Eiki Nagao, Presenter: Nothing to Disclose

Takashi Yoshiura MD, PhD, Abstract Co-Author: Nothing to Disclose

Akio Hiwatashi MD, Abstract Co-Author: Nothing to Disclose

Koji Yamashita MD, Abstract Co-Author: Nothing to Disclose

Hironori Kamano MD, Abstract Co-Author: Nothing to Disclose

Hiroshi Honda MD, Abstract Co-Author: Nothing to Disclose

Previous studies have shown that a 3D turbo spin-echo (TSE) sequence provides higher contrast-to-noise ratio (CNR) for brain metastases than a conventional gradient-echo (GE) sequence. Moreover, motion-sensitized driven-equilibrium (MSDE) preparation effectively suppresses disturbing high signal intensities of enhancing blood vessels in post-contrast images. However, clinical usefulness of these new techniques has not been established. Purpose of this study was to evaluate the usefulness of a 3D TSE sequence with MSDE preparation (TSE-MSDE) through an observer study.

Two-hundred twenty-seven consecutive patients who were suspected to have brain metastasis underwent 3 T MRI studies. For each patient, post-contrast images were obtained using both a 3D GE sequence (MPRAGE) and 3D TSE-MSDE. Thirty-four patients including 17 who were found to have 1 to 9 brain metastases and 17 with no metastasis were selected and used for the observer study. Nine radiologists read TSE-MSDE, MPRAGE, and both of the two in the first, second and third reading session, respectively. Jackknife free-response receiver operating characteristic (JAFROC) analysis was used to evaluate the radiologists’ performance in the detection of brain metastases. Sensitivities, false-positive results per case (FP/case), figures-of-merit (FOM), and reading times were compared among the three sessions.

Compared with MPRAGE, TSE-MSDE was associated with significantly higher sensitivity, significantly higher FOM and significantly shorter reading time. However, it was also associated with higher FP/case. Combined TSE-MSDE/MPRAGE was associated with significantly higher sensitivity and significantly higher FOM compared with MPRAGE alone, while there was no significant difference in FP/case between combined TSE-MSDE/MPRAGE and MPRAGE alone.  

Compared to conventional MPRAGE, TSE-MSDE improved diagnostic performance of radiologists in detecting brain metastases through suppression of blood vessels and increased CNR, but it increased the risk for false-positives. Combined with MPRAGE, TSE-MSDE achieved high diagnostic performance while maintaining a low false-positive rate.

Three-dimensional turbo spin-echo sequence with motion-sensitized driven-equilibrium preparation may increase radiologists’ diagnostic performance in detecting brain metastases.

Nagao, E, Yoshiura, T, Hiwatashi, A, Yamashita, K, Kamano, H, Honda, H, Usefulness of Three Dimensional Turbo Spin Echo Imaging with Motion Sensitized Driven Equilibrium Preparation in Detecting Brain Metastases: An Observer Study.  Radiological Society of North America 2010 Scientific Assembly and Annual Meeting, November 28 - December 3, 2010 ,Chicago IL. http://archive.rsna.org/2010/9002249.html