioning

confidence: 99%

Angle Dependency of Intraoral Coil for Magnetic Stimulation Targeting the Base of the Brain

Ando

Nozaki

Katayama

et al. 2022

ABE

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Non-invasive magnetic stimulation has the potential to be an effective treatment for Alzheimerʼs disease, which inevitably involves neurodegeneration of the hippocampus at the base of the brain. In this study, we fabricated an excitation coil designed to be mounted inside the oral cavity, i.e., an intraoral coil, to stimulate the base of the brain. The oral cavity has an advantage of being in closer proximity with greater transitability to the base compared with the convexity of the brain. We determined the optimum angle of the intraoral coil targeting the base to achieve the largest magnetic ux density. In the experiments, the coil angle was changed and the z-component of the magnetic ux density was measured at positions corresponding to three regions at the base of the brain: hippocampus, thalamus, and hypothalamus. Here, a single pulse current of approximately 1920 A at 3 kHz was applied to the intraoral coil with a power supply device used in actual transcranial magnetic stimulation (TMS). A maximum magnetic ux density of 10.3-17.2 × 10 −3 T was obtained at the base of the brain when the coil angle was between 35 and 40 degrees. Next, we conducted a numerical analysis using a numerical human head model. The z-component of the maximum magnetic ux density was obtained at coil angles between 35 and 40 degrees, and the result was consistent with the experimental result. Additionally, we evaluated the induced current density at the base of the brain by numerical analysis. The maximum value at the hippocampus was 2 A/m 2 when the coil angle was 90 degrees. This is the angle at which the central axis of the designed intraoral coil (a solenoid coil) is horizontal to the ground. Speci cally, the central axis of the present intraoral coil needs to be tilted to 60 degrees from the target.

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Design of an Intraoral Dipole Antenna for Dental Applications

Cited by 13 publications

References 70 publications

Correlation among alveolar bone assessments provided by CBCT, micro-CT, and 14 T MRI

Correlation among alveolar bone assessments provided by CBCT, micro-CT, and 14 T MRI

An improved intraoral transverse loop coil design for high‐resolution dental MRI

Angle Dependency of Intraoral Coil for Magnetic Stimulation Targeting the Base of the Brain

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