title: [Quantitative evaluation of Gd-EOB-DTPA uptake in phantom study for liver MRI].
abstract: Gd-EOB-DTPA is a new liver specific MRI contrast media. In the hepatobiliary phase, contrast media is trapped in normal liver tissue, a normal liver shows high intensity, tumor/liver contrast becomes high, and diagnostic ability improves. In order to indicate the degree of uptake of the contrast media, the enhancement ratio (ER) is calculated. The ER is obtained by calculating (signal intensity (SI) after injection-SI before injection) / SI before injection. However, because there is no linearity between contrast media concentration and SI, ER is not correctly estimated by this method. We discuss a method of measuring ER based on SI and T(1) values using the phantom. We used a column phantom, with an internal diameter of 3 cm, that was filled with Gd-EOB-DTPA diluted solution. Moreover, measurement of the T(1) value by the IR method was also performed. The ER measuring method of this technique consists of the following three components: 1) Measurement of ER based on differences in 1/T(1) values using the variable flip angle (FA) method, 2) Measurement of differences in SI, and 3) Measurement of differences in 1/T(1) values using the IR method. ER values calculated by these three methods were compared. In measurement made using the variable FA method and the IR method, linearity was found between contrast media concentration and ER. On the other hand, linearity was not found between contrast media concentration and SI. For calculation of ER using Gd-EOB-DTPA, a more correct ER is obtained by measuring the T(1) value using the variable FA method.
authors.affiliation: Department of Radiological Technology, Kanazawa University Hospital.
authors.forename: Norio
authors.initials: N
authors.lastname: Hayashi
authors.forename: Tosiaki
authors.initials: T
authors.lastname: Miyati
authors.forename: Wataru
authors.initials: W
authors.lastname: Koda
authors.forename: Masayuki
authors.initials: M
authors.lastname: Suzuki
authors.forename: Shigeru
authors.initials: S
authors.lastname: Sanada
authors.forename: Naoki
authors.initials: N
authors.lastname: Ohno
authors.forename: Takashi
authors.initials: T
authors.lastname: Hamaguchi
authors.forename: Yukihiro
authors.initials: Y
authors.lastname: Matsuura
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Kawahara
authors.forename: Tomoyuki
authors.initials: T
authors.lastname: Yamamoto
authors.forename: Osamu
authors.initials: O
authors.lastname: Matsui
mesh_terms: D003287:Contrast Media; D019786:Gadolinium DTPA; D007089:Image Enhancement; D008099:Liver; D008279:Magnetic Resonance Imaging / Q000295:instrumentation / Q000379:methods*; D019047:Phantoms, Imaging
chemical_list: D003287:Contrast Media; C073590:gadolinium ethoxybenzyl DTPA; D019786:Gadolinium DTPA