Comparison of 3- and 1.5-T dynamic breast MRI for visualization of spiculated masses previously identified using mammography.

OBJECTIVE. The purpose of this article is to determine the effectiveness of MRI for visualizing spiculated breast cancer lesions that were previously identified using mammography and to compare the diagnostic quality of 3- and 1.5-T dynamic MRI by assessing the visualization of spiculation in such lesions. MATERIALS AND METHODS. One hundred twenty MRI studies of breast cancers clearly identified as spiculated masses using mammography (71 MRI studies at 3 T that included both bilateral axial and unilateral sagittal images and 49 MRI studies at 1.5 T that included bilateral axial images only) were independently reviewed by three radiologists. The three different radiologists scored the visualization of the spiculation with respect to 3-T sagittal, 3-T axial, or 1.5-T axial images. RESULTS. The diagnostic quality of sagittal 3-T dynamic MRI studies, as determined by assessing the visualization of spiculation, was significantly better than that of axial 3-T (p = 0.009) and 1.5-T (p = 0.004) studies. For small (<1 cm) lesions, the diagnostic quality of sagittal 3-T studies determined by assessing the visualization of spiculation was significantly better than that of axial 1.5-T studies (p = 0.029). CONCLUSION. Unilateral sagittal in-plane and through-plane high-spatial-resolution 3-T images can offer particularly higher spatial resolution for improved assessment of spiculation than do axial in-plane high-spatial-resolution images obtained at 1.5 and 3 T.