All MRI scans were conducted on a GE 3.0-T MR750w whole body scanner
(Waukesha, WI) with an 8-channel phased array bilateral breast coil and with the
patients in the prone position. Each MRI scan included an axial T2-weighted
series, a dynamic contrast-enhanced MRI series, and an axial DWI series. The
rFOV DWI series used the Field of view Optimized and Constrained Undistorted
Single-Shot pulse sequence (33 (link)). This
sequence employs a 2D spectral-spatially selective radiofrequency (RF) pulse in
the presence of echo-planar shaped gradients for inner volume excitation.
Combined with a slice selective refocusing RF pulse, this 2D RF pulse has an
added advantage of fat suppression by placing the spatially-shifted fat outside
the refocusing slice. A pre-excitation chemical-shift fat suppression pulse was
also applied. Compared to conventional DWI, rFOV DWI allows a shorter echo train
for a desired resolution, with reduced image blurring and reduced artifacts.
Typical scan parameters for the rFOV DWI were as follows: TE/TR = 70/4000 ms,
slices = 13-16, slice thickness = 4 mm, slice gap = 0 mm, FOV = 16 x 16 cm,
acquisition matrix = 80 x 80, in-plane spatial resolution = 2 x 2 mm, scan
duration = 5 minutes, and b-values [signal averages] = 100 [4] and either 800
[16] or 1000 [16] s/mm2. An example image from this series is
presented inFigure 1A .
(Waukesha, WI) with an 8-channel phased array bilateral breast coil and with the
patients in the prone position. Each MRI scan included an axial T2-weighted
series, a dynamic contrast-enhanced MRI series, and an axial DWI series. The
rFOV DWI series used the Field of view Optimized and Constrained Undistorted
Single-Shot pulse sequence (33 (link)). This
sequence employs a 2D spectral-spatially selective radiofrequency (RF) pulse in
the presence of echo-planar shaped gradients for inner volume excitation.
Combined with a slice selective refocusing RF pulse, this 2D RF pulse has an
added advantage of fat suppression by placing the spatially-shifted fat outside
the refocusing slice. A pre-excitation chemical-shift fat suppression pulse was
also applied. Compared to conventional DWI, rFOV DWI allows a shorter echo train
for a desired resolution, with reduced image blurring and reduced artifacts.
Typical scan parameters for the rFOV DWI were as follows: TE/TR = 70/4000 ms,
slices = 13-16, slice thickness = 4 mm, slice gap = 0 mm, FOV = 16 x 16 cm,
acquisition matrix = 80 x 80, in-plane spatial resolution = 2 x 2 mm, scan
duration = 5 minutes, and b-values [signal averages] = 100 [4] and either 800
[16] or 1000 [16] s/mm2. An example image from this series is
presented in