Katsusuke Kyotani RT, Presenter: Nothing to Disclose

Yoshiharu Ohno MD, PhD, Abstract Co-Author: Research Grant, Toshiba Corporation Research Grant, Koninklijke Philips Electronics NV Research Grant, Bayer AG Research Grant, DAIICHI SANKYO Group Research Grant, Eisai Co, Ltd

Nobukazu Aoyama RT, Abstract Co-Author: Nothing to Disclose

Hideaki Kawamitsu MD, Abstract Co-Author: Nothing to Disclose

Saori Satou RT, Abstract Co-Author: Employee, Toshiba Corporation

Mizuho Nishio MD, Abstract Co-Author: Nothing to Disclose

Hisanobu Koyama MD, Abstract Co-Author: Nothing to Disclose

Takeshi Yoshikawa MD, Abstract Co-Author: Research Grant, Toshiba Corporation Research Grant, Koninklijke Philips Electronics NV

Sumiaki Matsumoto MD, PhD, Abstract Co-Author: Research Grant, Toshiba Corporation

Toshiaki Minami, Abstract Co-Author: Nothing to Disclose

Kazuro Sugimura MD, PhD, Abstract Co-Author: Research Grant, Toshiba Corporation Research Grant, Koninklijke Philips Electronics NV Research Grant, Bayer AG Research Grant, Eisai Co, Ltd Research Grant, DAIICHI SANKYO Group

To determine the utility of multi-phase transmit (i.e. 2-channel 4-port) RF system for B1 homogeneity and image quality of chest 3T MR imaging as compared with single transmit (i.e. 1-channel 2-port) and multi transmit (i.e. 2-channel 2-port) RF systems.

Phantom and human studies were performed by using single transmit, multi transmit and multi-phase transmit RF systems on 3T MR system. For B1 homogeneity assessment, our proprietary phantom and five volunteers were scanned by using a gradient-echo sequence with double-angle method adapted a long TR (TR 5000ms/ TE 1.8ms/ Flip angles 40 and 80 degree). In addition, five volunteers were also scanned by using ECG- and respiratory gated black-blood T1- and T2-weighted and STIR fast SE sequences. Then, B1 maps from phantom and human data obtained by each RF system were generated, and inhomogeneities of B1 maps were evaluated as standard deviation (SD) of ROI measurements. To quantitatively and qualitatively assess image quality, image qualities of T1- and T2-weighted and STIR images were evaluated as signal-to-noise ratios (SNRs), and assessed by means of five-point visual scoring system. To determine the utility of multi-phase transmit RF system for improving B1 inhomogeneity, SDs of phantom and human studies, SNR and visual score on each MR image were compared by Fisher’s protective least significant difference test.

On phantom and human studies, SDs of B1 map obtained by single transmit RF system were significantly larger than those by other RF systems (p<0.05). SNR and qualitative image quality on each sequence by single transmit RF system were significantly lower than those by other RF systems (p<0.05). Although multi and multi-phase transmit RF systems had no significant difference (p>0.05), SNR and qualitative image quality on each sequence by multi-phase transmit RF system was higher than those of multi transmit RF system.

Multi-phase transmit RF system had better potential for improvement of B1 homogeneity and image quality of chest 3T MR imaging than single and multi transmit RF systems.

Multi-phase transmit RF system had better potential for improvement of B1 homogeneity and image quality of chest 3T MR imaging than single and multi transmit RF systems.

Kyotani, K, Ohno, Y, Aoyama, N, Kawamitsu, H, Satou, S, Nishio, M, Koyama, H, Yoshikawa, T, Matsumoto, S, Minami, T, Sugimura, K, Multi-Phase Transmit RF System on 3T MR System: Comparison of B1 Homogeneity and Image Quality for Chest MR Imaging with Single and Multi Transmit RF Systems.  Radiological Society of North America 2012 Scientific Assembly and Annual Meeting, November 25 - November 30, 2012 ,Chicago IL. http://archive.rsna.org/2012/12043871.html