Abstract
In proton density-weighted (PDW) MR imaging, the patterns of signal intensity vary depending on the imaged material, and change with the flip angle (FA) applied to the imaged material. The correlation between the pre-determined FA and the actual FA applied to imaged objects was investigated using 4 types of phantoms having different dielectric properties. PDW images were acquired using the spin-echo (SE) method and different pre-determined FA. Dependency of the signal intensity distribution in the phantom on the pre-determined FA differed among phantoms: patterns for water and 0.402 w/w% saline solution phantoms changed with the pre-determined FA, whereas those for olive oil and 4.02 w/w% saline solution phantoms were barely affected by the pre-determined FA. Causes of these phenomena were considered to be the differences between the pre-determined FA and the actual FA among the phantoms; differences were also influenced by the positioning of the phantom. Our study showed that the actual FA in the phantom is greater than the pre-determined FA in high permittivity media, whereas it is reduced by an increased conductivity of the media.
| Original language | English |
|---|---|
| Pages (from-to) | 147-159 |
| Number of pages | 13 |
| Journal | Journal of X-Ray Science and Technology |
| Volume | 21 |
| Issue number | 2 |
| DOIs | |
| Publication status | Published - 2013 |
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Keywords
- conductivity
- finite element method
- flip angle
- MRI
- permittivity
- RF magnetic field
- signal intensity distribution
ASJC Scopus subject areas
- Radiology Nuclear Medicine and imaging
- Condensed Matter Physics
- Radiation
- Electrical and Electronic Engineering
- Instrumentation
- Medicine(all)
Cite this
Influence of permittivity and electrical conductivity on image pattern of MRI. / Harimoto, Takashi; Ohno, Seiichiro; Hattori, Kengo; Hirosue, Miyuki; Miyai, Masahiro; Shibuya, Koichi; Kuroda, Masahiro; Kanazawa, Susumu; Kato, Hirokazu.
In: Journal of X-Ray Science and Technology, Vol. 21, No. 2, 2013, p. 147-159.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Influence of permittivity and electrical conductivity on image pattern of MRI
AU - Harimoto, Takashi
AU - Ohno, Seiichiro
AU - Hattori, Kengo
AU - Hirosue, Miyuki
AU - Miyai, Masahiro
AU - Shibuya, Koichi
AU - Kuroda, Masahiro
AU - Kanazawa, Susumu
AU - Kato, Hirokazu
PY - 2013
Y1 - 2013
N2 - In proton density-weighted (PDW) MR imaging, the patterns of signal intensity vary depending on the imaged material, and change with the flip angle (FA) applied to the imaged material. The correlation between the pre-determined FA and the actual FA applied to imaged objects was investigated using 4 types of phantoms having different dielectric properties. PDW images were acquired using the spin-echo (SE) method and different pre-determined FA. Dependency of the signal intensity distribution in the phantom on the pre-determined FA differed among phantoms: patterns for water and 0.402 w/w% saline solution phantoms changed with the pre-determined FA, whereas those for olive oil and 4.02 w/w% saline solution phantoms were barely affected by the pre-determined FA. Causes of these phenomena were considered to be the differences between the pre-determined FA and the actual FA among the phantoms; differences were also influenced by the positioning of the phantom. Our study showed that the actual FA in the phantom is greater than the pre-determined FA in high permittivity media, whereas it is reduced by an increased conductivity of the media.
AB - In proton density-weighted (PDW) MR imaging, the patterns of signal intensity vary depending on the imaged material, and change with the flip angle (FA) applied to the imaged material. The correlation between the pre-determined FA and the actual FA applied to imaged objects was investigated using 4 types of phantoms having different dielectric properties. PDW images were acquired using the spin-echo (SE) method and different pre-determined FA. Dependency of the signal intensity distribution in the phantom on the pre-determined FA differed among phantoms: patterns for water and 0.402 w/w% saline solution phantoms changed with the pre-determined FA, whereas those for olive oil and 4.02 w/w% saline solution phantoms were barely affected by the pre-determined FA. Causes of these phenomena were considered to be the differences between the pre-determined FA and the actual FA among the phantoms; differences were also influenced by the positioning of the phantom. Our study showed that the actual FA in the phantom is greater than the pre-determined FA in high permittivity media, whereas it is reduced by an increased conductivity of the media.
KW - conductivity
KW - finite element method
KW - flip angle
KW - MRI
KW - permittivity
KW - RF magnetic field
KW - signal intensity distribution
UR - http://www.scopus.com/inward/record.url?scp=84880225464&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84880225464&partnerID=8YFLogxK
U2 - 10.3233/XST-130375
DO - 10.3233/XST-130375
M3 - Article
C2 - 23694908
AN - SCOPUS:84880225464
VL - 21
SP - 147
EP - 159
JO - Journal of X-Ray Science and Technology
JF - Journal of X-Ray Science and Technology
SN - 0895-3996
IS - 2
ER -