Three-dimensional fat-saturated T1-weighted MR imaging of the breast. The usefulness of precontrast imaging

The purpose of this study was to report the clinical usefulness of precontrast three-dimensional (3D) fat-saturated T1-weighted MR images (precontrast 3D images) in breast magnetic resonance (MR) imaging. MR imaging was performed at a 1.5T MR-system. In 31 consecutive patients with breast lesions, precontrast 3D images and postcontrast 3D fat-saturated T1-weighted MR images (postcontrast 3D images) were obtained and, then, subtraction images were generated from these two image sets. Contrast-to-noise ratio (CNR) between lesions and breast tissues was obtained in postcontrast 3D images and subtraction images, and they were compared. Radial-planar reconstruction images centering on the nipple were generated from precontrast 3D images, postcontrast 3D images and subtraction images, and they were reviewed by three experienced radiological technologists. Maximum intensity projection (MIP) images were generated from postcontrast 3D images and subtraction images, and they were also reviewed. Mean CNR on subtraction images was 41.48, and that on postcontrast 3D images was 25.60. Image artifacts were less on subtraction images compared to postcontrast 3D images. Precontrast 3D images revealed the presence of collection of bloody material in the mammary duct system in 1 of 31 patients. In conclusion, precontrast 3D images can be used for subtraction images which improve tumor-breast tissue contrast and overall image quality, and they can demonstrate intraductal bloody material collection which may cause overestimation of intraductal spread. (author)