Synopsis
The aim of this study was to compare a prototype simultaneous multi-slice single-shot echo planar imaging (SMS-ss-DWI-EPI) sequence with
conventional readout-segmented echo-planar imaging (rs-DWI-EPI) for diffusion-weighted imaging of the breast at 3T magnetic resonance
imaging (MRI). A reader study was conducted to evaluate image quality, lesion conspicuity and BI-RADS score. Our results show that although
the image quality with the conventional rs-DWI-EPI is superior, malignant lesions have improved visibility with the SMS-ss-DWI-EPI sequence.
Introduction
The addition of diffusion-weighted imaging (DWI) to contrast-enhanced breast MRI improves the classification of breast lesions, which leads in turn to an
increased positive predictive value of biopsies. Consequently, DWI with evaluation of the corresponding apparent diffusion coefficient (ADC) is included in
most state-of-the-art breast MRI protocols . The echo train of the readout-segmented echo-planar imaging-based DWI sequence (rs-DWI-EPI) was
shortened to reduce distortion and improve the resulting image quality. However, this sequence results in a lower signal-to-noise ratio (SNR) than singleshot
echo planar imaging (ss-EPI) . In practice, detection of lesions on DWI is often problematic due to a relatively low lesion conspicuity. To improve the
detectability of lesions and the speed of acquisition, a prototype DWI sequence, the simultaneous multi-slice single-shot DWI-EPI (SMS-ss-DWI-EPI), was
developed. In this study we compare this prototype sequence with rs-DWI-EPI at 3T, in terms of image quality (IQ), lesion conspicuity, and breast imaging
reporting and data system (BI-RADS ) score.
Methods
From September 2017 to August 2018, 15 women with known breast cancer or suspicious breast lesions were included, after providing signed informed
consent. Women were scanned with the conventional rs-DWI-EPI and the SMS-ss-DWI-EPI during the same clinical examination on a 3T MAGNETOM
Skyra system (Siemens Healthcare, Erlangen, Germany) using a 16-channel bilateral breast coil. Parameters of the rs-DWI-EPI sequence were: TR: 5450
ms, TE: 57 ms, FoV: 340 mm, voxel size: 1.2x1.2x5 mm , acquisition time: 4:23 min, b-values: 50, 850 s/mm , SPAIR fat suppression. Parameters of the
SMS-ss-DWI-EPI sequence were: TR: 4000 ms, TE: 70 ms, FoV: 360 mm, voxel size: 0.9(i)x0.9(i)x4 mm , acquisition time: 2:45 min, b-values: 50, 400