Dynamic breast MRI with spiral trajectories: 3D versus 2D

A three-dimensional (3)D spiral sequence was developed for dynamic breast m agnetic resonance (MR) imaging with much improved image quality. Partial Z phase encoding was applied to obtain thinner slices for a coverage of the w hole breast. Comparison between the 3D and a previously developed multi-sli ce 2D spiral sequences was performed on ten healthy volunteers without cont rast and five breast patients with gadolinium-diethylene triamine pentaacet ic acid (Gd-DTPA), The 3D spiral images had significantly less off-resonanc e blurring and spiral artifacts. With a small compromise on temporal resolu tion (7.7 seconds in 2D and 10.6 seconds in 3D), we obtained 32 interpolate d 3-5 mm slices (with 20 Z phase encodes) for a full coverage of 10-16 cm b reast with the same 1 x 1 mm(2) in-plane resolution as the 2D sequence, whi ch haad 12 8-13 mm slices. Contrast between glandular and soft tissue in no rmal breasts was increased by about 25%. The reduced repetition time in the 3D spiral acquisition led to an increased Gd-enhanced signal. The differen ce between the enhancement of malignant and benign lesions increased by sev enfold. We expect that this new development could lead to improved specific ity in characterizing breast lesions using MR imaging. (C) 2000 Wiley-Liss.