Wakako Kaneko MD, Presenter: Nothing to Disclose

Toshiki Kazama MD, Abstract Co-Author: Nothing to Disclose

Hirotaka Sato, Abstract Co-Author: Nothing to Disclose

Takashi Higashide MD, Abstract Co-Author: Nothing to Disclose

Ryota Shimofusa MD, Abstract Co-Author: Nothing to Disclose

Kohei Inoue MD, PhD, Abstract Co-Author: Nothing to Disclose

Ken Motoori MD, Abstract Co-Author: Nothing to Disclose

Takashi Uno, Abstract Co-Author: Nothing to Disclose

Excellent fat-suppression is essential for breast MRI. 3.0 T MR systems offer higher signal-to noise ratio images, however, due to magnetic field inhomogenity, fat-suppression is challenging. The purpose of this study is to compare the two fat suppression techniques, two-point Dixon techniques (FLEX) and frequency selective inversion method (SPECIAL) in contrast-enhanced MR images of the breast at 3.0-T unit.

This study was approved by the institutional review board with a waiver for informed consent. During a 3-month period, a prospective study was performed on 50 consecutive patients referred for breast MR imaging. Of these 50 patients, 43 women had histologically confirmed breast cancers. Of these 43 women, 3 cases that did not demonstrate any mass or abnormal enhancement were excluded from this study. A total of 40 women were included in this study. MR imaging was performed on a 3.0 T whole-body scanner (The Signa MR 750, GE Medical Systems, WI, USA). Both fat suppression techniqueswere applied to　contrast-enhanced three-dimensional T1-weighted images. Quantitative evaluation was performed with the use of operator-defined region of interest measurements of mean signal intensity in the enhanced lesions, the adjacent breast parenchyma, subcutaneous fat nearest to the lesion, and measurements of standard deviation of background noise. Strength of fat-suppression was measured by calculating signal of fat to noise ratio. Contrast noise ratios (CNR) of lesion-to-breast parenchyma, lesion-to-fat, and parenchyma-to-fat were determined Wilcoxon’s matched-pair signed rank test was used.

The signal of fat to noise ratio was significantly lower in two-point Dixon technique than that in frequency selective inversion method (P<0.001) All the CNR values obtained with two-point Dixon technique were significantly higher than those with frequency selective inversion method（P<0.001）

Compared to frequency selective inversion method, two-point Dixon technique suppressed the subcutaneous fat signal more potently and improved the contrast of the enhanced breast lesion against the parenchyma and the subcutaneous fat. Two-point Dixon technique may be a powerful fat suppression strategy for enhanced 3T MR imaging of the breast.

Two-point Dixon technique can demonstrate to be  a powerful fat suppression strategy and is recommended for MR imaging of the Breast at 3.0 T.

Kaneko, W, Kazama, T, Sato, H, Higashide, T, Shimofusa, R, Inoue, K, Motoori, K, Uno, T, Fat Suppression Strategies in MR Imaging of the Breast at 3.0 T: Comparison of the Two-point Dixon Technique and Frequency Selective Inversion Method.  Radiological Society of North America 2011 Scientific Assembly and Annual Meeting, November 26 - December 2, 2011 ,Chicago IL. http://archive.rsna.org/2011/11006787.html