Analysis of Endcap Effect for MRI Birdcage RF Coil by FDTD Method.
- Author:
Kyoung Nam KIM
1
;
Sung Taek CHUNG
;
Bu Sik PARK
;
Yoon Mi SHIN
;
June Sik KWAK
;
Jong Woon CHO
Author Information
1. Medinus, Korea. knkim@medinus.co.kr
- Publication Type:Original Article
- Keywords:
Birdcage RF Coil;
Endcap Shield;
FDTD
- MeSH:
Magnetic Resonance Imaging*;
Neuroimaging
- From:Journal of the Korean Society of Magnetic Resonance in Medicine
2003;7(2):137-143
- CountryRepublic of Korea
- Language:Korean
-
Abstract:
PURPOSE: B1 field of birdcage RF (radiofrequency) coil that is used most for brain imaging in magnetic resonance imaging (MRI) decreases toward endring from the coil center. We investigated how much RF B1 homogeneity effect the endcap shield brings form the coil center as it towards to endcap region. MATERIALS AND METHODS: We compared RF B1 field distribution by each finite difference time domain (FDTD) simulations for lowpass, highpass and hybrid birdcage RF coils. We selected the highpass birdcage RF coil that was the highest RF B1 field condition as simulation result, and studied how much RF B1 homogeneity effect was occurred when endcap shield was applied to endring area. RESULTS: B1 field of the highpass birdcage RF coil was higher than other birdcage RF coil types as simulation result. However, the RF B1 homogeneity was lower than other coil types. RF B1 field of highpass birdcage RF coil with endcap shield is similar with RF B1 field of hybrid birdcage RF coil and the overall RF B1 homogeneity in sagittal direction was better. CONCLUSION: In this paper, proposed method can apply improving RF B1 homogeneity of RF coil in clinical examination.
