TY - JOUR
T1 - Amide proton transfer imaging of diffuse gliomas
T2 - Effect of saturation pulse length in parallel transmission-based technique
AU - Togao, Osamu
AU - Hiwatashi, Akio
AU - Keupp, Jochen
AU - Yamashita, Koji
AU - Kikuchi, Kazufumi
AU - Yoshiura, Takashi
AU - Yoneyama, Masami
AU - Kruiskamp, Marijn J.
AU - Sagiyama, Koji
AU - Takahashi, Masaya
AU - Honda, Hiroshi
N1 - Funding Information:
This work was supported by Japan Society for the Promotion of Science (JSPS) Grants-in-Aid for Scientific Research KAKENHI, grant numbers: 26461827 (OT), 26293278 (TY), 26670564 (TY), 26461826 (AH), 26461828 (KY), http://www.jsps.go.jp/english/e-grants/index.html. This work was also supported by Philips Research Europe and Philips Electronics Japan. The funders provided support in the form of salaries for authors [JK and MY], but did not have any additional role in the study design, data collection and analysis, decision to publish, or preparation of the manuscript. The specific roles of these authors are articulated in the 'author contributions' section. This work was supported by JSPS KAKENHI Grant Number: 26461827, 26293278, 26670564, 26461826, and 26461828.^JSPS ^Japan Society for the Promotion of Science
PY - 2016/5/1
Y1 - 2016/5/1
N2 - In this study, we evaluated the dependence of saturation pulse length on APT imaging of diffuse gliomas using a parallel transmission-based technique. Twenty-two patients with diffuse gliomas (9 low-grade gliomas, LGGs, and 13 high-grade gliomas, HGGs) were included in the study. APT imaging was conducted at 3T with a 2-channel parallel transmission scheme using three different saturation pulse lengths (0.5 s, 1.0 s, 2.0 s). The 2D fast spin-echo sequence was used for imaging. Z-spectrum was obtained at 25 frequency off-sets from -6 to +6 ppm (step 0.5 ppm). A point-by-point B0 correction was performed with a B0 map. Magnetization transfer ratio (MTRasym) and ΔMTRasym (contrast between tumor and normal white matter) at 3.5 ppm were compared among different saturation lengths. A significant increase in MTRasym (3.5 ppm) of HGG was found when the length of saturation pulse became longer (3.09 ± 0.54% at 0.5 s, 3.83 ± 0.67% at 1 s, 4.12 ± 0.97% at 2 s), but MTRasym (3.5 ppm) was not different among the saturation lengths in LGG. ΔMTRasym (3.5 ppm) increased with the length of saturation pulse in both LGG (0.48 ± 0.56% at 0.5 s, 1.28 ± 0.56% at 1 s, 1.88 ± 0.56% at 2 s and HGG (1.72 ± 0.54% at 0.5 s, 2.90 ± 0.49% at 1 s, 3.83 ± 0.88% at 2 s). In both LGG and HGG, APT-weighted contrast was enhanced with the use of longer saturation pulses.
AB - In this study, we evaluated the dependence of saturation pulse length on APT imaging of diffuse gliomas using a parallel transmission-based technique. Twenty-two patients with diffuse gliomas (9 low-grade gliomas, LGGs, and 13 high-grade gliomas, HGGs) were included in the study. APT imaging was conducted at 3T with a 2-channel parallel transmission scheme using three different saturation pulse lengths (0.5 s, 1.0 s, 2.0 s). The 2D fast spin-echo sequence was used for imaging. Z-spectrum was obtained at 25 frequency off-sets from -6 to +6 ppm (step 0.5 ppm). A point-by-point B0 correction was performed with a B0 map. Magnetization transfer ratio (MTRasym) and ΔMTRasym (contrast between tumor and normal white matter) at 3.5 ppm were compared among different saturation lengths. A significant increase in MTRasym (3.5 ppm) of HGG was found when the length of saturation pulse became longer (3.09 ± 0.54% at 0.5 s, 3.83 ± 0.67% at 1 s, 4.12 ± 0.97% at 2 s), but MTRasym (3.5 ppm) was not different among the saturation lengths in LGG. ΔMTRasym (3.5 ppm) increased with the length of saturation pulse in both LGG (0.48 ± 0.56% at 0.5 s, 1.28 ± 0.56% at 1 s, 1.88 ± 0.56% at 2 s and HGG (1.72 ± 0.54% at 0.5 s, 2.90 ± 0.49% at 1 s, 3.83 ± 0.88% at 2 s). In both LGG and HGG, APT-weighted contrast was enhanced with the use of longer saturation pulses.
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U2 - 10.1371/journal.pone.0155925
DO - 10.1371/journal.pone.0155925
M3 - Article
C2 - 27227746
AN - SCOPUS:84973495949
VL - 11
JO - PLoS One
JF - PLoS One
SN - 1932-6203
IS - 5
M1 - e0155925
ER -